USMLE Success Academy Course Book
March 28, 2017 | Author: sang9071 | Category: N/A
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Download USMLE Success Academy Course Book...
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© 2009 – 2012 USMLE Success Academy, all right reserved.
Part 1 Introduction/Welcome............. p.1 Vitamins & Minerals................... p.23 Membrane Physiology............... p.37 Cellular Physiology.................... p.45 Neuromuscular Physiology....... p.56 Behavioral Medicine................. p.73 Vascular Phys & The Clotting Cycle...................... p.123 Gastrointestinal Medicine......... p.150
Part 2 Acids & Bases .............. p.1 Amino Acids.................. p.12 Proteins........................ p.21 Enzymes....................... p.53 Protein Sequencing..... p.59 Catabolic Biochem...... p.61 Anabolic Biochem....... p.89
Part 3 Rheumatology....... p.1 Neurology............... p.15 Cardiology............. p.56 Pulmonology......... p.81 Endocrinology......... p.101 Nephrology.............. p.130
Part 4 Oncology............... p.1 Bacteriology........... p.38 Fungi & Parasites... p.71 Virology.................... p.100 Immunology............ p.114
WEEK 1
11/26/11
YOUR JOURNEY STARTS NOW • Teaching you medicine in a whole new way • You will be called upon, but this is a friendly safe zone • Concepts taught today are going to change the way you see medicine – and you’re going to feel as though medical school was a huge ripoff!
How I like to teach…
Classroom Goals & ExpectaRons
• I don’t waste ,me (not yours, not mine)… we are going to get down to business during class hours
• Respect • Don’t be inRmidated • Incorrect answers are another chance to learn something new
• I ask lots of ques,ons… this will re‐inforce what you are learning, this links class material to USMLE‐style quesRoning
Take our work seriously, but have fun doing it!
1
11/26/11
TALENT vs. SKILL • Talent is something you are either born with or your aren’t • Skill is developed and can help you build on your natural talents
TALKING ABOUT STEP 1 • A test that tests your ability to test well • This is NOT a measure of your level of competence in medicine • Test‐taking skills does not predict your ability to be a big success in medicine
‘Hard work beats talent, when talent doesn’t want to work hard’
TALKING ABOUT STEP 1
STEP 1 AND YOUR SPECIALTY
• It is however (unfortunately) the BIGGEST factor in determining your ability to get interviews • More and more applicants every year, the one thing you all have in common is the Step 1… you’ve all taken it by the Rme you’ve applied
• How is a score of 240 required to get into plasRcs while general surgery takes people with low 200’s? • Why the primary care specialRes are no longer easy to get (more compeRRon means you need the scores)
2
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WHAT IT ALL MEANS • It means you need a good score to at least get them to read your full resume • Whether you have a failure or not, we’re going to put your score into the range that gets you interviews – that’s my promise to you! • Everybody studying for the boards is studying hard, but with real understanding of medicine you’ll be light‐years ahead of everyone!
THE REVERSE PYRAMID THEORY • In most things you want to start from the bofom of the pyramid • In medicine, starRng from the bofom is counter‐producRve BUT WHY?
ORGNIZING YOUR BRAIN • Med school threw hundreds of thousands of facts at you – how did they show you how to file it away and apply it? – they didn’t • Thinking in a high‐yield fashion (choosing the 90%) • We’ll show you how to master the 90% ‐ which is excellent in medicine!
STARTING AT THE TOP OF THE PYRAMID • The top is where the major concepts are at • When you know concepts above all else, you cannot be fooled – ever! • Learn a concept and it can help you master a thousands things… • You won’t have to keep re‐reading things, because you’ll recognize paferns and you’ll know what’s right and wrong, and which arRcles have merit.
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SEE THE CONCEPTS FIRST • Ever done a quesRon and felt like there wasn’t enough informaRon? • This is what separates the average students from the above‐average and excellent students • No,ce: It isn’t about intelligence, its about being properly equipped with the tools to succeed!
GETTING BACK TO BASICS • Whether you’re taking step 1, step 2 ck, step 3, or the Canadian boards… the basics never change • A test‐writer knows they can’t change concepts and clues – this is why they add extra useless informaRon – to trip you up!
IT’S ALL ABOUT THE CONCEPTS • Medicine is all about concepts • You’re going to learn how to apply them to everything, from there it is nothing but filling in the blanks
TEST‐WRITERS WRITE THE STUDY GUIDES • Ever noRced that you rarely see quesRons straight out of your study guides? • They know what you guys are using to study: FA, B&W, SECRETS • That’s why they’ll take the major concept inside and twist it slightly – 10% know the tricks (they get into derm and plasRcs), while 90% are playing a dangerous guessing game!
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TEST‐WRITERS KNOW THE STUDY GUIDES • Top schools have the test‐writers, meaning they also have test‐taking strategy sessions from the source • Would you rather learn how to shoot free‐ throws from Michael Jordan or a high‐ schooler? • We are going to help you overcome the hurdles and obstacles that are in front of you that you don’t even realize.
THE 3 P’S • PHYSIOLOGY • Damage normal physiology and you’ve got – PATHOLOGY • Want to fix damaged physiology – use PHARMACOLOGY • You don’t realize how intertwined they are, but you will soon.
THE VANNA WHITE THEORY • From Dr. Francis, it means they point you to images, charts, labs, etc. that have no relevance • If you get a quesRon with labs, or an xray, or a graph… unless they ask you directly about it, ignore it! It’s probably not even necessary.
4 THINGS YOU NEED FOR PHARM • MOA (you’re going to get tons of quesRons on MOA of drugs – that’s why were going to drill these into your brains) • ADVERSE EFFECTS • UNIQUE EFFECTS • TREATING AN OVERDOSE
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SAME INFO – DIFFERENT TEST • So many students think the USMLE’s are different from one to the next – they aren’t • The basic informaRon you have to know remains the same – it is only the angle at which they ask you a quesRon that seems to make it different.
STEP 1 vs. STEP 2 (or MCCEE) Q: A 24yr old female presents with contracRons and begins the iniRal stages of labor. During delivery it is noted that the fetus is 4000g, so the OB decides an episiotomy is warranted.
EXAMPLE…
Step 1: Which 3 muscles make up the urogenital diaphragm? Step 2: Which type of episiotomy is associated with the highest risk of infecRon?
BUZZ WORDS
INTERNAL MEDICINE
• Everybody says they are no longer being used! • How are we supposed to differenRate between 2‐3 common diseases? – buzzwords • They’re sRll there, they’re just used on a higher more intellectual level – ie. Its not straight out of your books. • The classic clues will always be around
• The boards test your ability to know internal and family medicine – that’s all. • Surgical principles all fall back to medicine • OB/GYN principles all fall back to medicine • Pediatric principles are just medicine on smaller people
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WHEN YOU REALLY UNDERSTAND MEDICINE • No more re‐reading • You will start to recognize the vast number of errors throughout the literature • Shot‐gun medicine • How to impress residents, afending, and just about anybody in the wards (from what I’ve read and understand)
SETTING A GOAL FOR YOURSELF • It isn’t a goal unRl you’ve wrifen it down • Feel the end result • Nothing worth having comes easy… or else we’d all by billionaires with 20 homes and 50 cars
EXERCISE NAMES • You think you know something unRl the test is in front of you • Drill, drill, drill • I am going to drill everything into your brain
AND FINALLY, A LOOK AT SOME DISCIPLINE‐SPECIFIC TIPS & TRICKS!
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ANATOMY • Details are not high‐yield • Anatomy of HY diseases, injuries, and common surgical procedures is high‐yield • Xray, CT, and MRI’s are becoming more and more high‐yield • Neuroanatomy is very high‐yield
BIOCHEMISTRY • Understanding the basics of biochemistry help you all across medicine… so it is all HY • Linking biochem with pathology is HY • Regulatory enzymes are very HY
BEHAVIORAL SCIENCE • Ethics is always HY • Biostats is not HY, but you will get a few easy points from knowing it • Personality d/o, anxiety d/o, etc are all HY • Psych‐pharm is HY
MICRO/IMMUNOLOGY • Bacteria is the highest‐yield • DisRnguishing characterisRcs is important • Immunology/vaccines/immunodeficiencies are all HY topics • Only 5% parasitology • Diagnosis is HY for microbiology
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PHYSIOLOGY • Very HY • Draw it all out • Master physiology once and you won’t forget it • Highly linked to patholgoy (pathophysiology)
PHARMACOLOGY • Extremely HY • MOA, Prototypes, and main side‐effects are HY • Don’t worry about trade names or dosages for Step 1 • Think about pharm as a “system‐based topic”, instead of a separate enRty of it’s own
PATHOLOGY • Highest‐yield topic • Is intertwined in everything we do • We are going to do it throughout the whole course, not as a separate enRty • ‘Buzzwords’ are sRll in full effect • Don’t panic when you get labs or images, they usually aren’t needed for answering the quesRon
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ENERGY DEPLETED STATE WHAT IS THIS STATE?
THE MOST IMPORTANT CONCEPTS YOU WILL EVER LEARN IN MEDICINE ENERGY DEPLETION, CELL DEATH, & THE GABA CONNECTION
ENERGY DEPLETED STATE WHAT IS THIS STATE? An energy depleted state is a concept whereby the body responds to a state of energy depleRon by presenRng with a very specific set of symptoms….. EVERY SINGLE TIME!!
ENERGY DEPLETED STATE All of the cells of the body use different amounts of energy, with some using a lot of energy and some using very lifle. WHAT DOES THIS MEAN FOR THE BODY?
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ENERGY DEPLETED STATE WHAT DOES THIS MEAN FOR THE BODY?
ENERGY DEPLETED STATE WHAT DOES THIS MEAN FOR THE BODY? The cells requiring more energy will suffer significantly while those needing less energy will be affected less.
ENERGY DEPLETED STATE
ENERGY DEPLETED STATE
The energy consumpRon hierarchy:
The energy consumpRon hierarchy:
#1 Brain
#1 Brain #2 Muscle Rssue
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ENERGY DEPLETED STATE
ENERGY DEPLETED STATE
The energy consumpRon hierarchy:
The energy consumpRon hierarchy:
#1 Brain #2 Muscle Rssue #3 ATPases (ie. AcRve transport systems)
#1 Brain #2 Muscle Rssue #3 ATPases (ie. AcRve transport systems) #4 Heart
ENERGY DEPLETED STATE The energy consumpRon hierarchy: #1 Brain #2 Muscle Rssue #3 ATPases (ie. AcRve transport systems) #4 Heart #5 Membrane movement (endo/exocytosis)
ENERGY DEPLETED STATE The 3 organs that consume the most energy: 1. The brain 2. The heart 3. The bone marrow This means we can expect, in a state of depleted energy, the brain, the heart, and then the bone marrow to be affected.
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ENERGY DEPLETED STATE So what does this all mean? No mafer what disease we encounter, all of the iniRal signs and symptoms are the exact same!!
ENERGY DEPLETED STATE When a child develops in an energy depleted state, what do you think will occur?
ENERGY DEPLETED STATE WHEN A DISEASE PRESENTS…. The body suffers and less energy is made. As we now know, the BRAIN is the first thing affected… When the brain lacks energy, we experience: ‐ SedaRon ‐ FaRgue ‐ Altered mental status/decreased arousal
ENERGY DEPLETED STATE When a child develops in an energy depleted state, what do you think will occur? MENTAL RETARDATION
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ENERGY DEPLETED STATE When an adult is exposed to chronic energy depleRon, what do you think occurs? MENTAL DETERIORATION
ENERGY DEPLETED STATE What can you expect with a deficiency of the primary acRve transports? States of edema ‐ Papilledema ‐ Pulmonary edema ‐ Ascites ‐ Cerebral edema ‐ Anasarca (full body swelling)
ENERGY DEPLETED STATE What can you expect to occur to the muscles? ‐ FaRgue ‐ Lack of strength ‐ Excessive soreness ‐ Intolerance to exercise
ENERGY DEPLETED STATE What should you expect from a lack of energy in the heart? ‐ Exercise intolerance ‐ Weakness (not enough 02 delivered to Rssues) ‐ Shortness of breath (this is a sign you will see common to all diseased states)
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ENERGY DEPLETED STATE Let’s put this into ac,on… What are the first important symptoms that bring someone to the doctor’s office? 1 – Weakness (they can’t perform their usual acRviRes) 2 – Shortness of breath (scary, they think they will die)
ENERGY DEPLETED STATE What do we take from this? Any disease that puts the body into a state of energy depleRon will cause the exact same signs and symptoms…. every single Rme!! STOP GUESSING, REVERT BACK TO THE STATE OF ENERGY DEPLETION
ENERGY DEPLETED STATE What are we going to see when they show up? The signs you will ALWAYS see are: 1 – Tachypnea 2 – Dyspnea
ENERGY DEPLETED STATE Let’s take this one step further…. Muscle weakness + difficulty breathing + urinary reten,on…. What will always occur as a result?
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ENERGY DEPLETED STATE
ENERGY DEPLETED STATE Some examples…
PULMONARY INFECTIONS AND
CANCER DIABETES CELIAC SPRUE
URINARY TRACT INFECTIONS
ENERGY DEPLETED STATE Now let’s take a look at complica,ons… We have many cells in the body that are very rapidly dividing, when there is no energy these cells fail to divide properly and we get a wide range of complicaRons… LET’S TALK ABOUT COMPLICATIONS…
WORRISOME COMPLICATION OF A DISEASE? • Think about what’s most important for you to live... • Brain • Heart • Kidneys • Just look for complicaRons with those at the top of the list
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ENERGY DEPLETED STATE The following are the rapidly dividing cells of the body that are affected by the energy depleted state… ‐ Hair ‐ Skin ‐ GI tract ‐ Kidneys ‐ Bladder ‐ Endometrium ‐ Vessels(endothelium) ‐ Breasts ‐ Sperm ‐ Nails/cuRcles ‐ Germ cells ‐ Bone marrow (ie. RBC, WBC, PLT)
ENERGY DEPLETED STATE Taking a look at complicaRons… GI tract… NAUSEA, VOMITING, AND DIARRHEA
ENERGY DEPLETED STATE Taking a look at complicaRons… The hair and skin… BRITTLE AND DRY
ENERGY DEPLETED STATE Taking a look at complicaRons… The Respiratory Tract… WEAKENED COUGH REFLEX = INFECTIONS
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ENERGY DEPLETED STATE Taking a look at complicaRons…
ENERGY DEPLETED STATE Taking a look at complicaRons…
In the Kidneys… ELECTROLYTES ALTERED (PCT shuts down)
Sperm Count… LOW
ENERGY DEPLETED STATE
ENERGY DEPLETED STATE
Taking a look at complicaRons… The Germ Cells = CANCERS
Taking a look at complicaRons… The Bone Marrow… DEPRESSED
Where do you expect cancers? 1st – SKIN (exposed to the most radiaRon) 2nd ‐ GI
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ENERGY DEPLETED STATE
ENERGY DEPLETED STATE
THEREFORE…
And finally…
No ma[er what the disease or condi,on… Remember this concept and you will always be able to answer the ques,ons…
WHAT WILL BE THE MOST COMMON CAUSE OF DEATH IN ANY DISEASED STATE THAT RESULTS IN A STATE OF ENERGY DEPLETION???
ENERGY DEPLETED STATE
ENERGY DEPLETED STATE
Think about the concept and make sense of the quesRon…. Think about the organs affected and in which order they are affected, then which consequence is most lethal…
What happens first… 1st – Brain is affected = AMS, demenRa (not immediately lethal). 2nd – The heart = CHF (lethal) Thus, in thinking it through, you don’t have to memorize anything to realize that the most common cause of death will be…
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ENERGY DEPLETED STATE
ENERGY DEPLETED STATE
HEART FAILURE!!!
You now have the ability, through this concept, to understand what will happen in almost every single medical condiRon, without having to memorize a single thing. Now… all that’s le\ in diseases is filling in the gaps!
MAKING CONNECTIONS THROUGHOUT MEDICINE • 1 simple concept opens up the ability to explain the presentaRon of a thousand things • Stop reading the whole arRcle, look for the 1 unique thing about it • PresentaRons may not always be the same, but the causes of death are always the same.
DIABETES AS AN EXAMPLE • No insulin means no glucose into the cells = no nrg • We’re already in the energy‐depleted state • Everything we just covered fits • Weakness and SOB • Tachypnea and dyspnea • Altered mentaRon, weakness, etc
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YOU KNOW 98% OF ALL DISEASES ALREADY
NEXT… INFLAMMATION & CELL DEATH
• You’ve just been given the key to knowing almost every disease presentaRon • We sRll have to know how to fill in the gaps, which is what the course is going to cover for you… but we’re going to come back to this over and over again.
BIG‐PICTURE CONCEPT #2 INFLAMMATION & CELLULAR DEATH
NORMAL CELLS OF THE BODY • Normal cells have Na/K+ ATPase • Normal cells have a dormant Na/Ca exchanger for emergency
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THEN COMES THE INSULT
CELL TRIES TO CORRECT THIS
• Any insult will decrease the flow of blood and thus decreased the 02 supply • Na/K ATPase shuts down • K+ is freely leaking out • Na+ remains in the cell – water follows the N a+ …. We get swelling (1st sign of cellular death)
• Na/Ca exchanger works to move sodium out and pull calcium in • Na has a charge of 1+, while Ca has a charge of 2+ …. Cell is more likely to depolarize • FasciculaRon and swelling seen at the site of injury
THIS CREATES A MASS EFFECT
RECURRING INJURY
• In the brain this leads to a mass‐effect • CalcificaRon due to the acRvaRon of the Na/Ca exchanger leads to a ‘ring‐enhanced lesion’ • Is dystrophic calcificaRon • Not a major clue, more of an indicaRon that there is something causing a mass‐effect • Which drug shuts down the Na/K pump?
• Enough trauma for long enough is going to lead to dystrophic calcificaRons • Hard scars at the site of injury
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THE GABA CONNECTION • We’ll wait unRl we get to biochemistry as it fits in befer there…
VITAMINS AND MINERALS VITAMINS AND MINERALS Small and Powerful
While not the most exciRng topic in medicine, vitamins and minerals play such vital roles in our health that there are a wide range of quesRons that can be asked, let’s focus on all of the following…
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VITAMINS AND MINERALS • Vitamins A,D,E, and K (DEKA) – Fat soluble • Vitamins B1, B2, B3, B4, B5, B6, B9, B12 (the B vitamins) • Vitamin C • Calcium • Magnesium • Zinc • Copper • Iron • Trace elements (Selenium, Tin, Manganese, Fluoride)
Vitamin D Vitamin D Liver 25(OH)D Kidneys 1,25(OH)2D
VITAMIN D • EssenRal for proper formaRon of teeth and bones • SRmulates absorpRon and reabsorpRon of Ca2+ and PO4‐ • SRmulates osteoblasRc acRvity (builds bones) *opposite is PTH which sRmulates osteoclasRc acRvity (breaks down bone) ** Ca2+ and PO4‐ move in same direcRon when sRmulated by vitamin D (as opposed to opposite movement when PTH sRmulaRon)
Vitamin D deficiency In kids Rickets In adults Osteomalacia Vitamin D resistant rickets A defect in the renal reabsorpRon of PO4‐, when the PO4‐ leaks, Ca2+ is pulled with it. When you give vitamin D, calcium may rise temporarily but then it drops off again.
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Vitamin D excess Leads to hypercalcemia: 1. 2. 3. 4. 5.
Stones (kidney stones) Bones (bone pain) Moans (GI pain due to excess Ca2+) Groans Psychic overtones (Mental problems)
VITAMIN E • Because vitamin E is our best ally against oxidaRon, we are given protecRon from the following diseases… 1. Coronary artery disease 2. Alzheimer’s disease 3. Cancer 4. HemolyRc anemias (G6PD)
VITAMIN E • The main anRoxidant of the blood • Absorbs free radicals (MCC by viruses), and helps protect cells from damage
VITAMIN K • Required for gamma carboxylaRon • AddiRon of a 3rd carboxy gives vitamin K factors 2,7,9,10 and protein C & S, 30 negaRve charges, which provides for a strong afracRon towards clo{ng • Protein C shortest half life (t1/2) of 6hr (this is a thrombolyRc, thus it can actually cause clot formaRons) ** is why heparin is given before warfarin • Factor 7 half life of 2 days, since it takes 10 days for stead state (t1/2 x 5), we keep someone in the hospital for 10 days on hep + warfarin before they are therapeuRc
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VITAMIN K
WARFARIN
• Most of it is made up from the gut flora • Broad‐spectrum anRbioRcs can inhibit the synthesis of vitamin K • Bleeding can occur within 2 days • Importance of giving a newborn their vitamin K shot at birth
• Inhibits vitamin K epoxide reductase (the most important enzyme responsible for regeneraRng reduced vit K • UlRmately decreases the synthesis of the vitamin K dependent factors 2,7,9,10 • Decreases the acRvity of protein C • Requires heparin first during treatment
WARFARIN
HEPARIN
• Is an oral medicaRon (aka Coumadin) • Is teratogenic (crosses the placenta) • Monitor the PT (prothrombin Rme)
• Is a cofactor for anRthrombin 3 (protects against clots – in a protein C deficiency) – this is why we give heparin before warfarin • Blocks thrombin and clo{ng factors 9,10,11,12 • Can be reversed by protamine sulfate • Half‐Rme of 6hr • Bleeding is the MC complicaRon
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HEPARIN • Serious AE is heparin‐induced thrombocytopenia (HIT) • If you get this, switch to LMWH • Any paRent who has a hx of HIT should be given Agatroban next Rme they need heparin (is a direct thrombin inhibitor)
Vitamin A deficiency • • • •
Poor night vision (o|en a USMLE quesRon) Decrease in CSF producRon Hypoparathyroidism (is a co‐factor in PTH) Failure of maturaRon of epithelial cells
VITAMIN A • Helps with CSF producRon • A co‐factor in parathyroid hormone • Responsible for epithelial cell maturaRon (given when any organ is being worn away, as it sRmulates regeneraRon of the epithelium) • A weak anRoxidant • Responsible for visual acuity at night
Vitamin A excess • CSF overproducRon pseudotumor cerebri • Hyperparathyroidism = Hypercalcemia
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Vitamin A – pseudotumor cerebri • Papilledema • Headache • Always want to rule out a brain mass when these two symptoms are present • Commonly seen in overweight females
VITAMIN B1 ‐ Thiamine • Required for many dehydrogenase enzymes (pyruvate dehydrogenase, alpha‐ketogluterate dehydrogenase, branched‐chain AA dh, and transketolase). • Thiamine deficiency = lots of enzyme deficiencies • Most common populaRon suffering from B1 deficiency… Alcoholics
Pseudotumor Cerebri ‐ EvaluaRng • CT scan = ventricular enlargement • Management = Serial LP’s + cessaRon of vitamin A administraRon • Blindness is the main worrisome complicaRon
Thiamine Deficiency ‐ BeriBeri Dry BeriBeri Symptoms of alcoholism. NO Heart Failure Wet BeriBeri Above + Heart Failure
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Thiamine deficiency – Wernicke’s Encephalopathy • Posterior lobes affected • RecepRve aphasia • Ataxia, opthalmoplegia, short‐term memory impairment
VITAMIN B2 ‐ Riboflavin • An FAD co‐factor • Can be degraded by sunlight • Deficiency leads to angular chelosis (lesions in the corners of the mouth)
Wernicke‐Korsakoff Syndrome Confusion, nystagmus, opthalmoplegia, ataxia, psychosis
VITAMIN B3 ‐ Niacin • A component of co‐factors: NAD, NADH, NADP, and NADPH • Required in dehydrogenases: Pyruvate dh, AKG‐dh, and BCAA dh
NIACIN deficiency • Classic USMLE quesRon PELLEGRA: The 4d’s: Diarrhea, DermaRRs, DemenRa, and Death (sounds like our energy depleted state) Also causes Hartnup’s Disease – renal transport of tryptophan is disrupted, leading to same 4d’s
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VITAMIN B4 – Lipoic Acid • Is required for dehydrogenases: Pyruvate dh, AKG‐dh, and BCAA dh • There is no state of lipoid acid deficiency
VITAMIN B6 ‐ Pyridoxine • • • •
Is an important part of heme synthesis Is required for all transaminases Isoniazid can cause a deficiency Forms pyridoxylphosphate cofactor
VITAMIN B5 – Pantothenic Acid • Required for dehydrogenases: Pyruvate dh, AKG‐dh, and BCAA‐dh • No known deficient state (because it is present in almost all foods) • Is a component of co‐enzyme A
Pyridoxine deficiency • Neuropathy is the main symptom TreaRng a chronic neuropathy Give amitriptyline TreaRng a “shooRng” neuropathy Carbamazepine or GabapenRn
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VITAMIN B9 ‐ Folate • Used to make tetrahydrofolate (a requirement for nucleoRde synthesis) • Antagonized by sulfa drugs • Is the first thing to become deficient during rapid cellular division (cancer)
Folate deficiency • Deficiency leads to cell death, thus it is essenRal during embryogenesis and for the maintenance of new cells • Purposely depleRng folate is a cornerstone in most cancer regiments • Leads to suppression of hematopoeisis • Leads to megaloblasRc anemia…why?
Folate deficiency anemia
Folate deficiency
• Remember that folate is responsible for aiding in cellular division… • If folate is deficient, the nucleus afempts to divide over and over again, but it cannot, leading to the enlarged cell with a mulR‐lobed nucleus that could not divide.
• The most common reason for folate deficiency is overcooked vegetables • Those afempRng to get pregnant should take folic acid supplements for at least 12 weeks before becoming pregnant
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VITAMIN B12 ‐ Cyanocobalamin
VITAMIN B12 Deficiency
• Important in homocysteine methyltransferase (required for tetrahydrofolate producRon) • Important for methylmalonyl‐Coa Mutase (necessary for recycling of odd‐numbered fafy acids myelin producRon deficiency leads to neuropathy)
• Leads to neuropathy • Affects the corRcospinal tracts and dorsal column tracts. • The most common cause is pernicious anemia
VITAMIN C
Why vitamin C for a cold?
• Necessary for hydroxylaRon reacRons (proline and lysine collagen, elasRn producRon) • Vitamin C is the main anRoxidant in the gastrointesRnal tract
• Vitamin C is a great anRoxidant against viruses, which are the most common cause of a cold.
WHY IS VITAMIN C RECOMMENDED WHEN WE ARE BATTLING A COLD?
WHY DO WE INSIST IN GIVING IRON SUPPLEMENTS WITH ORANGE JUICE??
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Iron + Orange Juice?? • Iron is easily oxidized by free radicals, which renders it useless • Orange juice is rich in vitamin C, which is a great anR‐oxidant…
Iron + Orange Juice • Vitamin C prevents oxidaRon of iron and thus iron is usable to our bodies
Combine the two…… and…..
VITAMIN C Deficiency
MAGNESIUM
• Scurvy • Classically linked to pirates traveling the high seas • We don’t get proper producRon of collagen and elasRn bleed from mucus membranes, hair follicles
• Is a co‐factor in all kinase reacRons (phosphorylaRon reacRons), that produce ATP • Is a PTH co‐factor • USMLE QuesRon Magnesium and Calcium are linked as chronically low calcium that cannot be elevated is always suspect of low magnesium. *They are both linked by way of PTH, low Mg2+ = ineffecRve PTH = low Ca2+
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ZINC
COPPER
• Causes dysgeusia if deficient (abnormal taste)
• Required for collagen formaRon (hydroxylaRon of lysine) • Requirement of complex 4 in the ETC
COPPER Deficiency
COPPER Excess
• Menke’s kinky hair syndrome • Hair is orange colored • Hair feels like fine copper wire
• Wilson’s disease • AR • Ceruloplasmin deficiency leads to copper deposit in the lenRcular nucleus, iris, and liver..
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Wilson’s Disease • Liver – bleeding disorders, esophageal varices, cirrhosis • Neuropsych – behavioral changes and Parkinson’s symptoms • Eyes – Kayser‐Fleisher rings (copper deposit in the Descemet’s membrane of the cornea) • Kidneys – Renal tubular acidosis • Heart – cardiomyopathy
IRON • Required for the formaRon of heme and hemoglobin • “Ferrous” state is required for iron binding (2+) • Required for ETC complexes 3 and 4
Wilson’s Disease • Endocrine – low PTH = low Calcium, inferRlity Treatment: Penicillamine (chelator of copper)
Let’s talk about Trace Minerals • Trace minerals are required in very small amounts…. thus called “trace” They are: Chromium, Selenium, Fluoride, Tin, Manganese, and Molebdenum
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CHROMIUM • PotenRates the acRon of insulin • Associated with many types of diabetes • Chromium deficiency can lead to diabetes
FLUORIDE • Necessary for teeth and bone growth • An excess can block the enolase enzyme in glycolysis (2‐phosphoglycerate phosphoenylpyruvate)
SELENIUM • Required by the heart • Excess levels cause a specific smell of the breath that is like garlic • Deficiency can lead to dilated cardiomyopathy
TIN • Main use is in hair growth
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MANGANESE • Required for xanthine oxidase (hypoxanthine xanthine uric acid)… thus important in purine catabolism. • Required for many glycolysis enzymes
MEMBRANE FUNCTION MEMBRANE PHYSIOLOGY
• Provides shape (it’s most important role) • They are hydrophilic and hydrophobic (amphipathic) • Maintains the concentraRon gradient • Selects what can and cannot pass through
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FAT SOLUBLE COMPOUNDS • Don’t interact with the membrane, instead pass right through to nucleus • Only limiRng factor for these compounds is concentraRon • Steroids are important fat soluble hormones • Cor,sol is the only fat soluble hormone with a receptor in the cytoplasm
WATER SOLUBLE COMPOUNDS • Are hydrophilic • Must bind to a membrane receptor known as a 2nd messenger • Most vitamins are water soluble compounds (except D, E, K, A)
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• • • • • • • •
THE FACTORS AFFECTING DIFFUSION
MORE MEMBRANE FUNCTIONS
Concentra,on gradient (#1 factor) Molecule size Charge (greater charge = greater mov’t in water) pH (affect a molecule’s charge) Membrane thickness (thicker = harder) Surface area (more area = easier to cross) Flux (mov’t of unit area per unit Rme) Reflec,on co‐efficient
• Phagocytosis: specific form of endocytosis for internalizing solid parRcles such as bacteria • Endocytosis: main reason is for nutriRonal needs (proteins) • Exocytosis: main reason is for eliminaRon of waste products • Pinocytosis: is a form of cell‐drinking
TEMPERATURE REGULATION
MEMBRANE POTENTIALS
• Conduc,on: via contact • Convec,on: via movement • Radia,on: movement down a concentraRon gradient
• ConcentraRon gradient is always your most important factor • Na+, Ca2+, Mg2+, Cl, and HC03‐ all want to move inwards, while K+ wants to move outwards • Mg2+ is abundant inside the cell but afached to kinases (bound), thus Mg2+ sRll moves inwards • Ca2+ is abundant inside the cell but is sequestered inside the SR
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MEMBRANE POTENTIALS
ELECTROLYTE MOVEMENT
• DepolarizaRon = becoming more posiRve • 2 Rssues that absorb the most currents are the Purkinje fibers and Brain • Electricity destroys the charge of the basement membrane, thus electrocuRon prevents platelet adhesion
THE ELECTRICAL GRADIENT • Is determined by an ion’s Nernst number • An ion will behave so that it brings the cell’s electrical baseline closer to it’s Nernst number • Na+ = +65 • K+ = ‐95 • Ca2+ and Mg2+ = +120 • Cl‐ = ‐90
DRIVING FORCE • The speed at which ions will enter into a cell • [E‐ion – E‐membrane] = driving force • Conductance (G‐ion): defines the actual movement across a membrane • Permeability: Small ions move through channels, medium sized ions move through pores, and large molecules move through protein channels
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TRANSPORT PROTEINS
SECOND MESSENGER
• Require energy • Primary Ac,ve Transport: the MC is the Na/K ATPase, which pumps each against their gradient • Secondary Ac,ve Transport: uses the energy created from one ion moving down it’s gradient (Na/Ca exchanger) • Symport: moves in the same direcRon as Na • An,port: moves in opposite direcRon of Na
SECOND MESSENGERS • Used for those molecules that cannot pass directly through the membrane • The MC 2nd messenger is cyclic AMP (cAMP) • cAMP is the 2nd messenger for sympatheRc acRvity • cGMP is the 2nd messenger for parasympatheRc acRvity
cAMP • Is the most common and important 2nd messenger • Alpha receptor is sRmulated by 1st messenger, G‐protein sRmulates adenylyl cyclase which gets acRvated by ATP • cAMP then gets created from AC and can sRmulate protein kinase A (PKA) • Mg2+ is the co‐factor for PKA
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cGMP • Guanlyate cyclase is sRmulated and produces cGMP via GTP • cGMP then sRmulates protein phosphatase
PHOSPHODIESTERASE • Enzyme responsible for cAMP and cGMP degredaRon • Blocking PDE acRvity will increase cAMP and cGMP levels and thus prolong their physiological effects • Caffeine blocks PDE
BLOCKING PHOSPHODIESTERASE • Will elevate levels of cAMP and cGMP • At a certain point, cAMP will become parasympatheRc (don’t forget this) • Sexual arousal is parasympatheRc • This physiology is the basis for erecRle dysfuncRon medicaRons
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ED DRUGS AND NITRATES • Combining these two drugs can prove to be deadly • The nitrates increase cGMP, leading to the potenRal for significant vasodilaRon and unsafe drops in blood pressure • Minimum of 12hr in between Nitrate and Viagra/Cialis/Levitra • Ideally waiRng 24hr between
IP3‐DAG
CALCIUM AS A 2ND MESSENGER • IP3‐DAG (used by all hypothalamic hormones except for CRH, all smooth muscle contracRons by hormone or NE/E) • Calcium‐Calmodulin (smooth muscle contracRon by distenRon) • Calcium (2nd messenger for gastrin)
CALCIUM‐CALMODULIN • There is a 4:1 raRo of calcium to calmodulin • When there is distenRon (feces GI, food in esophagus, food in stomach, fetus in uterus, urine in the bladder) this system is sRmulated
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CALCIUM‐CALMODULIN
TYROSINE KINASE • Is the 2nd messenger for all growth factors • It uses magnesium as a co‐factor • MutaRons to tyrosine kinase have been linked to some types of cancer • It’s acRvity can be inhibited with the chemotherapy drug ImaRnab
NO AS A 2ND MESSENGER • SRmulates GC, leading to elevaRon of cGMP levels • Used as part of nitrates for vasodilatory properRes • Tachyphylaxis occurs (rapid tolerance) • Gives balanced vasodilaRon (veins and arteries equally)
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THE MOST IMPORTANT ORGANELLE
CELLULAR PHYSIOLOGY
• Is the nucleus • Damage to the nucleus will result in cellular death, every single Rme • Nuclear damage is the most important sign of irreversible cellular injury
IRREVERSIBLE CELLULAR INJURY
PROGRAMMED CELLULAR DEATH ‐ APOPTOSIS
• Programmed cellular death (apoptosis) • Non‐programmed cellular death (necrosis)
• Apoptosis is the term we use to describe programmed cellular death • Describes predetermined planning of a cell’s demise • Death of the cell is organized, neat, and will not sRmulate any inflammatory processes
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NUCLEAR SUICIDE • A|er the nucleus has told the cell to die, it too must die… • Karyolysis – dissolving of the nucleus • Karyorrhexis – chunks of nucleus break off • Pyknosis – blebs of nucleus break apart
COMMON TYPES OF NECROSIS • • • • • • • •
Ischemic necrosis Purulent necrosis Granulomatous necrosis Fibrinous necrosis Caseous necrosis Fat necrosis Hemorrhagic necrosis LiquefacRve necrosis
NON‐PROGRAMMED CELLULAR DEATH ‐ NECROSIS • Necrosis is the form of non‐programmed cellular death we are dealing with most o|en • Numerous ways necrosis can occur • The nucleus dies first, sRmulaRng an inflammatory mechanism • SRll uses the same methods of nucleus destrucRon as with apoptosis
COAGULATIVE NECROSIS • Is the MC form of necrosis • Caused by ischemia or infarcRon • The Rssue dies but it’s architecture remains intact • In most Rssues ischemia leads to coagulaRve necrosis, but in the CNS it leads to liquefacRve necrosis (lack of structural architecture)
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PURULENT NECROSIS • There is a presence of pus • Always be thinking bacteria when there is pus
FIBRINOUS NECROSIS • AnyRme there is a deposit of fibrin we worry about the following problems: 1. Collagen Vascular Disease 2. Uremia (renal failure) 3. Tuberculosis
GRANULOMATOUS NECROSIS • Is a non‐bacterial type of necrosis • Involves T‐cells and macrophages
CASEOUS NECROSIS • This necrosis has a ‘cheesy’ consistency as it is a white, so|, protein‐like substance • Caseous necrosis is frequently associated with tuberculosis
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FAT NECROSIS • Occurs in organs either made mostly of fat or surrounded by fat • The breast is a common locaRon – is associated with trauma to the breast • The pancreas sits on a cushion of fat and when chronic pancreaRRs occurs so does fat necrosis
LIQUEFACTIVE NECROSIS • Causes the formaRon of an abscess related to bacterial or fungal infecRons • The MC locaRon is the brain (due to hypoxic death – not infecRous processes) • Least likely to form in the lung due to it’s constant supply of oxygen
HEMORRHAGIC NECROSIS • Wherever we have 2 or more vascular supplies we can get hemorrhagic necrosis • Ischemia causes release of inflammatory mediators, then restored bloodflow re‐ introduces free radicals that lead to damage of cell’s structures • MC seen in brain and heart
CHROMOSOMAL ANOMALIES • When we mess with the nuclear structures in utero we are going to have major consequences • Most cases die, the 1% that live are the ones we will see and be tested on • Monosomies don’t develop enough Rssue • Trisomies develop too much Rssue
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MONOSOMIES • Non‐disjuncRon is the MCC of monosomies • MC Rme is during meiosis 1 • Based on numbers, the problem usually comes from the dad (billions of sperm vs. limited supply of eggs) • Based on odds, the problem is usually transmifed via the mom
COARCTATION
TURNER SYNDROME • • • • • • • • •
MCC is non‐disjuncRon from the father XO Short‐stature Webbed‐neck AorRc coarctaRon (pre‐ductal type) Streaked gonads Shield‐shaped chest CysRc hygroma Overall look nothing grows
TRISOMIES • Most die • Those who live develop extra ,ssue because there’s too many chromosomes • Patau = trisomy 13 • Edwards = trisomy 18 • Down’s = trisomy 21
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PATAU SYNDROME • • • • • •
Trisomy 13 Protruding abdomen (omphalocele) Polydactyly (too many fingers) Abdnormal ‘peeing’ system (GU abnormality) Palate is high‐arched Death within 3 months
TRISOMY 21
EDWARDS SYNDROME • 95% of paRents have rocker‐bofom feet • They die within 3 months
AVSD
100% of these paRents have mental retardaRon Robertsonian translocaRon AVSD is the MC cardiac anomaly MCC of cyanoRc disease at birth is transposiRon of the great arteries • ½ of Down’s paRent have hypothyroidism • Duodenal atresia (double bubble sign) • Hirschprung’s disease • • • •
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TRANSPOSITION OF THE GREAT ARTERIES
TETRALOGY OF FALLOT
OTHER TRISOMIES
FRAGILE‐X SYNROME
• XXX Is a normal female with 2 barr bodies (not problemaRc) • XXY Klinefelter’s syndrome
• Is the MCC of mental retardaRon in males • CharacterisRc features include: Long face Large/protruding ears Decreased muscle tone/mass Large testes (a|er purberty)
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THE SIGNS OF IRREVERSIBLE CELLULAR DAMAGE ONE LAST LOOK AT IRREVERSIBLE CELLULAR DAMAGE
• • • •
THE MCC IS ISCHEMIA 1st sign Nuclear Damage 2nd sign Lysosomal Damage 3rd sign Mitochondrial Damage
CONTROLLING CELL DIVISION WITH MEDICATIONS ~Chemotherapy~
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CHEMOTHERAPEUTICS • The goal is to slow or stop rapidly dividing cells • Leads to irreversible cellular death (afacks nucleus) • Is not selecRve, thus we get severe adverse effects • There is no “safe” chemotherapeuRc • Causes necrosis kills nucleus first leads to inflammaRon
CHEMOTHERAPEUTICS • For fast‐growing cancers An,metabolites • 2nd ling for fast‐growing cancers Microtubule Inhibitors • For slow‐growing cancers Alkyla,ng agents • Nutrient Depletors L‐Aspariginase
CHEMOTHERAPY SIDE EFFECTS • Think to our energy‐depleted state • You already know every side effect based on that profile • Why do we give chemotherapy every 7 days???
ANTIMETABOLITES • Work best on fast‐growing cancers • They all work by disrupRng the producRon of metabolites, so we stop the ability of rapidly dividing cells to regenerate
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ANTIMETABOLITES • • • • • •
ARA‐A ARA‐C Methotrexate 5‐Fluorouracil 6‐Mercaptopurine Azothioprine
ALKYLATING AGENTS • For slower‐growing cancers • Big‐picture is that they alkylate the guanine nucleobases in dsDNA • These tend to cause the worst nausea and vomiRng (manage with Ondasetron)
ALKYLATING AGENTS • • • • • • • •
Bleomycin Busulfan Doxorubacin CisplaRn Cyclophosphamide AnRmycin Melphalan Chlorambucil
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MICROTUBULE INHIBITORS • • • •
Are 2nd line for fast‐growing cancers VinblasRne VincrisRne Paclitaxel
NUTRIENT DEPLETION • L‐asparaginase • Converts asparagine into asparRc acid and ammonia so that ALL cannot make use of circulaRng asparagine (which it needs in order to divide) • Thus best for ALL • Tends to cause allergic reacRons and anaphylaxis on occasion
IMMUNOMODULATORS • Enhances our own NK cell’s killing ability • Levamisole
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THE CNS NEUROMUSCULAR PHYSIOLOGY
THE PARASYMPATHETIC SYSTEM
• • • •
The key to all neurological control Consists of brain and spinal cord Parasympathe,c System – craniosacral Sympathe,c System ‐ thoracolumbar
THE PARASYMPATHETIC SYSTEM • Long presynapRc, short postsynapRc fibers • Acetylcholine is the neurotransmifer used at both pre and post ganglionic fibers • Causes depolarizaRon of the cranial and sacral regions (thus are ‘craniosacral’) • 2nd messenger is cGMP • All of their receptors are muscarinic (except for ganglia or NM juncRons) – they are nicoRnic
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THE SYMPATHETIC SYSTEM
THE SYMPATHETIC SYSTEM • Short presynapRc and long postsynapRc fibers • Acetylcholine is used as the preganglionic neurotransmifer, NE is used at postganglionic fibers • Causes depolarizaRon in the brain and thoracolumbar areas • 2nd messenger is cAMP • Many are nicoRnic (except sweat glands – they are muscarinic) • Alpha and beta receptors are sympatheRc
INHIBITORY NEUROTRANSMITTERS
NEUROTRANSMITTER PRODUCTION
• GABA: inhibitory in the brain • GLYCINE: inhibitory at the spinal cord • Both cause a chloride ion influx
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ALPHA and BETA RECEPTORS • Alpha 1: smooth muscle contracRon • Alpha 2: smooth muscle contracRon and NT inhibiRon • Beta 1: increased cardiac contracRon, increased BP • Beta 2: smooth muscle relaxaRon
ALPHA 1 RECEPTORS • • • •
ContracRon of smooth muscles Causes constricRon of arteries Causes Rghtening of sphincters Causes mydriasis without cycloplegia
ALPHA AGONISTS • • • • •
Norepinephrine Epinephrine Ephedrine Pseudoephedrine Phenylephrine
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ALPHA ANTAGONISTS • • • • • • • • •
Alpha 1 specific blockers include: Prazosin Terazosin Doxazosin Tamsulosin Non‐specific alpha blockers: Phentolamine Phenoxybenzamine Yohimbine
NON‐SELECTIVE ALPHA BLOCKERS • Phentolamine: is short‐acRng drug used to diagnose pheocromocytoma… tends to cause reflex tachycardia • Labetalol: has both alpha and beta blocking abiliRes, is preferred over phentolamine, is excellent for HTN emergencies • Phenoxybenzamine: an irreversible alpha 1,2 blocker, is given before pheocromocytoma surgery to prevent HTN crisis • Yohimbine and Mirtazapine: are alpha‐2 antagonists
ALPHA 1 BLOCKERS • Will lower blood pressure • Prazosin: used for BPH, 1st dose phenomenon, long‐term use causes orthostaRc hypotension • Terazosin and Doxazosin are both DOC’s for BPH • Tamsulosin (Flomax): 2nd line for BPH, used when the others cause significant side‐effects
ALPHA 2 RECEPTORS • Found on all presynap,c fibers (thus inhibit NE release) • Found on the Islet cells of the pancreas (thus inhibit insulin secreRon)
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ALPHA 2 AGONISTS • Alpha Methyl Dopa: DOC for pregnancy‐ induced HTN • Clonidine: primary use is HTN, suppresses SNS ou€low from CNS, sRmulates PNS ou€low (thus slows HR)… drawback is high risk of HTN • Guanabenz: less commonly used, it’s main side effect is drowsiness/sedaRon
BETA AGONISM • Beta 2 receptors will… • Relax all smooth muscle (main benefit is the ability to bronchodilate) • SRmulate insulin release from islet cells of pancreas • Increase heart’s contracRlity but not it’s rate
BETA AGONISM • • • • •
Beta 1 receptors will… Increase CNS acRvity Increase renin release Increase HR and contracRlity SRmulate glucagon release (from alpha cells of pancreas)
BETA 1 AGONISTS • Dobutamine: sRmulates the heart without excess tachycardia. • Used for heart failure and cardiogenic shock • Most worrisome side‐effect is fatal arrhythmias • Isoproterenol: beta 1 and beta 2 sRmulaRon • Main use is in refractory heart blocks and bradycardia • Once used for asthma because of beta 2 sRmulaRon, but no longer used
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BETA 2 AGONISTS • This class is mainly used as asthma medicaRons • Albuterol: the MC inhaler for asthma, provides rapid bronchodilaRon, t ½ is 4hr) • Terbutaline: oral asthma medicaRon, useful for asthma and/or bronchospasm • Salmuterol: a long‐acRng beta agonist (LABA), t ½ 12hr, used twice per day to control asthma (Advair)
STRIATED vs. NON‐STRIATED • Striated muscles contain sarcomeres, which give them the striated appearance • Cardiac and skeletal muscle is striated • Smooth muscle lacks sarcomeres and is therefore non‐striated
THE MUSCLES
SKELETAL MUSCLE • Appears striated under the microscope (arranged in bundles, bands, sheets) • FuncRons as a motor unit (1 nerve fiber sRmulates all muscle fibers it innervates) • Intracellular calcium is used for contracRon • Demonstrates ‘recruitment’ • Contains no autonomics or syncyRal acRvity
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CARDIAC MUSCLE • Uses intracellular calcium for contracRon, but requires extracellular calcium to trigger that intracellular release • Complete autonomics and syncyRal acRvity • ‘Gap JuncRons’ are intercellular connecRons, required to pass signals between cells so they fire in tandem • Connected by intercalated discs
SMOOTH MUSCLE • Uses intracellular calcium for contracRon • Extracellular calcium is needed to sRmulate the 2nd messenger systems (IP3‐DAG and Ca‐Calmodulin) • Has full autonomics • Has parRal syncyRal acRvity (ie. GI has peristalsis) • Contains no sarcomeres • Contains no troponin • AcRn and myosin are bound by a ‘latching’ mechanism • There is no myosin ATPase acRvity (MLCK and MLCP work together)
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NEUROMUSCULAR TRANSMISSION
AXONAL TRANSPORT
How to disrupt axonal transport
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CONTRACTION
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THE FUNCTIONAL UNIT OF MUSCLE – The Sarcomere
LENGTH vs. TENSION
THE GOLGI TENDON ORGAN • Located at the muscle inserRons • Ensures we don’t hold maximum tension on our muscles (keeps sarcomeres safe) • Will prevent max tension from going past 1s • Once sRmulated, a muscle has no choice but to relax
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MUSCLE STRAINS vs. SPRAINS • Strain = overstretching of a muscle • Occurs when muscles go from a relaxed to strained state too abruptly • Treat a strain with NSAIDS that also relax the muscles (Baclofen, Cyclobenzaprine)
MUSCLE STRAINS vs. SPRAINS • Sprains = a tear to the tendon or ligament caused by excessive stretching • Treat with RICE (Rest, Ice, Compression, ElevaRon)
THE FRANK‐STARLING MECHANISM
NEUROMUSCULAR DISEASES
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INFLAMMATORY MYOPATHY PROFILE • • • •
Elevated ESR Elevated White Blood Cells Elevated AST, ALT, and Aldolase myoglobinemia
MUSCULAR DYSTROPHIES • Duchenne’s • Becker’s • Myotonic
LIST OF INFLAMMATORY MYOPATHIES • Myosi,s • Polymyosi,s • Dermatomyosi,s • Fibrosi,s • Polymyalgia rheuma,ca • Temporal arteri,s
DUCHENNE’S MUSCULAR DYSTROPHY • Is the MC encountered form of muscular dystrophy • No dystrophin is made (Xp21 gene) • Is an x‐linked recessive disease (onset before 5yr of age) • Gower’s sign • Calf pseudohypertrophy • DefecRve dystrophin protein
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BECKER’S MUSCULAR DYSTROPHY • Decreased amount of dystrophin made • An x‐linked recessive disease • Looks just like Duchenne’s but onset is later and progression is slower (ie. All findings are similar) • Early onset (8yr) is more associated with cardiac involvement, while later onset (12yr) is less likely to involve the heart • Many paRents live normal lives, however at some point most end up walking with cane/crutches, or need a wheelchair
MYOTONIC DYSTROPHY • A highly variable disease that is slow to progress and is chronic • Autosomal dominant • 2 types: Type 1 affects facial/jaw/neck muscles, and usually presents with cataracts • Type 2 affects the proximal muscles mainly (thighs, pelvis) • Manage symptoms as they come
GUILLAN‐BARRE SYNDROME
NEUROLOGICAL DISORDERS INVOLVING MUSCLES
• Ascending muscular weakness/paralysis • Commonly begins around 2 weeks a|er a viral infecRon (MC Campylobacter) • Is an autoimmune a[ack against the peripheral nerves (caused by Gangliosides) • Mild cases only damage myelin (good px) • Severe cases may damage axon (worse px) • The most worrisome complicaRon is respiratory failure (intubaRon necessary in ~ 30% of cases)
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DIABETES MELLITUS • MC presents in a ‘glove‐and‐stocking’ distribuRon • Caused by sorbitol accumulaRon (from aldol ‐reductase pathway), as well as decreased blood flow • Goal is Rght blood‐glucose control throughout life
SYPHILIS • Tabes dorsalis affects the posterior horns of the nerves • Argyll‐Robertson pupil • Later stages of syphilis may present with shooRng/stabbing neuropathies • Tx shooRng pain with Carbamazepine
MYASTHENIA GRAVIS • Autoimmune afack against the Ach receptors • MC presenRng symptom is a middle‐aged female with ptosis • PaRents develop weakness as the day progresses • Diagnose with Edrophonium test • Treat with NeosRgmine ** may be associated with a Thymoma
ANTICHOLINERGIC DRUGS • • • •
Atropine Benztropine Glycopyrolate Ipratropium
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LAMBERT EATON SYNDROME • AnRbodies formed against the voltage‐gated calcium channels in the presynapRc nerve • Is a paraneoplasRc syndrome • Proximal muscles are most harshly affected (closest to trunk) • Autonomic problems also occur • Diagnose with EMG • Treat the underlying cancer (if present)
MULTIPLE SCLEROSIS • Seen MC in middle‐aged females • Scanning speech, intenRon tremor, nystagmus • AnR‐myelin anRbodies affect random areas in the brain • MRI is the best diagnosRc test (shows mulRple areas of demyelinaRon) • Acute episodes: IV corRcosteroids • LT Management: DMOD’s
MULTIPLE SCLEROSIS • • • • •
4 main types: Relapsing‐Remi{ng Primary progressive Secondary progressive Progressive‐relapsing
• Prognosis is best when…. Relapsing‐remi{ng type, female gender, early age of onset, few afack in iniRal years, presence of opRc neuriRs, sensory problems at onset
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MRI of MS PaRent
METACHROMATIC LEUKODYSTROPHY • Arylsulfatase A deficiency • Affects the G&D of myelin, so myelinaRon is disrupted • Looks like MS in a 5‐10yr old • OpRc neuriRs • Internuclear opthalmoplegia • Management is similar to MS (IV steroids, IVIG, plasmapharesis when respiratory problems begin)
AMYOTROPHIC LATERAL SCLEROSIS
LOWER MOTOR NEURON DISEASES
• Aka “Lou Gehrig’s disease” • MC seen in males (middle age) • Ventral horn and corRcospinal tract neuron degeneraRon • IniRal presentaRon: fasciculaRons, muscle atrophy, weakness • Progressive presentaRon: progression to rest of body (usually in descending fashion) • NO sensory involvement • No treatment
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WERDNIG‐HOFFMAN DISEASE • An x‐linked recessive disease • Is a severe form of spinal muscle atrophy • At birth, infants present with hypotonia, tongue fasciculaRons, breathing difficulRes, poor feeding, and a weak cry • Diagnose with EMG • Treatment is supporRve, most infants die by 2yr
FRIEDREICH’S ATAXIA • An X‐linked recessive triplet repeat disorder • Caused by mutaRon of FXN gene that codes for Frataxin (on chromosome 9) • Sclerosis and degeneraRon of the dorsal root ganglion, spinocerebellar tracts, lateral corRcospinal tracts, and posterior columns • Usually starts between 5‐15yr of age • MC si/sx are: arm/leg weakness, gait instability, hearing and visual impairment, slurred speech, scoliosis
CHILDHOOD CEREBELLAR DISEASES
ATAXIA TELANGIECTASIA • Disrupts co‐ordinaRon and weakens the immune system (IgA deficiency) • Telangiectasias are superficial, red‐colored spider veins all over the body • SupporRve measures are all that can be undertaken • PaRents usually die between teenage years and early 20’s (MC d/t immune system dysfuncRon)
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ADRENOLEUKODYSTROPHY
CEREBRAL PALSY
• X‐linked recessive • DefecRve carniRne shufle results in accumulaRon of long‐chain FA’s in cytoplasm • Adrenal insufficiency can cause Addison’s disease • Mental difficulRes and deterioraRon are common, as well as adrenal problems • Most paRents end up in coma within 2yr of
• Defini,on: any permanent neurological damage suffered prior to the age of 21yr • Spas,c diplegia: is a mid‐line corRcal problem • Spas,c hemiplegia: is a corRcal problem on 1 side of the brain (contralateral side affected) • Choreoathetosis: involve the basal ganglia (Kernicterus) • Atonic: frontal cortex is involved, CSF involved
BEHAVIORAL SCIENCES
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5 AREAS YOU’RE TESTED ON… 1. 2. 3. 4. 5.
Mood and psychoRc disorders Personality disorders Defence mechanisms Sexual deviance BiostaRsRcs
3 TIMES WHEN WE CAN HOSPITALIZE AGAINST THEIR WILL • They are a danger to themselves • They are a danger to others • They are so impaired that they cannot feed themselves, afain shelter, or clothe themselves.
HOW TO ENSURE A HIGH SCORE IN BEHAVIORAL • Focus on the symptoms are you most likely to see on the exam. • Remember that psychiatric illnesses put major impairment on someone’s life. • Always eliminate drugs as a cause of the problem • MedicaRon + psychotherapy is ALWAYS superior to one or the other.
DSM 4 DISORDER CLASSIFICATIONS • Clinical disorders (Class 1) • Personality disorders/mental retardaRon (Class 2) • Medical condiRons (Class 3) • Social and Environmental factors (Class 4) • Level of funcRoning (Class 5)
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PROGNOSIS OF PSYCH DISORDERS • Favorable when: sx are acute, insight into their problem is good, and they’ve had high premorbid levels of funcRonality • Poor when: sx are subacute and/or chronic, insight into their disorder is poor, they had low‐levels of premorbid funcRonality
MOOD DISORDERS • We have the ‘ups’ • We have the ‘downs’
DEPRESSIVE DISORDERS • What is normal? • Sadness • Grief/bereavement
STAGES OF GRIEF • • • • •
Denial Anger Bargaining Depression/guilt Acceptance
**always be wary of someone who is grieving without funcRonality, as this indicates a depressive disorder.
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GRIEF
GRIEF
• Offering empathy is the #1 way to help, then a support group. • Everybody goes through 5 stages, but can become stuck in certain stages • A grieving person is sRll funcRonal • Normal grief can last up to 2 months (a|er that we diagnose with major depressive disorder).
The Theory of Compassion: ‐ A paRent feels you give them more compassion and Rme based solely on how and where you posiRon yourself in their room or in your clinic. ‐ Si{ng at the head of the bed vs the foot of the bed makes your paRent feel like you care more, lowering any potenRal for being sued.
DISORDERS WITH FEATURES OF DEPRESSION
BIPOLAR DISORDER
• • • •
DYSTHYMIA CYCLOTHYMIA MELANCHOLY BIPOLAR DISORDER
• • • • • • •
Seen in 1% of the populaRon Men = female Seen more commonly in younger age groups Bipolar 1 (MDD + MANIA) Bipolar 2 (MDD + HYPOMANIA) For diagnosis we only need to see 1 episode Rule out cocaine and/or amphetamine use
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BIPOLAR MANAGEMENT Major goals of treatment: 1. Treat and reduce severity of manic or depressive episodes. 2. Reduce the frequency of episodes 3. Avoid cycling from one phase to another 4. Help the paRent funcRon normally between episodes
DRUG‐INDUCED MANIA • Cocaine and amphetamines • Mania + tachycardia, HTN, mydriasis, arrhythmias • Classic USMLE quesRon is person in their 20’s with an MI (usually caused by cocaine) • For acute management, CCB’s are effecRve
BIPOLAR MEDICATIONS • 1st line is Lithium (effecRve short and long‐ term for bipolar management) • 2nd line are anR‐seizure medicaRons such as Valproate and Carbamazepine (3rd line) • When using lithium blood levels must be checked frequency due to small safety margins • Watch for polyuria with Lithium as it can cause nephrogenic DI
MORE ABOUT LITHIUM • Is 1st line for bipolar disorder • Is a ‘mood stabilizer’, so it doesn’t work for acute mania or acute depression • Hyponatremia • Hypercalcemia + hypophosphatemia • Nephrogenic diabetes insipidus • Epstein’s anomaly of the fetus • Occasional bone marrow suppression
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3 LEVELS OF DEPRESSION Acute reac,ve depression ( or = 2 weeks) Bipolar disorder (combined with mania) Incidence in the general populaRon is 1‐3% (rule) • If they have 1 risk factor the chances are 10% • • • •
MDD – OTHER COMPLAINTS • Sleep disturbances (excessive, short burts of REM, excessive REM, early morning awakening) • Guilt • Learned helplessness • Learned hopelessness • Various soma,c complains are common
MAJOR DEPRESSIVE DISORDER • • • • •
ANHEDONIA (MC sx) SIG E CAPS Failure to funcRon day‐to‐day Must conRnue at least 2 weeks 2 episodes of 2 weeks at least 2 months apart is a common presentaRon (do a thorough history)
CATECHOLAMINE THEORY OF DEPRESSION • Catecholamine levels are lower in paRents who are depressed • This is why depression recurs when untreated • This is why we give medicaRons to elevate these catecholamines
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CATECHOLAMINES AND DEPRESSION • Norepinephrine (a purely sympatheRc catecholamine) • Serotonin (sympatheRc in brain, parasympatheRc in the periphery) • Dopamine (sRmulates CTZ, movement disorders, psychosis) • Replenish them and you can expect these effects
CATECHOLAMINES AND DEPRESSION • Takes ~ 4 weeks to increase catecholamine levels • Takes paRent minimum 4 (more realisRcally 6‐8 weeks) before they feel much befer • PaRent must be made very well aware of this • Suicide risk increases in first 90 days of treatment (WHY?)
ANTI‐DEPRESSIVE MEDICATIONS • • • • •
SSRIs (1st lines, low side‐effects, anorgasmia) TCAs MAOIs HETEROCYCLICS ATYPICALS (low side‐effect profile)
THE SSRI’S • • • • • •
Citalopram (Celexa) Escitalopram (Lexapro) Fluoxe,ne (Prozac) Fluvoxamine (Luvox) Paroxe,ne (Paxil) Sertaline (Zolo|)
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SELECTIVE SEROTONIN RE‐UPTAKE INHIBITORS Block the re‐uptake of 5HT (post‐synapRcally) Lower number of side‐effects Major side effect is anorgasmia Off‐label use for premature ejaculaRon in young men • SSRI MAOI requires a 2‐week wait • MAOI SSRI requires a 4‐week wait (5HT crisis) • • • •
SSRI SIDE‐EFFECTS • Generalized side‐effects occur MC during weeks 1‐4 (N/V, headache, drowsiness, anhedonia, apathy) • Major drawback to use is it’s long waiRng period for it to reach full potenRal. • Anorgasmia (very common) • Diminished libido (common) • ErecRle dysfuncRon (rare) • Weight‐gain • If above AE’s are disturbing, switching to Bupropion can give relief
TRICYCLIC ANTI‐DEPRESSANTS
TCA’S IN USE TODAY
• Were the first type of anR‐depressant • Not used anymore for depression due to significant side‐effect profile • 4 main accons • 1 – Block re‐uptake of 3 catecholamines pre‐ synapRcally. • 2 – AnR‐cholingeric (strong) • 3 – Block α1 receptors (causes hypotension) • 4 – Block AV conducRon (ventricular arrhythmias)
• IMIPRAMINE: bed‐we{ng (anR‐cholinergic property) • AMYTRIPTYLINE: chronic neuropathy/pain, diabeRcs are main populaRon using them • CHLOMIPRAMINE – approved for OCD but not 1st line • NORTYPTILINE: used in elderly populaRon • DESIPRAMINE: used in elderly populaRon
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THE MAOI’s • • • •
Phenylzine Tranylcypramine Isocarboxazine Selegeline (Parkinson’s management)
MAOI – Serotonin Syndrome • • • • •
Caused by MAOI interacRng with SSRI Hyperthermia Muscle rigidity Excessive flushing Altered mental status
MONOAMINEOXIDASE INHIBITORS (MAOI) • Breaks down catecholamines • As we age our levels of MAO rise, thus increased depression risk with age (10%) • Selegeline – the only MAOBI (used for Parkinson’s disease) • Can cause serotonin syndrome if mixed with SSRIs (or not given enough Rme between use) • Can cause a hypertensive crisis if ingested with tyramine‐rich foods
MAOI – Hypertensive Crisis • Wine and cheese are broken down into Tyramine • Tyramine is a potent analog of NE • No MAO to break it down • Leads to excessive spike in BP
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HETEROCYCLICS • Trazadone – most worrisome adverse effect is priapism
ATYPICAL ANTI‐DEPRESSANTS • Have much lower side‐effect profiles than other drugs • Bupropion (Wellbutrin) – works mainly on DA, 5HT, and NE • Wellbutrin’s biggest downfall is that it lowers seizure threshold • Has a much lower sexual side‐effect profile, and has been shown to increase libido
ATYPICAL ANTI‐DEPRESSANTS • • • • •
Bupropion (Wellbutrin) DuloxeRne (Cymbalta) Mirtazapine (Rameron) Venlafaxine (Effexor, ChanRx) Trazadone
INTRACTABLE DEPRESSION • Electroconvulsive therapy (ECT) • Is excellent for cases where medicaRons do not help the paRent • Main indica,ons include: pregnancy, unresponsive to medicaRons, and paRents who are acutely suicidal
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ANXIETY & PSYCHOTIC DISORDERS
TYPES OF ANXIETY/PSYCHOSIS • Worry – situaRonal and controlled • Anxiety – an outward manifestaRon of your worry • Panic A[acks – usually situaRonal • Phobias – irraRonal fear leading to avoidance • Delusions – falsely held beliefs despite the proof of the contrary
TYPES OF ANXIETY/PSYCHOSIS • Illusions – mispercepRon of a sRmulus • Hallucina,ons – percepRon without a sRmulus • Psycho,c disorder – dx made when there is a loss with reality • Obsessive‐Compulsive disorder – recurrent thoughts/acRons • Post‐trauma,c stress disorder – violent incident that causes stress a|er‐the‐fact
WORRY • Is similar to sadness in the mood disorders… is situaRonal and we can o|en pull ourselves out of it. • Unlike anxiety, we can’t see worry on someone’s face
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ANXIETY • An outward manifestaRon of your worry • Specific: 1 thing in parRcular is causing anxiety • General: worried about many things/ everything • Social: provoked by social situaRons • Disorder: when it causes social impairment to the point where you avoid situaRons
PHOBIAS • There is an irraRonal fear that leads to avoidance • MC include acrophobia, arachnophobia, clostrophobia, agoraphobia • People with these phobias recognize the irraRonality
PANIC ATTACKS The MC type of anxiety Usually situaRonal May be intense sympatheRc overdrive Most people feel as though they’re having a heart afack, there is a feeling of impending doom • 1st step is always to rule out a more serious problem (MI – so get an EKG) • • • •
DELUSION, ILLUSION, HALLUCINATION • These are commonly confused terms • A delusion is when you have a falsely‐held belief despite social proof of the contrary • An illusion (think magician) is when you misperceive a sRmulus • A hallucina,on is when you perceive something without a sRmulus being there (think of the desert oasis)
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OBSESSIVE‐COMPULSIVE DISORDER • Obsessive thoughts lead to anxiety • Compulsions act to temporarily relieve the anxiety • Obsessions commonly involve contaminaRons and cleanliness, doubt, symmetry • Relief is temporary (very short‐lasRng) • This person recognizes the absurdity of their disorder, wheras people with OC personality see nothing wrong • Treat with SSRI’s + psychotherapy
POST‐TRAUMATIC STRESS DISORDER • There must be a traumaRc/violent event that scars them (classic example is a war veteran) • PaRents relives incident via subconscious or in a dream • The stress of anything that triggers this leads them to avoid stressors (places and acRviRes) • Detachment from others is common • Depression is common • Acute stress disorder (within 4 weeks and median > mode • Negacvely Skewed – means the values are exccesively low… in this case the mean
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