Anatomy Part i

MEDPRIME REVIEW CENTER BAGUIO CITY Review Questions for Discussion on Anatomy (Extremities, Back, Head and Neck, and Chest) Dr. Vibar

A. GROUPINGS 1. Rotator cuff muscles – tendons of it stabilize joint (Anterior, superior and posterior) * Weakest on inferior – unprotected by muscle

SKELETAL SYSTEM Total Bones in the body: 206 1. According to shape A. Long – with ends and shaft (Metacarpal, Humerus, Phalanx) B. Short – Length and width are equal (Carpals and Tarsals) C. Flat – Parietal bone of the skull and Ribs D. Irregular – Vertebrae, Hip Bone 2. According to location A. Axial – within the central axis with vertebral, thoracic case, ribs, sternum B. Appendicular – Upper and lower extremities, pelvis, pectoral girdle (Clavicle and Scapula) 3. According to germ layer A. Mesoderm  Supporting tissue (bones, muscles and cartilages)  Mesenchyme/ stem cells  gives rise to supporting tissue BONE FORMATION A. Direct – intramembranous  Mesenchyme  Direct bone B. Indirect – intracartilagenous (Endochondral)  Mostly of bones except flat bones of skull Skeletal muscle – paraxial mesoderm Cardiac muscle – visceral/ sphlanchnic

Supraspinatus

JOINTS 1. Mobility A. IMMOBILE (Synarthroses)  Fibrous - Sutures – Sutures of the skull - Syndesmosis – Fibula/Tibia; Radius/Ulna - Gomphosis – Connection with tooth between mandible and maxilla. B. SLIGHTLY MOVABLE (Amphiarthrosa  Cartilagenous 1. Primary – synchondrosis – Hyaline (Example: Costal cartilages) 2. Secondary – symphysis – Fibrocartilage (Example: Intervertabral disks, pubis symphysis) C. FREELY (Diarthroses)  Synovial Plane Sternoclavicular joint, acromioclavicular joint Hinge/ Ginglymus Elbow, knee and ankle joints Pivot/ Trochoid Atlantoaxial, radioulnar joints Condyloid Metacarpophalangeal joints Ellipsoidal Waist Saddle Carpometacarpal of thumb Ball and Socket/ Hip joint, shoulder joint Enarthroses 2. Medium A. Fibrous 1. Collagenous – most widely distributed 2. Elastic 3. Reticular – lymphatic tissue, hematopoietic B. Cartilagenous 1. Hyaline (most common) 2. Elastic 3. Fibroelastic C. Sinovial joints MUSCLES * Rotator Cuff Muscles (SITS) A. Supraspinatus (MC affected; inflammation of the rotator cuff)  manifested by pain anterior and superior to the shoulder joint during abduction B. Infraspinatus C. Teres MINOR D. Subscapularis

Infraspinatus Teres Minor Subscapularis Deltoid muscle Teres Major

Suprascapular nerve Suprascapular nerve Axillary nerve Subscapular nerve Axillary nerve Subscapular nerve

Abductor Lateral rotator Lateral rotator Medial rotator Abductor Medial rotator

Quadrangular Space Bounded Above: Teres minor Below: Teres major Medial: Long head of the Triceps brachii Lateral: Surgical neck of the humerus Contents: Axillary nerve (Circumflex nerve) – MC injured during dislocation Posterior circumflex humeral vessels *Action of supination (Biceps brachii muscle) innervated by Musculocutaneous * Lumbricalis – flexes the MCP joints innervated by the median nerve (lateral part) and by the ulnar nerve (medial part) * Extensor digitorum – innervated by the radial nerve Hypothenar muscles (Innervated by the ulnar nerve) AFO A: Abductor digiti minimi F: Flexor digiti minimi O. Opponens digiti minimi Thenar muscles (innervated by the median nerve) AFO A: Abductor pollicis brevis F: Flexor pollicis brevis O: Opponens pollicis *Palmar interossi – ADduct fingers * Dorsal interossi – ABduct fingers  both innervated by the ulnar nerve Anterior Arm: Musculocutaneous Posterior Arm: Radial Posterior Forearm: Radial Anterior Forearm: Median (Thenar – lateral), Ulnar (Hypothenar – medial) * Abduct and adduct of fingers  ulnar nerve * Extension of fingers  radial nerve * Flexion of fingers  ulnar nerve Muscles of the Arms Anterior: Flexor Posterior: Extensor - Musculocutaneous - Radial - Brachialis: main flexor - Triceps brachii: main extensor - Biceps brachii: Supinator of forearm of the forearm * Flexor Muscles of Forearm are all innervated by the Median nerve EXCEPT Flexor carpalis and the flexor digitorum profundus that is innervated by the ulnar nerve *Medial epicondyle of humerus  contains the common flexor tendon  origin of the pronator teres located at the humeral head *Extensor muscles of forearm  innervated by the radial nerve Superficial: Brachioradialis (Flexor)  radial nerve *Tennis elbow – affectation of the lateral epicondylitis * Golfer’s elbow – affectation of the medial epicondylitis BRACHIAL PLEXUS (C5, C6, C7, C8 and T1) TERMINAL BRANCHES of the Plexus Musculocutaneou Lateral cord

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s Axillary Radial Ulnar Median

- Fall on the outreached hand - Anterior displacement - Smith’s - Fall on the back of the hand

Posterior cord Posterior cord Medial cord Medial and lateral cord From C5 and C6

Long Thoracic * Erb-Duchenne’s Syndrome - Lesion at C5 and C6 - Proximal muscles in UE - Waiter’s tip - Altered sensation on the lateral side of arm *Klumpke - C8 and T1 - Distal muscles of the UE (Hand) - Altered sensation on the medial side of the arm - APE hand, claw hand

Proximal row Scaphoid/ Navicular Lunate Triquetral Pisiform

Distal row Trapeziu m Trapezoi d Capitate Hamate

* Long Thoracic Nerve Lesion - Winged scapulae - Anterior serratus muscle - Abnormal: Weak protraction - Median border/ vertebra is prominent * Axillary nerve lesion - Dislocation of shoulder and surgical neck *Radial nerve lesion - Spinal fracture and midshaft of humerus - Wrist drop *Median nerve lesion - Proximal = Supracondylar fracture = Hand of Benediction - Distal = Carpal tunnel syndrome or lunate dislocation = Ape Hand  weakness of opposition of the thumb * Ulnar nerve lesion - Proximal = medial epicondyle, weakness in flexion - Distal = Fracture of hook of hamate; Claw hand Cubital Fossa – Contents to medial to lateral A. Median Nerve B. Brachial Artery C. Biceps brachii D. Radial Nerve AXILLARY ARTERY - From 1st rib to Teres major * Tendon of the Pectoralis minor divides the artery into 3 parts 1. 1st part: Superior thoracic artery 2. 2nd part: Thoracoacromial artery and Lateral Thoracic 3. 3rd part: Subscapular, Anterior and Posterior Circumflex artery Cephalic Vein (lateral)  Drains to the axillary vein Basilic (Lateral)  Brachial vein * Median antecubital vein  connection of cephalic and basilica vein CLAVICLE - 1st bone to begin ossification - Last bone to complete ossification * Medial 2/3 Convex * Lateral 1/3 Flattened - Fracture of the Clavicle - Fall on shoulder or outstretched hand: Most commonly fractured bone - Medial segment elevated by the pull of the SCM - Lateral segment displaced downward by gravity and pull of deltoid and pectoralis major - Cause brachial plexus injury/ lower trunk - Haemorrhage from the subclavian artery or vein * Fracture of the lower end of radius - Posterior and superior displacement - Dinner/ Silver fork deformity (Colle’s)

ANATOMICAL SNUFFBOX - Lateral – tendonds of EPB and Abd PL - Medial – tendon of EPL - Floor – Scaphoid and Lunate * Radial artery; styloid process of radius; base of 1st metacarpal bone can be palpated CARPALS *Most commonly fractured: Scaphoid *Most commonly dislocated: Lunate  Carpal Tunnel Syndrome (median n.)

HUMERUS * Surgical neck of the humerus: Axillary nerve * Supracondylar ridge: Median nerve * Radial/ Spiral groove: Radial nerve * Medial epicondyle: Ulnar nerve THIGH A. Anterior: Flexor of the thigh and extensor of the leg innervated by the Femoral nerve - Quadriceps femoris - Rectus femoris - Vastus lateralis - Vastus medialis - Vastus intermedius - Iliopsoas muscle - Tensor Fascia lata: Medially rotate - Sartorius: Laterally rotate - Pectineus B. Posterior: Extensor of the thigh, flexion of the leg  innervated by the sciatic Nerve - Hamstring muscles - Semitendinosus - Semimembranosus - Biceps femoris - Adductor magnus (has dual innervation) - Hamstring part (Sciatic nerve) - Adductor part (Obturator nerve) C. Medial: Adducts thigh  innervated by the Obturator nerve - Adductor longus - Gracilis Adductor Canal – Transmission for structures - Subsartorial canal, Hunter’s canal - Fascial tunnel in the thigh running from the apex of the femoral triangle to the Adductor hiatus in the tendons of Adductor magnus Muscle , vastus medialis, sartorius - Contents: Femoral Artery and Vein Saphenous Nerve Nerve to vastus medialis FEMORAL SHEATH - Funnel shaped fascial tube formed by the prolongation of iliopsoas and transversalis fascia of the abdomen - Compartments A. Lateral – femoral artery B. Intermediate – femoral vein C. Medial – femoral canal - Contents NAVEL N: Femoral Nerve and its branches A: Femoral Artery

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V: Femoral Vein E: Empty space (allows vein and lymph vessels to distend without compromising adjacent structures L: Lymph nodes Muscles of the Gluteal Region * Superficial group – Gluteus Maximus (Extensor of thigh)  Inferior gluteal nerve * Intermediate group – Gluteus medius and Gluteus minimus (Abductor and medial rotator of thigh)  Superior gluteal nerve * Deep group – Piriformis, Obturator internus, superior and inferior Gemelli, Quadratus femoris (lateral rotator of thigh) LUMBAR PLEXUS: know with branches and how it is related to Psoas - Formed by L1, L2, L3, and L4 - Branches: 1. Iliohypogastric (L1) 2. Ilioinguinal (L1) 3. Genitofemoral nerve (L1 and L2)  Cremasteric reflex 4. Lateral femoral cutaneous (L2 and L3) 5. Femoral nerve (L2, L3 and L4) 6. Obturator nerve (L2, L3 and L4) * All branches from the lateral side of the Psoas except: - Genitofemoral nerve on Anterior - Obturator nerve on Medial LUMBOSACRAL PLEXUS * To the lower limb that leave the pelvis through the Greater Sciatic foramen 1. Sciatic (L4, L5, S1, S2, and S3) – largest nerve in body - Supplies no structures in gluteal region, skin of the foot and leg posterior thigh muscles 2. Superior Gluteal (L4, L5 and S1) – injury to this structure would produce: Waddling gait, pelvis sag on the side of unsupported limb (+) Trendelenburg sign 3. Inferior Gluteal (L5, S1 and S2) 4. Nerve to the Quadratus femoris 5. Nerve to Obturator internus 6. Posterior cutaneous nerve of the thigh HIP JOINT STABILITY - Stability when a person stands on one leg with the foot of the opposite leg raised above the ground depends on 3 factors - Head of the femur must be located normally within the acetabulum - Neck of femurmust be intact and must have a normal angle with shaft of femur - Function of the Gluteus minimus and medius Flexion Anterior Compartment of thigh Extension Posterior Compatment of thigh and Glutues Maximus Adduction Medial Compartment of thigh Abduction Gluteus medius and minimus Medial Rotation Glutues medius and minimus Lateral Rotation Piriformis, etc * Femoral nerve lesion - May be damaged due to abscess of the psoas - Inability to flex the thigh at the hip and extend the leg at the knee - * Diminished patellar tendon reflex * Sciatic nerve lesion - Susceptible to damage from an IM injection in the lower medial quadrant of the gluteus maximus * Inferior gluteal nerve lsion - Weakness in the ability to laterally rotate and extend the thigh at hip joint (Example: climbing stairs or rising from a chair) * Saphenous nerve lesion - Pain and paresthesia in skin of the medial aspect

- No motor loss * Obturator nerve lesion - Unable to adduct of thigh - Paresthesia in skin of medial aspect of thigh * Fracture of Femoral neck = Shortened and lateral rotation * Medial Circumflex femoral – supply of the hip joint * Dislocation: Thigh shortened and medially rotated (Sciatic nerve is compressed) * Dorsiflex with foot and ankle joint  function of the anterior compartment ANTERIOR LEG MUSCLES (Innervated by the Deep peroneal nerve) - Tibialis anterior - Extensor digitorum longus - Extensor hallucis longus - Peroneus tertius LATERAL LEG MUSCLES (innervated by the Superficial peroneal nerve) - Plantar flexion and eversion - Peroneus longus - Peroneus brevis POSTERIOR LEG MUSCLES (innervated by the TIbial nerve) - Plantar flexion and flexion of leg - Superficial: Gastrocnemius, Plantaris, Soleus - Deep: Popliteus, Flexor digitorum, Tibialis * All PERONEAL muscles are for eversion ACHILLES TENDON – common attachment of the gastrocnemius and soleus *Popliteus – Unlocks the knee - Posterior compartment - Supplied by the tibial nerve POPLITEAL FOSSA - Terminal of Sciatic nerve - Tibial nerve - Common peroneal nerve (MC injured nerve in the LE) - Popliteal Artery and Vein DEEP TENDON REFLEXES C5 Biceps brachii C6 Brachioradial is C7 Triceps L4 Patellar S1 Achilles tendon *Adductor hiatus  where the femoral artery becomes the popliteal artery * Vena Commitantes - Tributaries are: A. Anterior/ Posterior Tibial B. Popliteal C. Femoral D. External Iliac E. Internal Iliac F. Common Iliac * Saphenous vein - Great saphenous vein  Femoral vein - Lesser saphenous vein  Popliteal vein *Dorsalis Pedis artery Lateral: Tendon of external digitorum longus Medial: Tendon of extensor hallucis longus * Sciatic nerve divides into the (1) Tibial and (2) Common Peroneal then the peroneal nerve then again is subdivided into the (1) Deep and (2) Superficial * Action of Dorsiflexion – anterior compartment – Deep peroneal nerve

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* * * *

Action of Plantar Flexion – posterior compartment – Tibial nerve Plantar flexion + Eversion – lateral compartment Peroneus muscle – Eversion Tibialis anterior and posterior – Inversion

Common Peroneal/ Fibular Nerve lesions - Frequently injured nerve of the lower extremity - Pain and paresthesia lateral leg and entire dorsum - Foot drop - Steppage gait Deep Peroneal/ Fibular Nerve lesions - Foot drop - Paresthesia in skin of webbed space between the 1st and 2nd toe Superficial Peroneal/ Fibular Nerve lesions - Weakness in eversion of foot Tibial Nerve lesions - Can’t stand on tiptoe - Paresthesia on skin of posterior leg, sole and lateral foot KNEE JOINT - Extracapsular Ligaments - Ligamentum patellae - Lateral and Medial collateral ligament - Lateral: Forced Adduction of the tibia on the femur - Medial: Forced Abduction of tibia on the femur - Oblique popliteal ligament - Strength of the knee joint depends on the 1. Tone: brought about by the Quadriceps 2. Strength of the ligaments - Intracapsular ligaments A. Anterior cruciate ligament - Prevents forward sliding of tibia on femur - Posterior displacement of femur in tibia - Lax during flexion B. Posterior cruciate ligament - Prevents backward sliding - Anterior displacement of the femur on tibia - Lax during extension *UNHAPPY TRIAD OF O’DONOGHUE - ACL, Tibial collateral ligament and Medial Meniscus (TERRIBLE TRIAD) *Anterior Drawer sign: Forward sliding of the tibia on femur due to rupture of the anterior cruciate ligament *Posterior Drawer sign: Backward sliding of the tibia on femur due to damage of the posterior cruciate ligament LESION OF CORTICOSPINAL TRACT * Above the level of decussation, manifest contralaterally * Below the level of decussation, manifest ipsilaterally SKULL A. Paired bones 1. Cranial: - Parietal - Temporal

B. Unpaired bones 1. Cranial: - Frontal - Occipital - Sphenoid - Ethmoid

SKULL FRACTURE Anterior cranial fossa – anosmia, periorbital bruising (Raccoon’s Eye) and CSF leakage through the nose (Rhinorrhea) LAYERS OF THE SCALP SCALP S: Skin C: Connective tissue A: Aponeurosis L: Loose Connective tissue P: Periosteum Three Primary Brain 1. Forebrain / Prosencephalon - Telencephalon - Cerebrum

- Diencephalon - Thalamus 2. Midbrain / Mesencephalon - Mesencephalon - Midbrain 3. Hindbrain / Rhombencephalon - Metencephalon – Pons, Cerebellum - Myeloncephalon - Medulla *Neural tube  forms the CNS which composes of the brain and spinal cord * Neural crest  forms the PNS and ANS composed of the cranial, spinal and autonomic ganglia and the plexuses CEREBRUM Brodman’s area: Function of the cerebrum Primarily motor area: Pre-central gyrus: Brodman area 4 Primary somasthetic area: Post-central gyrus; Brodman area 3, 1, 2 Primary visual area: Brodman area 17 Primary auditory area: Brodman area 41, 42 Broca’s area: Brodman area 44, 45; motor aphasia (expression) Wernicke’s area: Brodman area 22; sensory aphasia (receptive) SENSORY AND MOTOR Rule # 1 All areas are supplied by MCA except the LEG areas (ACA) Rule # 2 (+) occlusion of the right side  presents at contralateral side (+) occlusion of the right ACA: loss of sensory and motor left lower extremity CORTICOSPINAL TRACT - Desce nding pathway (motor) * The decussation is located at the lower medulla Paralysis Atrophy Fasciculation Clonus Pathologic reflex Muscle tone

UMN Spastic (-) (-) (+) (+) Increase

LMN Flaccid (+) (+) (-) (-) Decrease

VENTRICULAR SYSTEM *Lateral ventricle (Cerebrum) * 3rd ventricle (Thalamic) * 4th ventricle (Pons, cerebellum and medulla) Choroid plexus -----------------------> Lateral ventricle ----------------------> 3rd ventricle Foramen of Monroe -----------------------> 4th ventricle ---------------------------------------------> Subarachnoid Aqueduct of Sylvius Foramen of Magendie and Luschka space Drains to the internal jugular vein