EXPERIMENT 2

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VPP3231

VETERINARY PHYSIOLOGY I LABORATORY REPORT REFLEX ACTION IN A FROG

NAME

MATRIC NO.

CIK NASRIAH BINTI SAID

156721

IFFAH NADZIRAH BINTI ABD RAZAK 157613 AFIQAH BINTI ZAINURIN

158593

MUHAMAD FAIZAL BIN HAHLAN

160107

MUHAMAD ALIF BIN ZAKARIA

158677

NURUL HAFIZAH BINTI ABU JAZID

158322

MAJDI BIN AHMAD

159530

c GROUP 10

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c cc c c   c 1)c To determine strength of a single threshold stimulus 2)c To determine strength of a single maximal stimulus 3)c To study the effect of frequency of the stimulus c    = Scissors,glass probe,thread,Petri dish,forceps,Pasteur pipette,Ringers solution. c   c (A) Normal Frog. 1.c The frog was left on the table. The position of the head, eyes, forelimb and hind limb was observed. 2.c The closing and opening of the nostrils and as well as the movement of the floor of the buccal cavity was observed. The respiration rate of the frog was calculated. 3.c Maintenance of equilibriuma) The frog was left on the dorsal recumbence position and it¶s action was observed. b) The frog was left on a piece of wood and the wood rotated horizontally at a slow rate. The movement and position of the head, eyes, forelimb and hind limb was observed. c) The wood was tilted to the front, back, left and right. The response of the frog was observed. 4.c Muscular tension a) The tension of the thigh and lower leg muscle was felt and palpated. b) When the frog is in a sitting position, one of t he hind limb was pulled gently and the tension was felt. The limb was then released after that c) The toes were pinched and any actions observed was recorded.

5.c The frog is then put into a water tank and the frog¶s swimming action and style was observed.

(B) Spinal Frog 1.c The brain of the frog was destroyed using a surgical needle. 2.c The above method 1-5 was repeated on the frog and any difference in observations was recorded.

(C) Double Pithed Frog 1.c The spinal cord of the frog was destroyed using a surgical needle. 2.c The above method 1-5 was repeated on the frog and any difference in observations was recorded. (II) Pithing of the frog 1.c The frog is held with the left hand, with three fingers positioned below the stomach, the forefinger above the head and the thumb on the top of the vertebral column. 2.c Using a scalpel, the skin from the area below the head to the forth vertebra was removed. 3.c The needle is inserted into the cranium through the occipital Atlantic joint, then the foramen magnum and into the brain. 4.c The needle is then retrieved back from the cranium cavity until the foramen magnum where the needle is inserted into the spinal canal instead for the destruction of the spinal cord. 5.c When the spinal cord is destroyed, the hind limb would seem tense, convulse violently and may urinate.

(III) Preparation of the Gastrocnemius muscle-Sciatic Nerve

(A) Dissection of the Sciatic Nerve 1.c The pithed frog if positioned with its stomach facing the table. The skin around the urostyle region is lifted up and was cut all the way up until the head. 2.c The skin from the urostyle until the knee joint was cut. 3.c The sciatic nerve was observed when the urostyle was lifted up.

4.c To prevent any damage to the nerve, the pelvic girdle that is connected to the vertebra column was cut and removed. 5.c The nerve was lifted up gently to prevent any damage. 6.c The sciatic nerve was cut from its origin until the knee joint and both nerve endings were tied with a piece of thread. 7.c To prevent dehydration, the sciatic nerve was constantly being moisturized with Ringer¶s solution.

(B) Dissection of the Gastrocnemius Muscle 1.c The skin around one leg was removed. 2.c Using a pair of forceps, the skin was separated from the skin (just like removing a pair of socks). 3.c The gastrocnemius muscle was separated from the surrounding muscle using a glass probe. 4.c The Achilles tendon was cut at the distal end of the gastrocnemius muscle. 5.c Using a pair of scissors, the lower end of the limb was detached at the knee joint region. 6.c The proximal end of the limb was also detached. 7.c Using a glass probe, all the upper muscle of the hind limb that surrounds the femur was separated. 8.c The sciatic nerve at the proximal ending was cut. 9.c All muscle from the femur was cut at the knee joint region. 10.cThe Achilles tendon was tied to a piece of thread.

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Observations Position of= a.c Head

Normal Frog

Spinal Frog

Double Pithed Frog

Normal (facing forward)

The head was tilted to the left.

The head was facing down.

b.c Eyes

Both eyes were widely open and looking forward.

The left eye was partially closed. The right eye was open.

Both left and right eyes were closed.

c.c Body, fore limb and hind limb

It was in normal sitting position.

The body was tilted to the left in sitting position.

The up and down The floor of the movement of the mouth was moving floor of the mouth. in normal rhythm

The floor of the mouth was moving in a slower rhythm

The appendages were in full extension and total limpness. The floor of the mouth was not moving.

Respiration rate

66 times / minute

30 times / minute

-

It immediately corrected its body and returned to the normal position.

It corrected its body back to the normal position.

It remained on its dorsal recumbence. No corrective action took place.

Maintenance of equilibrium a.c Being placed on the table.

b.c Being placed It moved against the It slowly moved on the direction of the against the direction of wooden board wooden board. the wooden board. moved horizontally.

No movement was observed.

c.c Being placed on the tilted wooden board.

4

It slowly moved in the opposite direction of the wooden board.

No movement was observed.

The extensor muscle was tense.

The extensor muscle was not as tense as that of a normal frog.

The muscles were flaccid.

The flexor muscle was tense.

The flexor muscle was not as tense as that of a normal frog.

The muscles were flaccid.

The frog retracted its feet immediately. It swam with the breast stroke method.

The frog retracted its feet in a slower rate.

No reaction was observed.

It floated in water rather than swam, with body slightly sank to its left.

No movement was observed.

Muscle tension a.c Thigh and lower leg muscle b.c Extension of the leg.

c.c Pinching of the toes

5

It moved in the opposite direction of the wooden board.

Swimming motion

c c

 c Reflex action is the involuntary functioning or movement of any organ or body part in response to a particular stimulus. The function or action occurs immediately, without the involvement of the will or consciousness. When a receptor is stimulated, it sends a signal to the central nervous system, where the brain co-ordinates the response. But sometimes, a very quick response is needed, one that does not need the involvement of the brain. This is a reflex action. Reflex actions are rapid and happen without us thinking. For example, you would pull your hand away from a hot flame without thinking about it. The spinal cord is the medium by which motor and sensory impressions are conducted to and from the brain. It receives impressions from all parts of the body by means of the sensory nerves, and conveys them to the brain, where they produce sensation. It conducts the command of the brain to the voluntary muscles by the motor nerves, and thus causes movement. In all this the brain is the power, and the cord the conductor ; but, as well as this, the cord has a special function ²that of reflex action. If the connection of the cord with the brain be severed, and the skin supplied by afferent nerves below the injured part be irritated,

movement will be produced in the part supplied by efferent nerves from the same part of the cord. This is reflex action. The irritation of an afferent nerve connected with the spinal cord sends an impulse to a nerve centre (gray matter) in the cord, and without communication with the brain this nerve centre has the power of sending back an impulse by an efferent nerve (or nerves), producing contraction of the muscle or muscles in which the efferent fibres terminate. A person paralyzed from spinal injury will thus draw up his legs and kick out when the soles of his feet are tickled. Both in the brain and cord active power is confined to the gray matter. The brain itself gives rise to reflex actions²actions which take place without the will or consciousness of the individual, such as instinctive shrinking from a threatened blow, or blinking from a flash of light. As we can see here for a normal frog, reflex action will occur normally sine it brain and spinal cord is not damaged. As explain before, reflex action is a very quick response that does not need the involvement of the brain. Thus, reflex action is still occurs in the spinal frog. But for the double pithed frog (without central nervous system) there will be no reaction occur because there will not have any integrator between afferent and efferent pathway.Thus, the effector will not detecting anything so no reaction will occur and the frog lost it equilibrium.

Temperature and pH are factor that required for minimal contraction. For temperature, heat within certain limits accelerates all phases of the muscular contraction; the latent period is shortened, the rapidity and effectiveness of the contraction are increased while the relaxation phase is especially accelerated. Cold has opposite effects. These again are most pronounced on the relaxation phase which becomes progressively slower and more prolonged as the temperature is lowered until a critical minimum temperature is reached. At this temperature the properties of irritability and contractility are reversibly suspended. The most favorable temperature for muscular activity is about one degree above the normal body temperature. At a certain critical high temperature the muscle substance is irreversibly destroyed. This is the reason why the contraction during cool not power as during the warm. While for pH, different pH's were obtained by varying CO2 in the gas phase, while the HCO3- concentration was kept constant. The main effects of a decrease in pH on the isometric twitch and tetanus were a reduction in tension and rate of tension development and an increase in latent period. A decrease in pH had no effect on the time to maximum tension or the half-relaxation time.

 cc Reflex action is fast reaction which does not involve brain of the animal but only involve the spinal cord which the important for the reflex action to occur. Different temperature and Ph has different effect on the muscle contraction.

    c http=//chestofbooks.com/health/body/massage/Margaret-D-Palmer/Lessons-onMassage/Reflex-Action-Of-The-Spinal-Cord.html http=//www.frankswebspace.org.uk/ScienceAndMaths/biology/reflex-actions.htm http=//www.tutorvista.com/content/science/science-ii/control-coordination/reflex-action.php http=//www.ncbi.nlm.nih.gov/pmc/articles/PMC1319000/pdf/janatphys00201-0052.pdf http=//www.tutornext.com/experiment-reflex-action/14048 Cunningham, J.G.2002.Textbook of Veterinary Physiology. 3 rd Ed., W.B. Saunders, USA