laboratory - frogheart

الرحمن الله الرحمن بسم الله بسمالرحيمالرحيم

الله} فضل الله} وكان فضل وكانعظيما { عظيما {عليك عليك

العظيم الله العظيم صدق الله صدق

NERVE AND MUSCLENERVE AND MUSCLEEXPERIMENTSEXPERIMENTS

The autonomic nervous systemThe autonomic nervous system

Responsible for control of involuntary or visceral bodily functions:

1-cardiovascular system

2-respiratory

3-digestive

4-urinary

5-reproductive

6-key role in the body’s response

to stress

The A.N.SThe A.N.S..

Sympathetic system:

Flight or fright system.

Parasympathetic system:

Feed or breed or rest response

A.N.SA.N.S

Effect of A.N.S. on the heartEffect of A.N.S. on the heart

Sympathetic stimulation:

Increase chronotropic and the inotropic effects on the heart.

Receptors are: alpha and beta adrenergic receptors

Parasympathetic stimulation:

Negative inotropics.

RememberRemember

+ve chronotropic:

Means increase in heart rate

+ve inotropic:

Means increase in contractility.

Idea of the experimentsIdea of the experiments::

To analyze the effect of different autonomic To analyze the effect of different autonomic

drugs on the frog’s heart contractiondrugs on the frog’s heart contraction..

PreparationPreparation

The frog chest is open:

The heart is connected to the kymograph to The heart is connected to the kymograph to

record the eventsrecord the events

Imp. DefintionsImp. Defintions

Sympathomimtics:Meds the stimulation of the sympathetic system

e.g. adrenaline

Sympatholytics:Inhibits the sympathetic system.

Parathympatholyics:

Blocks the action of the parasympathetic system e.g. atropine sulfate

Effect of autonomic drugs on the Effect of autonomic drugs on the frog’s heartfrog’s heart

Effect of adrenaline on frog’s heart:

-record the normal beats of the heart.

-pour adrenaline and record the effect.

Comment:

Adrenaline a sympathomimetic drug increases heart rate and force of contract as it activates beta adrenoceptors.

AcetylcholineAcetylcholine

B) Effect of acetylcholine on frog’s heart:

-record the normal beats of the heart.

- Pour acetylcholine and record the effect.

Comment:

-Acetylcholine a parasympathetic drug, decreases the heart rate as it stimulates the muscarinic receptors.

Effect of AtropineEffect of Atropine

C) Effect of atropine: -record the normal beats of the heart -pour atropine and record the effect.

-pour acetylcholine and record the effect -wash with ringer.

-pour acetylcholine, observe. -pour atropine then record the effect

Comment: -Atropine applied before acetylcholine blocks the inhibitory effect of

the acetylcholine thus the heart continues to beat normally.-Atropine applied after acetylcholine does not block the inhibitory

action of the acetylcholine.

CurvesCurves

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