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BIOC34H3 Lecture Notes - Lecture 5: Adrenal Medulla, Medulla Oblongata, Pacemaker Potential

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amberherring123
21 Jan 2017
School
UTSC
Department
Biological Sciences
Course
BIOC34H3
Professor
Stephen Reid

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Document Summary

2 of the nerves from sympathetic nerve are going to the av node. Sympathetic stimulation of the sa node leads to an increase in the slope of the pacemaker potential. Parasympathetic stimulation does the opposite, with no innovation of the ventricular muscle. Parasympathetic system does not have any role in stroke volume regulation, but it can regulate heart rate. Slows down the rate of the pacemaker cells, and the transmission of the wave of depolarization through the av node, down the ventricles. Only the sympathetic innovation is going down to the ventricles. Norepinephrine is released by the sympathetic nerve. On the heart and blood vessels, there are several receptors, known as alpha and beta receptors. In the heart, there are very few alpha receptors, beta receptors the predominant receptors. Effect of epinephrine and nor epinephrine is complicated, depends on if it is coming from a nerve or adrenal gland.

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Related Questions

Question 1

  1. A moderate increase in extracellular potassium will

Increase heart rate due to a more negative EK

Decrease heart rate due to a more negative EK

Increase heart rate due to a less negative EK

Decrease heart rate due to a less negative EK

Question 2

  1. Apply Atropin will directly

Decrease parasympathetic innervation and increase heart rate

Increase parasympathetic innervation and decrease heart rate

Decrease sympathetic innervation and increase heart rate

Increase sympathetic innervation and decrease heart rate

Frog ECG is recorded using

An electrical stimulator

Three wires including the one that is connected to the hook

A force transducer

Three wires and a force transducer

Question 4

  1. How would you differentiate atrial contractions fromventricular contractions?

A.

Observe the heart beating and tap the table to label it

B.

From the size of the contractions

C.

Correlate it with the electrical trace, if the electrical traceis typical.

D.

Both A and C

Question 5

  1. In this week's experiment, _________signal(s) will be recordedto study the frog cardiac functions.

mechanical (contractile)

electrical (ECG)

both mechanical and electrical

blood flow

Question 6

  1. In this week's experiment, the heart is hooked at the________

either atrium or ventricle

ventricle

atrium

sympathetic/increase

parasympathetic/decrease

Sympathetic/decrease

parasympathetic/increase

Question 8

  1. The frog heart can be slowed or stopped by over stimulation ofthe vagus nerve. When apply ACh to the heart, if the frog heartstop beating, you should

Wash the heart with warm Ringers

Apply a few drops of Isuprel

Massage the heart

All of the above

Observe the trace and do nothing

Question 9

  1. The pacemaker in the frog heart is the __________ and thepacemaker in the mammalian heart is the ________

AV, SA node

SV, SA node

SA, SV node

SA, SA node

Question 10

  1. Which of the following statements is TRUE regarding the frogheart

There is no autorhythmic cells found in the frog ventricle.

Oxygenated and deoxygenated blood are mixed completely insidethe frog ventricle

There are two atria and two ventricles.

Deoxygenated blood flows to the frog lungs and skin.

1) The external layer of the heart wall is the

Multiple Choice

endocardium.

myocardium.

epicardium.

parietal pericardium.

2) Check all that are characteristics of cardiac muscle.

Check All That Apply

Cells are long and cylindrical.

Cells are short and branching.

Cells have multiple nuclei at the periphery of the cell.

Cells have one or two nuclei in the center of the cell.

They are composed of thick and thin filaments.

The functional contractile unit is the sarcomere.

3) Match the chamber of the heart with the structure(s) from which it receives blood.

Coronary sinus

Pulmonary veins

Right atrium

Left atrium

Match each of the options above to the items below.

Right atrium

Right atrium Open choices for matching

Right ventricle

Right ventricle Open choices for matching

Left atrium

Left atrium Open choices for matching

Left ventricle

4) The less extensive distribution of T-tubules contributes to the more delayed onset and prolonged contraction of cardiac muscle tissue compared to skeletal muscle tissue.

True or False

5) The cells of the ___________ act as the heart's pacemaker, which establishes the pace for cardiac activity.

Multiple Choice

atrioventricular (AV) node

sinoatrial (SA) node

atrioventricular (AV) bundle

Purkinje cells

6) Match the cardiac vein with its description.

Travels close to the right marginal artery

In posterior interventricular sulcus

In anterior interventricular sulcus

In the posterior portion of cornary sulcus

Match each of the options above to the items below.

Great cardiac vein

Great cardiac vein Open choices for matching

Middle cardiac vein

Middle cardiac vein Open choices for matching

Small cardiac vein

Small cardiac vein Open choices for matching

Coronary sinus

7) Parasympathetic innervation to the heart comes from the medulla oblongata via the left and right ___________ nerves.

8) Check all that are components of the sympathetic innervation of the heart.

Check All That Apply

Cervical sympathetic ganglionCervical sympathetic ganglion

Spinal cordSpinal cord

Vagus nerve (CN X)Vagus nerve (CN X)

Cardiac nerveCardiac nerve

Sympathetic postganglionic axon

9) Check all that occur during ventricular contraction.

Check All That Apply

The AV valves open to allow blood to enter the ventricles from the atria.The AV valves open to allow blood to enter the ventricles from the atria.

The semilunar valves remain closed to prevent backflow of blood into the ventricles.The semilunar valves remain closed to prevent backflow of blood into the ventricles.

The semilunar valves open to allow blood to flow into the large arteries.The semilunar valves open to allow blood to flow into the large arteries.

The AV valves close to prevent backflow of blood into the atria.

Question 1 (1 point)Save Question 1Save
Which of the following will increase blood flow to a given regionof the body?

A smaller pressure gradient between the arteries and thatregion.

Vasoconstriction of the arterioles feeding that region.

An increase in blood viscosity via dehydration.

An increase in diameter of the arterioles feeding the region.
Question 2 (1 point)Save Question 2Save
Which of the following statements pertaining to the innervation ofthe heart is TRUE?

The heart is directly activated by the somatic nervoussystem.

The heart muscle is directly activated by the autonomic nervoussystem.

NE released by sympathetic neurons binds to beta-adrenergicreceptors and increases heart rate.

ACh released by parasympathetic neurons binds to nicotinicreceptors and decreases heart rate.
Question 3 (1 point)Save Question 3Save
The prolonged depolarization in cardiac myocytes is due primarilyto which channel type?

Voltage-gated sodium channels

Voltage-gated potassium channels

Funny (F-type) sodium channels

Long-lasting (L-type) calcium channels
Question 4 (1 point)Save Question 4Save
Which of the following statements about the pacemaker potentialgenerated by the SA node is FALSE?

Its intrinsic rate is about 70 depolarizations per minute.

The rate of depolarization can be affected by autonomicinnervation.

Funny (F-type) sodium channels play a role in the gradualdepolarization.

In the complete absence of extrinsic input (hormones or neurons),the SA node will continue to depolarize
Question 5 (1 point)Save Question 5Save
Match the description in the left hand column with the terms in theright hand column that BEST correspond (one match per term, allselections are used).

The period of the cardiac cycle when the heart is contracting

The period during diastole when the pressure in the atria exceedsthe pressure in the ventricles.

The period during systole when all heart valves are closed.

The difference between end-diastolic volume and end-systolicvolume.

The period of the cardiac cycle when the heart is relaxing.

1.
Systole
2.
Diastole
3.
Stroke volume
4.
Isovolumetric contraction
5.
Ventricular filling