Cardioanatomy Heart Anatomy and Basic Funtions

Question 1

Cardiovascular:

Answer 1

-Heart, Arteries, veins, and blood

Question 2

Cardiovascular Function

Answer 2

-Transportation

	-Blood=Transport Vehicle

	-Carries Oxygen, Nutrients, waste, and hormones

	-Movement provided by pushing of the heart

Question 3

-Outermost: Pericardium and Epicardium

Answer 3

-Pericardium is the membrane that anchors the heart to the diaphragm and sternum

	-Pericardium secretes lubricant(Serous fluid)

-Epicardium is the outermost layer of the heart

Question 4

-Middle:

Answer 4

Myocardium

-Contains contractile muscle fibers

Question 5

-Innermost

Answer 5

Endocardium

-Lines cardiac chambers

Question 6

-Humans have 4 chambers of the heart

Answer 6

-2 Artia

	-Superiour: Primary receiving chambers, does not actually pump

-2 Ventricles

	-Pumps blood

	-Contraction: Blood sent out of the heart to be circulated

-Chambers ares separated by septum

-Due to separated chambers heart functions as a double pump

Question 7

-Pulmonary Circulation

Answer 7

Pulmonary: Deoxygenated blood

-Involves right side of the heart

Pathways:

-Superior and inferior vena cava

-Right Atrium -> Tricuspid valve

-Right ventricle -> Pulmonary semilunar valave

-Left pulmonary artery

-Lungs

Question 8

Systemic Circulation

Answer 8

-Systemic: Oxygenated Blood

Involves left side of heart

-Pathways

-Left pulmonary vein

-Left atrium -> Bicuspid valve

-left Ventricle -> Aortic semilunar valve

-Aorta

-All other tissues

Question 9

-Electrical Activity of the heart SA Node

Answer 9

-Normally the electrical activity of the heart is intisave in the sinus or sinatrial (SA) node located in the right atrium. The Sa node is a collection of special cells capable of spontaneously generating electric signals. Cells that have the ability to generate electrical activity spontaneously are said to have automatically. Because the SA node normally has the greatest degree of automaticity of all the cardiac cells, it usually controls the rate at which the heart beats. In this way the SA node serves as the primary pacemaker of the heart, discharging at around 60 to 100 BPM at rest.

Question 10

Autonomic nervous systems influence on the SA node

Answer 10

the rate at which the SA node fires can vary significantly. Increase activity of the sympathetic system increases the heart rate. Stimulation of the sympathetic system occurs with stress, anxiety, exercise, hypoxemia and administration of curtain medications. On the other hand, slowing of the heart rate occurs as a result of vagal stimulation, which is parasympathetic response.

Question 11

atrial kick

Answer 11

Once the SA node initiates the electrical signal the impulse spreads across the atria in a wavelike fashion. The electrical impulse travels through the atria by the way of the internodal pathways, causing depolarization, and then contraction. Contraction of the atria just before ventricle contraction (systole) aids in the filling the ventricles with the blood accounts for about 10% to 30% of subsequent stroke volume. This atrial contraction is often referred to as the atrial kick.

Question 12

Heart electical conduction process

Answer 12

1.) SA Node located in the superior right atrium
2.) Internodal Conduction Tract passes through the interatrial septum
3.)Internodal atrial Conduction tracts
4.) AV node where depolarization happens, then contraction. Contacts atria first then has a 1/10th of a second paulse and contract the ventricles
5.) Bundle of His
6.)Left Bundle branch
7.) Left posterior fascicle
8.) Left anterior facicle
9.)Right Bundle branch
10.)Pukenje Network
11.) Pukenje fibers (End at the apex of the hear and work its way back up to the SA Node

Question 13

HEART BLOCK

Answer 13

the AV node can protect the ventricles from excessively, rapid atrial rates that the ventricles could not tolerate. Damages to the AV junction as may occur with the myocardial infarction , usually leads to excessive delays of the electrical impulses passing into ventricles.

Question 14

How does the AV node serve as the backup pacemaker?

Answer 14

-The AV junction normally guides only electrical impulses from the arteries into the ventricles. Under certain circumstances, however, it can also serve as the backup pacemaker. The AV junction has automaticity qualities similar to those of the SA node. If the SA node fails to function properly and does not pace the heart, the AV junction can serve as the pacemaker of the ventricles. When this occurs the ventricular rate is usually between 40 to 60 BPM and the ECG reveals a distinct pattern

Question 15

What happens after impulses leave the AV node?

Answer 15

it travels rapidly through the bundle of HIs and then into the left and right bundle branches. This stimulus travels simultaneously through the bundle branches into the myocardium. At the end of the bundle branches are countless fingerlike purkinje fibers pass the electric impulses rapidly throughout the myocarduim to create a coordinated contraction of the left and right ventricles

Question 16

Dominat and escape pacemakers/ heart rate

Answer 16

Dominant Pacemaker = SA node w/ 60-100 bpm

Escape Pacemakers (in order)
-AV node (40-60 bpm)
-Bundle Branches (30-40 bpm)
-Purkinje network (30-40 bpm)