The cardiovascular system

Question 1

What us the heart?

Question 2

The heart is a pump that exertspressure on the blood in order to causeit to flow through a series of one-way valves

Question 3

What are the 4 different layers of the heart

Answer 3

Myocardium
Pericardium
epicardium
Endocarium
each layer helps pump blood

Question 4

myocadium

Question 5

pericardium

Question 6

Endocardium

Question 7

Pericardium

Question 8

What is the pace maker of the heart

Answer 8

SA node
sinotrial node genrates a upper heart chamber that causes the othersto contract

Question 9

SA & SV node

Answer 9

The SA (sinoatrial) node generates an electrical signal that causes the upper heart chambers (atria) to contract. The signal then passes through the AV (atrioventricular) node to the lower heart chambers (ventricles), causing them to contract, or pump.

Question 10

arrhythmia

Answer 10

Irregular heart beat

Question 11

How does the heart beat

Answer 11

An electrical signal comes from the SA node (sinoatreial node)

• small mass if tissue located in the located in the right upper chamber of the heart

The sinus node generates an electrical stimulus regularly, 60 to 100 times per minute under normal conditions.

The atria are then activated.
The electrical stimulus travels down through the conduction pathways and causes the heart’s ventricles to contract and pump out blood.

The 2 upper chambers of the heart (atria) are stimulated first and contract for a short period of time before the 2 lower chambers of the heart (ventricles).

.The electrical impulse travels from the sinus node to the atrioventricular node (also called AV node).

.There, impulses are slowed down for a very short period, then continue down the conduction pathway via the bundle of His into the ventricles.

.There, impulses are slowed down for a very short period, then continue down the conduction pathway via the bundle of His into the ventricles.

Question 12

What are the heart valves and their functions?

Answer 12

Tricuspid valve. Located between the right atrium and the right ventricle.
Pulmonary valve. Located between the right ventricle and the pulmonary artery.
Mitral valve. Located between the left atrium and the left ventricle.
Aortic valve. Located between the left ventricle and the aorta.

Triscupid valve -
Has three leaflets or cusps.
Separates the top right chamber (right atrium) from the bottom right chamber (right ventricle).
Opens to allow blood to flow from the right atrium to the right ventricle.
Prevents the back flow of blood from the right ventricle to the right atrium.

Pulmonary Valve (or Pulmonic Valve)
Heart valve anatomy animation(link opens in new window)
Has three leaflets.
Separates the right ventricle from the pulmonary artery.
Opens to allow blood to be pumped from the right ventricle to the lungs (through the pulmonary artery) where it will receive oxygen.
Prevents the back flow of blood from the pulmonary artery to the right ventricle.

Mitral Valve
Has two leaflets.
Separates the top left chamber (left atrium) from the bottom left chamber (left ventricle).
Opens to allow blood to flow from the left atrium to the left ventricle.
Prevents the back flow of blood from the left ventricle to the left atrium.

Aortic Valve
Has three leaflets, unless it’s abnormal from birth, i.e., bicuspid aortic valve.
Separates the left ventricle from the aorta.
Opens to allow blood to leave the heart from the left ventricle through the aorta and the body.
Prevents the backflow of blood from the aorta to the left ventricle.

Question 13

What is a pulse

Answer 13

“A pulse occurs when theleft ventricle contracts, forcingmore blood into an already fullaorta and arterial system, a waveof distension (swelling) andelongation (lengthening) occurs

Question 14

e

Answer 14

Systole - the peak of pressureproduced when myocardiumcontracts* Diastole – the trough pressurewhen the myocardium relaxes* Heart rate – number ofventricular systoles in a minute* Stroke volume – volume ofblood ejected from the leftventricle with each ventricularsystole* Cardiac output – The amount ofblood pumped out of the heart inone minute

Question 15

What are the two main heart noises

Answer 15

Heart Noises* two main heart noises. - Lubb-dupp sound.* The first sound - Lubb, is thelonger lasting deeper sound.– closure of the atrio-ventricularvalves (bicuspid and tricuspid)
* The second sound, - Dupp is higher pitched and less long-lasting.– closure of the aortic andpulmonary valves.* bruits. (murmurs) may occur dueto forceful contraction of the atria -valve incompetence

Question 16

Venous return

Answer 16

. Venous return is the volume of blood that returns from the veins to the atria each minute and is ~5 l/min

Question 17

what can prevent the pump from working

Answer 17

Extended periods of standing still prevent the muscle pump from working.– pooling of the blood in the veins of the lower legs.– This reduces the venous return- drop in blood pressure-fainting (syncope).

Question 18

varicose veins

Question 19

Arteries
veins
capillaries

Answer 19

Arteries carry oxygenated blood away from the heart. They’re tough on the outside but they contain a smooth interior layer of epithelial cells that allows blood to flow easily. Arteries also contain a strong, muscular middle layer that helps pump blood through the body.

Capillaries connect the arteries to veins. The arteries deliver the oxygen-rich blood to the capillaries, where the actual exchange of oxygen and carbon dioxide occurs. The capillaries then deliver the waste-rich blood to the veins for transport back to the lungs and heart.

Veins carry the blood back to the heart. They’re similar to arteries but not as strong or as thick. Unlike arteries, veins contain valves that ensure blood flows in only one direction. (Arteries don’t require valves because pressure from the heart is so strong that blood is only able to flow in one direction.) Valves also help blood travel back to the heart against the force of gravity.