Cardiovascular Physiology

Question 1

Through which veins does de-oxygenated blood enter the right atrium?

Answer 1

Superior and inferior vena cava

Question 2

Through which artery does blood leave the right atrium?

Answer 2

Pulmonary artery

Question 3

Through what veins does blood enter the left ventricle?

Answer 3

Pulmonary veins

Question 4

Through which artery does blood leave the left ventricle?

Answer 4

aorta

Question 5

what separates the two sides of the heart?

Answer 5

Septum (cardiac muscle)

Question 6

What is the command centre of the heart?

Answer 6

Sinoatrial node

Question 7

What is the pathway of electrical signals in the heart?

Answer 7

1) Sinoatrial node causes action potentials
2) spreads through the atria causing contraction
3) fibrous skeleton delays the action potential from reaching the ventricles
4) reaches the bundle of his
5) action potentials spread through the purkinje fibres, causing contraction of both ventricles

Question 8

What valves are present in the right side of the heart?

Answer 8

tricuspid valves

Question 9

What valves are present in the left side of the heart?

Answer 9

mitral valves

Question 10

What systems cause innervation of the heart?

Answer 10

Parasympathetic and sympathetic

Question 11

What effect does the parasympathetic system inflict on the heart?

Answer 11

Dominant at rest and controls the reduction of HR and reduction of force on contraction

Question 12

What effect does the sympathetic system have on the heart?

Answer 12

increases both HR and force of contraction, releases noradrenaline

Question 13

Through which nerve does the parasympathetic system effect the heart?

Answer 13

Vagus nerve

Question 14

what features are common in all blood vessels?

Answer 14

Lumen, single layer of endothelial cells

Question 15

what features are common in veins and arteries?

Answer 15

Tunica intima, smooth muscle, tunica adventitia

Question 16

What are the differences between veins and arteries?

Answer 16

Veins have larger lumen, Lumen more elastic in veins, majority of blood volume held in veins, less smooth muscle in veins, smaller tunica adventitia

Question 17

what nervous system effects blood vessels?

Answer 17

Sympathetic

Question 18

how does the sympathetic nervous system effect the blood vessels?

Answer 18

releases noradrenaline which constricts blood vessels. Circulating adrenaline also constricts most blood vessels but dilates the vessels to the heart, lungs and skeletal muscle.

Question 19

What occurs in capillaries?

Answer 19

They are the site for solute and fluid transfer

Question 20

What are the four types of artery?

Answer 20

elastic, muscular, resistance, arteriole

Question 21

How do low pressure veins still manage to return blood to the heart against gravity?

Answer 21

Muscles either side of the veins contract to help push the blood through the valve system that veins also have in order to prevent back-flow

Question 22

What differences does smooth muscle have over cardiac and skeletal?

Answer 22

1) is smooth- no striations
2) phosphorylation dependant constriction rather than calcium
3) autonomic nerve control

Question 23

what are the different types capillaries?

Answer 23

Continuous, Fenestrated, discontinuous

Question 24

What is the most common form of capillaries and where are they found?

Answer 24

Continuous, they are found in most tissues and organs

Question 25

where are fenestrated capillaries found and what is their main feature?

Answer 25

mainly found in the liver, glands and kidney glomeruli.

main feature is fenestrae which are small windows in teh capillaries that allow the movement of water and salts

Question 26

what four pressure gradients effect the fluid movement in capillaries?

Answer 26

capillary pressure
interstitial pressure
oncotic osmosis pressure
oncotic pressure interstitium

Question 27

what is normally the greatest pressure in the capillaries?

Answer 27

hydrostatic pressure

Question 28

what is the purpose of the lymphatic system?

Answer 28

connects circulatory and immune system, removes fluid that diffused through capillaries and into the interstitial liquid and returns it back to the venous system

Question 29

what type of capillaries are found in the lymphatic capillaries?

Answer 29

discontinuous, in order to allow the diffusion of solutes in the interstitial liquid

Question 30

what are the 3 main layers of the heart itself?

Answer 30

Epicardium (outer layer of serous pericardium, myocardium (muscle layer, cardiac myocytes), endocardium (inner layer lining chambers)

Question 31

what is stroke volume?

Answer 31

volume of blood ejected from the heart

Question 32

define end diastolic volume

Answer 32

volume of blood in the ventricle just before it contracts

Question 33

define ejection fraction

Answer 33

fraction of the end diastolic volume pumped

Question 34

what is cardiac output and how can it be calculated?

Answer 34

cardiac output is the blood pumped from a ventricle and it can be calculated by multiplying the heart rate by stroke volume

Question 35

what is intrinsic control?

Answer 35

forces which are controlled by the heart itself e.g., force of contraction, venous return (mechanical)

Question 36

what is extrinsic control?

Answer 36

Factors outside of the heart e.g., autonomic nerve, circulating hormones

Question 37

how can you calculate stroke volume?

Answer 37

end diastolic volume x ejection fraction

Question 38

what is preload?

Answer 38

the force exerted by the volume of blood entering the ventricles and exerting a force on the myocardium

Question 39

what are the phases of the cardiac action potential?

Answer 39

0- depolarisation
1- repolarisation
2- plateau
3- repolarisation
4- baseline

Question 40

What are the regions of an ECG?

Answer 40

P wave
QRS complex
T wave
PR interval
QT interval

Question 41

What ion is the cause of depolarisation in pacemaker cells?

Answer 41

Ca++ ions