Cardiovascular and Circulatory System

Question 1

Give the functions of the circulatory system

Answer 1

Distribution of gases and other molecules

Chemical signalling

Thermoregulation

Mediates inflammation and the immune response

Question 2

Name and describe the basics of the 2 main circulations of the cardiovascular system

Answer 2

Pulmonary Circuit:
Right ventricle –> Lungs –> left atrium

Systemic Circulation:
Left ventricle –> capillary beds –> right atrium

Question 3

Give the terms for the contraction and relaxation of the heart

Answer 3

Contraction - Systole

Relaxation - Diastole

Question 4

Describe the timing relationship between the contraction of both atria, and of both ventricles.

Answer 4

Both atria contract at the same time

Both ventricles contract at the same time

Question 5

Name and describe the layers of the heart

Answer 5

Epicardium (external) - visceral serous pericardium

Myocardium (middle) - Cardiac muscle layer. thickest layer

Endocardium (internal) - continuous with the endothelium of the blood vessels connecting with the heart

Question 6

Name the chambers of the heart

Answer 6

Right atrium
Left atrium
Right ventricle
Left ventricle

Question 7

Name the great vessels of the heart, and name the chamber they flow into or out of

Answer 7

Superior vena cava - into the right atrium

Inferior vena cava - into the right atrium

Pulmonary veins - into the left atrium

Pulmonary trunk - out of the right ventricle

Aorta - out of the left ventricle

Question 8

Name and give the location of the cardiac valves

Answer 8

Tricuspid valve - from right atrium to right ventricle

Pulmonary valve - from the right ventricle to the pulmonary trunk

Mitral (bicuspid) valve - from left atrium to left ventricle

Aortic valve - from left ventricle to the aorta

remember the tricuspid is before the bicuspid, as you “try before you buy”

Question 9

What is the purpose of the cardiac valves?

Answer 9

To ensure uni-directional blood flow through the heart

Question 10

Give the locations of the SA node, and the AV node

Answer 10

SA node - the top right of the right atrium

AV node - at the bottom of the interatrial septum

Question 11

Describe the basic process of conduction in the heart

Answer 11

1: The impulse starts at the sino-atrial node. Causing both atria to contract
2: The impulse travels to the atrio-ventricular (AV) node
3: Travels down the right and left bundles in the interventricular septum
4: Spreads out to myocardium through conducting fibres. Causing both ventricles to contract

Question 12

Name and describe the 3 layers most blood vessels are comprised of

Answer 12

Tunica intima - the innermost layer. Endothelium

Tunica media - the middle layer. Smooth muscle and elastic fibres

Tunica adventitia - the outermost layer. Connective tissue

Question 13

What is the name of the interior of a blood vessel?

Answer 13

The lumen

Question 14

Nerves, arteries and veins often are found in a together, name this grouping?

Answer 14

A neurovascular bundle

Question 15

Define the terms “Birfurcation” and “Trifurcation”

Answer 15

Birfurcation - division of a vessel or nerve into 2 branches

Trifurcation - division of a vessel or nerve into 3 branches

Question 16

Define vasoconstriction and vasodilation

Answer 16

Vasoconstriction - contraction of the smooth muscle of the arterioles (Not Arteries) to reduce blood flow

Vasodilation - dilation of the smooth muscle of the arterioles (Not Arteries) to increase blood flow

Question 17

Define sympathetic tone

Answer 17

The low level, background, contraction of arteriolar smooth muscle due to tonic (continuous) stimulation by sympathetic nerves.

It maintains the normal diameter of the arterioles

Question 18

Define anastomoses and give its purpose

Answer 18

Anastomoses - where arteries connect directly (with not capillary bed)

Their purpose is to provide alternative routes (collaterals) for blood to flow past an arterial occlusion

Question 19

Define the term infarction

Answer 19

Irreversible cell death due to hypoxia, caused by he loss of arterial blood supply

Question 20

Define the term terminal (end) artery, and give the consequence of its occlusion

Answer 20

Terminal (end) arteries - an artery that provides the only arterial blood supple to the area of the body (e.g. there are no collaterals)

The occlusion of a terminal artery can result in infarction

Question 21

How does the aorta help to maintain peripheral flow during diastole?

Answer 21

Elastic recoil. Its elastic walls, which have expanded during systole, recoil, reducing its internal volume thus increasing pressure

Question 22

Name the 4 parts of the aorta, and give their locations

Answer 22

The ascending aorta - as it leaves the heart

Arch of the aorta - as it arches round

Thoracic aorta - as it descends behind the heart

Abdominal aorta - as it descends through the abdomen

Question 23

Name the branches of the arch of the aorta

Answer 23

As blood flows:

1: Brachiocephalic trunk
2: Left common carotid artery
3: Right subclavian artery

Question 24

Name the artery that supplies the upper limb

Answer 24

Axillary artery

Question 25

Describe the arteries that bifurcate from the abdominal aorta to supply the lower limb

Answer 25

``` -Abdominal aorta into - Common iliac arteries (x2) into -internal iliac arteries (x2) and external iliac arteries (x2) ```

Question 26

Compare the lumens of arteries and veins

Answer 26

Arteries lumens are maintained in a circular shape Veins lumens are not maintained in a circular shape and are collapsed when empty

Question 27

Where in the body can veins with valves be found

Answer 27

In the limbs

Question 28

Name and describe the 3 elements that important in allowing venous return

Answer 28

Venous valves - ensure uni-directional flow against gravity in the limbs Skeletal muscle pump - the contraction of skeletal muscles (mainly in the lower limb) force blood to move through the valves Accompanying veins - small veins usually run alongside an artery in a sheath. The pulsation of the artery pushes the venous blood along

Question 29

Name and describe the 2 types of vein

Answer 29

Superficial veins - Smaller and run withing the superficial fascia Deep veins - Larger and run deep to the deep fascia & in cavities. Often in neurovascular bundles *superficial veins drain into deep veins

Question 30

Name and describe the 2 main venous systems

Answer 30

Hepatic portal venous system - Drains blood from the absorptive parts of the GI tract and associated organs to the liver for "cleaning" Systemic venous system - drains blood from all other organs and tissues

Question 31

Describe the wall of a capillary

Answer 31

Its walls are made up of a single layer of endothelial cells

Question 32

Describe the transition to different vessel types as blood circulates through the body

Answer 32

``` Arteries to Arterioles to Capillaries to Venules to Veins ```

Question 33

What is the function of lymphatic capillaries?

Answer 33

To collect tissue fluid (fluid that leaks out when blood flows through a capillary bed)

Question 34

Describe the flow of lymph through the lymphatic system

Answer 34

The lymphatic capillaries form lymphatic vessels These superficial vessels drain into deep lymphatic vessels These flow through lymph nodes The lymph is returned into venous circulation at the venous angles in the root of the neck

Question 35

Describe which regions of the body drain lymph into which duct

Answer 35

The lymphatics from the top right of the body drain into the right venous angle. The lymphatics from the rest of the body drain in through the thoracic duct