Blood Vessels

Question 1

Pulmonary Circulation

Answer 1

Deoxygenated blood carried away from the heart by pulmonary artery.
Oxygenated blood carried to the heart by pulmonary veins.

Question 2

Systemic Circulation

Answer 2

Oxygenated blood carried away from the heart by arteries.
Deoxygenated blood carried to the heart by veins.

Question 3

Arteries

Answer 3

Always carry blood away from the heart.
Pulmonary arteries are the exception - all carry oxygenated blood
Thick, muscular walls
Aorta is the largest artery – first artery through which blood in the systemic system flows through on leaving the heart.

Question 4

The aortic arch

Answer 4

The two regions are the ascending aorta, and the descending aorta – important arteries branch off the aortic arch:
The carotid arteries – carry blood to the head
The subclavian arteries – carry blood to the arms

Question 5

The abdominal aorta

Answer 5

Located on the left side of the body
The important arteries that branch of the abdominal aorta are:
The ciliac artery - carries blood to liver stomach and spleen
The renal arteries – carry blood to kidneys
The iliac arteries – carry blood to legs (via the femoral arteries)

Question 6

Veins

Answer 6

Always carry blood back to the heart (except for pulmonary veins – veins, carry deoxygenated blood)
Veins have thinner walls than arteries

Question 7

The vena cava

Answer 7

Superior vena cava - collect blood from upper body and head, short vein
Inferior vena cava – collect blood from lower body, long vein, located on right side of body

Question 8

Capillaries - definition

Answer 8

This is where exchange of gases (oxygen and carbon dioxide) and chemicals take place between the blood and the interstitial tissue

Question 9

Venules

Answer 9

These are the narrowest type of vein and receive deoxygenated blood from the capillary bed

Question 10

Blood flow through the capillary bed

Answer 10

Pre-capillary sphincters control the flow of blood from the ateriole into each capillary
When one pre-capillaries sphincter constricts, blood is diverted into all the branches of the network, when it relaxes blood flows into the capillary
Each pre-capillaries, sphincter, alternately, contracts and relaxes, altering vessel diameter - vasomotion
Low, oxygen concentration is enhance relaxation – auto regulation

Question 11

Veso vasorum - blood supply to the blood vessel walls

Answer 11

Walls of arteries and large veins are too thick to allow diffusion between bloodstream and tissues of the vessel.
So, the walls of large vessels contain small arteries and veins that supply the cells of the tunica media and tunica externa. These blood vessels are called the vaso vasorum.

Question 12

What is the correct order of the blood vessels through which blood passes if travelling from the heart to the liver and back again?

Answer 12

Left ventricle, aorta, ciliac artery, hepatic artery, arteriole, capillary, venule, hepatic vein, inferior vena cava, right atrium

Question 13

Cellular structure of a blood vessel

Answer 13

All vessels consist of 3 layers
Tunica intima (inner layer) - endothelia line the blood vessel
Tunica media (middle layer) - vascular smooth, muscle cells, collagen, and elastin fibres, often the thickest layer
Tunica adventita (outer layer) - outer protective layer, fibroblasts

Question 14

Arteries compared to veins

Answer 14

Arteries have thick are more muscular walls with an enlarged tunica media layer

Question 15

Elastic arteries

Answer 15

Arteries close to the heart must be able to expand and recoil in order to maintain a constant blood pressure throughout the heartbeat cycle – they contain a large number of elastic fibres (collagen and elastin) to do this
Examples
Aorta, pulmonary artery, subclavian, artery, carotid artery

Question 16

Muscular arteries

Answer 16

Elastic arteries branch into smaller muscular arteries, and these contain fewer elastic fibres but more smooth muscle
Muscular arteries are able to actively regulate blood flow to meet demand by muscular contraction
Examples
Coronary arteries, femoral arteries

Question 17

Arterioles

Answer 17

The tunica media of arterioles is one or two muscle cells thick
Vasodilate at low oxygen, vasoconstrict under sympathetic stimulation
More pressure is required to push blood through a constricted vessel than through a dilated one. The force opposing blood flow is called resistance hence why arterioles are known as resistance vessels.

Question 18

Capillaries - continuous

Answer 18

Most capillaries in the body
Very restricted permeability
Permits exchange of water, small, solutes, and lipid-soluble materials between the blood and interstitial fluid

Question 19

Capillaries - fenestrated

Answer 19

Facilitate the rapid exchange of water and solutes between blood and interstitial fluid

Question 20

Capillaries - sinusoid

Answer 20

Free exchange of water, solutes and large plasma proteins

Question 21

Defenestration is the act of throwing someone out of a window but which class of blood vessel, sometimes contains windows?

Answer 21

Capillaries

Question 22

Vasculogenesis

Answer 22

Refers to the formation of entirely new blood vessels
This occurs only during embryonic development

Question 23

Angiogenesis

Answer 23

Refers to the sprouting of new branches from pre-existing blood vessels
This process occurs throughout life example, new capillaries will develop in your muscles if you train

Question 24

Atherosclerosis

Answer 24

Refers to the buildup of fatty deposits within the walls of arteries
These can trigger clot formation become dislodged, blocking arteries
Can cause heart attacks, strokes, kidney disease

Question 25

Arterioles - definition

Answer 25

These are the narrowest type of artery and deliver oxygenated blood to the capillary bed