Vascular Strcuture

Question 1

What is a capillary bed

Answer 1

A network of capillaries surrounding tissue

Question 2

How are capillaries suited for exchanging materials between blood and body tissue

Answer 2

The tunica external and media are absent and the endothelial cells have small spaces between them. This allows exchange of material to and from the tissue

Question 3

Function of a vein

Answer 3

Collect deoxygenated low pressure blood and return it to the heart

Question 4

What is the size of a veins lumen

Answer 4

Large

Question 5

Why do veins have large lumens

Answer 5

To offer the least resistance to prevent back flow of blood

Question 6

How is blood flow increased to tissue

Answer 6

Vasodilation increases blood tissues

Question 7

What effect does a drop of blood pressure have on the body

Answer 7

It stimulates baroreceptors in the aorta and carotid arteries

Question 8

What is diastolic blood pressure

Answer 8

Lowest pressure exerted against the blood vessel walls which occurs in ventricular diastole

Question 9

What is systolic blood pressure

Answer 9

Highest pressure exerted against the blood vessel walls which occurs during ventricular systole

Question 10

3 ways that blood pressure can be altered

Answer 10

Vessel length
Diameter
Blood viscosity

Question 11

What happens if the vessel is long in length

Answer 11

The longer = greater frictional resistance

Question 12

How does vessel diameter affect blood pressure

Answer 12

Smaller the tube = greater frictional resistance

Question 13

How does blood viscosity affect blood pressure

Answer 13

Higher the viscosity = greater resistance

Question 14

3 layers of blood vessels

Answer 14

Tunica intima
Tunica media
Tunica externa

Question 15

What happens to elastic arteries when ventricles contract

Answer 15

Semi lunar valves open and the force of blood stretches the elastic arteries

Question 16

What happens to elastic arteries when ventricles relax

Answer 16

Blood moves down pressure gradient towards their heart and closes semilunar valves, the elastic forces recoiled into the periphery and the flow is constant

Question 17

What determines the leakiness of capillaries

Answer 17

Amount of tight junctions

Question 18

What is vascular tone

Answer 18

Refers to blood vessels being vasodilated or vasoconstricted

Question 19

What is a muscle pump

Answer 19

When muscles contract, the veins also contract so blood is squeezed and the valves makes sure that blood only moves towards the heart

Question 20

Blood flow is directly proportional to…

Answer 20

Pressure gradient - high to a low

Question 21

Blood flow is inversely proportional to…

Answer 21

Resistance

Question 22

What are baroreceptors

Answer 22

Primary sensory receptor found in the aortic arch

Question 23

What effect does a stretched baroreceptors have

Answer 23

Increases impulse to cardiovascular centre of medulla oblongata

Question 24

What two factors help control cardiac output

Answer 24

Heart rates and stroke volume

Question 25

What factors effect how we control blood vessel diameter

Answer 25

Hormones - Adrenalin
Vasodilation/constriction (arteriolar)

Question 26

What does blood pressure represent

Answer 26

The force added from the heart and the peripheral resistance provided by blood vessels

Question 27

3ways to measure blood pressure

Answer 27

Mean arterial pressure
Systolic pressure
Diastolic pressure

Question 28

What is hypotension

Answer 28

Low blood pressure, poor nutrition, pooling of blood in elderly

Question 29

What is hypertension

Answer 29

High blood pressure due to increased peripheral resistance, obesity and smoking is the cause