UNT 2 - KA5

Question 1

What are all components of blood carried around in

Answer 1

All of the components of blood are carried around the body in different types of blood vessels

Question 2

What are the three main types of blood vessel found in the body

Answer 2

• arteries
• capillaries
• veins

Question 3

What are the 4 main points about Nat 5 arteries vs veins (blood pressure and direction)

Answer 3

Artery - much thicker muscular wall than veins, carry blood at high pressure , narrower central channel, carry blood away from the heart

Vein - thinner muscular wall than artery, carry blood at low pressure towards the heart, wider central channel, carry blood towards the heart

Question 4

What do veins contain which arteries do not

Answer 4

Veins also contain structures called valves - these prevent the back flow of blood and ensure it only travels in one direction

Question 5

What is the cycle of blood circulation (think acv)

Answer 5

Blood circulates from the heart through the arteries to the capillaries then to veins and back to the heart. There is a decrease in blood pressure as blood moves away from the heart

Question 6

What happens to blood pressure as it moves away from the heart

Answer 6

Decreases

Question 7

What does pulmonary circulation relate to

Answer 7

Pulmonary circulation relates to the lungs

Question 8

How does the pulmonary artery differ from all other arteries in the body

Answer 8

It is unusual as arteries usually carry oxygenated blood whereas the pulmonary artery carries deoxygenated blood from the heart to the lungs where it picks up oxygen

Question 9

How does the pulmonary vein differ from all other veins in the body

Answer 9

The pulmonary vein carries oxygenated blood from the lungs to the heart this is unusual because most veins carry deoxygenated blood

Question 10

What is the function of the coronary arteries

Answer 10

The coronary arteries supply the cardiac muscle of the heart with blood containing glucose and oxygen

Question 11

Blood vessel - artery

Answer 11

Arteries have an outer layer of connective tissue containing elastic fibres and a middle layer containing smooth muscle with more elastic fibres.

Question 12

Blood vessel - vein

Answer 12

Veins have an outer layer of connective tissue containing elastic fibres but a much thinner muscular wall than arteries. They contain valves to prevent the back flow of blood

Question 13

Blood vessel - capillary

Answer 13

Capillaries allow exchange of substances with tissues through their thin walls

Question 14

What is the benefit of the thick muscular wall in arteries

Answer 14

Thick muscular wall helps withstand pressure of heart pumping

Question 15

What is the endothelium surrounded by

Answer 15

The endothelium lining the central lumen of blood vessels is surrounded by layers of tissue

Question 16

What is the role of the elastic walls of arteries

Answer 16

The elastic walls of the arteries stretch and recoil to accommodate the surge of blood after each contraction of the heart

Question 17

What can the smooth muscle in arteries do

Answer 17

The smooth muscle can contract or relax causing vasoconstriction or vasodilation to control blood flow

Question 18

What is the role of the central lumen

Answer 18

Central lumen of an artery is where the blood flows through - this is relatively narrow

Question 19

What type of wall do capillaries have

Answer 19

Each capillary has a very thin wall called the endothelium (only one cell thick)

Question 20

What does the endothelium of a capillary line

Answer 20

Lines the central lumen of the capillary

Question 21

What are capillaries the site of

Answer 21

Capillaries are the site of material exchange

Question 22

What type of blood vessels can carry out vasoconstriction and vasodilation

Answer 22

Arteries

Question 23

What can happen to the smooth muscle surrounding arteries to control blood flow

Answer 23

To control blood flow the smooth muscle surrounding arteries can contract causing vasoconstriction or relax causing vasodilation

Question 24

What do capillaries allow

Answer 24

Capillaries allow exchange of substances with tissues through their thin walls

Question 25

What are arterioles and venules

Answer 25

- smaller/narrower arteries - smaller/narrower veins

Question 26

Describe a functional difference between arteries and veins

Answer 26

- arteries carry blood that is oxygenated/HIGH BP - Veins carry blood that is deoxygenated/low BP

Question 27

Vasodilation

Answer 27

During strenuous exercise arteries leading to working muscles undergo vasodilation. This allows an increase in blood flow to the skeletal muscles involved in strenuous exercise

Question 28

Vasoconstriction

Answer 28

At the same time arteries leading to abdominal organs such as the small intestine undergo vasoconstriction. This reduces blood flow to these organs during the period of strenuous exercise

Question 29

Why can arteries carry out vasoconstriction and vasodilation

Answer 29

Muscular walls thicker than veins

Question 30

Where do capillaries exist

Answer 30

Capillaries exist in a dense network called a capillary bed

Question 31

What is exchanged in capillary beds

Answer 31

It is here that gases, nutrients and waste materials are exchanged with tissue cells

Question 32

What is everybody cell near and bathed in

Answer 32

Every body cell is near a capillary and constantly bathed in a liquid called tissue fluid

Question 33

What is pressure filtration

Answer 33

When blood arrives at the arteriole end of a capillary bed, High pressure forces the plasma through the thin walls of the capillaries into the tissue fluid surrounding the cells

Question 34

How many substances are forced through capillary walls

Answer 34

Most of the dissolved substances in the plasma are also forced through the capillary walls.

Question 35

Which molecules remain behind in the plasma

Answer 35

Only the large protein molecules, and blood cells of course remain behind in the plasma

Question 36

What does tissue fluid supply cells with

Answer 36

Tissue fluid supplies body cells with glucose, oxygen and other substances down the concentration gradient

Question 37

Which substances diffuse out of the cells into the tissue fluid

Answer 37

Carbon dioxide and other metabolic wastes diffuse out of the the cells and into the tissue fluid to be excreted in the opposite direction

Question 38

What happens to blood pressure at the venule side of capillary bed

Answer 38

At the venule side of the capillary bed the blood pressure has fallen

Question 39

What happens to the tissue fluid at the Venule side of the capillary bed

Answer 39

Here much of the water In the tissue fluid returns to plasma by osmosis. At the same time carbon dioxide and additional waste products enter the plasma by diffusion

Question 40

What happens to excess tissue fluid

Answer 40

lymphatic vessels absorb excess tissue fluid and return it as lymph to the circulatory system

Question 41

How much of the tissue fluid returns to the bloodstream

Answer 41

Not all the tissue fluid returns to the bloodstream in the capillaries

Question 42

What is the composition of tissue fluid and blood plasma

Answer 42

Tissue fluid and blood plasma are similar in composition with the exception of plasma proteins, which are too large to be filtered through the capillary walls