Blood Vessels and Blood in Mammals

Question 1

What are the 5 types of Blood Vessels?

Answer 1

-Arteries
-Arterioles
-Capillaries
-Veins
-Venules

Question 2

What doe Arteries carry?

Answer 2

-Carry blood Away from heart
-Carry oxygenated blood other than the pulmonary artery

Question 3

What type of pressure is the blood under in the arteries?

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Answer 3

High pressure

Question 4

What features are present in the arteries?

Answer 4

-Thick layer of elastic tissue in wall
-Thick smooth muscle layer
-Lumen
-Folded endothelium

Question 5

What is Lumen?

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Answer 5

Space in the centre

Question 6

What is endothelium?

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Answer 6

Membrane so a layer of cells

Question 7

What type of cells are the endothelium tissues made from?

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Answer 7

Squamous Epithelium Cells

Question 8

What is the function of elastic tissue?

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Answer 8

Allows arteries to stretch and recoil as blood flows through to help maintain BP and even out flow.

Question 9

What is the function of the folded endothelium?

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Answer 9

Same function as elastic tissue

Question 10

What is the function of smooth muscle?

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Answer 10

To withstand the high pressure of blood and in smaller arteries, allow vasoconstriction and vasodilation

Question 11

What also help to maintain Blood Pressure?

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Answer 11

The small lumen

Question 12

What do arteries branch into?

Answer 12

Arterioles

Question 13

What is the structure of the arterioles?

Answer 13

Similar structure to arteries but have less smooth muscle and elastic tissue than arteries and have a smooth unfolded endothelium

Question 14

What is the main function of arterioles?

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Answer 14

Control the amount of blood flowing to a particular area by vasoconstricting and vasodilating

Question 15

What is vasoconstriction?

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Answer 15

Lumen decreases in diameter

Question 16

What is vasodilation?

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Answer 16

Lumen increases in diameter

Question 17

Why do arterioles have less smooth muscle than arteries?

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Answer 17

The pressure is lower in arterioles than arteries

Question 18

Why do arterioles still have a need for some smooth muscle?

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Answer 18

For vasoconstriction and vasodilation

Question 19

Why do arterioles have a smooth unfolded epithelium?

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Answer 19

-To allow easy blood flow with little restriction
-Unfolded as less pressure

Question 20

What structure allows the terminal arterioles to control the amount of blood flowing into a particular capillary/tissue?

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Answer 20

Pre Capillary Sphincters

Question 21

What do arterioles branch into?

Answer 21

Capillaries

Question 22

What happens in capillaries?

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Answer 22

Where substances are exchanged between cell/tissues and the blood

Question 23

Why is the endothelium (capillary wall) is one cell thick?

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Answer 23

To provide a short diffusion pathway

Question 24

Why do capillaries have tiny pores or gaps in their epithelium?

Answer 24

To make it easier for substances to pass out of the capillary.

Question 25

What are these tiny pores or gaps also known as?

Answer 25

Fenestrations

Question 26

Why is it useful that the capillary lumen can only fir one red blood cell through at a time?

Answer 26

More of the surface areas of the blood cell in contact with endothelium so there is a reduced diffusion pathway and slows the flow to increase diffusion time

Question 27

Why is it useful that red blood cells are squeezed as they pass through the narrow lumen?

Answer 27

When RBC are squeezed it causes oxygen to dissociates from the haemoglobin which is useful as the tissues need the oxygen

Question 28

What do capillaries branch into?

Answer 28

Venules which are smaller versions of veins

Question 29

What features do venules have?

Answer 29

Valves and thin walls with a small amount of smooth muscle and elastic tissue

Question 30

What do venules branch into?

Answer 30

veins

Question 31

What do veins do?

Answer 31

-Carry blood towards the heart -Carry deoxygenated blood except the pulmonary vein

Question 32

What pressure is the blood under in the veins?

Answer 32

Low pressure

Question 33

Why do veins only have a thin layer of smooth muscle and elastic tissue in their walls?

Answer 33

No high pressure to withstand which allows blood to move through veins

Question 34

Why do veins have a large lumen and a smooth unfolded endothelium?

Answer 34

Reduce resistance of blood flow

Question 35

Why do veins have valves?

Answer 35

To prevent backflow of blood

Question 36

What carries blood around the body?

Answer 36

Blood vessels

Question 37

What type of system does blood vessels carry blood around?

Answer 37

Closed circulatory system

Question 38

What are the main components of blood?

Answer 38

-Plasma (55%) -Platelets and White Blood Cells(1%) -Red Blood Cells (44%)

Question 39

Why is blood described as a tissue?

Answer 39

As it is a collection of similar specialised cells that perform a specific function

Question 40

What are Red Blood Cells also known as?

Answer 40

Erythrocytes

Question 41

What are White Blood Cells also known as?

Answer 41

Leukocytes

Question 42

What is the function of platelets?

Answer 42

They are involved in the clotting mechanism of blood. Prevents blood loss and infection

Question 43

How does the structure of platelets differ from red blood cells?

Answer 43

-Fragments of large cells -don't have haemoglobin or cytoplasm.

Question 44

Give an example of a protein that would be transported in the plasma.

Answer 44

Haemoglobin, Hormones, Enzyme, Antibodies, Plasma

Question 45

Explain why the blood of different animals is not always red.

Answer 45

As haemoglobin is what makes blood red so animals who's blood isn't red means they don't have haemoglobin in their blood.

Question 46

How is the blood able to flow back to the heart at low pressure?

Answer 46

Skeletal muscles compress the veins which contain valves so blood only flows in one direction