Blood vessels

Question 1

How many miles of blood vessels do we have

Answer 1

60,000

Question 2

How long does it take a drop of blood to circulate your body

Answer 2

60 seconds

Question 3

How many endothelial cells in circulatory system

Answer 3

1 trillion

Question 4

What is angiogenesis

Answer 4

process where body regulates rebuilding and breaking down of new blood vessels

Question 5

What does to many and too little blood vessels cause

Answer 5

> cancer by feeding diseased tissue
< tissue loss

Question 6

3 tissue layers of vessels

Answer 6

Tunica Externa
Tunica Media
Tunica Intima

Question 7

What is Tunica Externa

Answer 7

Outer coat - mainly consist of collagen fibres

Question 8

What is Tunica Media

Answer 8

Middle coat - mainly consists of Muscle and elastic tissue

Question 9

What is Tunica Intima

Answer 9

Inner coat - Consisting mainly of endothelial cells, some collagen fibres

Question 10

What are the differences between the various blood vessels

Answer 10

Related to their function within the circulatory system

Question 11

What do arteries do

Answer 11

Transport blood away from the heart

Question 12

How is blood pumped and how does this affect the arteries

Answer 12

Pumped at high pressure - arteries structured to withstand and maintain high pressure

Question 12

How are lumen arteries structured

Answer 12

Relatively narrow to maintain high pressure

Question 13

Structure of Tunica intima

Answer 13

Formed by an endothelium, mainly consists of endothelial cells

Question 14

Structure of tunica media

Answer 14

Smooth, Elastic muscle that forms the thickest layer of artery wall - Enables vessels to flex + withstand high BP

Question 15

Structure of tunica externa

Answer 15

Connective tissue, consists mainly of tough collagen fibres, provide strength and durability

Question 16

Where are arteolies

Answer 16

Branch off from arteries

Question 17

Structure of arterioles

Answer 17

Similar in structure to arteries with less elastic tissue and more smooth muscle

Question 18

How does structure of arterioles help

Answer 18

Enables them to constrict and reduce blood flow through the capillaries

Question 19

Where are capillaries

Answer 19

Branch off from arterioles

Question 20

What size are capillaries

Answer 20

Smallest blood vessels

Question 21

What do capillaries form

Answer 21

Capillary beds - bring blood as close to cells as possible to enable efficient exchange of substances

Question 22

What is lumen

Answer 22

Very narrow ~7um in diameter, just enough for individual RBCs to pass through one at a time -> Slows down blood flow to allow substances to diffuse in and out

Question 23

What is endothelium

Answer 23

Very thin, only one cell thick to allow efficient diffusion

Question 24

What is basement membrane

Answer 24

Anchors capillaries in position within tissues

Question 25

What are venules

Answer 25

Drains blood from capillary beds and feed it back into veins

Question 26

Structure of venules

Answer 26

Contain smooth muscle, can constrict to control blood flow through capillaries

Question 27

What do veins do

Answer 27

Transport blood back to the heart; at lower BP than arteries impacting structure

Question 28

Structure of veins

Answer 28

Lumen Tunica intima Tunica Media Tunica Externa Valves - contain valves to prevent backflow of blood away from the heart & prevents blood pooling in bottom of body due to gravity

Question 29

Blood flow in veins during contraction

Answer 29

As skeletal muscles contract, blood beyond the site of contraction is forced towards the heart opening the valves

Question 30

Blood flow in veins during relaxation

Answer 30

blood pushes back against the valves causing them to close and prevent blood being forced away from the heart again

Question 31

What causes varicose veins

Answer 31

if a vein wall becomes weakened, valves may no longer close properly

Question 32

What are varicose veins like

Answer 32

Enlarged, bumpy, and varicose

Question 33

Where does variocse veins happen

Answer 33

Superficial veins (Skin surface underneath muscle)

Question 34

How to get rid of varicose veins

Answer 34

Can be surgically removed without affecting blood flow, as most blood is returned to the heart by deep veins