L13- Vessels

Question 1

blood vessels can be

Answer 1

Continuous, Fenestrated or Sinusoid

Question 2

Continuous

Answer 2

• Continuous basement membrane and endothelial layer (tunica intima)

Question 3

Fenestrated

Answer 3

• Continuous basement membrane

- Fenestrations within endothelial layer

Question 4

sinusoidal

Answer 4

• Incomplete basement membrane

- Intercellular gap in epithelial layer(discontinuous)

Question 5

on entering circulation, newly formed RBC travel from

Answer 5

venule intermediate veins  larger vein  vena cava

Question 6

RBC matures within

Answer 6

2 days

Question 7

newly formed WBC

Answer 7

WBCs take the same route at RBC

Question 8

T cells need to

Answer 8

mature in the thymus and lympathics

Question 9

B cells

Answer 9

already mature

Question 10

precapillary sphincters

Answer 10

control flow in microciruclation

Question 11

when precaipplary spinsters are open

Answer 11

open blood flows freely to capillary bed
- oxygen and nutrient rich blood flows from there arteries, through etc capillaries releasing nutrients and oxygen to the tissue and then into the venule

Question 12

function of precapillary sphincters

Answer 12

 Control fluid exchange between the capillaries and the body tissue

Question 13

definition of a vein

Answer 13

vein is an elastic blood vessels which transports blood to the heart (right ventricle)

Question 14

structure of a vein

Answer 14

• wide lumen
• thin wall
• 3 layers: tunica intima, tunica media, tunica externa
• valves

Question 15

valves in veins

Answer 15

Non return valves (fibroelastic cartilaginous ) assists flow towards the heart

Question 16

why are valves needed in veins

Answer 16

• Low pressure system
• Relies on muscle contractions to return blood to the heart
• Vein problems occur due to blood clot or vein defect behind the valves

Question 17

size of veins

Answer 17

Range in size: 1-1.5cm in diameter

Question 18

smallest type of vein

Answer 18

venule

Question 19

venules

Answer 19

Receive blood from arterioles and capillaries

Question 20

venules branch into

Answer 20

larger veins e.g. carry blood to the largest vein in the largest vein in the body

Question 21

largest vein in the body

Answer 21

the vena cava

- Superior and inferior vena cava drain into the right atrium of the heart

Question 22

types of vein

Answer 22

• pulmonary
• systemic
• superficial
• deep

Question 23

pulmonary veins

Answer 23

• Carries oxygenated blood from the lungs to the left atrium of the heart

Question 24

systemic veins

Answer 24

• Return oxygen depleted blood from the rest of the body to the right atrium of the heart

Question 25

superficial veins

Answer 25

• Located near the surface of the skin and not located near a corresponding artery (e.g. in hands)

Question 26

deep veins

Answer 26

• Located deep between tissues and typically located near a corresponding artery with the same name ( e.g. femoral artery and vein)

Question 27

artery vs vein

Answer 27

- Artery has thicker tunica externa | - Very thin elastic layer in low pressure vein

Question 28

artery defintiiton

Answer 28

are elastic blood vessels that convert. blood away from the heart

Question 29

structure of an artery

Answer 29

Small lumen and thicker walls to deal with higher BP.

Question 30

layers of artery

Answer 30

Consists of 3 main layers: • Tunica intima- elastic membrane and smooth muscle lining • Tunica media- smooth muscle and elastic fibres. o This layer is thicker in arteries than in veins and has two distinct elastic layers • Tunica externa- strong outer covering composed of collagen and elastic fibres o Allows arteries to stretch but prevents over expansion due to higher blood pressures than in the veins

Question 31

capillaries function

Answer 31

supply all cells with their requirements e.g. oxygen and nutrients - take away waste products

Question 32

structure of capillaries

Answer 32

very tin cell wall (allow for exchange) | - very narrow lumen (just wide enough for RBC to pass through)

Question 33

structure of wall in veinsq

Answer 33

- thin - mainly fibrous tissue - contains far less muscle and elastic tissue than arteries

Question 34

why do veins not need strong walls

Answer 34

- most of the BP has been lost | - wide lumen offers less resistance to blood flow

Question 35

why do arteries have thick, strong and elastic walls

Answer 35

needed to withstand the pulsing of the blood, prevent bursting and maintain pressure wave - prevents back flow

Question 36

vasculogenesis

Answer 36

Formation of new blood vessels - E.g. during embryo development, newly formed cancers and endometriosis

Question 37

precursors of new blood vessels found

Answer 37

in bone marrow (angioblasts)

Question 38

angiogenesis

Answer 38

Formation of new blood vessels from existing ones | - E.g. during fetal development, collateral arteries, postnatal lung development

Question 39

collateral arteries

Answer 39

Arterioles which form a pathway around blockage- protect tissues that may become compromised

Question 40

why do collateral arteries form

Answer 40

o Chronic diseases such as ischaema | o During development (brain and joints)

Question 41

the pericyte is a

Answer 41

smooth muskie like cell found inside the basal lamina close to the basement membrane

Question 42

pericyte is a key component of which blood vessel

Answer 42

capillaries - prevent endothelial cell proliferation

Question 43

pericyte also involved in

Answer 43

nerve cell communications in the BBB (maintains tight capillaries)

Question 44

pericytes can differentiate into

Answer 44

endothelial, smooth muscle or fibroblast