Histology of the CVS

Question 1

What are the layers of blood vessels and the heart made of?

Answer 1

Innermost epithelium
Middle muscle layer
Outer connective tissue layer

Question 2

What are the 3 layers of blood vessels and the heart?

Answer 2

Tunica intima
Tunica media
Tunica adventitia/externa

Question 3

What are the layers of the heart called?

Answer 3

Endocardium
Myocardium
Epicardium

Question 4

What are the 3 main histological types of arteries?

Answer 4

Elastic arteries
Muscular arteries
Arterioles

Question 5

What makes up the endocardium?

Answer 5

Simple squamous epithelium sitting on a basement membrane (connective tissue)

Question 6

What does the endocardium do?

Answer 6

Line heart chambers
Form valves

Question 7

What makes up the myocardium?

Answer 7

Myocytes (cardiac muscle cells) connected by intercalating discs

Question 8

What makes up the epicardium?

Answer 8

Simple squamous epithelium on a basement membrane (of connective tissue)

Is a visceral layer of serous pericardium and may be fatty

Question 9

How is an artery made up histologically?

Answer 9

Thick muscular wall
Thin adventitia

Question 10

How is a vein made up histologically?

Answer 10

Thin muscular wall
Larger
Thick adventitia
Valves to prevent backflow

Question 11

What are valves in veins made of?

Answer 11

Endothelial projections into lumen

Question 12

How are capillaries made up histologically?

Answer 12

Endothelial cell folded on itself
(single cell thick)

Very thin Tunica intima
No media or adventitia

Question 13

What are the 3 types of capillary?

Answer 13

Continuous
Fenestrated
Discontinuous/sinusoids

Question 14

What is a continuous capillary and what does it do?

Answer 14

Single cells
Can control what it exchanges as material must pass through the cell or between cells

Question 15

Where are continuous capillaries located?

Answer 15

In muscles

Question 16

What are fenestrated capillaries and what do they do?

Answer 16

Single cell with gaps in it
Have pores
Filter molecules by molecular weight &/or charge

Question 17

Where are fenestrated capillaries located?

Answer 17

Endocrine glands
Kidneys renal corpuscle

Question 18

What are discontinuous capillaries and what do they do?

Answer 18

Single cells with gaps between endothelial cells (and basement membrane)

Allow free passage of fluid and cells

Question 19

Where are discontinuous capillaries located?

Answer 19

Liver
Spleen
Bone marrow

Question 20

What’s the difference between elastic and muscular arteries function?

Answer 20

Elastic - expand and recoil
Muscular - controls distribution of blood to regions

Question 21

What are some elastic artery examples?

Answer 21

Aorta
Common carotid
Pulmonary

Question 22

What are some muscular artery examples?

Answer 22

Coronary arteries
Radial
Femoral

Question 23

What are elastic arteries made up of histologically?

Answer 23

Extensive elastic fibres in T. media

Question 24

What is histologically of note about arteries?

Answer 24

Elastic fibres are concentrated in 2 well defined sheets
- internal elastic lamina just under epithelium
- external elastic lamina between T. media and T. adventitia

Question 25

What do arterioles do?

Answer 25

Control amount of blood going into tissue
Supply blood to the capillary bed

Question 26

What are the layers of arterioles?

Answer 26

T. intima
T. media
No IEL/EEL or T. adventitia

Question 27

What’s the difference between superficial and deep veins?

Answer 27

Superficial
- Thick walled
- No surrounding support

Deep
- Thin walled
- Surrounding support from deep fascia and muscles

Question 28

What does the lymphatic system do?

Answer 28

Drains tissue fluid from blood capillaries into the venous system

Question 29

What are lymphatic vessels made up of?

Answer 29

Lined by very thin endothelium
Anchoring filaments