Anatomy of the CVS 2

Question 1

What makes up the endocardium and epicardium?

Answer 1

Simple Squamous Epithelium + Basement Membrane + Connective Tissue

Question 2

The heart is essentially a twisted blood vessel. What are the comparable layers between the heart wall and vessel’s walls?

Answer 2

Endocardium - Tunica Intima

Myocardium - Tunica Media

Epicardium - Tunica Adventitia

Question 3

The epicardium is slightly different to the tunica adventitia, what is the difference?

Answer 3

The tunica adventitia lacks epithelium and a basement membrane.

Question 4

Whats the difference between the myocardium and tunica media?

Answer 4

Myocardium = Cardiac Muscle

Tunica Media = Smooth Muscle & Elastic Tissue

Question 5

What are the visible differences between arteries and the accompanying vein (histologically)?

Answer 5

Diameter: Vein > Artery
Thickness of Wall: Artery > Vein
Thickness of Tunica Media: Artery > Vein
Thickness of Tunica Adventitia: Vein > Artery

Question 6

Which level of vessel have the greatest individual diameter and total cross-sectional area?

Answer 6

Arteries/Veins have the biggest individual diameter

Capillaries have the largest total cross-sectional area

Question 7

Look at histology images in lecture of arteries etc.

Answer 7

Remember Tunica Intima is fucking tiny in an artery and Tunica Media is pretty Phat.

Question 8

Name 3 types of arteries + their function and examples

Answer 8

Elastic - Large Conducting - Aorta, Common Carotid, Pulmonary Trunk
Muscular - Distributing to regions - Coronary, Radial & Femoral
Arterioles - Terminal branches supplying capillary bed.

Question 9

The aorta is an elastic artery, during which stage of the cardiac cycle is it stretched?

Answer 9

During Systole

Question 10

How do elastic arteries maintain the pressure during dystole?

Answer 10

The arteries recoil in order to maintain pressure even when the heart relaxes.

Question 11

What allows the elastic arteries to recoil and stretch?

Answer 11

Extensive amounts of elastic fibres in the Tunica Media arranged into layers or laminae.

Question 12

How are elastic fibres produced?

Answer 12

They’re secreted by smooth muscle

Question 13

How do you differentiate between veins and arteries histologically?

Answer 13

Generally:
Arteries are smaller in diameter and have a thicker wall
Veins have a thicker Adventitia but a thinner Media

Question 14

How do you tell between an elastic and muscular artery?

Answer 14

A muscular artery only has elastic fibres in 2 laminae, one at each edge of the T. Media.
An elastic artery has a T. Media full of dark blue elastic fibres

Question 15

What do we call the two elastic laminae in a muscular artery?

Answer 15

Just under the epithelium (T. Intima) is the Internal Elastic Lamina (IEL)
Between the T. Media & T. Adventitia is the External/Outer Elastic Lamina (OEL)

Question 16

Whats differnt about an arteriole to larger arteries histlogically?

Answer 16

Arterioles lack a Tunica Adventitia
The T. Media is only a couple layers of muscle thick
There is no elastic Laminae

Question 17

What are the functions of arterioles?

Answer 17

Controlling Blood Pressure

Controlling blood flow to capillary beds

Question 18

What nervous system innervates the arterioles?

Answer 18

Sympathetic Nervous System

Question 19

What layers are present in a capillary wall?

Answer 19

Just the Tunica Intima. So it can exchange nutrients and gases easily

Question 20

What are pericytes?

Answer 20

Pericytes are an incomplete layer of cells around the basement membrane of capillaries.

Question 21

What do pericytes do?

Answer 21

They contract to control the flow of blood in capillaries.

Question 22

Why is the BP of capillaries lower than that of the Aorta?

Answer 22

Because theyre cross sectional area is larger overall than that of the aorta.

Question 23

What are the 3 types of capillary?

Answer 23

Continuous - Complete endothelial & basal lamina layers
Fenestrated - Complete basal lamina but fenestrated endothelial lining
Discontinuous - Incomplete basal lamina and fenestrated endothelial lining.

Question 24

What is the function of continuous capillaries?

Answer 24

They can control what is exchanged because it must pass through the cell or junctions to get in/out. (i.e. selective transport)

Question 25

What tissue are continuous capillaries found in?

Answer 25

Muscle

Question 26

What are fenestrations?

Answer 26

Pores

Question 27

Where are fenestrated capillaries found?

Answer 27

In endocrine glands and kidney renal corpuscles

Question 28

Some fenestrated capillaries have protein diaphragms over the pores, what do they do/

Answer 28

Protein diaphragms filter the molecules attempting to pass through by molecular weight and/or charge

Question 29

What do discontinuous capillaries do?

Answer 29

Allow free passage of any fluid, molecule or cell.

Question 30

Where are discontinuous capillaries found?

Answer 30

Liver Spleen Bone Marrow

Question 31

What are sinusoids?

Answer 31

A type of discontinuous capillary with a large diameter and phagocytic cells in its T. Intima

Question 32

Where do you find sinusoids?

Answer 32

Wherever larger amounts of exchange take place. Specifically: - liver - Some endocrine glands

Question 33

What does an arteriovenous (AV) shunt do and where would you find one?

Answer 33

Its a vessel enabling blood to bypass the capillary beds. | Theyre found in the skin for thermoregulation

Question 34

How do arterioles control which capillaries/shunts receive blood?

Answer 34

Precapillary sphincters can control what capillaries or shunts are open.

Question 35

Describe the structure of veins?

Answer 35

The T. Intima is thin The IEL & OEL are thin or absent The T Media are thin or absent T. Adventitia is made of collagenous tissue

Question 36

What prevents backflow out of veins?

Answer 36

Valves projecting from the endothelium (T. Intima)

Question 37

Which is thicker a deep or superficial vein?

Answer 37

Deep veins are thick walled and superficial veins are thin walled.

Question 38

The superficial vein has no support, what supports the deep vein?

Answer 38

The deep fascia and muscle

Question 39

In what tissue are superficial veins found?

Answer 39

Inside the superficial fascia

Question 40

Where do we most commonly find lymph nodes?

Answer 40

Alongside major veins | Around the origins of major arteries

Question 41

How is flow kept in the right direction in the lymphatic system?

Answer 41

VALVES

Question 42

Are lymph capillaries fenestrated?

Answer 42

Ye....NO

Question 43

What lines the blind ended lymphatic capillaries?

Answer 43

A rudimentary basal lamina (often absent) | Very thin endothelium

Question 44

The lymph capillaries are kept at the -ve hydrostatic pressure so they can drain fluid from the tissues. How are they kept open (instead of being flattened by the higher pressure outside.)

Answer 44

Anchoring filaments | They're fine collagenous filaments that link the endothelial cells to the surrounding tissue.

Question 45

How do we easily tell a lymph capillary from venules and arterioles?

Answer 45

Lymph capillaries lack any RBCs in they're lumen, it should be clear.

Question 46

What supplies blood to the blood vessels themselves?

Answer 46

The Vasa Vasorum ("vessels of the vessels)

Question 47

Some blood vessels contain lymphatics, what layer are these found in?

Answer 47

The T. Adventitia

Question 48

What nerves supply blood vessels?

Answer 48

Sympathetic and parasympathetic.