Anatomy of the CVS 2 Flashcards Preview

B3. Cardiovascular system > Anatomy of the CVS 2 > Flashcards

Flashcards in Anatomy of the CVS 2 Deck (48)
Loading flashcards...
1
Q

What makes up the endocardium and epicardium?

A

Simple Squamous Epithelium + Basement Membrane + Connective Tissue

2
Q

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

A

Endocardium - Tunica Intima

Myocardium - Tunica Media

Epicardium - Tunica Adventitia

3
Q

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

A

The tunica adventitia lacks epithelium and a basement membrane.

4
Q

Whats the difference between the myocardium and tunica media?

A

Myocardium = Cardiac Muscle

Tunica Media = Smooth Muscle & Elastic Tissue

5
Q

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

A

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

6
Q

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

A

Arteries/Veins have the biggest individual diameter

Capillaries have the largest total cross-sectional area

7
Q

Look at histology images in lecture of arteries etc.

A

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

8
Q

Name 3 types of arteries + their function and examples

A

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

9
Q

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

A

During Systole

10
Q

How do elastic arteries maintain the pressure during dystole?

A

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

11
Q

What allows the elastic arteries to recoil and stretch?

A

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

12
Q

How are elastic fibres produced?

A

They’re secreted by smooth muscle

13
Q

How do you differentiate between veins and arteries histologically?

A

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

14
Q

How do you tell between an elastic and muscular artery?

A

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

15
Q

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

A

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)

16
Q

Whats differnt about an arteriole to larger arteries histlogically?

A

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

17
Q

What are the functions of arterioles?

A

Controlling Blood Pressure

Controlling blood flow to capillary beds

18
Q

What nervous system innervates the arterioles?

A

Sympathetic Nervous System

19
Q

What layers are present in a capillary wall?

A

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

20
Q

What are pericytes?

A

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

21
Q

What do pericytes do?

A

They contract to control the flow of blood in capillaries.

22
Q

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

A

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

23
Q

What are the 3 types of capillary?

A

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

24
Q

What is the function of continuous capillaries?

A

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

25
Q

What tissue are continuous capillaries found in?

A

Muscle

26
Q

What are fenestrations?

A

Pores

27
Q

Where are fenestrated capillaries found?

A

In endocrine glands and kidney renal corpuscles

28
Q

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

A

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

29
Q

What do discontinuous capillaries do?

A

Allow free passage of any fluid, molecule or cell.

30
Q

Where are discontinuous capillaries found?

A

Liver
Spleen
Bone Marrow

31
Q

What are sinusoids?

A

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

32
Q

Where do you find sinusoids?

A

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

33
Q

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

A

Its a vessel enabling blood to bypass the capillary beds.

Theyre found in the skin for thermoregulation

34
Q

How do arterioles control which capillaries/shunts receive blood?

A

Precapillary sphincters can control what capillaries or shunts are open.

35
Q

Describe the structure of veins?

A

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

36
Q

What prevents backflow out of veins?

A

Valves projecting from the endothelium (T. Intima)

37
Q

Which is thicker a deep or superficial vein?

A

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

38
Q

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

A

The deep fascia and muscle

39
Q

In what tissue are superficial veins found?

A

Inside the superficial fascia

40
Q

Where do we most commonly find lymph nodes?

A

Alongside major veins

Around the origins of major arteries

41
Q

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

A

VALVES

42
Q

Are lymph capillaries fenestrated?

A

Ye….NO

43
Q

What lines the blind ended lymphatic capillaries?

A

A rudimentary basal lamina (often absent)

Very thin endothelium

44
Q

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.)

A

Anchoring filaments

They’re fine collagenous filaments that link the endothelial cells to the surrounding tissue.

45
Q

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

A

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

46
Q

What supplies blood to the blood vessels themselves?

A

The Vasa Vasorum (“vessels of the vessels)

47
Q

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

A

The T. Adventitia

48
Q

What nerves supply blood vessels?

A

Sympathetic and parasympathetic.