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Flashcards in CVS S1 Deck (36):
0

What surrounds the heart?

The pericardium

1

What layers make up the pericardium? Answer from outermost to innermost.

The fibrous pericardium
The parietal layer of serous pericardium
The visceral layer of serous pericardium

2

Describe "venae comitantes"

A pair of veins (occasionally more) that accompany an artery in such a way that the pulse aids the return of venous blood to the heart. They share a sheath and appear to anastomose.

3

What are the names of blood vessel types in order from the left ventricle to the right atrium?

Large artery (elastic/conducting), medium artery (muscular/distributing), arteriole, metarteriole, capillary, post-capillary venule, venule, medium vein, large vein.

4

How much blood does the adult body contain?

5-6 litres

5

How much blood is pumped through the heart every minute at rest?

About 5 litres per minute

6

How many litres of blood are pumped through the heart every minute during exercise?

Up to 25 litres

7

How much fluid enters back into circulation via the lymphatic system per hour?

100ml per hour

8

What three major arterial trunks originate from the trunk of the aorta?

Brachiocephalic, common carotid and subclavian arteries.

9

Where does the aorta terminate?

In the abdominal cavity, where it bifurcated into the right and left common iliac arteries in the pelvis

10

What are the three layers of arteries and veins from outermost to innermost layer?

Tunica adventitia, tunica media, tunica intima

11

What are end arteries? Give examples.

End arteries are terminal arteries that supply most or all of the blood supply to an area of the body without significant collateral circulation. Eg, coronary, splenic and renal arteries.

12

What is a risk associated with end arteries?

If occluded, there will be very little or no circulation to the tissues downstream of the occlusion

13

What is a precapillary sphincter and where are they found?

Found in metarterioles in place of continuous smooth muscle as seen in the walls of arterioles. Made up of singly spaced smooth muscle cells, they help control blood flow to the capillary bed.

24

What are the types of capillary?

Sinusoid, fenestrated and continuous.

25

What are the main characteristics of continuous capillaries?

The most common type
Continuous endothelial layer
Have tight or occluding cellular junctions

26

Where can continuous capillaries be found?

Nervous tissue
Muscle
Connective tissue
Lungs
Exocrine glands

27

What are the main features of fenestrated capillaries?

Have "windows" or interruptions in the endothelial layer which are bridged by a thin diaphragm

28

Where can fenestrated capillaries be found?

Parts of the gut, the renal glomerulus and endocrine glands.

29

What are the main features of sinusoidal/discontinuous capillaries?

Larger diameter (30-40μm)
Slower blood flow
Gaps in capillary wall large enough for cells to pass through

30

Where can sinusoid capillaries be found?

Liver
Spleen
Bone Marrow

31

What is the diameter of a capillary?

7-10μm

32

What is the diameter of a postcapillary venule?

10-30μm

33

How are venules different from post capillary venules?

Continuous smooth muscle returns to the tunica media in venules, and the diameter is between 50μm and 1mm

34

If a vein is accompanied by an artery, do they have the same diameter?

No. The vein would have the larger diameter.

35

Describe the tunica of large veins

Reasonably thin tunica intima, thin tunica media, well developed tunica adventitia
EXCEPTION: leg veins- these have thicker smooth muscle layers in the tunica media, possibly to resist gravity.

36

What is the diameter of large veins?

>10mm

37

How is venous blood returned to the heart?

Skeletal muscle contraction and valves act together

38

Where may venae comitantes be found?

Eg ulnar, brachial and tibial venae comitantes

39

Give some examples of large veins

Vena cava, pulmonary, portal, iliac, azygous and internal jugular veins

40

How much blood flows to the brain per minute?

750ml/min

41

How much blood flows to the heart per minute? (Minimum and maximum)

300-1200ml/min

42

How much blood flows to the kidney per minute?

1200ml/min

43

How much blood flows to the gut and liver per minute? (Min and max)

1400-2400ml/min

44

How much blood flows to the skin per minute? (Min and max)

200-2500ml/min

The large difference is due to use as thermoregulator

45

What are the general components of the cardiovascular system?

A pump (the heart)
Distribution vessels (arteries)
Flow control (resistance vessels)
Capacitance- the ability to cope with blood volume changes (large veins store blood)