Cardiovascular System Flashcards Preview

Semester 1-Body Logistics > Cardiovascular System > Flashcards

Flashcards in Cardiovascular System Deck (37)
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1
Q

What does the CV system do? (2)

A
  1. Circulates and transports nutrients, O2, CO2, hormones and blood cells to and from cells of body
  2. Fights disease, stabilises temp, pH and helps maintain homeostasis
2
Q

What are the essential components of the human CV system?

A

Heart
Blood
Blood vessels

3
Q

What is the pulmonary circulation?

A

“Loop” through the lungs where blood is oxygenated

4
Q

What is the systemic circulation?

A

“Loop” through the rest of the body to provide oxygenated blood and receive deoxygenated blood

5
Q

What is a closed CV system?

A

Blood never leaves the network of arteries, veins and capillaries

6
Q

How much blood does an average adult have?

A

5L of circulating blood, of which 2L is RBCs and 3L is plasma

7
Q

What % of our blood lies in the peripheral veins?

A

65%

8
Q

What % of our blood lies in the heart and lungs?

A

20%

9
Q

What % of our blood likes in the peripheral arteries?

A

10%

10
Q

What % of our blood lies in capillaries?

A

5%

11
Q

What is the name of the mechanism that prevents exsanguination if the closed CV system is breached?

A

Haemostasis

12
Q

What is haemostasis?

A

Balance of pro-coagulant and anti-coagulant systems

13
Q

What is bridging?

A

Compression of a segment of a coronary artery during systole, resulting in narrowing that reverses during diastole

14
Q

What is an end artery?

A

Terminal artery supplying all or most of the blood to a body part without significant collateral circulation

15
Q

What are some examples of functional end arteries? (4)

A

Coronary arteries
Splenic artery
Cerebral arteries
Renal arteries

16
Q

What is an absolute end artery?

A

Anatomically true end artery

17
Q

Give an example of an absolute end artery

A

Central artery to the retina

18
Q

Why is there an atrioventricular delay?

A

To prevent simultaneous contraction of the atria and ventricles

19
Q

Complete the sentence:

Left ventricle contraction causes the BP in the aorta to rise to approx ____mmHg (systolic pressure).

A

120

20
Q

Complete the sentence:

The aortic semilunar valve closes. The walls of the aorta recoil, maintaining pressure on the blood and moving it towards the heart and smaller vessels. Aortic pressure drops to __-__ mmHg (diastolic pressure)

A

70-80

21
Q

What are the three layers of the walls of arteries and veins?

A
Tunica intima-next to lumen
Tunica media
Tunica adventitia (outer)
22
Q

What is the commonest site for an aneurysm?

A

Infrarenal abdominal aorta

23
Q

How many layers of smooth muscle cells does the tunica media contain?

A

40

24
Q

Why do the muscular arteries have many layers of smooth muscle layers?

A

Propulsion vessels-push blood forward and can contract to allow vasoconstriction

25
Q

What are metarterioles?

A

Arteries that supply blood to capillary beds

26
Q

What is a precapillary sphincter?

A

Individual muscle cells are spaced apart and each encircles the endothelium of a capillary arising from the metarteriole

27
Q

Complete the sentence:

When the precapillary sphincter are open, there is _________ blood flow through the capillary bed

A

Plentiful

28
Q

Complete the sentence:

When the precapillary sphincters are closed, the blood flow through the capillary bed is greatly _______

A

Reduced

29
Q

What are capillaries made of?

A

Single layer of endothelium and its basement membrane

30
Q

What are pericytes?

A

Form branching network on the outer surface of the endothelium. Capable of dividing into muscle cells or fibroblasts during angiogenesis, tumour growth and wound healing

31
Q

True or false: postcapillary venules are more permeable than capillaries

A

TRUE

32
Q

True or false: veins have a larger diameter than arteries and a thinner wall that has more CT and fewer elastic and muscle fibres

A

TRUE

33
Q

Define capacitance

A

Ability of a blood vessel to increase the volume of blood it holds without a large increase in pressure. Inversely proportional to elasticity

34
Q

What is another term given to veins?

A

Capacitance vessels

35
Q

How does venous blood get from the legs back to the heart in a standing human?

A

Skeletal muscle contraction (calf muscle pump)
Thoracic pump-diaphragm lowers down when breathe in and creates negative pressure in chest cavity and ‘sucking’ effect, attracts blood to right atrium

36
Q

What does calf muscle pump failure lead to?

A

Venous hypertension

37
Q

What is venous pooling?

A

Too much blood in lower limbs and insufficient blood return to the heart so less brain to the brain, leading to fainting