Cardiovascular System Flashcards Preview

ESA 1 - Body Logistics > Cardiovascular System > Flashcards

Flashcards in Cardiovascular System Deck (22)
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1
Q

What are the functions of the CVS?

A
  1. Circulates and transports nutrients, O2, CO2, hormones and blood cells to and from the cells of the body.
  2. Fights disease.
  3. Helps maintain homeostasis (pH and temperature).
2
Q

What are the 3 essential components of the CVS?

A
  • Heart
  • Blood
  • Blood vessels
3
Q

What are the 2 circulation components of of the CVS?

A
  • Pulmonary circulation: ‘loop’ through lungs where blood is oxygenated.
  • Systemic circulation: ‘loop’ through rest of body to provide oxygenated blood and receive deoxygenated blood.
4
Q

Where in the CVS is blood found at any one time?

A
  • Heart & lungs - 20% (1L)
  • Peripheral arteries - 10% (0.5L)
  • Capillaries - 5% (0.25L)
  • Peripheral veins - 65% (3.25L)
5
Q

How much blood does the average adult have and what is this composed of?

A
  • 5L

- 2L erythrocytes, 3L plasma

6
Q

Which side of the heart is stronger and why?

A
  • Left side is more muscular and robust to deal with higher pressure.
  • Right side is more fragile due to lower pressure.
7
Q

Which vessels vascularise the heart tissue?

A

Right and left main coronary arteries which arise from the aorta.

8
Q

Which characteristic of the left coronary artery helps prevent occlusion?

A

Left anterior descending coronary artery shows bridging - compression of a segment of the artery during systole, resulting in narrowing that reverses during diastole.

9
Q

What is an end artery?

A
  • Terminal artery supplying all or most of the blood to a body part without significant collateral circulation.
  • Undergo progressive branching without the development of channels connective with other arteries - if occluded, there is insufficient blood supply to dependent tissue (hypoxia, pain and cell death).
10
Q

Give examples of functional and absolute end arteries.

A
  • Functional: coronary arteries, splenic artery, cerebral arteries and renal arteries.
  • Absolute (anatomically true): central artery to retina.
11
Q

What is the response to occlusion in collateral circulation?

A

Arterial branching develops over time to bypass the occlusion in response to stenosis.

12
Q

Name the valves located in the heart.

A
  • Tricuspid valve (between right atrium and ventricle)
  • Pulmonary valve (between right ventricle and pulmonary artery)
  • Mitral valve (between left atrium and ventricle)
  • Aortic valve (between left ventricle and aorta)
13
Q

How is contraction generated in heart cells?

A
  • Natural pacemaker: sinoatrial (SA) node spontaneously generates action potentials.
  • AP at SA node causes contraction of right and left atria (travels via Backmann’s Bundle)
  • AP travels from SA node to atrioventricular (AV) node.
  • AP travels down left and right bundle branches and in Purkinje fibres to cause ventricular contraction.
14
Q

What is the atrioventricular delay?

A
  • Pause in AP conductivity between atria and ventricles.

- Prevents simultaneous contraction to allow ventricular filling.

15
Q

What is ventricular fibrillation?

A
  • Erratic heart rhythm with no communication between AV node and ventricles. Heart shimmers, no output or contraction.
16
Q

Describe the general structure of arteries.

A
1- Tunica intima
   - Endothelium
   - Subendothelial layer
- Internal elastic lamina
2- Tunica media
- External elastic lamina
3- Tunica adventitia
17
Q

Describe the general structure of veins.

A
1- Tunica intima
   - Endothelium
   - Subendothelial layer
2- Tunica media
3- Tunica adventitia
18
Q

Which blood vessel gives rise to the major arteries?

A

The aortic arch. Gives rise to:

  • right and left coronary arteries (supplying heart)
  • subclavian arteries, common carotid arteries and brachiocephalic trunk (supplying body)
19
Q

Describe the blood flow/pressure in elastic arteries (aorta).

A
  • Systole: left ventricle contraction causes blood pressure in aorta to rise to approx. 120 mmHg (systolic pressure) - walls of elastic aorta and other elastic arteries stretch.
  • Diastole: aortic semilunar valve closes causing aortic pressure to drop to 70-80 mmHg (diastolic pressure) - walls of aorta recoil, maintaining pressure of the blood and moving it towards the small vessels.
20
Q

Why are elastic arteries called capacitator vessels?

A
  • Act as pressure reservoirs: act as auxiliary pumps during diastole, giving back the elastic energy stored during systole.
21
Q

How does the structure of elastic arteries support their function?

A

Tunica media is composed of elastin fibres, collagen and matrix produced by smooth muscle cells as need to be elastic (stretch and recoil).

22
Q

What is an aneurysm and where is the most common site for this to occur?

A
  • Dilatation of a blood vessel.

- The infrarenal abdominal aorta due to the reduced presence of elastin fibres.