Circulation (Mon 16th)

Question 1

Why is the heart important?

Answer 1

For blood flow, nutrient transport, heat distribution, immunological defence, regulation of pH, osmolality and hormone transport.

Question 2

What is CO?

Answer 2

The volume of blood pumped per ventricle per minute is known as Cardiac Output (CO)
CO= SV x HR

Question 3

What is Venous Return?

Answer 3

VR: the amount of blood returning from the body to the right ventricle. Under steady state conditions VR = CO

Question 4

Pressure gradient?

Answer 4

Difference in pressure between aorta and vena cava

Question 5

Structure myocardial muscle cells?

Answer 5

-branched, single nucleus, attached to each other by specialised junctions called intercalated discs. Intercalated disks are made of 2 components: desmosome and gap junctions

Question 6

Pulmonary circulation?

Answer 6

Right side – pumps blood to the lungs, then to the left pump (pulmonary circulation).

Question 7

Systemic circulation?

Answer 7

Left side - pumps blood to the rest of the body and back to the right side (systemic circulation)

Question 8

How much blood does the heart have to pump?

Answer 8

Total volume of blood in your body is about 5.5 litres

Question 9

Functional role of vessels:

Answer 9

Functional role of vessels:
Distribution (arteries), arterioles (muscular walls for resistance, cause blood pressure to drop so capillaries can work) exchange (capillaries) and collection (veins)

Question 10

Average SV per ventricle?

Answer 10

75 mils

Question 11

Blood flow is proportional to pressure gradient means?

Answer 11

blood flow depends on intensity of pressure

Question 12

Specialisations to improve co-ordination: electrical conduction

Answer 12

intercalated discs- gap junctions and  desmosomes
 bundle of His - Purkinje fibres  
 annulus fibrosis (fibrous ring that electrically  insulates)