Introduction

Question 1

Why do we need a CVS?

Answer 1

all cells are metabolically active needing O2 and producing CO2. Diffusion too slow in large organisms to supply and remove gases and other products/waste

Question 2

What vessels supply the heart with its own blood supply?

Answer 2

Coronary Arteries

Question 3

What are capillaries composed of?

Answer 3

A single layer of endothelial cells surrounded by a basal lamina

Question 4

What factors affect diffusion?

Answer 4

Area available for exchange, diffusion resistance due to barriers/nature of the molecule/path length, concentration gradient

Question 5

what is the area of exchange between capillaries and tissues dependent on?

Answer 5

capillary density which correlates with the metabolism of the cells

Question 6

True or false, a substance will have a lower concentration in capillary blood than arterial blood usually? What does this depend on?

Answer 6

True. It depends on the rate of use by the tissues and blood flow through the bed (less flow and higher usage means more of a gradient).

Question 7

what does blood flow drive in the CVS?

Answer 7

O2 diffusion into the cells

Question 8

what is perfusion rate?

Answer 8

the rate of blood flow in vessels which much increase with more metabolically active tissues

Question 9

what are some important tissues that need a high perfusion rate?

Answer 9

Brain (constant), Heart (inc exercise), Skel musc (inc exercise), Kidneys (constant), gut (after meal)

Question 10

What is the average cardiac output of a 70kg male?

Answer 10

5 Litres per Minute which can increase to 25L/m

Question 11

What are the components of the pericardium

Answer 11

An outer fibrous layer, a parietal layer, a pericardial cavity and a visceral layer (epicardium)

Question 12

What is cardiac tamponade and how is it treated?

Answer 12

excess buildup of fluid in the pericardial cavity compressing the heart due to the inflexible fibrous layer (can’t diastolically fill). Treated by pericardiocentesis (removal of fluid with a needle)

Question 13

Why is the transverse pericardial sinus important

Answer 13

Allows the great vessels to be clamped off using an aortic cross clamp to perform a heart-lung bypass.

Question 14

What coronary artery is responsible for most MIs

Answer 14

Anterior Interventricular Artery

Question 15

During which phase do the coronary arteries fill

Answer 15

diastole

Question 16

where does the coronary sinus drain to?

Answer 16

Right atrium

Question 17

Coronary arteries have few anastomoses. What does this mean?

Answer 17

Have few collateral supply so are said to be end arteries

Question 18

What are C. Arteries prone to?

Answer 18

atheromas leading to plaques and thrombus

Question 19

What happens if a C. Artery is blocked

Answer 19

Leads to myocardial infarction