Cardiovascular System

Question 1

What are the three principal components of the cardiovascular circulatory system?

Answer 1

Heart, Blood and Blood Vessels

Question 2

What is the function of the cardiovascular system impacted by?

Answer 2

The Endocrine system, nervous system and kidneys

Question 3

What is haematocrit?

Answer 3

Percent of blood volume that is erythrocytes

Question 4

what is bulk flow?

Answer 4

Rapid flow of blood throughout the body

Question 5

What are the two ‘loops’ of the cardiovascular system?

Answer 5

• Systemic

- Pulmonary

Question 6

What does the systemic loop of the cardiovascular system do?

Answer 6

Carries blood from the left ventricle via the aorta, systemic arteries and then microcirculation to the major parts of the body and back to the heart by the vena cava

Question 7

What does the pulmonary loop of the cardiovascular system do?

Answer 7

Carries oxygen poor blood from the right ventricle via the pulmonary trunk, splitting into the pulmonary arteries

Question 8

Describe the pathway that blood goes from leaving the heart via the systemic loop, coming back to the heart, then leaving via the pulmonary loop and back

Answer 8

• Left Ventricle
• Aorta
• Arteries
• Arterioles
• Capillaries
• Venules
• Veins
• Vena Cava
• Right Atrium
• Right Ventricle
• Pulmonary Trunk
• Pulmonary Arteries
• Pulmonary Arterioles
• Pulmonary Capillaries
• Pulmonary Venules
• Pulmonary Veins
• Left Atrium

Question 9

What is blood pressure measured in?

Answer 9

mm Hg

Question 10

What is blood flow measured in?

Answer 10

mL/min

Question 11

What is resistance, and what is its relationship to blood flow?

Answer 11

Resistance is the measure of friction that impedes flow. Has a negative proportional relationship with flow

Question 12

What three things contribute to resistance?

Answer 12

• Blood viscosity
• Total blood vessel length
• Blood vessel diameter

Question 13

what factors affect blood pressure

Answer 13

Volume of blood

Compliance of blood vessels

Question 14

What is the maximal arterial pressure reached during peak ventricular ejection referred to as?

Answer 14

Systolic Blood pressure

Question 15

What is the minimal arterial pressure reached just before ventricular ejection referred to as?

Answer 15

Diastolic blood pressure

Question 16

What is the term used to describe the difference between Systolic and diastolic bp?

Answer 16

Pulse pressure

Question 17

What is the function of arterioles regulated by?

Answer 17

Neural, hormonal and local chemicals

Question 18

what are the two functions of arterioles?

Answer 18

• Constriction, to divert blood away from tissues

- Dilation, to increase blood flow to tissues

Question 19

What changes are detected locally to cause active hyperaemia in an organ?

Answer 19

• Decreased O2 and increased CO2
• Increased K+
• Inreased NO2
• Increased H+
• Increased Adenosine

Question 20

What is reactive hyperaemia?

Answer 20

Huge increase in blood flow after complete occlusion

Question 21

What hormones are responsible for extrinsic control of arteriole resistance?

Answer 21

Epinephrine (dilates or constricts)
Angiotensin II (constricts)
Vasopressin (constricts)

Question 22

What extrinsic factors apart from hormones can affect arteriole resistance?

Answer 22

Sympathetic nervous system action

Question 23

What are the three types of capillary?

Answer 23

• Continuous
• Fenestrated
• Sinsuoidal

Question 24

What are continuous capillaries?

Answer 24

• Found in skin and muscle.
• Most common
• Have tight junctions

Question 25

What are fenestrated capillaries?

Answer 25

More permeable, found in intestines and hormone producing tissues

Question 26

What are sinusoidal capillaries?

Answer 26

Incomplete basement membrane, Found in liver, bone marrow and lymphoid tissue

Question 27

What is the process of capillary growth called?

Answer 27

Angiogenesis

Question 28

What are the endothelial cells of the capillary wall separated by?

Answer 28

Water filled Intercellular clefts

Question 29

What does blood enter capillaries via?

Answer 29

Metarterioles?

Question 30

What is at the boundary between metarterioles and capillaries?

Answer 30

Precapillary sphincters

Question 31

What is a benefit of the slow movement of blood through the capillaries?

Answer 31

Maximises time for substance exchange

Question 32

What are the three mechanisms allowing substance exchange between the plasma and ISF?

Answer 32

• Diffusion
• Vesicle transport
• Bulk flow

Question 33

What are the two major functions of veins?

Answer 33

• Serve as low pressure conduits to return blood to heart

- Maintain peripheral venous pressure

Question 34

What are the factors determining venous pressure?

Answer 34

• Amount of blood in veins

- Compliance of walls

Question 35

What three mechanisms propagate blood flow through the veins?

Answer 35

• Norepinephrine facilitated smooth muscle contraction
• skeletal muscle pump
• respiratory pump

Question 36

What does the sympathetic nervous system innverate in the cardiac cycle, and via what neurotransmitter?

Answer 36

Entire heart muscle and node cells, via norepinephrine

Question 37

What does the parasympathetic nervous stem innverate in the cardiac cycle, and via what neurotransmitter?

Answer 37

The node cells, via acetylcholine

Question 38

Explain the pathway that an action potential takes in the cardiac cycle, starting at the Sinoatrial Node

Answer 38

• SA Node
• Atrial muscle
• AV Node
• Bundle of HIS
• Left/Right bundle branch
• Left/right Purkinje fibres
• Ventricular muscle cells

Question 39

What type of ion channels cause depolarisation of myocardial cells?

Answer 39

Voltage Gated L-type CA2+ channels