Topic 6.2: The Blood System

Question 1

The Blood System and William Harvey (3)

Answer 1

a) Blood vessels connected by a single network
b) Unidirectional bloodflow
c) The heart is a central pump (arteries = from heart; veins = to heart)

Question 2

Further Discoveries of the Blood System

Answer 2

a) Arteries and veins are connected by capillaries

b) There is a separate circulation for the lungs

Question 3

Blood components

Answer 3

a) Red blood cells
b) White blood cells
c) Platelets
d) Plasma

Question 4

Material transported by the blood

Answer 4

a) Nutrients
b) Antibodies
c) CO2
d) Hormones
e) O2
f) Urea
g) Heat

Question 5

Blood vessels

Answer 5

a) Arteries
b) Veins
c) Capillaries

Question 6

Arteries

a) Function
b) Pressure
c) Lumen diameter
d) Wall thickness
e) Wall layers
f) Muscle & elastic fibers
g) Valves

Answer 6

a) Send blood away from heart
b) High
c) Narrow
d) Thick
e) 3x Tunica
f) Large amounts
g) No

Question 7

Veins

a) Function
b) Pressure
c) Lumen diameter
d) Wall thickness
e) Wall layers
f) Muscle & elastic fibers
g) Valves

Answer 7

a) Send blood to heart
b) Low
c) Wide
d) Thin
e) 3x Tunica
f) Small amounts
g) Yes

Question 8

Capillaries

a) Function
b) Pressure
c) Lumen diameter
d) Wall thickness
e) Wall layers
f) Muscle & elastic fibers
g) Valves

Answer 8

a) For material exchange with tissues
b) Low
c) Extremely narrow (one cell wide)
d) Extremely thin (single thick)
e) Tunica intima
f) None
g) No

Question 9

Heart structure

Answer 9

a) Right / Left atrium
b) Right / Left ventricle
c) Tricuspid valve
d) Bicuspid valve
e) Pulmonary valve
f) Aortic valve
g) Vena cava
h) Pulmonary artery
i) Pulmonary vein
j) Aorta

Question 10

Blood flow from the right side of the heart (3)

Answer 10

a) Deoxygenated blood (from tissues) enters right atrium via the vena cava
b) Blood in the right ventricle is pumped to lungs via the pulmonary artery
c) Gas exchange at the lungs (capillaries ↔ alveoli) oxygenates the blood

Question 11

Blood flow from the left side of the heart (3)

Answer 11

a) Oxygenated blood (from lungs) enters the atrium via the pulmonary vein
b) Blood in the left ventricle is pumped to the body tissues via the aorta.
c) Material exchange occurs at the respiring tissue (deoxygenates the blood)

Question 12

How is the contraction in the heart created?

Answer 12

Myogenic, initiated by the heart

Question 13

Mechanism of Heartbeat by SA node (4)

Answer 13

a) Electrical signals are initiated by SA node in the right atrium
b) This pacemaker stimulates the atria to contract and also relay signals to AV node
c) The AV node sends signals to ventricular Purkinje fibers (via a Bundle of His within the wall of the septum)
d) The Purkinje fibers cause the ventricular walls to contract

Question 14

Rhythm of the SA node

Answer 14

60 - 100 bpm

Question 15

Methods used to regulate the heart rate (2)

Answer 15

a) Medulla due to changes in CO2 and O2 levels (pH / Pressure)
b) Epinephrine increases heart rate to prepare for vigorous physical activity

Question 16

How does the medulla regulate the heartbeat?

Answer 16

a) Sympathetic nerves release noradrenaline (⇑ heart rate)

b) Parasympathetic nerves release acetylcholine (⇓ heart rate)

Question 17

Systole phase of the cardiac cycle

Answer 17

a) As atria contract, atrial pressure exceeds ventricular pressure
b) As ventricles contract, ventricular pressure exceeds atrial pressure
c) Pressure builds until the ventricular pressure exceeds the arterial pressure
d) Semilunar valves open and blood flows into arteries

Question 18

Diastole phase of the cardiac cycle

Answer 18

a) As blood flows into arteries, ventricular pressure drops.
b) Backflow closes semilunar valves
c) When ventricular pressure drops below atrial pressure, the AV valves open and cardiac cycle is repeated.

Question 19

Coronary arteries definition

Answer 19

Blood vessels that surround the heart and nourish the cardiac tissue to keep the heart working.

Question 20

Process of coronary occlusion

Answer 20

a) Vessels are damaged by cholesterol deposition (atherosclerosis)
b) The deposits reduce vessel diameter and increase blood pressure
c) The stress damages arterial walls (and is repaired with fibrous tissue)
d) The vessel wall loses elasticity and forms atherosclerotic plaques
e) If a plaque ruptures, blood clotting is triggered, forming a thrombus
f) If the thrombus blocks blood flow, a myocardial infarction results

Question 21

Consequences of coronary occlusion

Answer 21

a) If coronary arteries become occluded, the region of heart tissue nourished by the blocked artery die.
b) Blood pumped through the heart is at high pressure and cannot supply O2 and nutrients to the heart

Question 22

Risk factor for coronary occlusion

Answer 22

a) Age
b) Genetics
c) Obesity
d) Diet
e) Exercise
f) Sex
g) Smoking