Chapter 8: Heart and Lungs

Question 1

List the layers of the heart from the innermost to the outermost

Answer 1

Endocardium (lining of chambers)
Myocardium (muscle of heart)
Epicardium (thin protective covering)
pericardium (protective sac for heart)

Question 2

Briefly describe the passage of blood through the heart

Answer 2

Right side IN~>dOx from body
Right side OUT~>dOx to lungs
blood oxygenated in lungs
Left side IN~>Ox from lungs
Left side OUT~>Ox to body

Question 3

What are the major differences between veins and arteries?

Answer 3

Arteries: take blood away from the heart, stronger and thicker
Veins: bring blood to the heart, have valves to keep blood flowing and prevent back flow, less muscular

Question 4

This atrioventricular valve sits between the right atrium/ventricle

Answer 4

Tricuspid valve

Question 5

This atrioventricular valve sits between the left atrium/ventricle

Answer 5

Bicuspid/mitral valve

Question 6

This semilunar valve is responsible for blood leaving the right side of the heart

Answer 6

Pulmonary valve

Question 7

This semilunar valve is responsible for blood leaving the left side of the heart

Answer 7

Aortic valve

Question 8

What is the name of the heart’s natural pacemaker and where is it located?

Answer 8

The sinoatrial (SA) node. It sits in the wall of the right atrium

Question 9

Why does a heartbeat make 2 distinct thumps?

Answer 9

Signals from the SA node reach the atria first, therefore they pump slightly before the ventricles

Question 10

When the ventricles of the heart contract, it is called systole. When the heart relaxes, it is called diastole. With this in mind, how is blood pressure measured?

Answer 10

Systolic ~> 120 mm Hg
——————
Diastolic ~> 80 mm Hg

Question 11

What is the name for high blood pressure?

Answer 11

Hypertension

Question 12

What is cardiac output and how is it calculated?

Answer 12

Cardiac output is a measurement of how much blood the heart moves per minute. It is calculated by taking the amount of blood that comes out with every beat (stroke), and multiplying it with how many times the heart beats.
stroke volume x heart rate

Question 13

What is the name for the process of creating new red blood cells?

Answer 13

Erythropoiesis

Question 14

What are the 4 main components of blood? What is the most abundant cell type in blood?

Answer 14

Plasma
Platelets
White blood cells
Red blood cells
The most abundant cell type is RBCs, which make up a hematocrit (concentration of RBCs in the blood) of ~45%

Question 15

What is hemoglobin? What are reticulocytes?

Answer 15

Hemoglobin is a protein and iron molecule that is found in red blood cells. It what oxygen binds to when it is being transported by RBCs. Reticulocytes are immature RBCs that are created by erythropoietin in the bone marrow

Question 16

What role does CO2 play in the body?

Answer 16

CO2 helps regulate the body’s pH balance and ionic equilibrium (chloride shift)

Question 17

What is maximal aerobic power and how is it calculated?

Answer 17

Maximal aerobic power is measured by VO2 Max, which is the maximum volume of oxygen the body can use in a minute. It is calculated by taking the a-v O2 difference (the amount of oxygen extracted by the tissues) and multiplying it with the cardiac output
Cardiac output x a-v O2 diff. = VO2 Max

Question 18

What are 2 factors affecting oxygen uptake?

Answer 18

O2 EXTRACTION: the ability of the tissues to extract O2. The Bohr Effect describes how O2 is released from hemoglobin with high levels of CO2
CAPILLARIZATION: the number of capillaries in the tissue. This can be increased with training

Question 19

The respiratory system can be divided into 2 zones: the conduction zone and the respiratory zone. What makes up the respiratory zone?

Answer 19

The alveoli, which includes the alveolar duct, alveolar sac, and the alveolar capillaries

Question 20

Briefly describe inspiration and expiration

Answer 20

Inspiration: diaphragm and intercostal muscles contract, expanding the lungs and decreasing air pressure and pulling new air in
Expiration: muscles relax, lungs shrink, pushes air out

Question 21

True or false: in hot conditions, the heart rate increases and the stroke volume decreases

Answer 21

True

Question 22

What is peripheral vasoconstriction?

Answer 22

The body’s response to cold conditions where peripheral blood vessels constrict and keeping blood closer the rest of the body