12.12 Mass transport in humans

Question 1

Function of the heart

Answer 1

Pump blood around the body

Question 2

Heart cells

Answer 2

Cardiomyocytes

Question 3

What does deoxygenated blood return to the heart in?

Answer 3

Vena (vein) into right atrium

Question 4

Direction of blood flow through heart

Answer 4

Deoxygenated blood return to right atrium via vena
Passes through atria-ventricular valve into right ventricle and out via semi lunar valve into pulmonary artery
Blood passes through the lungs, returns to left atrium via pulmonary vein
Passes through atrio-ventricular valve into left ventricle
Through semi lunar valve into aorta

Question 5

Function of right atrium

Answer 5

Vena cava brings blood from body

Question 6

Function of right ventricle

Answer 6

Pulmonary artery takes blood to the lungs

Question 7

Function of left atrium

Answer 7

Pulmonary vein brings blood from the lungs

Question 8

Function of left ventricle

Answer 8

Aorta takes blood got body

Question 9

Pressure definition

Answer 9

The amount of force acting on a surface

Question 10

Systole definition

Answer 10

Contraction of heart muscle

Question 11

Diastole definition

Answer 11

Heart muscle relaxed

Question 12

Cardiac cycle

Answer 12

Arterial systole
Ventricular systole
Diastole

Question 13

Blood enters atrium

Answer 13

Blood volume increases pressure in atrium
Pressure in atrium greater than ventricle
Atrio ventricular valve opens

Question 14

Atrium muscles contract

Answer 14

Further increases pressure
Remaining blood forced into ventricle

Question 15

Blood enters ventricle

Answer 15

Increases pressure in ventricle due to volume of blood
Pressure in ventricle greater than atrium
Atrio ventricular valve closes

Question 16

Ventricle muscles contract

Answer 16

Further increases pressure in ventricle until greater than aorta
Semi lunar valve opens

Question 17

Blood enters aorta

Answer 17

Blood is pumped to body (left) or lungs (right)

Question 18

Ventricle muscles relax

Answer 18

Pressure in ventricle less than aorta
Semi lunar valve closes

Question 19

Blood enters atrium

Answer 19

Blood volume increases pressure in atrium

Question 20

What chambers does the blood flow through the heart?

Answer 20

Blood enters atrium
Atrium muscles contract
Blood enters ventricle
Ventricle muscles contract
Blood enters aorta
Ventricle muscles relax
Blood enters atrium

Question 21

Which heart valves ensure blood flow isn in one direction?

Answer 21

Atrio-ventricular
Semi-lunar

Question 22

Atrioventricular valves open and closed

Answer 22

Open: Greater pressure in atria than ventricles
Closed:Greater pressure in ventricles than atria

Question 23

Semi-lunar valves open and closed

Answer 23

Open: Greater pressure in ventricles than arteries
Closed: Greater pressure in arteries than ventricles

Question 24

What makes sure the valves only open open way?

Answer 24

Tendons that anchor the valves (heartstrings)

Question 25

Cardiac output equation

Answer 25

CO=SVxHR Cardiac output = Stroke volume x Heart rate

Question 26

Stroke volume definition

Answer 26

Volume of blood expelled from the left ventricle in one cardiac cycle

Question 27

Heart rate definition

Answer 27

Number of cardiac cycles per minute

Question 28

Cardiac output definition

Answer 28

Volume of blood expelled from the left ventricle per minute

Question 29

What are the two most common causes of blockage to the coronary arteries?

Answer 29

Atherosclerosis Thrombosis

Question 30

What is the deposit of fatty acid in the coronary arteries called?

Answer 30

Atheroma

Question 31

Risk factors of coronary heart disease

Answer 31

High cholesterol diet High lipid diet Smoking Lack of exercise Causes: High blood pressure Increase in blood toxins Increase cholesterol levels in the blood Leads to: Damage to the endothelium wall Increase in lipid uptake

Question 32

Risk factor definition

Answer 32

Any factor which increases a persons chances of developing a disease

Question 33

What are the risk factors for CHD?

Answer 33

Age Gender Genetic factors Smoking Stress High lipid/cholesterol diet

Question 34

Why is age a CHD risk factor?

Answer 34

Due to a gradual deposit over time

Question 35

Why is gender a CHD risk factor?

Answer 35

Men are at more risk until middle age, then the risk is similar, due to the protective effect of oestrogen in women up to menopause

Question 36

Why are genetic factors a CHD risk factor?

Answer 36

Due to genes but also linked to people in the same family have similar lifestyles

Question 37

Why is smoking a CHD risk factor?

Answer 37

Nicotine is a vasoconstrictor which increases blood pressure, damaging endothelium. Smoking increases levels of cholesterol in blood Chemicals in cigarette smoke increases chance of developing thrombosis

Question 38

Why is stress a CHD risk factor?

Answer 38

Stressful lifestyles increase blood pressure

Question 39

Why is a high lipid/cholesterol diet a CHD risk factor?

Answer 39

Lipoproteins made in the lover form fats, cholesterol and proteins Cholesterol transported in the blood to damages areas with LDL Greater concentration of cholesterol, greater levels of LDL