AS PE Transport of Blood Gases

Question 0

What is systemic circulation?

Answer 0

Blood is ejected from the left ventricle through the aorta and transports oxygen rich blood to the body’s tissues. The blood is then returned to the heart via the vena cava

Question 1

What is pulmonary circulation?

Answer 1

Blood which is ejected from the right ventricle, through the pulmonary artery to the lungs to saturate the haemoglobin with oxygen. The blood is then transported through the pulmonary veins back to the left side of the heart

Question 2

Give 3 characteristics of arteries

Answer 2

Narrow lumen
Thick layer of elastic fibres
Thick outer wall to withstand high pressure

Question 3

What are the 5 different vessels which make up the transport system for the blood?

Answer 3

Arteries
Arterioles
Veins
Venules
Capillaries

Question 4

What is the term used to describe the process of sending more blood to the working muscles during exercise?

Answer 4

Redistribution of blood
Or
The vascular shunt

Question 5

When we exercise, skeletal muscles help compress veins and force blood back to the heart, what is this mechanism called?

Answer 5

Skeletal Muscle Pump

Question 6

What structures prevent the back flow of blood within the veins

Answer 6

Pocket valves

Question 7

Venous return during exercise is aided by pressure changes in the thoracic cavity (chest) resulting from an increase in the rate and depth of breathing. What is this mechanism called?

Answer 7

Respiratory pump

Question 8

What is blood pressure?

Answer 8

The force exerted by the blood on the walls of the blood vessels.

Question 9

State two variables which determine blood pressure

Answer 9

Cardiac output (Q) and Peripheral Resistance
PR x Q = Blood Pressure

Question 10

What 3 factors determine Peripheral Resistance?

Answer 10

Peripheral Resistance is determined by;
Viscosity of blood (thickness of the blood)
Vessel length
Vessel diameter

Question 11

The relative thickness of the blood and it’s resistance to flow is known as what?

Answer 11

Viscosity

Question 12

What is systolic pressure?

Answer 12

The force generated when the chambers of the heart contract.

Question 13

What is diastolic pressure?

Answer 13

The force generated when the chambers of the heart relax.

Question 14

What type of exercise causes the greatest increase in blood pressure, aerobic or anaerobic?

Answer 14

Anaerobic

Question 15

The total cross sectional area of the capillaries is greater than the aorta, true or false?

Answer 15

True. The blood is ‘spread out’ and this accounts for the low blood pressure in capillaries.

Question 16

Capillaries are the sites for gaseous exchange. How does the structure of the capillaries allow this?

Answer 16

Walls are one cell thick, this allows for a short diffusion pathway and an efficient exchange of O2 and CO2.

Question 17

What type of muscle is found in the walls of blood vessels?

Answer 17

Smooth muscle

Question 18

What structures regulate the flow of blood into the capillaries?

Answer 18

Pre-capillary sphincters

Question 19

The process of controlling diameter of arteries is known as venomotor control. True or false?

Answer 19

False. It is vasomotor control.

Question 20

What is the formula HbO2 better known as?

Answer 20

Oxyhaemoglobin.

Question 21

What is the Bohr Shift?

Answer 21

When the oxyhaemoglobin dissociation curve shifts to the RIGHT. Oxygen will dissociate (unload) from the haemoglobin more quickly to meet the demand at respiring skeletal muscles.

Question 22

During exercise, there is an increase in the A-VO2 diff. What does it stand for?

Answer 22

Arterio-venous oxygen difference - it is a measure of oxygen consumption. For SYSTEMIC circulation It shows that there is more oxygen in the arteries than in the veins, which is due to the uptake and use of oxygen by the respiring skeletal muscles.

Question 23

Which helps increase blood flow to the working muscles during exercise; vasodilation or vasoconstriction of the capillaries supplying the ‘non essential’ organs?

Answer 23

Vasoconstriction - the blood flow is partially shut off to organs such as the intestines to allow greater flow of blood to the respiring skeletal muscles.

Question 24

How is carbon dioxide transported from the muscles to the alveoli?

Answer 24

It is transported in the blood.
5% dissolves unchanged in the blood plasma.
10% combines with haemoglobin to form carbaminohaemoglobin.
85% is converted to bicarbonate in the blood.