Transport in Animals

Question 1

suggest and explain what effect tachycardia might have on blood flow from the heart?

Answer 1

• The heart would pump less blood and less blood would go around the body.
• The ventricles do not have time to fill before contracting.

Question 2

suggest why the foramen ovale is open in the fetus before birth. it is closed when we grow up.

Answer 2

• The fetus is not breathing so little blood goes into the lungs.
• The blood in the lungs is not oxygenated.

Question 3

difference between the fetal hemoglobin and adult hemoglobin.

Answer 3

• contains gamma sub unites

This creates a higher affinity for oxygen.

Question 4

why does tissue fluid not contain erythrocytes?

Answer 4

It is too big to pass through the pores of the endothelium cells.

Question 5

Role of hemoglobin in transporting oxygen around the body?

Answer 5

Hb has a higher affinity in the lungs to bind to oxygen.

It binds to oxygen to form oxyhemoglobin. It then unloads where pp is lower.

Question 6

describe how the hydrogen carbonate ions are produced in the erythrocytes?

Answer 6

• CO2 enters the erythrocytes.
• Produced by CO2 binding with water to form carbonic anhydrase.
• this then disassociates to form H+ ions and hydrogen carbonate ions.

Question 7

Why does the Bohr Effect occur?

Answer 7

• Oxygen has a low affinity to bind to hb. reduces the affinity of hb for oxygen.
• it laters the shape of hb.
• it provides a buffering effect.
  formation of haemoglobonic acid. HHB.

Question 8

State the definition of health.

Answer 8

This is when a person has a good balance of physical and mental wellbeing, this is due to an absence fo disease.

Question 9

Describe how components of tobacco smoke can affect the cardiovascular system of smokers. (7 marks)

Answer 9

• nicotine is inhaled
• this increases the stickiness of platelets
• this forms blood clots and restricts the blood flow in arteries
• reduced blood flow
• carbon monoxide combines with hb permanently
• this reduces the carrying capacity of the blood
• increased heart rate
• damage to blood vessels
• this can lead to a heart attack or a stroke.

Question 10

why does the fetal hb curve to the left of the adult hb?

Answer 10

because it has a higher affinity to O2 as is in the placenta and low pp for O2. This means that it is able to take up oxygen in the placenta at low pp.

Question 11

suggests why treatments of using fetal hb against sickle anemia might be beneficial?

Answer 11

it has a higher affinity for o2 than sickle hb when there is a low affinity for oxygen.
- The red blood cells do not change shape.

Question 12

why is lignin essential in the wall of xylem vessels?

Answer 12

Provides strength and support. It prevents the tubes from collapsing and creates a hollow tube.

Question 13

Why is cartilage essential in the trachea?

Answer 13

provides strength and stops it from collapsing when you do inspiration. The volume of the chest cavity increases.

Question 14

pressure fluctuates as blood flows along the aorta. What causes this fluctuation?

Answer 14

• this is due to the contraction of the left ventricle leading to an increase in pressure.

Question 15

the number of fluctuations per min?

Answer 15

Heart Rate

Question 16

explain what causes the overall change in pressure as blood flows from the aorta to the arteries and to the capillaries.

Answer 16

• blood flows into larger vessels

- the sectional area of the arteries is greater than the aorta

Question 17

why is it important that blood pressure changes when flowing from the aorta to the capillaries?

Answer 17

The capillary wall is only one cell thick therefore it can damage the capillary walls.

Question 18

two advantages of keeping blood inside vessels?

Answer 18

maintain high blood pressure and blood flow to be directed.

Question 19

describe and explain how the walls of an artery withstand and maintain high hydrostatic pressure.

Answer 19

withstand pressure:

• thick walls
• collagen
• folded endothelium

maintain pressure:

• elastic tissue to cause recoil
• smooth muscle
• narrow lumen

Question 20

explain why the walls of the left ventricle are thicker than the walls of the left atrium:

Answer 20

the left ventricle pumps blood out to the rest of the body so a larger distance. it needs to push blood against a greater resistance so it needs to create a higher pressure.

Question 21

how does pressure changes in the heart bring about the closure of the AV valves?

Answer 21

• higher pressure in the ventricles as it contracts. There is a higher pressure than the arterials.

Question 22

state two reasons why the blood smear has been stained?

Answer 22

• we can now see red blood cells and white blood cells

- creates a contrast so we can see the cell.

Question 23

why is the fetal hemoglobin curve to the left of the adult hemoglobin curve?

Answer 23

• fetal hemoglobin has a higher affinity (for oxygen) ( than adult hemoglobin)
  -(fetal Hb) takes up oxygen in low(er) partial pressure of oxygen
• placenta has a low partial pressure of oxygen
  -at a low partial pressure of oxygen / in the placenta,
  adult (oxy) hemoglobin will dissociate

Question 24

benefits of the Bohr shift:

Answer 24

more CO2 produced so more O2 relased.