3.3.4.1 Mass Transport in animals Flashcards Preview

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Flashcards in 3.3.4.1 Mass Transport in animals Deck (33)
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1
Q

Give some ways in which cardiac output is increased during vigorous exercise

A

Increased heart rate
Increased stroke volume
More adrenaline

2
Q

Explain what causes the blood pressure in the aorta to be higher than the blood pressure in the pulmonary artery

A

Left ventricle has thicker muscle

3
Q

Explain why a vein is described as an organ

A

It’s made of tissue

4
Q

Explain how the elastic tissue helps even out the pressure of the blood going through the arteries

A

Elastic tissue stretches when pressure gets too high

And recoils when pressure returns to normal

5
Q

The Cardiac cycle is controlled by the sinoatrial node (SAN) and the atrioventricular node (AVN). Describe how

A

The SAN initiates heartbeat
SAN sends waves of electricity across the atria causing atrial contraction
AVN delays to allow the atria to empty (and the ventricles to fill up) before the ventricles contract
AVN them sends a wave of electrical impulses down “bundle of His”
This causes the ventricles to contract from the base up (ventricular systole)

6
Q

An increase in respiration in the tissues of a mammal affects the oxygen dissociation curve of haemoglobin. Describe and explain how

A

Increase in carbon dioxide so the curve moves to the right

7
Q

People living in high altitudes have more red blood cells than people living at sea level l. Explain the advantage of this to people living at high altitudes

A

They will have more haemoglobin so can pick up more oxygen in the lungs

8
Q

Explain how having a low protein diet can result in the accumulation of tissue fluid

A

The water potential in the capillaries is not as low as it is in a protein rich diet
So more tissue fluid is formed at the arteriole end and less water is absorbed into the capillaries (at the venular end) by osmosis

9
Q

Explain ways in which the composition of tissue fluid differs from that of blood plasma

A

Tissue fluid contains little protein (as protein molecules are too large to pass through the capillary walls)
Tissue fluid contains less glucose as some of the glucose will have entered tissue cells

10
Q

Explain how fluids leave the capillaries at the arterial end

A

Hydrostatic pressure is greater than the osmotic effect so molecules are forced out

11
Q

Explain the meaning of the term atheroma

A

A fatty deposit forming in cells in the artery wall

12
Q

Explain why atheroma may lead to a blood clot

A

The fatty substance narrows the arteries

This results in an uneven flow of blood and can damage the endothelium

13
Q

Explain how the shape of a red blood cell allows it to take up a large amount of oxygen in a short time

A

It’s has a large surface area to volume ratio for diffusion

It is flat and thin so oxygen can reach all haemoglobin rapidly

14
Q

Describe how the increase in pressure of the blood in the arteries is a result from the events in the cardiac cycle

A

Increase in blood pressure caused by blood leaving the heart and entering the arteries
This is a result of ventricular systole

15
Q

Describe the part played by proteins in the plasma in returning tissue fluid to the capillaries

A

A high concentration of protein produces a lower water potential so water moves into the capillaries by osmosis

16
Q

Give some changes that will increase blood flow through the skeletal muscles

A

Increase in heart rate
Increased volume of blood pumped per beat
Dilation of vessels
Increased blood pressure

17
Q

Explain some advantages of increasing the blood flow through the skeletal muscles during exercise

A

More oxygen supplied for respiration so less anaerobic respiration
More glucose supplies for respiration
Carbo dioxide rapidly removed from respiring cells

18
Q

Describe how the regular contractions of the atria and the ventricles is initiated and coordinated by the heart itself

A

Cardiac muscle is myogenic
SAN sends a wave of electrical impulses across the atria
This initiates the contraction of the atria
AVN then spreads an electrical signal across the ventricles causing the ventricles to contract once they have filled with blood

19
Q

During exercise the oxygen dissociation curve moves tot the right. Explain the advantage of this

A

Haemoglobin releases more oxygen for respiration

20
Q

Describe how haemoglobin loads and unloads oxygen in the body

A

Haemoglobin picks up oxygen at high partial pressures e.g. In the lungs
Haemoglobin unloads oxygen at low partial pressures e.g. In respiring tissues

21
Q

Explain how the structure of arterioles enables the regulation of blood flow to different parts of the body

A

Muscles in the walls for the arterioles contact increasing blood flow

22
Q

When is the arterial pressure at its maximum value?

A

When the ventricles are contracting

23
Q

If the oxygen dissociation curve is further to the left it means the haemoglobin has a _____________ affinity for oxygen

A

Greater

24
Q

If the oxygen dissociation curve is further to the right it means the haemoglobin has a _____________ affinity for oxygen

A

Lower

25
Q

the hydrostatic pressure falls from the arteriole end of the capillary to the venuole end - why?

A

loss of fluid/water

26
Q

give 2 ways the structure of the fishes gills are adapted for gas exchange

A

many lamellae/filaments so a large SA

thin so a short diffusion pathway

27
Q

How does the countercurrent flow in fish ensure max amount of oxygen passes into the blood flowing through the gills?

A
  1. water and blood flow opposite directions
  2. blood always meets water with a higher concentration of oxygen
  3. diffusion gradient maintained across the full length of the gill
28
Q

give 2 ways the aorta structure is suited to function

A
  1. Elastic tissue - stretch and recoil /spring back
  2. muscle layer for contraction
  3. Thick walls to resist pressure and stop it bursting
  4. smooth endothelium - reduces friction
  5. semi lunar valve - prevents back flow
29
Q

How is an insects tracheal system adapted for gas exchange?

A
  1. tracheoles thin walls SO short diffusion distance
  2. highly branched so short diffusion distance
  3. highly branched so a large surface area
  4. abdonimal pumping to move air SO maintains concentration gradient
30
Q

Role of the heart in TF formation?

A

contraction produces a high pressure

This forces WATER (and dissolve substances) out of the capillaries

31
Q

Blockage of lymphatic system could cause lymphodema - HOW?

A

prevents EXCESS TF from returning

32
Q

name the blood vessels that carry blood to the heart muscle

A

coronary arteries

33
Q

binding of one molecule of oxygen to Hb makes it easier for a second oxygen to bind - why?

A
  1. binding of the 1st changes to tertiary structure

2, uncovering 2nd binding site

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