3 Substance exchange- Mass transport (animals) Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

What is haemoglobin and its function?

A

Globular protein with a quaternary structure (4 polypeptide chains) found in red blood cells
Carries oxygen from lungs around the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is dissociation?

A

When red blood cells reach tissues in the body (e.g. muscle cells), O2 is released from oxyhaemoglobin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are haem groups?

A

Each polypeptide chain in a haemoglobin molecule has a haem group- a prosthetic group attached to the protein. These contain iron (what makes haemoglobin red)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How do oxygen and haemoglobin bind?

A

-Haemoglobin has a high affinity (attraction) for oxygen
-When red blood cells reach lungs, O2 diffuses into them- binding to haemoglobin. 4 oxygen molecules bind to one haemoglobin due to the haem groups
-Oxygen + haemoglobin = oxyhaemoglobin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is (pO2) partial pressure?

A

-Concentration of oxygen in the cells
-Important in determining whether oxygen binds to haemoglobin
-Determines affinity of haemoglobin for oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What happens when partial pressures of oxygen are high/low?

A

High- haemoglobin has a high affinity for oxygen, binds to haemoglobin
Low- haemoglobin has a low affinity for oxygen, dissociates from haemoglobin
Percentage saturation is low as oxygen dissociates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does the effect of pO2 on the affinity of haemoglobin allow?

A

Allows oxygen to be transported from lungs (where there’s lots of oxygen) to respiring tissues (where oxygen is limited). So, it travels to the cells which need it the most

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What effect does high altitude have on haemoglobin?

A

-Haemoglobin has a high affinity for oxygen, birds also possess this
-Advantage as air at higher altitudes has a much lower partial pressure than sea level

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What effect does high metabolic rate have on haemglobin?

A

-Haemoglobin that dissociates with oxygen very easily
-Oxygen can then be quickly and easily supplied to the cells for use in respiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What happens as partial pressure increases?

A

-Affinity of haemoglobin for oxygen increases slightly
-When first O2 molecule binds, the protein undergo a conformational change
-This allows the other O2 molecules to bind more easily and percentage saturation of haemoglobin increased quickly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What causes a plateau in percentage saturation?

A

As more O2 molecules bind to haemoglobin, it becomes more difficult for them to bind and percentage saturation of haemoglobin plateaus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What creates an S-shaped curve?

A

-Increasing affinity of haemoglobin with increasing partial pressure of oxygen
-This is called the dissociation curve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the Bohr effect?

A

The partial pressure of carbon dioxide influencing the affinity of haemoglobin for oxygen
High pCO2- Rate of oxygen dissociation decreases, as respiring cells use oxygen in respiration, making CO2. So, they have a low pO2 and high pCO2.
Increased dissociation =shift in oxyhaemoglobin curve to right - oxygen will dissociate from haemoglobin at a lower pO2 than normal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the circulatory system?

A

Specialised system for transporting nutrients throughout their bodies + removing waste products, that multicellular organisms require

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the role of the heart in the circulatory system?

A

-Centre of the circulatory system
-Double system- blood flows through the heart twice in one circuit
-Deoxygenated blood pumped to lungs
-Oxygenated blood pumped around body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the role of the coronary arteries in the circulatory system?

A

Heart= muscle that’s constantly contracting and relaxing, so needs a constant supply of oxygen for respiration
Coronary arteries supply blood to the heart

17
Q

What are the roles of the pulmonary artery and vein?

A

Artery- deoxygenated blood pumped out of heart to lungs via here
Oxygen diffuses into deoxygenated blood in lungs, becomes oxygenated
Vein- oxygenated blood flows into heart from lungs via here

18
Q

What are the roles of the aorta & vena cava?

A

Aorta- oxygenated blood pumped out of heart around body via here. Blood is very high pressure to ensure blood can be pumped to all tissues in body
Oxygen dissociates with blood at respiring cells in body and blood becomes deoxygenated
Vena Cava- deoxygenated blood flows into heart from body via here

19
Q

What are the roles of the renal vein & artery?

A

Oxygenated blood flows out of aorta, to the kidneys
Artery- oxygenated blood enters the kidney via here
Oxygen diffuses out of blood to be used in kidney cells, blood becomes deoxygenated
Vein- deoxygenated blood flows out of kidneys via here

20
Q

What is the role of the right atrium?

A

-Deoxygenated blood flows into right atrium from body
-Vena cava= pumps deoxygenated blood into right atrium (first chamber it flows through)

21
Q

What is the role of the right ventricle?

A

-Deoxygenated blood flows into here when walls of right atrium contract
-Atrioventricular valves prevent blood from flowing back into atria ventricles
-Blood pumped out of pulmonary artery to the lungs when the walls of right ventricle contract
-Semi-lunar valves prevent blood from flowing back into right ventricle from pulmonary artery

22
Q

What are the roles of the left atrium and ventricle?

A

-Oxygenated blood flows into left atrium from lungs
-Pulmonary vein pumps oxygenated blood into left atrium
-Oxygenated blood flows flows into left ventricle when walls of left atrium contract
-Atrioventricular valves prevent blood from flowing back into atria from ventricles
-Walls of left ventricle are thicker than right, as they transport blood all around the body

23
Q

What is the role of the aorta?

A

-When left ventricle contracts, blood is pumped out of heart to rest of body
-Oxygenated blood leaves heart through aorta
-Semi lunar valves prevent blood from flowing back into left ventricle from aorta

24
Q

What is the cardiac cycle?

A

The flow of blood from the lungs to the heart and around the body
Continuous relaxing and contracting of the heart

25
Q

What happens during the first step of the cardiac cycle?

A

Atrial contraction

-Blood from lungs flows into left atrium and from body into right atrium simultaneously
-Atria contract and pressure increases (volume decreases)
-Blood in atria is forced into ventricles
-Ventricles are relaxed, fill with blood (volume increases)

26
Q

What happens during the second step of the cardiac cycle?

A

Ventricular contraction

-Atria relax, (volume increases) ventricles contract (volume decreases)
-Pressure in ventricles now increases
-Pressure shuts atrioventricular valves so blood doesn’t flow back into atria
-Blood in ventricles is forced out, out from the heart through pulmonary artery/aorta

27
Q

What happens during the third stage of the cardiac cycle?

A

Relaxation

-Blood in pulmonary artery & aorta at high pressure; this shuts atrioventricular valves so blood doesn’t flow back into ventricles
-Both ventricles (volume increase ) & atria relax (volume slight decrease), atrioventricular valves reopen
-Blood flows into ventricles and atria from pulmonary vein & vena cava
-Cycle continues

28
Q

What is the structure and function of the arteries?

A

-Transport blood away from heart, to organs
-Walls have thick layers of muscle; maintain high pressure so blood can be pumped around body
-Can stretch due to elastic fibres in artery wall
-Endothelium folded; allows arteries to stretch

29
Q

What is the structure and function of the arterioles?

A

-Arteries reach organ and split into smaller vessels, arterioles
-Smaller, Thinner walls, less elastic tissue
-Control direction of blood flow; contracting restricts blood flow and relaxing allows blood to flow

30
Q

What is the structure and function of veins?

A

-Transport blood back to heart
-Lumen wider than arteries, allows blood to flow at low pressure
-Thin muscle walls & elastic tissue in walls
-Have valves throughout to prevent backward flow of blood, so it reaches heart

31
Q

What is the structure and function of capillaries?

A

-Small vessels (allow only 1 RBC at a time), branch from arterioles into millions of capillaries; form networks (capillary beds) around body cells, creates large surface area for exchange of substances between bloodstream and tissues
-Blood pressure very low
-Fenestration; gaps to allow faster diffusion
-Thin walls (one cell thick, endothelium), pass close to body cells to allow exchange between blood + organs. Diffusion distance of substances (e.g. oxygen) from bloodstream to tissues very short; allows efficient exchange)

32
Q

What is tissue fluid?

A

Combination of water, oxygen and nutrients- surrounds cells in body
Substances carried in capillaries are transported to cells via tissue fluid

33
Q

How is tissue fluid formed and transported?

A

-There’s high pressure in capillaries at capillary bed entrance, creating a pressure gradient between the outside and the inside
-Fluid in capillaries flows down pressure gradient into surrounding space (pressure filtration), this creates tissue fluid- can now diffuse/be transported into cells
-Pressure inside capillaries decreases due to movement of fluid out of capillaries; pressure at exit is lower than entrance of capillary bed
-Fluid moves out of capillaries, plasma proteins remain inside; concentration increases and water potential decreases, gradient established. Water diffuses via osmosis back into capillaries from tissue fluid
-Excess tissue fluid flows into lymphatic system (recycles it into bloodstream)