Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology > Transport in animals > Flashcards

Transport in animals Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

What factors affect the need for a transport system?

A

Size,
SA:V ratio
Level of metabolic activity

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

What are common features of an efficient transport system?

A

Fluid medium to transport nutrients and waste products
Pump to create needed pressure for circulation of fluid
Exchange surfaces - enter/exit medium.

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

What is an open circulatory system?

A

A circulatory system in which the blood is not held in vessels.

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

What can efficient transport systems also include?

A

Vessels/tubes to carry the transport medium
2 circuits to deliver oxygen and exchange gases.

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

What are disadvantages of an open circulatory system?

A

Low blood pressure - flows slowly.
Circulation affected by body movements.

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

What are the advantages of a closed circulatory system?

A
  • Blood is under higher pressure
  • Oxygen and nutrients are delivered faster to tissues
  • CO2 and waste products are removed faster
  • Transport not dependent on body movements.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is a single circulatory system?

A

The blood flows through the heart once for each circuit of the body at lower pressure.

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

How have fish adapted to having a single circulatory system?

A
  • Counter current flow maintains a large diffusion gradient for gas exchange - energy efficient.
  • Most fish are exothermic and water is thermally insulating - less energy needed to provide heat.

Blood pressure drops as it passes through capillaries in gills, so the rate oxygen and nutrients are delivered is limited.

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

What is a double circulatory system?

A

Blood flows through the heart twice for each circuit in the body.

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

What are the 2 separate circuits in a double system?

A
  • Pulmonary circuit - blood from heart to lungs for gas exchange then back.
  • Systemic circuit - blood from heart to rest of body.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the advantages of a double circulatory system?

A

Blood pumped at high pressure in systemic, low in pulmonary - prevents capillaries in lungs being damaged.
Blood flows faster to body.
Mammals are more active - energy for movement and for thermoregulation

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

What is blood for?

A
  • delivers oxygen and nutrients to respiring tissues
  • removes CO2 and waste products
  • carries hormones
  • distributes heat and warms extremities
  • blood plasma holds dissolved gases and provides fluid medium for blood cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Why are blood vessels important?

A

Pumped at high pressure, deliver nutrients and remove waste efficiently.
All lined with endothelium - single layer of cells (smooth) to reduce friction. Also lumen - where blood flows.

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

What is the structure and function of arteries?

A

Away from heart at high pressure - thick walls.
Narrow lumen to maintain pressure. Inner elastic tissue can stretch/recoil.
Middle layer is a thick layer of smooth muscle - vasoconstriction/dilation.
Outer layer is thick layer of collagen and elastic tissue - strength to withstand pressure.

Near the heart have more elastic tissue to maintain a smooth heart rate.

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

What is the structure and function of arterioles?

A

Similar to arteries, but smaller. Contraction of smooth muscle directs blood flow to divert flow to areas needing more oxygen.

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

What is the structure and function of capillaries?

A

Exchange of metabolic substances - efficiently.
Single celled layer of endothelium - reduced diffusion distance, so increased rate.
Leaky walls, gaps between endothelial cells allow blood plasma and dissolved substances to leave the blood.
Highly branched with large surface area.
Narrow lumen - RBC must squeeze against endothelium.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are venules?

A

No valves, deliver blood from capillary beds to veins.
Thin layers of muscle and elastic tissue outside endothelium.
Thin outer layer of collagen.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the structure and function of veins?

A

Low pressure blood back to the heart - wide lumen.
Valves so 1 way flow.
Contraction of skeletal muscle compresses veins.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is tissue fluid?

A

To exchange nutrients and gases between body cells and blood.
Contains same nutrients and gases as blood. No blood cells/proteins as too big.

20
Q

How is tissue fluid formed?

A
  1. Formed at arterial end of capillary bed (higher hydrostatic pressure)
  2. Forces fluid out through gaps into spaces surrounding cells –> tissue fluid.
  3. Cells take up O2 + nutrients and release metabolic waste by diffusion, facilitated diffusion across plasma membrane.
  4. Hydrostatic pressure at venule end is v low - some tissue fluid enters capillary so waste can enter blood.
  5. Water potential of blood plasma decreases.
  6. Differences in hydrostatic pressure and water potential allows water to re-enter and tissue fluid into capillaries.
21
Q

What is hydrostatic pressure?

A

The pressure a fluid exerts when pushing against the sides of a vessel/container

22
Q

What is oncotic pressure?

A

The pressure created by the osmotic effects of the solutes.

23
Q

What happens to any remaining tissue fluid?

A

Some enters lymphatic system to maintain internal fluid environment.
Lymph contains more lymphocytes - drain back into blood via subclavian vein in chest.

24
Q

How is a pressure created which pushes fluid out capillary at arteriole end and into venule end?

A

Oncotic pressure of blood pulls H2O back into blood.
Hydrostatic pressure of tissue fluid pushes back into capillaries, but oncotic pressure (negative) of it pulls water into tissue fluid.
At arteriole end, hydrostatic pressure of blood greater than tissue fluid. Tissue fluid forced out capillary.
At venule end, net hydrostatic pressure lower than net oncotic - tissue fluid forced into vessel.

If net pressure positive, fluid forced out capillaries (vice versa)

25
Q

What is the role of haemoglobin?

A

Transport oxygen in RBCs. Changing its shape, it changes its affinity for oxygen.

26
Q

What is the structure of haemoglobin?

A

Polypeptide chain and a ham group with Fe2+ ion.
1 O2 molecule can bind to each Fe2+.
Haem groups have high affinity for O2, but held within structure of protein, so it is difficult for oxygen to bind.

27
Q

What does haemoglobin saturation depend on?

A

Partial pressure of O2 (conc of O2 measured by relative pressure it contributed to a mixture of gases).
High pO2 - haemoglobin loads O2.

28
Q

What is the dissociation equation for haemoglobin?

A

O2 + haemoglobin -> oxyhaemoglobin (reversible)

29
Q

What is positive cooperativity?

A

The binding of the the 1st oxygen molecule makes the binding of the 2nd one easier.

30
Q

Explain the shape of the oxygen dissociation curve.

A

Shallow at low pO2.
As pO2 increases, diffusion gradient increases as 1 O2 associates with a haem group.
This greatly increases the affinity for oxygen - gradient steepens.
As haemoglobin is near full saturation, curve levels off.

31
Q

How is foetal haemoglobin different?

A

Higher affinity for oxygen, so curve is to the left. Must bind where oxygen affinity is lower so adult releases oxygen into fluid.

32
Q

How is carbon dioxide excreted?

A

Removed by blood to the lungs. Mostly as hydrogen carbonate ions in blood plasma.

33
Q

How are hydrogencarbonate ions formed?

A

CO2 diffuses into RBCs and combines with H2O –> carbonic acid. (catalysed by carbonic anhydrase).
Carbonic acid dissociates –> hydrogen carbonate ion + H+.
It diffuses out cell to blood.
Cl- diffuse in to balance charge = CHLORIDE SHIFT.
Haemoglobin acts as buffer –> haemoglobinic acid.

34
Q

What is the Bohr effect?

A

The effect that extra CO2 has on haemoglobin. Explains release of more o2 in areas of high CO2 conc.

35
Q

What are the functions and structures of the atria and ventricles?

A

Atria = thin walled chambers
Ventricles = thick walled chambers. Left is thicker.

36
Q

What are the 4 main blood vessels connecting the heart to the rest of the body?

A

Aorta - oxygenated blood from left ventricle to body
Vena cava - deoxygenated blood from body tissues
Pulmonary artery - deoxygenated blood to the lungs
Pulmonary vein - oxygenated blood back from the lungs

37
Q

What is cardiac muscle?

A

A specialised type of heart muscle, consisting of branched fibres separated by intercalated discs. Many mitochondria.
Is myogenic so can contract automatically.

38
Q

What are the stages of the cardiac cycle?

A

Atrial systole, ventricular systole, diastole.

39
Q

What happens during atrial systole?

A

The atria contract, decreasing their volume and increasing atrial pressure, forcing blood into ventricles.

40
Q

What happens during diastole?

A

Heart completely relaxed and blood returns to atria via pulmonary vein and vena cava. Pressure rises in atria as they fill, causing atrioventricular valves to open.

41
Q

What happens during ventricular systole?

A

After a short delay, the ventricle walls contract and force blood into aorta and pulmonary artery at high pressure. Atria begin to fill with blood.

42
Q

Explain what happens on a PQRS graph.

A
  1. Atrial systole generate a small increase in pressure
  2. During ventricular systole, pressure in ventricles exceeds that of atria + AV valves close
  3. When ventricular pressure higher than aorta/pulmonary artery, semilunar valves open
  4. In diastole, pressure higher in arteries than ventricles, forcing SL valves shut. (stops back flow).
43
Q

What happens during the pressure changes in blood vessels during the cardiac cycle?

A

Walls of arteries have thick layers to match pumping of heart.
Fluctuations become less dramatic as vessels become smaller - vanish by arterioles.
Blood pressure drops to almost 0 in capillary beds and stay low in veins.
- More time for substance exchange

44
Q

What is the sequence of events controlling basic heart rate?

A
  1. SAN electrical excitation contract atria
  2. Wave prevented by non conductive tissue
  3. Wave enters AVN - sends wave of excitation down Purkyne fibres (bundle of His)
  4. Causes ventricles to contract from bottom up
45
Q

Label a PQRS complex.

A

1st peak in ECG trace is excitation of atria = P wave
large peak = electrical stimulation of ventricles = QRS complex
last peak is diastole = T wave

46
Q

What are examples of abnormal heart rates?

A

Bradycardia - too slow
Tachycardia - too fast
Atrial fibrillation - atria beat faster than ventricles
Ectopia - ventricular beat too early (irregular).

Biology (32 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions