Brainscape's Knowledge GenomeTM

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


See full index

Bio Component 3 > Adaptations for Transport: Animals > Flashcards

Adaptations for Transport: Animals Flashcards

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

Describe an open circulatory system eg in insects

A
  • Fluid is pumped at a relatively low pressure from one main long, dorsal tube-shaped heart running the length of the body
  • Fluid called haemolymph bathes the tissues directly, enabling the exchange of substances
  • When the heart relaxes, the haemolymph is sucked slowly back to the heart
  • There is no respiratory pigment in haemolymph as oxygen diffuses directly to respiring cells through the tracheal system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Describe a closed circulatory system eg in mammals and fish

A
  • Blood circulates in a fully enclosed system of blood vessels
  • The heart is a muscular pump, pushing blood at high pressure and with a rapid flow rate
  • Organs are not in direct contact with the blood but are bathed in tissue fluid
  • Blood contains a respiratory pigment which carries oxygen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe a closed circulatory system eg in earthworms

A
  • Has dorsal and ventral vessels running the length of the body
  • These are connected by 5 pairs of pseudohearts
  • Blood contains a respiratory pigment which carries oxygen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Define single circulation and state where its found

A

Blood passes through the heart once in one complete circulation
Eg in fish

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

Define double circulation and state where its found

A

Blood passes through the heart twice in one complete circulation
Eg in mammals

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

What are the 2 circuits in double circulation?

A

Pulmonary circulation
Systemic circulation

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

Define the pulmonary circulation

A

All of the blood vessels involved in transporting blood from the heart to the lungs

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

Define the systemic circulation

A

All of the blood vessels involved in transporting blood from the heart to the rest of the body (excluding the lungs)

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

State and explain 3 advantages of a double circulation system over a single circulation system

A
  1. Maintains a high blood pressure in the systemic circulation - Increased rate of flow to the tissues = increased rate of oxygen supply to tissues for aerobic respiration
  2. Allows for a lower pressure in the pulmonary circulation - reduces the build up of tissue fluid in the lungs which would reduce the efficiency of gas exchange
  3. Rapid circulation in the systemic circuit
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Why is it important that the oxygenated and deoxygenated blood is kept separate in double circulation?

A

Maintains a steep concentration gradient for oxygen at the tissues and carbon dioxide in the lungs for efficient gas exchange

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

State the function of arteries

A

Transport blood away from the heart

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

State the function of veins

A

Transport blood to the heart

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

State the function of capillaries

A

Allow gas exchange of substances with body cells

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

Why is a layer of endothelium an important feature of blood vessels?

A

Smooth to reduce friction and minimal resistance to blood flow
In capillaries: short diffusion pathway as only 1 cell thick

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

What is the function of smooth muscle in arteries?

A
  • Withstands high blood pressure
  • Can constrict to restrict blood flow (vasoconstriction)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the function of elastic fibres in arteries?

A
  • Sustain pressure
  • Elastic recoil maintains blood pressure and aids pumping
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the function of collagen fibres?

A

They’re resistant to overstretching

18
Q

Describe the structure of veins

A
  • Wide diameter lumen to deliver large volumes of blood back to the heart
  • Thin walls as the pressure inside is much lower, due to further distance from the heart
  • Thin muscle layer in the walls can be compressed easily to allow contrasting skeletal muscle to squeeze veins and push blood upwards towards the heart
  • Pocket valves ensure that blood flows in one direction
19
Q

How do the valves in veins work?

A
  • Blood tries to flow back
  • Blood fills the pocket above the valve
  • This forces the valve shut
20
Q

Why do veins above the heart have no valves?

A

Gravity will draw blood down towards the heart

21
Q

Describe the structure of arteries

A
  • Thick layer of smooth muscle to withstand high blood pressure
  • Thick layer of elastic fibres for elastic recoil to maintain high blood pressure
22
Q

Describe the structure of capillaries

A
  • Walls are one cell thick, some have pores in their walls
  • Walls are permeable to water and dissolved substances eg glucose, amino acids, urea, oxygen and carbon dioxide
  • Thin capillary walls allow for a more efficient exchange of materials and gases as there is a shorter diffusion pathway and a large cross sectional area
  • Narrow lumen restricts blood flow, slowing down the blood to allow more time for exchange of materials at the tissues
23
Q

Give the function of the tendinous chords in the heart

A

They prevent the inversion of the valves by becoming tense, thus pulling the valves, holding them in closed position, preventing back flow

24
Q

Describe blood flow through the heart from the lungs

A
  1. Oxygenated blood travels from the lungs to the heart in the pulmonary vein
  2. Blood leaves the pulmonary vein and enters the left atrium
  3. The left atrium contracts and forces blood into the left ventricle through the left atrio-ventricular valve
  4. The ventricle contracts and the left atrio-ventricular valve closes, forcing blood upwards into the aorta through the semi-lunar valve
  5. Oxygenated blood leaves the heart via the aorta to travel to body tissues
25
Q

Describe blood flow through the heart from the body tissues to the lungs

A
  1. Deoxygenated blood from the body returns to the heart in the vena cava
  2. Deoxygenated blood moves from the superior and inferior vena cava into the right atrium
  3. The right atrium contracts and blood moves into the right ventricle through the right atrio-ventricular valve
  4. The right ventricle contracts, closing the right atrio-ventricular valve and forcing blood into the pulmonary artery through the semi-lunar valve
  5. Deoxygenated blood travels in the pulmonary artery toward the lungs
26
Q

What 3 stages make up the cardiac cycle?

A
  1. Atrial systole
  2. Ventricular systole
  3. Diastole
27
Q

Describe atrial systole

A

Both atria contract forcing the tricuspid and bicuspid valves open.
Blood flows from the atria (higher pressure) to the ventricles (lower pressure)
Back flow of blood into the veins is prevented by closure of the valves in the veins

28
Q

Describe ventricular systole

A

Both ventricles contract forcing the blood up and out of the heart (higher pressure) into the arteries (lower pressure)
The bicuspid and tricuspid valves close due to pressure from blood in the ventricles. This prevents the back flow of blood into the atria
The semi-lunar valves in the aorta and pulmonary artery open

29
Q

Describe diastole

A

Atria and ventricles relax creating a low pressure in the heart
The semi-lunar valves in the aorta and pulmonary artery close due to blood in the aorta (higher pressure) attempting to flow backwards into the ventricles (lower pressure)
Blood flows from the veins through the atria and into the ventricles as there is higher pressure in the veins

30
Q

Why is the mean pressure in the lung capillary lower than the muscle capillaries?

A
  • Reduced flow rate which allows for more time for gas exchange
  • Less tissue fluid produced
31
Q

What causes a drop in pressure in blood vessels?

A

Friction with vessel walls

32
Q

The heartbeat is initiated from within the heart muscle itself and not due to external stimulation. What is this called?

A

Myogenic

33
Q

Describe how the heartbeat is controlled

A
  • The sino-atrial node (SAN) acts as a pacemaker
  • A wave of depolarisation arises at the SAN and electrical impulses spread over the 2 atria causing them to contract simultaneously
  • The electrical stimulation is prevented from spreading to the ventricles by a thin layer of connective tissue which acts as a layer of insulation
  • After a short delay the nerve impulse reaches the atrio-ventricular node (AVN). This passes on the impulse to the ventricles
  • From the AVN the impulse passes down the Bundle of His to the apex of the heart
  • The bundle branches off into Purkinje fibres in the ventricular walls which carry the wave of depolarisation upwards through the ventricle muscle
  • The impulses cause the cardiac muscle in each ventricle to contract simultaneously from the apex upwards, forcing blood up and out of the heart
34
Q

What does ECG stand for?

A

Electrocardiogram

35
Q

What does the P wave show?

A

The depolarisation of the atria during atrial systole

36
Q

What does the QRS wave show?

A

The spread of depolarisation through the ventricles, resulting in ventricular systole

37
Q

What does the T wave show?

A

The relaxation and repolarisation of the ventricular muscles during ventricular diastole

38
Q

What does the length of the PR interval indicate?

A

Time taken for the electrical impulses to spread from the atria to the ventricles through the atrioventricular nodes

39
Q

Why is the QRS wave bigger than the P wave?

A

Ventricles have more muscle than the atria so the amplitude is bigger than the P wave

40
Q

Suggest the change in the QRS wave of a person with enlarged ventricle walls

A

A QRS complex showing greater voltage range

Bio Component 3 (8 decks)

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