Brainscape's Knowledge GenomeTM

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


See full index

Module 3:Exchange And Transport > Transport in animals > Flashcards

Transport in animals Flashcards

1
Q

Why do small animals not need a transport system and large animals do

A
  • Cells are close to the environment to which they live
  • Diffusion will supply enough O2 and nutrients to supply the cell
  • Larger organisms will have two layers of cells
  • Diffusion distance too long
  • Diffusion alone will be to slow to supply all the requirements
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What factors influence the need for a transport system

A
  • size
  • SA:V
  • Level of metabolic activity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How does size affect the need for a transport system

A
  • cells inside larger organism is further from the surface
  • diffusion pathway is increased
  • Diffusion rate is reduced and too slow to supply all the requirements
  • Outer layers of cells use up supplies so less will reach the cells inside the body
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How does SA:V affect the need for a transport system

A
  • smaller animals have a large SA:V so have sufficient area of body surface in which exchange can occur
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How does metabolic activity affect the need for a transport system

A
  • animals need energy for food so can move around
  • releasing energy from food by aerobic respiration requires O2
  • If animals active cell needs good supplies of O2 and nutrients to supply energy for movement
  • animals also need more energy for insulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Features of a good transport system

A
  • a fluid/medium to transport O2 and wastes (Blood)
  • pump to create pressure that will push fluid around the body (Heart)
  • Exchange surfaces that enables substances to enter/leave the blood (capillaries)
  • tube/vessels to carry blood by mass flow
  • two circuits - one to pick up O2 and another to deliver O2 to tissues
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is a single circulatory system

A

Fish
Blood flows through the heart once
Heart - Gills - Body - Heart

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

What is a double circulatory system

A

Mammals
- two separate circuits, blood flows through the heart twice
Pulmonary circulation: blood to lungs to pick up O2
Systemic circulation: 02 and nutrients to tissues
Heart- Body - Heart - Lungs - Heart

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

Disadvantages of a single circulatory system

A
  • blood pressure drops as blood passes through the tiny capillaries of the gills
  • Blood has LP as flows around body and won’t flow very quickly
  • rate of O2 deliverance and CO2 removal limited
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Why do fish have a single circulatory system

A
  • not as metabolically active as don’t need to maintain their body temperature
  • Need less energy
  • SCS supplies enough O2 and nutrients to meet requirements
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Why does the pressure change in DCS

A
  • blood pressure isn’t high in pulmonary circulation otherwise damages the delicate capillaries in the lungs
  • Heart increases pressure as it has passed through the lungs, so blood is under higher pressure and flows through body quickly
  • systemic circulation carries at higher pressure then pulmonary circulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is an open circulatory system

A

Blood is not held in vessels

-blood circulates through body cavity, tissues and cells bathed directly in blood

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

How does an insects circulatory system work

A

OCS

  • muscular pumping organ like the heart that lies just underneath the dorsal (upper) surface of the body
  • Blood from body enters heart through pores called ostia
  • heart then pumps blood towards head by peristalsis
  • at forward end of the heart (nearest the head) blood simply pours out into the body cavity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What happens in the CS of more active insects

A
  • open ended tubes attached to the heart

- direct blood towards active parts of the body

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

Disadvantages of OCS

A
  • blood pressure low
  • Blood flow slow
  • circulation of blood affected by body movements/ lack (some have to be constantly active to help circulate the blood)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is a closed circulatory system

A

One in which blood is held within vessels

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

Advantages of a closed circulatory systems

A
  • high pressure so blood flows more quickly
  • rapid delivery of O2 and nutrients
  • rapid removal of CO2 and other wastes
  • transport independent of body movements
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Features of arteries

A
  • Carries blood away from the heart
  • blood at high pressure so artery wall must be thick in order to withstand pressure
  • lumen small to maintain HP
  • Inner wall folded to allow lumen to expand as blood flow increases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

3 layers of arteries

A
  • inner layer (tunica intima) - thin layer of elastic tissue which allows wall to stretch and recoil to help maintain BP
  • Middle layer (tunica media) - thick layer of smooth muscle
  • Outer layer (tunica adventitia) thick layer of collagen and elastic tissue - provides strength to withstand HP and recoil to maintain pressure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Features of arterioles and why the smooth muscle in it is so important

A
  • small blood vessels that distribute blood from artery to capillaries
  • Consist of a layer of smooth muscle
  • Contraction of muscle constricts diameter of arteriole
  • increases resistance to flow and reduced rate of blood flow
  • Constriction of arteriole walls used to divert flow of blood to regions of the body demanding more O2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Features of capillaries

A

Have thin walls to allow exchange of materials between blood and tissue fluid

  • narrow lumen same as RBC, RBC squeezed against walls helping transfer O2 as reduces diffusion distance, increases resistance and reduces rate of flow
  • walls consist of a single layer of flattened endothelial cells - reduces diffusion distance
  • Walls are leaky - allow blood plasma and other dissolved substances to leave the blood
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Features of venules

A

Small blood vessels that collect blood from capillaries and leads them into the veins
- Consists of thin layers of muscle and elastic tissue outside the endothelium, and thin outer layer of collagen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Features of veins

A

carry blood back to the heart, BP is low so walls don’t need to be thick

  • lumen large to ease flow of blood
  • walls have thinner layers of collagen and smooth muscle and elastic tissue then arteries
  • contain valves to prevent back flow
  • walls are thin so contraction of surrounding skeletal muscle applies pressure to blood forcing blood to move in direction determined by valves
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What does plasma consist of

A

Fluid portion of the blood
contains many dissolved substances i.e. O2, CO2, minerals, glucose, amino acids, hormones, plasma proteins
Cells i.e. RBC, WBC, platelets, lymphocytes
Plasma proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is tissue fluid

A

fluid surrounding cells and tissues

- similar to blood plasma but does not contain most of the cells in blood/ plasma proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

How is tissue fluid formed

A

By plasma leaking from capillaries

  • surrounds cells in tissue and supplies them with O2 and nutrients
  • happens because as plasma leaks it carries all the dissolved substances into the tissue fluid
  • mass flow rather than diffusion
  • waste products from cell metabolism carried back into capillary as some of the tissue fluid returns to the capillary
  • some neutrophils/ few proteins/ few fats
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Why does the formation of tissue fluid happen

A
  • artery reaches tissues branches into arterioles into capillaries
  • at arterial end of capillary blood is at high hydrostatic pressure which pushes blood fluid out of holes in capillary wall
  • fluid that leaves consists of plasma with dissolved nutrients and O2, cells and plasma proteins are too large to leave
  • tissue fluid surrounds so exchange of gases and nutrients can occur across plasma membranes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

How does the tissue fluid return back to the blood

A

blood pressure at the venous end of the capillary is much lower
- carries CO2 and other waste products such as urea back into the blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What happens to the tissue fluid that doesn’t return back into the blood

A
  • some tissue fluid is directed into another tubular system called the lymphatic system
  • drains excess tissue fluid out of the tissues and returns it to the blood system in the subclavian vein in the chest
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What does the lymphatic system consist of

A
  • similar in composition to tissue fluid
  • contains more lymphocytes as these are produced by lymph nodes
  • few proteins/ more fats
  • lymph nodes play important role in immune response
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Hydrostatic/ Oncotic pressure of blood plasma

A

high/ slightly negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Hydrostatic/ Oncotic pressure of tissue fluid

A

low/ less negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Hydrostatic/ Oncotic pressure of lymph

A

low/ less negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is hydrostatic pressure

A

pressure fluid exerts when pushing against the sides of a blood vessel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is oncotic pressure

A

pressure created by the osmotic effects of the solutes

- if has negative figure tends to pull water back into the blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

How do you work out which way the fluid is moving

A
  • work out difference in hydrostatic pressure
  • work out difference in oncotic pressure
  • add them together, if number is negative then moves back into the capillary
37
Q

What kind of muscle is the heart

A

The cardiac muscle

38
Q

Where are the ventricles and atria in the heart

A
  • two main pumping chambers - ventricles

- two thin walled chambers above ventricles - atria

39
Q

External features of the heart

A

Lying over the surface are coronary arteries that supply oxygenated blood to the heart

  • if become constricted can have severe consequences
  • restricted blood flow reduced delivery of O2 and nutrients
  • may cause angia/ heart attack
40
Q

How does the blood enter the heart

A
  • deoxygenated blood flows through vena cava into the right atrium
  • oxygenated blood flows from pulmonary vein into left atrium
41
Q

What happens after blood enters the atria

A
  • blood flows through the atrioventricular valves into the ventricles
42
Q

What are attached to the valves

A

tendinous cords to prevent the ventricles turning inside out when the ventricle walls contract

43
Q

What separates the ventricles from each other

A

the septum

- ensure oxygenated/ deoxygenated blood stay separate

44
Q

What happens after the blood enters the ventricles

A

deoxygenated blood flows into pulmonary artery

oxygenated blood flows into aorta - carries blood to arteries

45
Q

What are the semi- lunar valves

A

at the base of the major arteries

- prevent blood flowing back to the heart as the ventricles relax

46
Q

Features of the atria

A
  • muscle of atria walls is very thin as don’t need to create that much pressure
  • function is to receive blood from the veins and push it into the ventricles
47
Q

Features of the right ventricle

A
  • thicker then walls of atria enabling it to pump blood out of the heart
  • pumps deoxygenated blood to the lungs
  • not very high pressure as could damage alveoli and lungs are just behind so does not need to travel very far
48
Q

Features of the left ventricle

A
  • 2x/ 3x thicker then right ventricle

- blood pumped out of aorta and need sufficient pressure to overcome the resistance of systematic circulation

49
Q

Features of cardiac muscle

A

consists of fibres that branch producing cross bridges

  • helps spread the stimulus around the heart and ensures muscle can produce a squeezing rather then a simple reduction in length
  • lots of mitochondria between muscle fibrils to supply energy for contraction
  • muscle separated by intercalated discs which facilitate synchronised contraction
  • each cell has a nucleus and divided into contractile units called sarcomeres
50
Q

What is the cardiac cycle

A

the sequence of events in one full heartbeat

51
Q

Explain cardiac cycle sequence

A

1) Diastole - muscular walls of 4 chambers relax, elastic recoil causes chambers to increase in volume allowing blood to flow in from the vein
2) Atrial Systole - right and left atria contract, thin wall makes only small amount of pressure pushing blood into ventricles
3) Ventricular systole - right and left ventricles pump - contraction at base (apex) so blood is pushed upwards towards the arteries

52
Q

Main purpose of the valves

A

Blood flow is in correct direction

-opened/closed by changed in blood pressure in various chambers in the heart

53
Q

How do the atrioventricular valves work after systole

A

ventricular walls relax and recoil

  • pressure in ventricles rapidly drops below pressure in the atria
  • blood in the atria push the atrio-ventricular valves open
  • blood entering heart flows straight through atria and into ventricles
  • pressure in atria and ventricles rise slowly as they fill with blood
  • valves remain open while atria contract but close when atria relax
  • as ventricles contract (systole) pressure of blood in the ventricles rises
  • when pressure rises above that in the atria the blood starts to move upwards
  • this prevents blood flowing back to atria
54
Q

When are the semi - lunar valves closed

A
  • before ventricular contraction, the pressure in the major arteries is higher then ventricles
  • this means the semi - lunar valves are closed
55
Q

When are the semi-lunar valves open

A

Ventricular systole raises blood pressure in the ventricles quickly

  • once pressure in ventricles is above pressure in arteries the semi-lunar valves are pushed open
  • blood under high pressure so forced out in one powerful spurt
  • once ventricles walls have finished contracting, the heart muscles start to relax (diastole)
56
Q

What happens to the semi-lunar valves after diastole

A
  • elastic tissues in the walls of the ventricles recoils
  • This stretches the muscle out again and the ventricle returns to its original size
  • This causes pressure in the ventricles to drop quickly
  • As it drops below the pressure in the major arteries, the blood starts to flow back towards the ventricles
  • Semi lunar valves are pushed closed by blood collecting in the pockets of the valves
  • this prevents blood returning to ventricles
57
Q

What is our pulse

A

Wave created when semi lunar valves close

58
Q

Why is their elastic tissue in the heart

A
  • artery walls stretch when blood leaves the heart
  • when blood leaves the heart these walls stretch
  • elastic recoil helps maintain pressure in aorta as pressure drops when blood moves out
  • further blood flows along arteries the more the pressure drops and fluctuations become less obvious
59
Q

Why is important to maintain the pressure gradient between the aorta and arterioles

A

to keep blood flowing towards the tissues

60
Q

What does myogenic mean

A

muscle can initiate its own contraction

- muscle will contract relax rhythmically even if not connected to the body

61
Q

What is fibrillation

A

When the contractions of the heart chambers aren’t synchronised

62
Q

What is the SAN (sino-atrial node)

A

at top of right atrium, near the point where vena cava empties blood

  • small patch of tissue that sends out waves of electrical excitation at regular intervals in order to initiate contractions
  • also known as the pacemaker
63
Q

How do the atria contract

A
  • wave of excitation spreads over both walls of the atria
  • travels along membranes of muscle tissue
  • as wave of excitation passes it causes the cardiac muscle to contract
  • this is an arterial systole
64
Q

What is the atrio- ventricular node (AVN)

A

tissue at base of atria unable to conduct wave of excitation so cannot spread down ventricle walls

  • at top of interventricular septum is AVN
  • only route that can initiate wave of excitation through to the ventricles
65
Q

Why is the wave of AVN excitation delayed

A

allows time for atria to finish contracting and for blood to flow down into ventricles before they begin to contract

66
Q

How do the ventricles contract

A
  • after delay wave of excitation carried away from AVN and down specialised tissue called purkyne tissue
  • this runs down interventricular septum
  • at base of septum wave of excitation spreads out over walls of ventricles
  • as excitation spreads up from the base (apex) of the ventricles it causes it to contract
  • this means ventricles contract from base upwards
  • this pushes blood up towards major arteries of the heart
67
Q

What is purkyne tissue

A

consists of specially adapted muscle fibres that conduct wave of excitation from AVN down to septum of the ventricles

68
Q

How do you monitor the activity of a heart

A

Using an electrocardiogram

  • involves attaching a number of sensors to the skin
  • electrical activity generated by the heart spreads through tissues next to the heart and outwards towards the skin
  • sensors on the skin pick up electrical excitation created by the heart and convert it into a trace
69
Q

What do the different letters of the waves show

A

P wave - excitation of atria
QRS wave - excitation of the ventricles
T wave - diastole

70
Q

What are the different types of heart rhythm

A

Sinus rhythm - normal
Bradycardia - slow
Tachycardia - fast
Atrial fibrillation - atria beating more frequently then ventricles
Ectopic Heart beat - third beat is an early ventricular beat

71
Q

What does haemoglobin become when it picks up oxygen

A

oxyhaemoglobin

72
Q

Features of haemoglobins haem group

A
  • each polypeptide chain contains single iron ion

- iron ion can attract and hold an oxygen molecule - high affinity for O2

73
Q

How is O2 transported around the body

A

O2 becomes associated with haemoglobin at alveoli and bind reversibly

  • takes O2 out of solution and maintains a steep conc gradient allowing more O2 to enter the blood and diffuse into cells
  • blood carries O2 from lungs to heart before round body to supply tissues
  • O2 then dissociated from haemoglobin at tissues as cells need O2 for respiration
74
Q

What is meant by partial pressure of O2

A

concentration of O2 measured by the relative pressure that it contributes to a mixture of gases
- measured by KPa

75
Q

What is the S shaped curve called to describe Percentage saturation with oxygen vs partial pressure of O2

A

haemoglobin dissociation curve

76
Q

What happens at low oxygen tension

A

haemoglobin does not readily associate with O2 molecules

  • haem groups that attract O2 are at the centre of the haemoglobin molecule
  • difficult for O2 to reach the haem group and associate
  • difficulty in combining with first O2 molecule accounts for low saturation level of haemoglobin at low O2 tensions
77
Q

What happens as O2 tension rises

A

diffusion in haemoglobin molecule increases
- after one group attaches causes conformational change changing haemoglobins shape so O2 can associate with haem groups more easily

78
Q

What happens as the haemoglobin reaches 100% saturation level

A

Curve levels off

79
Q

How is fetal haemoglobin different

A

has a higher affinity for 02 then adult haemoglobin so to the left of the curve
- because fetal haemoglobin must be able to associate with O2 in an environment where oxygen tension is low enough for adult haemoglobin to release O2

80
Q

Why is the oxygen tension low in the placenta

A

fetal haemoglobin absorbs O2 from surrounding fluid

  • this causes O2 from mothers blood fluid into the placenta
  • reduces O2 tension in mothers blood, which in turn makes maternal haemoglobin dissociate with more 02
81
Q

What does affinity mean

A

a strong attraction

82
Q

How is CO2 transported

A

5% directly in the plasma
10% combined directly with haemoglobin to form carbaminohaemoglobin
85% transported in the form of hydrogencarbonate ions

83
Q

How are hydrogencabonate ions formed

A
  • CO2 diffuses into blood plasma of RBC where it forms a weak acid called carbonic acid catalysed by carbonic anhydrase
  • carbonic acid dissociates to release H+ and hydrogencarbonate ions
84
Q

What is the chloride shift

A

Hydrogen carbonate ions move out of the cell chloride ions move into the erythrocytes to balance the charge

85
Q

What happens as hydrogen carbonate ions enter the blood

A

To stop blood from becoming acidic from hydrogencarboante building up in the blood hydrogen ions are taken out of solution by associating with haemoglobin to form haemoglobinic acid
- haemoglobin acts as a buffer

86
Q

What happens as haemoglobin releases oxygen

A

haemoglobin becomes available to take up hydrogen ions forming haemoglobinic acid
- where tissue is more active more CO2 is released affecting the haemoglobin

87
Q

What is the Bohr effect

A

Describes the effect an increasing concentration of CO2 has on haemoglobin

88
Q

Describe the Bohr effect

A
  • CO2 enters RBC forming carbonic acid which dissociates to release H+ ions
  • H+ ions effect pH of cytoplasm making it more acidic
  • increased acidity alters tertiary structure of haemoglobin and reduces affinty of haemoglobin for oxygen
  • haemoglobin can’t hold as much O2 and O2 released into tissues - more respiring tissues - more CO2 so more O2
  • more CO2 present haemoglobin becomes less saturated with O2
89
Q

What happens to the haemoglobin dissociation curve if more CO2 is present

A

Shifts downwards and to the right

Module 3:Exchange And Transport (7 decks)

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