Topic 3B: More Exchange Systems Flashcards

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1
Q

Why is digestion important

A

Larger biological molecules in food are too big to cross the cell membranes meaning this can’t be absorbed from the gut into the blood r

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2
Q

What digestive enzyme breaks down starch

A

Amylase

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3
Q

What 2 polysaccharides is starch made out of

A

Amylose and amylopectin

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4
Q

How does amylase work

A

By catalysis hydrolysis reactions that break the glycosidic bonds in starch to produce maltose

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5
Q

Where is amylase produced

A

Salivatory glands

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6
Q

What are membrane-bound disaccharides

A

Enzymes that are attached to the cell membrane of epithelial cells lining through ileum
Helping to break down disaccharides into monosaccharides

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7
Q

What are lipase enzymes

A

Catalyse the breakdown of lipids into monoglycerides

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8
Q

How do lipase enzymes work

A

Involves hydrolysis of ester bonds in lipids

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9
Q

What do bile salts do and where are they produced

A

Produced by liver and emulsify lipids

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10
Q

What do micelles do

A

Help products of digestion to be absorbed

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11
Q

How are micelles formed

A

Monoglycerides and fatty acids stick with the bile salts to form micelles

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12
Q

What does exopeptidases do

A

Acts to hydrolyse peptide bonds at the ends of a protein molecule

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13
Q

What does endopeptidases do

A

Acts to hydrolyse peptide bonds within a protein

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14
Q

What does dipeptidases do

A

They are exopeptidases that work specifically on dipeptides
Act to separate the amino acids that make up a dipeptide by hydrolysing the peptide bond

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15
Q

Where are dipeptidases found

A

Cell-surface membrane of epithelial cells in the small intestines

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16
Q

What’s the role of haemoglobin

A

To carry oxygen around the body

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17
Q

What’s the structure of haemoglobin

A

Large protein with a quaternary structure, made up of 4 peptide chains each chain had a haem group
It can carry 4 oxygen molecules at one time

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18
Q

What does a haem group do

A

Contains iron giving Hb its red colour

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19
Q

What’s the name of the structure when HB and oxygen bind?

A

Oxyhaemoglobin

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20
Q

What’s the process called when oxygen joins to Hb

A

Association or loading

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21
Q

What’s the process called when oxygen leaves oxyhaemoglobin

A

Disassociation or unloading

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22
Q

What is meant by affinity for oxygen

A

Tendency a molecule has to bind to with oxygen

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23
Q

What affects affinity

A

Partial pressure of oxygen

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24
Q

What’s partial pressure of oxygen a measure of

A

Oxygen concentration

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25
Q

When does oxygen load/unload

A

Loads when there’s a high pO2
Unloads when there’s a low pO2

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26
Q

What happens when cells respire

A

They use up oxygen lowering Po2

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27
Q

What does an oxygen dissociation curve show

A

How saturated the haemoglobin is with oxygen at any given pO2

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28
Q

What is Hb like in an organism with low oxygen environments

A

Hb has a higher affinity for oxygen than human Hb
As there isn’t must oxygen available
Hb has to be good at loading any available o2

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29
Q

What is Hb like in an organism with high activity levels

A

Hb has a lower affinity for oxygen than human as they need Hb to easily unload oxygen so it’s available to use

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30
Q

How does size affect the type of Hb

A

Small mammals tend to have high SA:V ratio than larger mammals
So they lose heat easily and quickly so have a high metabolic rate to help keep warm
So have a increased oxygen demand meaning they have Hb with lower affinity than humans as they need Hb to easily unload o2

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31
Q

What is cardiovascular disease

A

General term used to describe diseases associated with the heart and blood vessels

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32
Q

What is coronary heart disease

A

A type of cardiovascular disease, which occurs when coronary arteries have a lot of atheromas in them which restricts blood flow to the heart muscles
It can lead to myocardial infarction

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33
Q

Name 4 risk factors associated with cardiovascular disease

A

High blood pressure
High blood cholesterol
Poor diet
Smoking

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34
Q

Why do large mammals need specialised mass transport

A

Due to larger mammals smaller sa:v ratio they need to carry raw materials from specialized exchange organs to their body cells

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35
Q

What is the circulatory system made up of

A

Heart and blood vessels

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36
Q

What does the heart do

A

Pumps blood through blood vessels to reach different parts of the body

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37
Q

Name the 4 blood vessels in the circulatory system

A

Arteries
Arterioles
Veins
Capillaries

38
Q

Where does the pulmonary artery carry blood from and to

A

From the heart to the lungs

39
Q

Where does the pulmonary vein carry blood from and to

A

From lungs to the heart

40
Q

Where does the aorta carry blood from and to

A

From the heart to the body

41
Q

Where does the vena cava carry blood from and to

A

From the body to the heart

42
Q

Where does the renal artery carry blood from and to

A

From the body to the kidneys

43
Q

Where does the renal vein carry blood from and to

A

Fro kidneys to the vena cava

44
Q

What does the blood transport around the body

A

Respiratory gases
Digestion products
Metabolic waste
Hormones

45
Q

How many circuits is there in the human circulatory system
and what are they

A

2
One from the heart to the lungs back to the heart
Other takes the blood around the body

46
Q

The heart has its own blood supply where does this come from

A

Coronary arteries

47
Q

What do arteries do

A

Carry blood from the heart to the rest of the body

48
Q

What’s the structure of arteries

A

Their walls are thick and muscular and have elastic tissue to stretch and recoil as the heart beats helping to maintain the high pressure
Inner lining (endothelium) is folded allowing the artery to stretch

49
Q

All arteries carry what type of blood and what is the exception

A

Oxygenated
Except her pulmonary arteries which take deoxygenated blood to the lungs

50
Q

What are arterioles

A

Arteries divide into smaller vessels called arterioles

51
Q

What do arterioles do

A

These form networks throughout the body
Blood is directed to different areas of demand in the body by muscles inside arterioles which contract to restrict the blood flow or relax to allow full blood flow

52
Q

What do veins do

A

Take blood back to the heart under low pressure

53
Q

What features do veins have making them adapted to their job

A

Wider lumen than equivalent arteries with very little elastic or muscles tissue
Veins contain vaves to stop there blood flowing backwards
Blood flow through veins is helped by contraction of the body muscles surrounding them

54
Q

All veins carry what type of blood and what is the exception

A

Deoxygenated blood
Pulmonary veins which carry oxygenated blood to heart from the lungs

55
Q

What do arterioles branch into

A

Capillaries

56
Q

What is the smallest blood vessel

A

Capillaries

57
Q

What are capillaries adapted for

A

Efficient diffusion
Substances are exchanged between cells and capillaries

58
Q

Where are capillaries found near

A

Cells in exchange tissues

59
Q

What are a few features of capillaries making them adapted to their functions

A

One cell thick which shortens diffusion pathway along with being found near cells in exchange tissue
Large number of capillaries to increase SA for exchange

60
Q

What are networks of capillaries in tissue called

A

Capillary beds

61
Q

What is tissue fluid

A

Fluid that surrounds cells in tissues

62
Q

What is tissue fluid made from

A

Molecules that leave the blood plasma (oxygen, nutrients and water)

63
Q

Why does tissue fluid not contain RBC’s or big proteins?

A

Too large to be pushed out through capillary walls

64
Q

What do cells like in from tissue fluid

A

Oxygen and nutrients and release metabolic waste into it

65
Q

What happens in capillary bed

A

Substances move out of the capillaries into the tissue fluid by pressure filtration

66
Q

How is tissue fluid formed

A

At the start of the capillary bed, nearest the arteries the hydrostatic pressure inside the cap is greater than that in the tissue fluid
The difference in hydrostatic pressure means an overall outward pressure forces fluid out of the cap into spaces around the cells forming tissue fluid
So the hydrostatic pressure is much lower at the venue end of the capillary bed

67
Q

Once the tissue fluid is formed what happens

A

Due to fluid loss an increasing conc of plasma proteins the WP at the venule end of the cap bed is lower then the WP in the tissue fluid
Meaning some water re-enters the capillaries from the tissue fluid at the venule end by osmosis
Any excess tissue fluid is drained into the lymphatic system which transports this excess fluid from the tissues and passes it back into the circulatory system

68
Q

How is the left ventricle adapted to do its job effectively
And how is it different to the first ventricle

A

Thicker more muscular walls than the right ventricle allowing it to contact more powerfully and limp blood all the way around the body
The right side is less muscular so it’s contractions are only powerful enough to pump blood to nearby lungs

69
Q

How are ventricles adapted to do its job effectively

A

They have thicker walls than the atria therefore they can push blood out of the heart where as the atria just need to push blood a short distance into the ventricles

70
Q

What does the atrioventricular valve do (AV)

A

Link the atria to the ventricles and top blood flowing back into the atria when the ventricles contact

71
Q

What does the semi-lunar value do (SL)

A

Link the ventricles to the pulmonary artery and aorta stopping blood flowing back into the heart after the ventricles contact

72
Q

In the heart what do the cords do

A

Attract the AV values to the ventricles to stop them being forced up into the the atria when the ventricles contract

73
Q

How do heart values work

A

They only open one way, whether they’re open or closed depends on the relative pressure of the heart chambers
If there a higher pressure behind a valve it’s forced open but if it’s a higher pressure in front of the valve it’s forces shut
Meaning that the flow of blood is unidirectional only flowing in one direction

74
Q

What is the cardiac cycle

A

An ongoing sequence of contraction and relaxation of gut atria and ventricles led that keeps blood continuously circulating around the body

Volume of atria and ventricles changes as they contract and relax
Pressure changes also occur, due to changes in the chamber volume

75
Q

What are the 3 stages if the cardiac cycle

A

1) Ventricles relax and atria contract
2) Ventricles contract and atria relax
3) Ventricles relax and atria relax

76
Q

What happens in step one of the cardia cycle

A

The ventricles are relaxed and the atria contract
Decreasing the volume of chambers and increasing pressure inside the chambers
Pushing blood into the ventricles
There’s a slight increase in ventricle pressure and chamber volume d the ventricles receive the ejected blood from contacting atria

77
Q

What happens in step two of the cardia cycle

A

The atria relax and the ventricles led contract increasing their pressure
The pressure become higher in the ventricles than the atria which forces the AV valve shut to prevent back-flow The pressure in the ventricles is also higher than the aorta and pulmonary artery
Forcing open the SL valves and blood is forced out into into these arteries

78
Q

What happens in step three of the cardia cycle

A

The ventricles and atria both relax
Higher pressure in the pulmonary artery and aorta closes the SL valve to prevent back-flow into the ventricles
Blood returns to the heart and the atria fill again due to the higher pressure in the vena cava and pulmonary vein
In turn this starts to increase pressure in the atria
Ventricles co tune to relax and pressure falls below pressure of the atria and AV valves open
Allowing blood to flow passively into ventricles from atria
Atria contract and the whole process begins again

79
Q

How do you calculate cardia output

A

Strove volume x heart rate

80
Q

How does a atheroma form

A

The wall of the artery is made up of several layers
Endothelium is usually smooth and unbroken if damage occurs if it then WBC and lipids from the blood clump together under the lining to form fatty streaks
Overtime more WBC’s lipids and connective tissue build up and harden forming fibrous plaque called atheroma
This plaque partially blocks the lumen of the artery and restrict blood flow, which causes blood pressure to increase

81
Q

How does an aneurysm form

A

It starts with the formation of atheromas
Atheroma plaques damage and weaken arteries
They also narrow arteries increasing blood pressure
When blood travels through a weakened artery at high pressure, it may push through inner layer of the artery through the outer elastic layer to form an aneurysm
This aneurysm may burst casing a haemorrhage

82
Q

What is an aneurysm

A

A balloon-like swelling of the artery

83
Q

What is a thrombosis

A

Formation of a blood clot

84
Q

How does a thrombosis form

A

Starts with the formation of atheromas
An atheroma plaque can rupture the endothelium of an artery
This damages the artery wall and leaves a rough surface
Platelets and fibrin accumulate at the site of damage and form a blood clay
This can cause a com,eye blockage of the artery or it come become dislodged and block a blood vessel elsewhere in the body
Debris from the rupture can cause another blood clot to form further down the artery

85
Q

How does a myocardial infarction happen (heart attack)

A

The blood contain oxygen needed by heart muscle cells to carry out respiration
If a coronary artery become completely blocked an area of the heart will be completely cut off from its blood supply, receiving no oxygen
This causing a heart attack

86
Q

What are the effects of a heart attack

A

Can cause damage and death of the heart muscle
If large areas of the heart muscles are affected complete heart failure can occur which is fatal

87
Q

What are some of the symptoms of a heart attack

A

Chest and upper body pain
Shortness of breath
Sweating

88
Q

How is high blood pressure a risk factor for cardiovascular disease

A

High pressure increases the risk of damage to the artery walls
Damages walls have an increased risk of atheroma formation causing further increase in blood pressure
Atheromas can also so cause blood clots to form which could block flow of blood to the heart which can lead to a heart attack

89
Q

How is high blood cholesterol and poor diet a risk factor for cardiovascular disease

A

If it’s high then they risk is increased
This is because cholesterol is one of the main constituents of the fatty deposits ggat form atheromas
Atheromas can lead to increased blood pressure and blood clots which could cause a heart attack
A diet in high saturated fast is associated with high blood cholesterol levels
A diet high in salt also increases risk of CVD as it increases bp

90
Q

How is smoking a risk factor for cardiovascular disease

A

Both carbon monoxide and nicotine found in cigarette smock increases risk of CVD and heart attacks
CO combines with Hb and reduced the amount of oxygen that is transported in the blood and also reduces the amount of oxygen available to tissues
If the heart muscle doesn’t receive enough oxygen it can lead to a heart attack
Smoking also decreases amount of antioxidants in the blood these help protect cells from damage meaning with less the coronary artery walls are mod likely to damage forming atheromas

91
Q

How can we reduce the risk of CVD

A

Not smoke, eat less fatty foods
Exercise

92
Q

What are some of that risk factors for CVD that cant be controlled

A

Genetic predisposition to coronary artery disease of having high blood pressure due to having another condition