Transport In Humans Flashcards
1
Q
What is diffusion?
A
The movement of substances from an area of high to low concentration
2
Q
Which factors increase the rate of diffusion?
A
Higher temperature
Shorter diffusion distance
Steeper concentration gradient
Large surface area
More energy (active transport)
3
Q
Which substances do organisms need to exchange with their environment?
A
Glucose
Oxygen
Carbon dioxide
Water
4
Q
What does a small size mean?
A
Short diffusion distance
5
Q
How do unicellular organisms rely on diffusion?
A
Through their cell membrane for the exchange of substances with their environment
6
Q
As an organism gets larger, its surface area to volume ratio gets …?
A
Smaller
7
Q
When the size of an object increases the …?
A
Surface area and volume both increase
BUT the volume increases more quickly
8
Q
What do multicellular organisms (humans) have?
A
Specialised exchange surfaces
9
Q
What do specialised exchange surfaces do?
A
Increase our surface area to volume ratio
10
Q
How do specialised exchange surfaces increase our SA:volume?
A
By giving us extra surface on the insides of our body
E.g. lungs - contain millions of alveoli
11
Q
What is transported in the blood?
A
Nutrients
Ntibodies
Carbon dioxide
Hormones
Oxygen
Urea
Heat
12
Q
What are the blood components?
A
Red blood cells
White blood cells
Platelets
Plasma
13
Q
What is another name for a red blood cell?
A
Erythrocyte
14
Q
What is another name for white blood cells?
A
Lymphocyte
Phagocyte
15
Q
Function of red blood cells
A
To carry blood from the lungs to our body’s tissues so our cells can use it in cellular respiration
16
Q
What do exchange systems do?
A
Get substances in and out of our bodies
17
Q
What do transport systems do?
A
Transport those substances to the parts of our bodies that need them
18
Q
What does a larger surface area mean there is more surface for?
A
Heat loss
19
Q
What shape do animals in cold environments tend to be?
A
Round
20
Q
Why are animals in cold environments usually round shaped?
A
To reduce surface area
21
Q
Why do animals in cold environments tend to be large/have large volumes?
A
More respiration = more heat
22
Q
What do animals in hot environments tend to have?
A
Long limbs and big ears to increase their surface area for heat loss
23
Q
What size do animals in hot environments tend to be?
A
Smaller/have smaller volumes
24
Q
What happens if an animal in a hot environment has a big volume?
A
It will need longer legs/bigger ears to lose the heat
25
What is haemoglobin?
A red pigment
Large protein
26
Function of haemoglobin
To bind to oxygen to become oxyhemoglobin and carry it around the body to the tissues
27
What shape does a red blood cell have?
Small biconcave disc
28
What does a small biconcave disc shape provide (red blood cell)?
A large surface area
Short diffusion distance
29
Does a red blood cell have a nucleus?
No
30
Why doesn’t a red blood cell not have a nucleus?
So there is more space for haemoglobin and oxygen
31
Why are red blood cells flexible?
So they can squeeze through the capillaries
32
Do white blood cells have a nucleus?
Yes
33
Function of white blood cells
To defend us against pathogens
34
What 3 ways do white blood cells protect us against pathogens?
Phagocytosis
Producing antibodies
Producing antitoxins
35
Plasma makes up …?
50% of the blood’s volume
36
What does the plasma make the blood?
Watery so it can flow
37
What does the plasma carry?
Nutrients (glucose and amino acids)
Waste products (CO2 and urea)
Hormones
Proteins
Antibodies
Antitoxins
Heat
38
What is a platelet?
A fragment of a cell
39
What do some white blood cells have?
A lobed nucleus
40
What is plasma?
A straw coloured liquid made mostly of water
41
Function of platelets
To clot blood at a wound to prevent infection and blood loss
42
What does blood loss mean?
Not enough blood left over to deliver oxygen to the tissues
43
What are two types of blood which can be given to patients?
Artificial blood
Blood transfusion (real blood)
44
What does artificial blood consist of?
Salt water
45
Benefits of artificial blood
Adds volume to the circulatory system
46
What does adding volume to our circulatory system keep (artificial blood)?
Keeps our blood vessels full and allows the heart to keep on pumping
47
Cons of artificial blood
Doesn’t contain any red blood cells
—> doesn’t allows us to transport anymore oxygen
48
How much artificial blood can replace our blood?
Around 1/3
49
Benefit of blood transfusion
Has its own red blood cells
50
Do humans have a single or double circulatory system?
Double
51
What does each circuit do (double circulatory system)?
One circuit: sends blood to the lungs to get oxygen
Other circuit: sends that oxygen-rich blood to the rest of the body
52
Where do arteries carry blood?
AWAY from the heart
53
Arteries
Carry blood AWAY from the heart
Blood is HIGH pressure
Walls are THICK: made of muscle and elastic to withstand the high pressure
Blood is OXYGENATED
STRONG pulse
54
What are the artery walls made of?
Muscle and elastic
55
Why are the artery walls thick and made of muscle and elastic?
To withstand the high pressure
56
Where do capillaries carry blood?
FROM arteries TO veins
57
Capillaries
Carey blood FROM arteries TO veins
Blood is LOW pressure
Walls are 1 CELL THICK and PERMEABLE
Blood is OXYGENATED and DEOXYGENATED
Exchange substances with our cells (nutrients + oxygen)
Take away waste products (CO2)
NO pulse
58
Why are the capillary walls 1 cell thick and permeable?
To allow short and easy diffusion
59
Why is the blood pressure low in capillaries?
It flows more slowly and so gives the blood time to exchange things with the tissue
60
Where do veins carry blood?
TOWARDS the heart
61
Veins
Carry blood TOWARDS the heart
Blood is VERY LOW pressure
Walls are THIN: made of elastic fibres and smooth muscle
VALVES
Blood is OYXGENATED
NO pulse
62
What are the vein walls made of?
Small layers of elastic fibres and smooth muscle
63
Why are the vein walls thin?
Because of the low pressure
64
What do valves in veins do?
Stop back flow of blood because of the low pressure
65
Equation for rate of blood flow
How much blood has flowed
——————————————
Time taken
66
What is an organ system?
A group of organs that work together to perform a common function
67
What organs make up the circulatory system?
Heart
Blood vessels
Blood
68
What does the muscle tissue in arteries provide?
Strength and allows the arteries to direct blood flow
69
What does the elastic tissue in arteries allow?
The arteries to stretch and recoil
70
Which waste products are exchanged between the blood in the capillaries and the body tissues?
Urea
Carbon dioxide
71
Which nutrients are exchanged between the blood in the capillaries and the body tissues?
Glucose
Amino acids
72
Function of the heart
To pump blood, to ensure it keeps flowing through the blood vessels
73
Function of blood vessels
Hold the blood and direct it around the body
74
Function of the blood
Fluid that carries all the substances such as oxygen, nutrients, cells and waste products
75
Why is the muscle in the left ventricle thicker to the right?
More force is needed to pump blood around the body
76
Where does the right side of the heart pump blood to?
The lungs
77
Where does the left side of the heart pump blood to?
The body
78
How many chambers is the heart made up of?
4
79
What is the heart protected by?
The ribs
80
What does the heart act as?
A pump pushing blood around the body
81
How does the heart pump blood around the body?
The muscles in the walls of the heart regularly contract, squeezing out the blood
82
Cycle of the heart (deoxygenated blood)
1) deoxygenated blood enters the vena cava into the right atrium
Tricuspid valves are CLOSED
2) the right atrium walls CONTRACT
INCREASES PRESSURE pushes open the tricuspid valve
Blood moves into the RIGHT VENTRICLE
3) the right ventricle CONTRACTS
INCREASED PRESSURE closes the tricuspid valve
4) ventricles CONTINUE contracting
INCREASED PRESSURE pushes open the semilunar valves
5) as the blood enters the pulmonary artery the PRESSURE RISES which CLOSES the semilunar valve
Blood leaves through the PULMONARY ARTERY
83
What is heart rate?
The number of times the heart beats per minute (bpm)
84
What is the resting heart rate controlled by?
A group of cells located in the right atrium called the pacemaker
85
How does the pacemaker work?
Cells in the pacemaker send out electrical impulses that initiate a contraction in the muscle (the heart beat)
86
How do the electrical impulses from the pacemaker reach all of the muscle in the heart?
The heart has fibres which conduct electricity so the signal reaches all of the muscle
87
What happens when the heart beats?
Contraction (to pump blood out) —> relaxation (to fill with blood again)
88
Why does your heart rate increase when you exercise?
1) when exercising, your muscles need more energy to contract
2) this energy comes from respiration in your cells
3) respiration needs oxygen and glucose, so your body needs more of them
4) the heart rate needs to beat faster and harder to pump more blood around the body
5) so it can deliver more oxygen and glucose to the muscles and remove more carbon dioxide
89
What sends signals to increase heart rate?
The nervous system
90
How is the heart rate controlled during exercise?
1) the muscles use more oxygen and make more CO2
2) the brain (medulla) detects the change in CO2 levels
3) its sends electrical impulses through the nervous system to the heart
4) these impulses make the heart beat faster and with more force
5) this helps deliver more oxygen and glucose to the muscles and remove CO2
91
Why does the heart rate stay high after exercise?
1) oxygen is required in the muscles to break down the lactic acid from anaerobic respiration
2) this is to repay the oxygen debt
92
What are examples of physical and chemical barriers (immune system)?
Skin
Hairs in the nose
Enzymes in tears
93
What is the time taken for the heart rate to return to resting rate called?
The recovery time
94
Who have strong heart muscles?
Physically fit people
95
What do stronger heart muscles mean?
Lower heart rates and better recovery times because their hearts can push out more blood each pump (more efficient)
96
What does the production of adrenaline do?
Increases the heart rate as part of a ‘fight or flight’ response
—> prepares the body to respond to something
97
What happens when your body experiences something to respond to?
A signal is sent to the adrenals to release adrenaline into the blood
98
How is skin a physical barrier (immune system)?
Pathogens can’t get through
It secretes oils and anti microbial substances to kill the pathogens
99
How is the nose a physical barrier (immune system)?
Has lots of little hairs
Mucus to trap pathogens and other particles
100
What happens if pathogens get through the nose?
Trachea, bronchi, bronchioles are covered in a layer of mucus
—> traps any particles
To stop mucus building up they are lined with cilia hairs
—> which waft the mucus to the back of the throat to be swallowed
Stomach produces hydrochloric acid (very strong, pH 2) which kills nearly all pathogens
101
What happens in phagocytosis?
1) phagocyte tracks the pathogen
2) binds to the pathogen
3) phagocyte engulfs the pathogen
4) enzymes are used to digest and destroy the bacteria inside a phagosome
102
How do lymphocytes work?
1) detects the pathogen and produces antibodies
2) the antibodies are complementary to the antigens found on the bacteria
3) once bound, the antibodies either kill the bacteria or immobilise it
103
How do anti-toxins work?
1) pathogen produces toxins (tiny poisons which can damage our cells)
2) in response, our white blood cells produce anti-toxins
—> small molecules that can bind and counteract these toxins so they can’t do us any damage
104
What does CHD stand for?
Coronary heart disease
105
What is coronary heart disease?
When the coronary arteries start to get blocked by the build up of layers of material
(Build up of plaque)
106
What does the build of fatty material in coronary arteries do?
Causes the lumen of the arteries to become narrower and less blood can flow through
107
What happens when the lumen of coronary arteries becomes narrower?
Less oxygen reaches the heart muscle which can cause strain on the heart and potentially cause a heart attack
108
Function of anti-toxins
To bind and neutralise the toxins produced by bacteria
109
What is the heart made of?
Cardiac muscle (myocardium)
110
What do muscles require to contract?
Energy
111
Why does the heart have arteries?
To provide oxygen and glucose and to take away the carbon dioxide
112
Why is it important that the heart has a good blood supply?
So that it can contract and push oxygenated blood around the body
113
Where are the coronary arteries found?
In the walls of the ventricles and the atria
114
Function of coronary arteries
To supply blood to the heart muscle
115
What is plaque mostly formed from?
Cholesterol
116
What can CHD lead to?
Chest pain
Heart attack
Heart failure
Irregular heart beat
Death
117
Risk factors of CHD
Fatty diet
Obesity
Smoking
Blood pressure
118
What are the two main treatments for CHD
Stents
Statin
119
What are stents
An expandable tube placed inside the artery to ensure blood can keep flowing
120
Benefits of stents
Surgery is quick
Lasts a long time
121
Drawbacks of stents
Surgery has risks: heart attack, infection
Developing a blood clot near the stent (thrombosis)
122
What is statin?
Medication that alters the balance of cholesterol
—> decreases LDL (bad cholesterol) and increases HDL (good cholesterol)
123
What does too much LDL cause?
Fatty deposits in arteries
124
What does HDL do?
Gets rid of fatty deposits
125
Benefits of statins
Lowers risk of:
CHD
Strokes
Heart attacks
126
Drawbacks of statins
Have to be taken regularly
Side effects:
Headaches
Kidney failure
127
What can immunity be?
Active or passive
128
What is active immunity?
Production of antibodies by the immune system (your body)
Occurs when you get the disease or have a vaccine
129
What is passive immunity?
You are given antibodies (not make by your body)
E.g. babies get antibodies from their mother through the placenta or breast milk
130
Why is active immunity long lasting?
Because your body remembers how to fight it
131
Why is passive immunity short-term?
Because your body doesn’t remember how to make them
132
How long does active immunity take?
Takes time
133
How long does passive immunity take?
Immediate
134
Active immunity examples
Natural: infection
Artificial: vaccination
135
Passive immunity examples
Natural: maternal antibodies
Artificial: monoclonal antibodies
136
What does carbon monoxide do (CHD)?
Reduces O2 transport ability
Increases breathing rate and heart rate
(Increased strain on heart)
137
What does nicotine do (CHD)?
Narrows blood vessels and increases clot risk
138
What does tar do (CHD)?
Increases breathing rate and heart rate
(Increased strain on heart)
139
What substances are in cigarettes?
Carbon monoxide
Nicotine
Tar
140
What increases blood pressure?
Stress
Smoking
Obesity
High salt diet
141
What does high blood pressure increase?
The force of the blood against the artery walls which can damage the vessels
