Transport systems Flashcards

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1
Q

What are the components of blood?

A
  • Red blood cells, white blood cells, platelets and plasma.
  • Over half of the volume of the blood is made up of plasma
  • The majority of the other half is made up of red blood cells
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2
Q

What is the structure of red blood cells?

A

Biconcave discs containing no nucleus but plenty of the protein haemoglobin.

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3
Q

What is the structure of white blood cells?

A

Large cells containing a big nucleus, different types have slightly different structures and functions.

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4
Q

What is the structure of platelets?

A

Fragments of cells.

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5
Q

What is the structure of plasma?

A

Straw coloured liquid which the other components of the blood are suspended within.

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6
Q

What does plasma transport?

A
  • Carbon dioxide - the waste product of respiration
  • Digested food and mineral ions
  • Urea - the waste substance produced in the breakdown of proteins by the liver. Transported to the kidneys.
  • Hormones
  • Heat energy - created in respiration (an exothermic reaction)
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7
Q

What are red blood cells?

A

Specialised cells which carry oxygen to respiring cells

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8
Q

How are red blood cells adapted?

A
  • They are full of haemoglobin, a protein that binds to oxygen to form oxyhaemoglobin.
  • They have no nucleus which allows more space for haemoglobin to be packed in
  • The shape of a red blood cell is described as being a ‘biconcave disc’ this shape gives them a large surface area to volume ratio to maximise diffusion of oxygen in and out
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9
Q

What are white blood cells?

A
  • White blood cells are part of the body’s immune system
  • These specialised cells defend against pathogenic microorganisms
  • There are two main types of white blood cell:
    Phagocytes
    Lymphocytes
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10
Q

What do phagocytes do?

A

Phagocytes carry out phagocytosis by engulfing and digesting pathogens

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11
Q

What do lymphocytes do?

A
  • Lymphocytes produce antibodies
  • This is a specific type of immune response as the antibodies produced will only fit one type of antigen on a pathogen
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12
Q

What is the human response to infection?

A
  • The pathogen enters the blood stream and multiplies
  • Phagocytes that encounter the pathogen recognise that it is an invading pathogen and engulf and digest (non-specific response).
  • Eventually, the pathogen encounters a lymphocyte which recognises its antigens
    and starts to produce specific antibodies to combat that particular pathogen
  • The lymphocyte also clones itself to produce lots of lymphocytes
  • Antibodies cause agglutination of pathogens
    and phagocytes engulf and digest the agglutinated pathogens
  • After the patient has recovered, they retain antibodies specific to the disease as well as memory cells
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13
Q

How are platelets helpful?

A
  • Platelets are fragments of cells that are involved in blood clotting and forming scabs where the skin has been cut or punctured
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14
Q

What is the importance of blood clotting?

A
  • Blood clotting prevents significant blood loss from wounds.
  • Scab formation seals the wound preventing entry of microorganisms that could cause infection.
  • It remains in place until new skin has grown underneath it, sealing the skin again
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15
Q

What is the structure of the heart?

A
  • The heart organ is a double pump
  • Oxygenated blood from the lungs enters the left side of the heart and is pumped to the rest of the body.
  • Deoxygenated blood from the body enters the right side of the heart and is pumped to the lungs.
  • A muscle wall called the septum separates the two sides of the heart
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16
Q

Why does the left ventricle have a thicker muscle than the right ventricle?

A

Because it has to pump blood at high pressure around the entire body,

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17
Q

What is the difference between veins and arteries?

A

Blood is pumped towards the heart in veins and away from the heart in arteries

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18
Q

Why does the heart need a constant supply of oxygen?

A

For aerobic respiration to release energy to allow continued muscle contraction

19
Q

What is the purpose of valves?

A

To prevent blood flowing backwards

20
Q

What is the purpose of the heart?

A
  • The heart pumps blood around the body in order to supply oxygen and glucose to respiring cells
  • The blood also removes waste products from the respiring cells
21
Q

Why do the cells of the muscles respire more rapidly during exercise? Also, why does heart rate increase?

A
  • In order to provide energy for muscle contraction
  • Heart rate increases to deliver oxygen and glucose and remove waste more frequently
22
Q

Why may the heart rate remain high after a period of exercise?

A

Because oxygen is required in the muscles to break down the lactic acid from anaerobic respiration

23
Q

What are the 3 main types of blood vessel?

A
  • Arteries
  • Veins
  • Capillaries
24
Q

What is the function of arteries?

A
  • Carry blood at high pressure away from the heart
  • Carry oxygenated blood (except the pulmonary artery)
25
Q

How is an artery adapted?

A
  • Thick muscular walls containing elastic fibres withstand the high pressure of blood and maintain the blood pressure as it recoils after the blood has passed through
  • A narrow lumen also helps to maintain high pressure
26
Q

What is the function of veins?

A
  • Carries deoxygenated blood at low pressure towards the heart (other than the pulmonary vein)
27
Q

How is a vein adapted?

A
  • A large lumen reduces resistance to blood flow under low pressure
  • Valves prevent the backflow of blood as it is under low pressure
28
Q

What is the function of capillaries?

A
  • Carry blood at low pressure within tissues
  • Carry both oxygenated and deoxygenated blood
29
Q

How is a capillary adapted?

A
  • Capillaries have walls that are one cell thick (short diffusion distance) so substances can easily diffuse in and out of them
  • The ‘leaky’ walls allow blood plasma to leak out and form tissue fluid surrounding cells
30
Q

What organ does does the renal artery and renal vein go to and from?

A

The kidneys.

31
Q

What organ does does the pulmonary artery and pulmonary vein go to and from?

A

The lungs.

32
Q

What organ does does the vena cava & pulmonary vein and aorta & pulmonary artery go to and from?

A

The heart.

33
Q

What is the purpose of vaccines?

A

Vaccines are used to induce immunity to infectious diseases

34
Q

How do vaccines work?

A
  • Once in the bloodstream, the antigens contained within the vaccine can trigger an immune response.
  • Lymphocytes recognise the antigens in the bloodstream and produce antibodies specific to the antigen encountered.
  • Memory cells and antibodies subsequently remain circulating in the blood stream
  • Future infection by the same pathogen will trigger a response that is much faster and much larger compared to the initial response
  • Due to the rapid nature of the response, the pathogen is unable to cause disease and the individual is said to be immune.
35
Q

What is the importance of vaccines?

A

Vaccines not only protect the vaccinated individuals, they also reduce the likelihood that an infected individual will spread the pathogen to others

36
Q

Disadvantages of vaccinations?

A
  • Mutations in the pathogen’s DNA/RNA can result in significant changes to the antigen of the pathogen meaning that lymphocytes no longer recognise the pathogen
  • Side-effects of vaccinations can reduce the uptake in the population
37
Q

Causes of coronary heart disease?

A
  • In coronary heart disease (CHD), layers of fatty material (plaque) build up inside the coronary arteries
  • These fatty deposits are mainly formed from cholesterol
  • If a coronary artery becomes partially or completely blocked by these fatty deposits, it loses its elasticity and cannot stretch to accommodate the blood which is being forced through every time the heart contracts
  • The flow of blood through the arteries is reduced, resulting in a lack of oxygen for the heart muscle
38
Q

What factors increase the chance of coronary heart disease?

A
  • Obesity (Carrying extra weight puts a strain on the heart)
  • High blood pressure (This increases the force of the blood against the artery walls and consequently leads to damage of the vessels)
  • High cholesterol (Speeds up the build up of fatty plaques in the arteries leading to blockages)
  • Smoking (Chemicals in smoke cause an increase in plaque build up and an increase in blood pressure)
39
Q

In the heart of a foetus, the two upper chambers (atria) are linked by a hole so that blood can pass between them. Why is this hole normally closed before the baby is born?

A
  • So that oxygenated and deoxygenated blood do not mix.
  • and so that oxygenated blood can be pumped around the body
40
Q

Why may a person’s blood vessels with sickle cell anaemia become blocked?

A

Sickle shaped red blood cells get caught.

41
Q

What are the functions of the atria?

A
  • To pump blood into ventricles
  • To receive deoxygenated blood blood from vena cava
  • To receive oxygenated blood from pulmonary vein
42
Q

Describe how the blood in the pulmonary artery differs from the blood in the aorta?

A
  • Is at a lower pressure
  • Contains a lower oxygen concentration
  • Contains a higher carbon dioxide concentration
43
Q

Why does a mouse use more oxygen per gram than a human?

A
  • It has a larger surface area to volume ratio
  • Therefore there will be more heat loss