Topic 1 - Human Transport Flashcards Preview

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Flashcards in Topic 1 - Human Transport Deck (57)
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1
Q

What is the transport system in humans?

A

The circulatory system, the blood

2
Q

What are the main 4 components of the blood?

A

Plasma, Platelets, Red Blood Cells, White Blood Cells

3
Q

What is the plasma?

What is its function?

A
  • A pale yellow liquid which carries nearly everything that needs transporting around your body.
  • Some substances are carried by being dissolved directly (eg CO2)
  • Function: Transporting carbon dioxide, digested food molecules, urea and hormones; distributing heat
4
Q

What are some examples of substances carried by the plasma?

A
Red + White blood cells
Platelets
Digested food products (glucose, amino acids)
Carbon dioxide (body cells to lungs)
Urea (liver to kidneys)
Hormones 
Heat energy
5
Q

Why does blood plasma carry heat energy?

A
  • Plasma helps to distribute heat throughout the body and to maintain homeostasis
  • Including acid-base balance in the blood and body.
  • It carries heat energy away from rapidly respiring cells (such as exercising muscles) and prevents them overheating
  • It also provides heat energy to regions of the body where respiration takes place more slowly.
6
Q

What are platelets?

More info

A

Small fragments of cells that help blood blot

No nucleus and suspended in the blood plasma

7
Q

Steps of platelets/ blood clotting:

A

1) when blood vessel is damaged, platelets clump together to ‘plug’ the damaged area
2) This is called blood clotting

8
Q

What do blood clots do?

A

They stop you losing too much blood and prevent microogansisms from entering the wound

9
Q

How are platelets held together in a clot?

A

Platelets are held together by a mesh of a protein called fibrin (though this process also needs other proteins called clotting factors to work)

10
Q

How do platelets stop bleeding (proteins)

A
  • They release chemicals (an enzyme which digests fibrinogen, which is soluble, to fibrin, which is insoluble) that cause soluble proteins to form a mesh of insoluble fibres across the wound.
    The fibrin mesh traps blood cells and causes a clot
  • stick together to form clumps that get stuck in the mesh
11
Q

What are red blood cells?

A
  • Red blood cells transport the oxygen required for aerobic respiration in body cells.
  • Carry oxygen from lungs to all the cells in the body.
  • They must be able to absorb oxygen in the lungs, pass through narrow blood capillaries and release this oxygen to respiring cells.
12
Q

What are the adaptations of red blood cells?

A
  • Biconcave shape = larger surface area for absorbing and releasing oxygen
  • They contain haemoglobin (which is what gives the blood it’s colour - contains a lot of iron)
    Haemoglobin can combine reversibly with oxygen = it means that it can combine with oxygen as blood passes through the lungs and release the oxygen when it reaches the cell
  • No nucleus = frees up space for more haemoglobin, they can carry more oxygen
  • Thin = only a short distance for the oxygen to diffuse to reach the centre of the cell
  • Small and flexible = can fit through narrow blood capillaries
13
Q

What does haemoglobin do?

A

Helps red blood cells absorb and release oxygen as oxygen needs to bind to something (the haemoglobin binds to the oxygen)

14
Q

Haemoglobin in lungs =

A

haemoglobin and oxygen –> oxyhaemoglobin

15
Q

Haemoglobin in body’s tissues =

A

oxyhemoglobin breaks down to haemoglobin releasing the oxygen (then taken by cells)

16
Q

What are white blood cells?

A

Important part of the immune system - ingest pathogens and produce antibodies

17
Q

What are pathogens?

A

Microorganisms that cause disease

18
Q

What is the job of the immune system?

A

To destroy the pathogens before they reproduce

19
Q

What are the two types of white blood cells?

A

Phagocytes and Lymphocytes

20
Q

What are phagocytes? Function?

A

Phagocytes detect things that are foreign to the body such as pathogens.
They then engulf and destroy them by digesting the pathogens using enzymes.
Phagocytes are non-specific, they attack anything that isn’t meant to be there.

21
Q

What are lymphocytes? Function?

A

Lymphocytes have a very large nucleus and produce chemicals (proteins) called antibodies

1) Every pathogen has unique molecules on it’s surface called antigens
2) When lymphocytes come across a foreign antigen, they will start to produce antibodies
3) Antibodies stick onto foreign microorganisms in the blood, this either kills the microorganisms (as they break open and die) or causes them to clump together making it easier for phagocytes to engulf and destroy them.

22
Q

lymphocytes, antibodies and memory cells

A
  • The antibodies produced are specific to that type of antigen and won’t lock onto any others
  • The antibodies are then produced rapidly and flow around the body to mark all similar pathogens
  • Memory cells are also produced, these remain in the body and remember a specific antigen.
  • They can reproduce very fast if the same antigen enters the body again
  • Therefore immune to most diseases you’ve already had. The body carries a ‘memory’ of what the antigen was like –> can produce loads of antibodies fast
23
Q

What is an antigen?

A

A substance which can induce an immune response

24
Q

What is an antibody?

A

Proteins that recognise and bind to antigens, which are unique molecules on the surface of pathogens (specific shape to match)
Specific proteins produced in response to exposure to a foreign agent.
Made by lymphocytes

25
Q

What is vaccination about?

A

Vaccination is a way of preventing disease by making the body respond as if it had already been infected

26
Q

What is the point of getting vaccinated?

A

When infected with a new pathogen, takes while for lymphocytes to produce the antibodies to deal with it. (In this time you can get very ill or even die)
To avoid this you can be vaccinated against some diseases

27
Q

Explain the process of vaccination

A

Vaccination involves injecting dead or inactive pathogens into the body
Thee carry antigens, so even though harmless will still trigger an immune response.
Your lymphocytes produce antibodies to attack them
Memory cells are also produces so if live pathogens of the same type ever appear, the antibodies to kill them will be produces much faster and in greater numbers.

28
Q

Define ‘heart’

A

An organ that pumps blood through the circulatory system

29
Q

What are the left chambers separated with from the right chambers?

A

A thick section of cardiac muscle called the ‘septum’

30
Q

How many chambers does the heart have?

A

4

31
Q

What are the bottom two chambers called?

A

The ventricles

32
Q

What are the top two chambers called?

A

The atriums

33
Q

Describe the flow of blood on the right side of the heart (left side on diagram)

A
  • Right atrium of heart receives deoxygenated blood from the body through the vena cava (superior + inferior)
  • Then moves through (the tricuspid valve) to the right ventricle, which pumps it to the lungs via the pulmonary artery
34
Q

Describe the flow of blood on the left side of the heart (right side of diagram)

A
  • Left atrium receives oxygenated blood from the lungs through the pulmonary vein
  • The oxygenated blood then moves through to the left ventricle (via bicuspid valve) which pumps it out round the whole body via the aorta
35
Q

What is the point of valves?

Provide information about valves

A
  • direction of blood flow in the heart is controlled flaps of tissue called valves.
  • the valves stop blood from moving in the wrong direction.
  • there are 4 valves: 2 semi lunar valves, tricuspid and bicuspid
  • held in place by strong like tendons
36
Q

Label a diagram

A

Deoxygentated from body -> into vena cavas (superior and inferior), right atrium, tricuspid valve, right ventricle, pulmonary artery -> lungs

Oxygenated from lungs -> into left pulmonary vein, left atrium, bicuspid valve, left ventricle, aorta

37
Q

Superior and Inferior vena cava where to/ used for?

A
Superior = head and upper body
Inferior = legs and lower body
38
Q

Heart muscle blood supply

A

Coronary arteries which branch off the aorta

39
Q

Why does the heart need its own blood supply?

A

So it can pump the blood around the body and complete it’s function by contracting and relaxing

40
Q

What is a capillary?

A
  • tiny blood vessels that flow through every tissue and connect arteries to veins.
  • very thin walls, 1 cell thick = increases rate of diffusion of substances
  • site of exchange of substances between the blood and tissues
  • blood at low pressure
41
Q

What is a vein?

A
  • large blood vessel
  • carries blood that is flowing back to the heart
  • ve’in’s = ‘in’to the heart
  • deoxygenated
  • thinner walls
  • no pulse
  • blood pressure very low
  • valves
42
Q

What is an artery?

A
  • large blood vessels
  • ‘a’rteries= ‘a’way from heart
  • higher blood pressure
  • thick, muscular, elastic walls = protect from bursting as high pressure
  • elastic = recoil which helps maintain the blood pressure and even out the pulses so there is a great change (reduction) in pressure by the time the blood enters the thin capillaries
43
Q

What are the 3 types of blood vessels?

A

Veins, capillaries, arteries.
Capillaries connect the arteries to veins.
The arteries deliver the oxygen-rich blood to the capillaries, where the actual exchange of oxygen and carbon dioxide occurs.
The capillaries then deliver the waste-rich blood to the veins for transport back to the lungs and heart.
Veins carry the blood back to the heart.

44
Q

What does the hormone adrenaline do?

A

It makes the heart beat faster, boosts the delivery of oxygen and glucose to the brain and muscles, preparing the body for ‘flight or fight’ mode

45
Q

What factors affect average resting heart rate?

A
  • obesity
  • exercise
  • adrenaline/ hormones
  • emotions
46
Q

Do veins carry blood to or from the heart?

A

Into

47
Q

Do arteries carry blood to or from the heart?

A

Away

48
Q

What are the blood vessels supplying the kidneys called?

A

renal artery/ renal vein

49
Q

What are the blood vessels supplying the lungs called?

A

pulmonary artery/ vein

50
Q

What are the blood vessels supplying the liver called?

A

hepatic artery/ hepatic portal vein

51
Q

Structure of white blood cells

A
  • no nucleus
  • flexible
  • it’s ameboid structure helps to ingest germs and unwanted particles. Also this structure helps it to squeeze out of capillary walls
52
Q

How does speed of blood flow affect gas exchange?

A

Slow blood flow = more efficient gas exchange, so quicker for oxygen to be replenished and CO2 removed

53
Q

What type of blood vessels should scientists use to obtain blood samples?

A

Veins: thin, low blood pressure, large blood vessel, no pulse, easy to access

54
Q

What can lead to coronary heart disease?

A

obesity
smoking
a diet high in fatty foods
lack of exercise

55
Q

What happens in CHD?

A
  • the coronary arteries that supply blood to the heart itself become narrowed by a build up of cholesterol
56
Q

What happens when coronary arteries become narrowed?

A
  • the supply of oxygen to the heart muscle is reduced, which can cause pain called angina
  • build up of cholesterol can lead to a clot forming
  • if the clot blocks the artery, stopping the supply of blood and oxygen to part of the heart muscle, then that part of the heart may stop working, causing a heart attack
57
Q

Can red blood cells divide to make new cells as they get older? Why/ why not?

A

No - this is because they lack a nucleus and nuclear DNA - instead they are cleaned out of the blood by the liver, and new ones are released into the blood from the bone marrow in long bones such as the femur.