Topic 1 - Human Transport

Question 1

What is the transport system in humans?

Answer 1

The circulatory system, the blood

Question 2

What are the main 4 components of the blood?

Answer 2

Plasma, Platelets, Red Blood Cells, White Blood Cells

Question 3

What is the plasma?

What is its function?

Answer 3

• 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

Question 4

What are some examples of substances carried by the plasma?

Answer 4

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

Question 5

Why does blood plasma carry heat energy?

Answer 5

• 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.

Question 6

What are platelets?

More info

Answer 6

Small fragments of cells that help blood blot

No nucleus and suspended in the blood plasma

Question 7

Steps of platelets/ blood clotting:

Answer 7

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

Question 8

What do blood clots do?

Answer 8

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

Question 9

How are platelets held together in a clot?

Answer 9

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

Question 10

How do platelets stop bleeding (proteins)

Answer 10

• 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

Question 11

What are red blood cells?

Answer 11

• 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.

Question 12

What are the adaptations of red blood cells?

Answer 12

• 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

Question 13

What does haemoglobin do?

Answer 13

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

Question 14

Haemoglobin in lungs =

Answer 14

haemoglobin and oxygen –> oxyhaemoglobin

Question 15

Haemoglobin in body’s tissues =

Answer 15

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

Question 16

What are white blood cells?

Answer 16

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

Question 17

What are pathogens?

Answer 17

Microorganisms that cause disease

Question 18

What is the job of the immune system?

Answer 18

To destroy the pathogens before they reproduce

Question 19

What are the two types of white blood cells?

Answer 19

Phagocytes and Lymphocytes

Question 20

What are phagocytes? Function?

Answer 20

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.

Question 21

What are lymphocytes? Function?

Answer 21

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.

Question 22

lymphocytes, antibodies and memory cells

Answer 22

• 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

Question 23

What is an antigen?

Answer 23

A substance which can induce an immune response

Question 24

What is an antibody?

Answer 24

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

Question 25

What is vaccination about?

Answer 25

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

Question 26

What is the point of getting vaccinated?

Answer 26

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

Question 27

Explain the process of vaccination

Answer 27

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.

Question 28

Define 'heart'

Answer 28

An organ that pumps blood through the circulatory system

Question 29

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

Answer 29

A thick section of cardiac muscle called the 'septum'

Question 30

How many chambers does the heart have?

Answer 30

4

Question 31

What are the bottom two chambers called?

Answer 31

The ventricles

Question 32

What are the top two chambers called?

Answer 32

The atriums

Question 33

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

Answer 33

- 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

Question 34

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

Answer 34

- 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

Question 35

What is the point of valves? | Provide information about valves

Answer 35

- 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

Question 36

Label a diagram

Answer 36

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

Question 37

Superior and Inferior vena cava where to/ used for?

Answer 37

``` Superior = head and upper body Inferior = legs and lower body ```

Question 38

Heart muscle blood supply

Answer 38

Coronary arteries which branch off the aorta

Question 39

Why does the heart need its own blood supply?

Answer 39

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

Question 40

What is a capillary?

Answer 40

- 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

Question 41

What is a vein?

Answer 41

- 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

Question 42

What is an artery?

Answer 42

- 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

Question 43

What are the 3 types of blood vessels?

Answer 43

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.

Question 44

What does the hormone adrenaline do?

Answer 44

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

Question 45

What factors affect average resting heart rate?

Answer 45

- obesity - exercise - adrenaline/ hormones - emotions

Question 46

Do veins carry blood to or from the heart?

Answer 46

Into

Question 47

Do arteries carry blood to or from the heart?

Answer 47

Away

Question 48

What are the blood vessels supplying the kidneys called?

Answer 48

renal artery/ renal vein

Question 49

What are the blood vessels supplying the lungs called?

Answer 49

pulmonary artery/ vein

Question 50

What are the blood vessels supplying the liver called?

Answer 50

hepatic artery/ hepatic portal vein

Question 51

Structure of white blood cells

Answer 51

- 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

Question 52

How does speed of blood flow affect gas exchange?

Answer 52

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

Question 53

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

Answer 53

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

Question 54

What can lead to coronary heart disease?

Answer 54

obesity smoking a diet high in fatty foods lack of exercise

Question 55

What happens in CHD?

Answer 55

- the coronary arteries that supply blood to the heart itself become narrowed by a build up of cholesterol

Question 56

What happens when coronary arteries become narrowed?

Answer 56

- 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

Question 57

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

Answer 57

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.