P2 2h blood / transport in humans

Question 1

what does blood consist of?

Answer 1

red blood cells, white blood cells, platelets and plasma

• over half of the volume of blood is made of plasma
• other is majority of red blood cells

Question 2

what is plasma like?

Answer 2

straw coloured liquid

Question 3

what are platelets like?

Answer 3

fragments of cells

Question 4

what are white blood cells like?

Answer 4

large cells containing a big nucleus

Question 5

what are red blood cells like?

Answer 5

discs with a concave, doesn’t have a nucleus, but lots of the protein haemoglobin

Question 6

what is the shape of red blood cells described as?

Answer 6

biconcave discs

- gives large surface area to volume ratio

Question 7

what is plasma important for?

Answer 7

the transport of many substances

Question 8

what are the substances that plasma transport?

Answer 8

carbon dioxide 
digested food and mineral ions
urea
hormones
heat energy

Question 9

what do platelets do?

Answer 9

involved in helping the blood clot

Question 10

how do platelets work?

Answer 10

• when the skin is broken platelets arrive to stop the bleeding
• a series of reactions occur within the blood plasma
• platelets release chemicals that cause soluble fibrinogen proteins to convert into insoluble fibrin and form an insoluble mesh across the wound
• forming a clot
• it will eventually dry up and will develop a scab

Question 11

what is the importance of blood clotting?

Answer 11

prevents continued / significant blood loss

scab formation seals the wound, prevents entry of micro-organisms

Question 12

what are white blood cells for?

Answer 12

defence against pathogenic microorganisms

Question 13

what are the two main types of white blood cells?

Answer 13

phagocytes

lymphocytes

Question 14

what do phagocytes do?

Answer 14

carry out phagocytosis by engulfing and digestion pathogens

Question 15

how do phagocytes work?

Answer 15

have a sensitive cell surface membrane that detects chemical produced by pathogenic cells

• once they encounter the pathogenic cell they engulf it and realise digestive enzymes to digest it
• non specific immune response

Question 16

what are lymphocytes?

Answer 16

produce antibiotics

Question 17

how do lymphocytes work?

Answer 17

antibodies are Y-shaped and that is specific to the antigens on the surface of the pathogen
- specific type of immune response

Question 18

what is immunity?

Answer 18

when an organism has sufficient levels of antibodies to protects it from a particular disease

Question 19

what is an antigen?

Answer 19

molecule found on the surface of a cell

Question 20

what is an antibody?

Answer 20

protein made by lymphocytes

Question 21

what is an antitoxin?

Answer 21

protein the neutralises the toxins produce by bacteria

Question 22

what are the stages of a response to infection?

Answer 22

1. pathogen enter blood stream and multiplies
2. release of toxins and infection of body cells causes symptoms in the patient
3. phagocytes engulf and digest pathogenic cell
4. pathogen encounters lymphocyte starts to produce specific antibodies to combat pathogen
5. lymphocytes clones it self producing antibodies
6. antibodies cause agglutination
7. phagocytes engulf and digest
8. after recovery, body retains antibodies

Question 23

why does the body retain antibodies and memory cells?

Answer 23

memory cells are lymphocytes that recognise the pathogen
- so if the patient encounters the same pathogen it will trigger a secondary immune response, would happen in a shorter time and memory cells produce much larger quantities of the antibody

Question 24

what are vaccines used for?

Answer 24

induce immunity to infectious diseases

Question 25

what is in a vaccine?

Answer 25

harmless versions of a pathogen

Question 26

how do scientists ensure vaccines contain harmless pathogens?

Answer 26

by killing it
making the pathogen unable to grow or divide
using fragments of pathogens rather then whole cells

Question 27

how can vaccines be administered?

Answer 27

orally, nasal and via injection

Question 28

how do vaccines work?

Answer 28

• lymphocytes recognise the antigens in the bloodstream
• the activated lymphocytes produce antibodies specific to the antigen encountered
• memory cells and antibodies subsequently remain circulating the bloodstream

Question 29

what are the importances of vaccines?

Answer 29

• protect individual
• reduce likelihood that na infected individual will spread the pathogen (spread of the disease)
• reduce cases can eradicate them

Question 30

what are the disadvantages of vaccinations?

Answer 30

• mutations in the pathogens DNA/RNA can result in significant changes to the antigen so lymphocytes no longer recognise the pathogen
• side effects such as swelling or rash even seizures

Question 31

where does oxygenated blood enter the heart?

Answer 31

enters from the left side of the heart to be pumped to the rest of the body

Question 32

what is special about the left ventricle and why?

Answer 32

has thicker muscle wall than the right ventricle

- this is because it had to pump blood at high pressure around the entire body

Question 33

where does deoxygenated blood enter the heart?

Answer 33

enters from the right and is pumped to the lungs

Question 34

what is the muscle that separates the two side of the heart?

Answer 34

septum

Question 35

where is blood pumped?

Answer 35

toward the heart in veins and away from the heart in arteries

Question 36

what do the coronary arteries supply?

Answer 36

cardiac muscle tissue of the heart with oxygenated blood

Question 37

what are valves for?

Answer 37

prevent blood flowing backward

Question 38

how is the pathway of blood through the heart?

Answer 38

• deoxygenated blood flows through the vena cave and into the right atrium
• atrium contracts and blood is forced through the tricuspid valve and into the right ventricle
• the ventricle contract and the blood is pushed through the the semilunar valve
• blood travels to the lungs where gas exchange takes place
• oxygenated blood returns via the pulmonary vein to the left atrium
• the atrium contracts and forces the blood via the bicuspid valve into the left ventricle
• the ventricle then contracts and blood is forced through the semilunar valve and out through the aorta

Question 39

what does buildup of plaque in the coronary arteries do?

Answer 39

looses elasticity
restricted blood flow = cause angina
complete blockage = cause heart attack
all leads to coronary heart disease

Question 40

what are the risk factor of coronary heart disease?

Answer 40

• obesity
• high blood pressure
• high cholesterol
• smoking

Question 41

what are the three main types of blood vessels?

Answer 41

arteries
veins
capillaries

Question 42

what are the arteries key features?

Answer 42

carry blood at high pressure away from the heart

• carry oxygenated blood
• thick muscular walls
• narrow lumen
• fast rate of blood flow

Question 43

what are some of the adapted features of arteries?

Answer 43

• thick walls with elastic fibres to withstand the high pressure and maintain the blood pressure
• narrow lumen to help maintain high pressure

Question 44

what are the key features of veins?

Answer 44

carry blood at low pressure toward the heart

• carry deoxygenated blood
• thin walls
• large lumen
• contain valves
• blood flow at a slow rate

Question 45

what are the adapted features of veins?

Answer 45

large lumen reduces resistant to blood flow under low pressure
valves prevent back flow of blood (low pressure)

Question 46

what are the main features of capillaries?

Answer 46

• low pressure carries blood
• carries both oxygenated and deoxygenated blood
• walls are one cells thick
• slow speed

Question 47

what are the adapted features of capillaries?

Answer 47

one cells tick to substances can easily diffuse

leaky walls allow blood plasma to leak out and form tissue fluid

Question 48

what vessels of the heart, lung and kidney carry blood toward the organ?

Answer 48

heart - vena cava, pulmonary veins
lung - pulmonary artery
kidney - renal artery

Question 49

what vessels of the heart, lung and kidney carry blood away from the organ?

Answer 49

heart - aorta, pulmonary artery
lung - pulmonary vein
kidney - renal vein