Topic 5 - Blood & Organs

Question 1

journey of blood around body

Answer 1

body tissues ->

vena cava ->

right atrium ->

right ventricle (through semilunar valve) ->

pulmonary artery ->

lungs ->

pulmonary vein ->

left atrium ->

left ventricle (through semilunar valve) ->

aorta ->

body tissues

Question 2

arteries

Answer 2

carry blood AWAY from the heart

Question 3

veins

Answer 3

carry blood TOWARDS the heart

Question 4

pulmonary artery

Answer 4

deoxygenated blood

from heart to lungs

only artery that carries deoxygenated blood

Question 5

pulmonary vein

Answer 5

oxygenated blood

from lungs to heart

only vein that carries oxygenated blood

Question 6

vena cava

Answer 6

deoxygenated blood

from body tissues to heart

Question 7

aorta

Answer 7

oxygenated blood

from heart to body tissues

Question 8

renal vein

Answer 8

deoxygenated blood

from kidneys to vena cava

Question 9

renal artery

Answer 9

oxygenated blood

from aorta to kidneys

Question 10

hepatic portal vein

Answer 10

deoxygenated blood

from gut to liver

Question 11

hepatic vein

Answer 11

deoxygenated blood

from liver to vena cava

Question 12

hepatic artery

Answer 12

oxygenated blood

from aorta to liver

Question 13

features of arteries

Answer 13

• carry blood away from heart
• large
• carry blood at high pressure
• thick muscular walls with elastic tissue
• narrow lumen keeps pressure high
• largest blood vessels

Question 14

features of capillaries

Answer 14

• carry blood through body tissues
• allow substances to exchange between tissues and blood
• smallest blood vessels
• permeable walls
• one cell thick -> short diffusion distance
• low pressure blood
• exchange of oxygen, carbon dioxide, glucose and urea

Question 15

features of veins

Answer 15

• carry blood towards the heart
• thin walls
• wide lumen
• low pressure blood
• contain valves, preventing backflow of blood

Question 16

components of blood

Answer 16

plasma
cells
platelets

Question 17

platelets

Answer 17

clot blood together during injury

stops blood loss, forming a physical barrier

Question 18

process of platelets healing a wound

Answer 18

• upon exposure to air, platelets release enzyme
• enzyme converts soluble fibrinogen into soluble fibrin
• fibrin -> sticky and forms net over wound
• net traps RBCS, forming blood clot
• phagocytes attract to wound and engulf pathogens
• blood clot hardens, forming a scab as new skin develops underneath

Question 19

RBCS

Answer 19

• carry oxygen from lungs to tissues
• contain protein haemoglobin, which binds to oxygen
• no nucleus -> more space for haemoglobin
• biconcave shape increases surface area

Question 20

WBCS

Answer 20

• defend against pathogens
• two types - phagocytes and lymphocyte B (memory cells)
• PHAGOCYTOSIS = process by which phagocyte binds to and engulfs pathogen

Question 21

Plasma

Answer 21

• carries substances and cells around body
• yellowish liquid
• carries RBC, WBC and platelets

Question 22

antigen

Answer 22

any substance that the body sees as foreign, causing an immune response

Question 23

antibodies

Answer 23

protein produced by WBC that binds to antigens

Question 24

Barriers that prevent the entry of pathogens

Answer 24

• nose hairs -> coated with mucus that catches pathogens
• enzymes in tears
• skin -> covers body, physically preventing pathogens from entering

Question 25

process of phagocytosis

Answer 25

- phagocyte tracks down pathogen + binds to it - membrane of phagocyte surrounds pathogen, engulfing it - digestive enzymes in phagocyte break down pathogen, destroying it

Question 26

herd immunity

Answer 26

when wide[sread vaccination occurs, preventing outbreaks of disease

Question 27

vaccines

Answer 27

dead or deactivated versions of disease that are injected into the body to stimulate an immune response and the production of memory cells, meaning the body will be able to defend against the real disease.

Question 28

drawbacks of vaccines

Answer 28

- dont always give full immunity - can cause severe reactions e.g. seizures - cause mild symptoms such as fever or sore arm

Question 29

cardiovascular disease

Answer 29

disease of the circulatory system

Question 30

coronary heart disease

Answer 30

when fatty plaque builds up due to high levels of cholesterol, causing lumen to narrow -> this redues the flow of blood through the coronary arteries can cause chest pain as heart is starved oxygen can cause heart attacks!!!!

Question 31

stent

Answer 31

- splints placed into the narrow artery to widen it - they are left there to maintain this - benefits: lasts a long time, immediate effect, quick surgery

Question 32

statins

Answer 32

- pills that decrease amount of cholesterol, which builds up to form fatty plaques - disadvantages: pills to be taken every day, can take months to see effects, side effects such as kidney failure and headaches

Question 33

what happens when heart valves are faulty?

Answer 33

blood can go backwards or not enough blood can pass through

Question 34

treatments for heart failure

Answer 34

- replacement with artificial heart (metal) - replacement with biological heart (animal / other human)

Question 35

kidneys

Answer 35

remove urea and regulate water & ion levels

Question 36

why is too much water in the body dangerous?

Answer 36

too much water - our cells can gain water and burst

Question 37

ultrafiltration

Answer 37

process by which small substances e.g. glucose, amino acids and water are absorbed from blood into kidneys

Question 38

selective reabsorption

Answer 38

process by which filtrate passes through kidneys and glucose is reabsorbed from tubules into blood

Question 39

ADH

Answer 39

responsible for regulating water levels in body -> negative feedback loop

Question 40

hypothalamus

Answer 40

gland in the brain that detects levels of water in the body

Question 41

low water levels in body response

Answer 41

1. hypothalamus detects low water 2. sends signal to pituitary gland to release more ADH 3. ADH travels around body in blood, stimulates kidneys to reabsorb more water from tubules 4. less urine, concentrated amounts

Question 42

high water levels in body response

Answer 42

1. hypothalamus detects high water 2. sengs signal to pituitary gland to release less ADH 3. ADH travels around body in blood, stimulateskidneys to reabsorb less water from tubules 4. more urine, dilute amounts

Question 43

nephron

Answer 43

a tiny unit within the kidney -> each kidney has millions of them

Question 44

features of the nephron

Answer 44

glomerulus, bowman's capsule, PCT, loop of hele, DCT, collecting duct

Question 45

what passes through the nephron?

Answer 45

glomerular filtrate

Question 46

where does ultrafiltration occur?

Answer 46

bowman's capsule / glomerulus

Question 47

where does selective reabsorption occur?

Answer 47

the PCT and DCT (convoluted tubules)