Thermoregulation

Question 1

What happens if body temp is too high

Answer 1

• sweat glands release onto skin surface
  = sweat evaporates
  = takes heat energy away with it
  = cools body down
• blood vessels vasodilate
  = more heat energy transferred to surroundings

Question 2

What is flushing

Answer 2

When body temp too high body flushes
- blood vessels get wider
- more blood flows through capillaries
- heat can transfer out of blood
= return to normal temp

Question 3

What happens if body temp too low

Answer 3

• blood vessels containing capillaries constrict
  = less blood flow near surface
  = less heat energy lost to surroundings
• muscles contract
  = produces a lot of energy from respiration
  = a lot of chemical reactions take place
  = result in a lot of heat energy produced as waste

Question 4

What is shivering

Answer 4

• skeletal muscles contract to release heat

Question 5

What’s the endocrine system

Answer 5

• consist of glands which secrete hormones directly into bloodstream

Question 6

Compare endrocrine vs nervous system

Answer 6

Nervous
- faster signalling
- uses electrical impulses which travel down neurones

Endocrine
- uses hormones which are chemicals carried in the bloodstream

Question 7

Pancreas function

Answer 7

Release hormones
- control concentration of glucose in blood

Question 8

Ovaries and testes function

Answer 8

Release hormones
- involved in puberty and reproduction

Question 9

Thyroid gland function

Answer 9

Produce hormones
- involved in growth and regulate body’s basal metabolic rate

Question 10

Adrenal glands function

Answer 10

Release hormone adrenaline
- produced in fear or stress

Question 11

Pituitary gland function

Answer 11

Release hormones into blood depending on conditions
- act on other glands
- trigger range of different effects on the body

Question 12

What controls glucose concentration in blood

Answer 12

• pancreas monitors blood glucose concentration
• releases insulin if too high

Question 13

Insulin function

Answer 13

Triggers body cells to take up glucose from blood
- also triggers liver and muscle cells to store excess glucose
= means glucose concentration returns to normal

Question 14

What happens to type 1 diabetes

Answer 14

Pancreas doesn’t produce enough insulin

Question 15

Describe type 2 diabetes

Answer 15

• body cells no longer respond to insulin produced by the pancreas - the person still makes insulin but their cells are resistant to it and don’t respond as well as they should
• treated with balanced diet and exercise
• obesity is a large risk factor

Question 16

What happens if blood glucose too low

Answer 16

• pancreas releases glucagon
• triggers liver cells to convert glycogen stores back to glucose
• then glucose released into blood
  = return to normal

Question 17

Adrenaline function

Answer 17

• increase heart rate
  = more oxygen and glucose delivered in the blood to the brain and muscles
  = prepares body to either fight or run away

Question 18

Where is the thyroid gland

Answer 18

Base of the neck
= produce thyroxine

Question 19

What happens when thyroxine levels fall
(Negative feedback cycle)

Answer 19

• pituitary gland releases TSH into the bloodstream
  = triggers thyroid gland to release more thyroxine into the blood
  = increased level of thyroxine detected by the brain
  = prevent pituitary gland from releasing TSH
  = thyroid gland releases less thyroxine

Question 20

Why we need to maintain body temp

Answer 20

Maintain temp that enzymes work best
Prevent damage to cells/ enzymes

Question 21

How are hormones transported

Answer 21

Blood plasma

Question 22

How does the decaying process warm things up

Answer 22

Microorganisms respire
Respiration releases thermal energy

Question 23

Why urine on hot day has high concentration of mineral ions and urea

Answer 23

• more sweating on hot day
• more water loss by sweating
• more water reabsorbed by kidney
  = lower volume of urine

Question 24

Define a hormone

Answer 24

Chemical messenger

Question 25

How does the body keep constant temperature

Answer 25

- temp receptors in thermoregulatory centre - TC detects core body temp - temp receptors in skin send impulses to TC= give info about skin temp - if core body temp too high = skin capillaries dilate = more blood flows and more heat lost - sweat glands release more sweat to cool body by evaporation - if core body temp too low = blood vessels constrict = reduce blood flow = less heat lost - muscles can shiver to release heat energy

Question 26

Perfect temp of internal body

Answer 26

37 deg = best for enzymes to work

Question 27

How to decrease body temp

Answer 27

Blood vessels supplying capillaries dilate = more blood through skin leads to greater heat loss

Question 28

Reason for increase core body temp

Answer 28

Increase in respiration = releases energy as a waste product

Question 29

Reasons for decreased skin temp

Answer 29

Sweating = evaporates and cools the skin

Question 30

Why is there increase of skin surface temp

Answer 30

Vessels supplying skin capillaries dilate = more blood flows nearer to surface of the skin = more heat lost

Question 31

How does body react to low blood sugar levels

Answer 31

Pancreas detects low blood glucose = produces glucagon = glucagon converted into glucose

Question 32

Why happens to amino acids that can’t be stored

Answer 32

Amino acids broken down to form urea in the liver Urea filtered by kidney and stored in bladder

Question 33

How does thermoregulatory centre send info to sweat glands in the skin

Answer 33

Via neurones

Question 34

Why more water lost through breathing

Answer 34

more energy needed = more respiration = increased breathing