year 11 first term

Question 1

what are hormones

Answer 1

hormones are chemical substances produced by glands and carried by the blood which alter the activity of one or more specific target organs

Question 2

what is the significance of glands having a good blood supply

Answer 2

endocrine glands have a good blood supply because they need the hormones they secrete to get into the bloodstream (specifically the plasma) as soon as possible in order for them to be transmitted to the target organs quickly and bring about a response

Question 3

what regulates hormone levels in the blood and what does it do when there is an imbalance

Answer 3

the liver
it transforms or breaks down any hormones that are in excess

Question 4

what are the effects of adrenaline in a fight or flight situation

Answer 4

• increased concentration of blood glucose for increased respiration in muscle cells
• increased heart and breathing rates for quick delivery of glucose and oxygen to and carbon dioxide from muscle cells
• diverted blood flow towards muscles and away from non-essential parts of the body (e.g. the alimentary canal) to ensure the availability of the reactants of respiration
• dilated pupils to allow as much light as possible to reach the retina so more information can be sent to the brain

Question 5

where is adrenaline secreted

Answer 5

the adrenal glands

Question 6

what is the role of adrenaline

Answer 6

to prepare the body to respond appropriately in a fight or flight situation

Question 7

where is insulin secreted

Answer 7

the pancreas

Question 8

what are the effects of insulin

Answer 8

• excess glucose in the blood is taken up by the muscles and liver for conversion into glycogen for storage

Question 9

what is the role of insulin

Answer 9

to lower blood glucose levels

Question 10

where is testosterone secreted

Answer 10

the testes

Question 11

what are the effects of testosterone

Answer 11

• stimulates the development of secondary sexual characteristics (puberty) in males

Question 12

what is the role of testosterone

Answer 12

it is the main sex hormone in males

Question 13

where is oestrogen secreted

Answer 13

the ovaries

Question 14

what are the effects of oestrogen

Answer 14

• stimulates the development of secondary sexual characteristics in females
• controls the menstrual cycle

Question 15

what is the pituitary gland

Answer 15

it is the ‘master gland’ situated at the base of the brain

Question 16

what does the pituitary gland secrete

Answer 16

• TSH: stimulates the activity of the thyroid gland
• LH: triggers ovulation in women
• FSH in women: stimulates the growth of eggs in the ovaries and controls the menstrual cycle
• FSH in men: controls the production of sperm

Question 17

what is the thyroid gland

Answer 17

it is one of the glands that play a role in metabolism, growth, development and body function regulation

Question 18

what does the thyroid gland secrete

Answer 18

thyroxine (a.k.a T4): plays roles in metabolic rate regulation, digestion, heart and muscle function, brain development and bone maintenance

Question 19

apart from insulin, which hormones does the pancreas secrete

Answer 19

pancreatic amylase: chemically digests carbohydrates
lipase: chemically digests lipids

Question 19

differentiate between the endocrine and nervous systems in terms of:
1. type of message
2. speed of transmission
3. length of effect
4. makeup

Answer 19

type of message
- chemical hormones
- electrical hormones

speed of transmission
- slower
- very fast

length of effect
- longer (until hormone is broken down)
- short (until nerve impulses stop)

makeup
- glands
- nerves (neurones), brain, spinal cord

Question 20

what is glucagon

Answer 20

• secreted by the pancreas when blood glucose levels fall
• stimulates the liver and muscle cells to convert stored glycogen back into glucose to be released into the blood for use e.g. respiration