endocrine system

Question 1

definition

Answer 1

• the endocrine system uses hormones to respond to changes in the environment or changes inside the body
• it is made up of endocrine glands

Question 2

endocrine glands

Answer 2

-endocrine glands produce and secrete specific hormones directly into the blood

Question 3

hormones

Answer 3

• chemicals that are carried in the blood plasma to other parts of the body
• they are relatively slow to act
• only affect particular cells in target tissues
• hormones tend to have a long-lasting effect

Question 4

pituitary gland

Answer 4

hormones: many - some stimulate other glands to release hormone eg thyroid stimulating hormone

Question 5

thyroid gland

Answer 5

hormone: thyroxine - regulates basal metabolic rate, heart rate, temperature

Question 6

adrenal gland

Answer 6

hormone: adrenaline - prepares for a fight or flight response

Question 7

pancreas

Answer 7

hormones: insulin and glucagon - regulate blood sugar

Question 8

ovary

Answer 8

hormones: oestrogen and progesterone - helps regulate menstrual cycle

Question 9

testes

Answer 9

hormone: testosterone - controls puberty and sperm production

Question 10

thyroxine and negative feedback

Answer 10

• the level of thyroxine in the blood is monitored by the hypothalamus
• when thyroxine in the blood is higher than the normal, the release of TSH by the pituitary gland is inhibited
• less thyroxine is released from the thyroid gland.
• the level of thyroxine in the blood falls to within the normal range
• when thyroxine in the blood is lower than the normal range, TSH is released by the pituitary gland
• the thyroid gland is stimulated to release more thyroxine
• the level of thyroxine in the blood rises to within the normal range

Question 11

TSH

Answer 11

• thyroid stimulating hormone
• released by pituitary gland, goes to thyroid gland
• controls the release of the thyroxine hormone

Question 12

adrenaline release

Answer 12

• adrenaline release is controlled by the sympathetic nervous system
• in scary or stressful situations, the brain sends nerve impulses to the adrenal glands (above kidneys) which stimulate it to release adrenaline
• nervous impulses used instead of hormones because hormones are slow acting so the response would take time to occur, which might put the body in danger

Question 13

hormonal vs nervous system

Answer 13

• Type of signal: nerve=Electrical (chemical at synapses), hormone=Chemical
• Effectors: nerve=muscles/glands hormone=target tissues
• Speed of response: nerve=rapid hormone=slower
• Duration of response: nerve=short (until nerve impulses stop), hormone=long (until hormone is broken down)
• both involved in homeostasis

Question 14

adrenaline functions

Answer 14

• stimulates the liver to break down glycogen into glucose
• increases breathing and heart rate
• stimulates more blood flow to muscles
• these responses allow an increased supply of oxygen and glucose to cells in the brain and muscles ->increased rate of aerobic respiration, supplying the cells with more ATP to respond appropriately to stress