Endocrine System

Question 1

Homeostasis

Answer 1

Maintaining a constant internal environment, despite changes in the external environment
Carried out by both endocrine and nervous system

Question 2

Feedback Systems

Answer 2

The body responds to a stimulus, and the response alters the original stimulus

Question 3

Homeostasis’ impact on fluid environment of cells

Answer 3

1. optimum nutrients, ions, gases, and water
2. constant temperature
3. optimum pressure

Question 4

Stages in a feedback system

Answer 4

1. stimulus
2. receptor
3. modulator
4. effector
5. response
6. feedback

Question 5

Endocrine gland

Answer 5

secretes substance into the bloodstream eg. hormones

Question 6

Exocrine gland

Answer 6

secretes substances onto a surface through a duct

Question 7

Hormones

Answer 7

secreted from an endocrine gland, transported by blood, affects target cells/organs, specific as they bind to certain receptors

Question 8

Paracrines

Answer 8

“local hormones”; chemicals secreted by all cells, used to communicate with adjacent cells

Question 9

Protein and amine hormones

Answer 9

attach to receptors on the cell membrane, causes secondary messengers to activate cellular enzymes

Question 10

Steroid hormones

Answer 10

attach to internal receptors on organelles, activates genes that control protein production (hormone-receptor complex)

Question 11

Functions of hormones

Answer 11

activate genes to produce enzymes or proteins, denature enzymes, change rate of enzyme or protein production

Question 12

Enzyme amplification

Answer 12

one hormone molecule can activate thousands of enzyme molecules - only a small amount of hormones are needed

Question 13

Removal of hormones

Answer 13

target cells, liver, kidney

Question 14

Releasing/inhibiting factors

Answer 14

produced by nervous system to trigger hormone production by endocrine glands (anterior pituitary)

Question 15

Hypothalamus

Answer 15

Regulates body temp, water balance, heart rate

Question 16

Pituitary gland

Answer 16

joined to the hypothalamus by the infundibulum; secretes hormones that regulate activity of endocrine glands

Question 17

Anterior pituitary

adenohypophysis

Answer 17

connected to hypothalamus by blood vessels; inhibiting and releasing factors secreted by hypothalamus trigger production of of hormones

Question 18

Posterior pituitary

neurohypophysis

Answer 18

Hormones pass from the hypothalamus to posterior pituitary through nerve impulses

Question 19

Hormones secreted by anterior pituitary

Answer 19

gonadotrophins, growth hormone, thyroid stimulating hormone, adrenocorticotrophic hormone, prolactin

Question 20

Hormones secreted by posterior pituitary

Answer 20

releases oxytocin, antidiuretic hormone

Question 21

Thyroid gland

Answer 21

produces thyroxine, calcitonin

Question 22

Effects of thyroxine

Answer 22

regulates metabolic rate by regulating energy production from cell respiration - increases body temperature

Question 23

Calcitonin

Answer 23

promotes storage of calcium in the bones, reducing blood calcium levels

Question 24

Pancreas

Answer 24

both exocrine and endocrine; secretes digestive enzymes, insulin, glucagon

Question 25

Effects of insulin

Answer 25

Reduces blood glucose levels, stimulates cells to take up glucose and store it as glycogen or fat

Question 26

Effects of glucagon

Answer 26

Increases blood glucose levels by stimulating breakdown of glycogen and fat from cells into glucose

Question 27

Gonads

Answer 27

antrogens, oestrogen and progesterone

Question 28

Adrenal medulla

Answer 28

(middle) secretes adrenalin and noradrenaline

Question 29

Adrenal cortex

Answer 29

produces corticosteroids - mineralocorticoids, glucorticoids, gonadocorticoids

Question 30

Effects of mineralocorticoids

Answer 30

main mineralocorticoid - aldosterone; retains sodium, removes potassium from body

Question 31

Effects of glucocorticoids

Answer 31

Required for normal metabolism; increase in ATP production, blood pressure, decreased immune response, depressed inflammatory response, slower healing. Low doses provide resistance to stress, high doses depress the immune system

Question 32

Parathyroids

Answer 32

produces parathormones

Question 33

Effects of parathormones

Answer 33

increases blood calcium and phosphate levels

Question 34

Thymus

Answer 34

decreases in size as child matures, secretes thymosins; maturations of T lymphocytes