5.4

Question 1

definition of endocrine system

Answer 1

a communication system using hormones as signalling molecules

Question 2

what do endocrine glands do

Answer 2

release hormones directly into the blood

Question 3

structure of the endocrine glands

Answer 3

• ductless
• consists of cells that manufacture and release the hormones directly into the blood in capillaries running through the gland

Question 4

what are target cells

Answer 4

the cells receiving the endocrine signal (hormones only have an effect in one type of tissue).

Question 5

what must target cells have in order to deal with non-steroid hormones

Answer 5

for non-steroid hormones, target cells must possess a specific receptor on their plasma membrane that is complementary to the shape of the signalling molecule

Question 6

endocrine organs

Answer 6

• pituitary gland
• thyroid gland
• thymus
• adrenal glands
• pancreas
• ovaries
• testes

Question 7

adrenal cortex definition

Answer 7

the outer layer of the adrenal gland

Question 8

adrenal medulla definition

Answer 8

the inner layer of the adrenal gland

Question 9

what hormones are released by the adrenal glands + what does it do

Answer 9

• adrenaline
• mineralcorticoids
• glucocorticoids
• cortisol

Question 10

adrenaline

Answer 10

stimulates the body to prepare for fight or flight:
increases heart rate, mental awareness
dilates pupils
inhibits action of gut
causing body hair to stand erect

Question 11

mineralcorticoids

Answer 11

help to control conc of Na + K in blood, maintain blood pressure

Question 12

glucocorticoids

Answer 12

helps to control the metabolism of carbohydrates, fat and proteins in the liver

Question 13

cortisol

Answer 13

released in response to stress/low blood glucose conc, used to make sex hormones

Question 14

what do α cells do

Answer 14

secrete glucagon

Question 15

what do β cells do

Answer 15

secrete insulin

Question 16

where are the α and β cells found

Answer 16

in a pancreas lobule in the islets of Langerhans

Question 17

what happens if there is a rise in blood glucose concentration

Answer 17

• detected by β cells
• β cells secrete insulin into blood
• insulin detected by receptors on liver+muscle cells
• liver+muscle cells remove glucose from blood, convert glucose to glycogen
• glucose conc falls

Question 18

what happens if there is a fallin blood glucose concentration

Answer 18

• detected by α cells
• α cells secrete glucagon into blood
• glucagon detected by receptors on liver cells
• liver cells convert glycogen to glucose and release glucose into blood
• glucose conc rises

Question 19

mechanism of insulin secretion

Answer 19

.draw diagram

Question 20

type 1 diabetes vs type 2 diabetes

Answer 20

type 1:

• younger people
• bodies immune system attacks+destroys β cells
• can’t make sufficient insulin

type 2:

• older people
• can’t produce enough insulin
• blood glucose conc permanently raised

Question 21

causes of type 1 diabetes

Answer 21

-result of an autoimmune response where bodies immune system attacks+destroys β cells, cannot synthesis sufficient insulin and cannot store excess glucose as glycogen

Question 22

causes of type 2 diabetes

Answer 22

-specific receptors on the surface of the liver and muscle cells become less responsive and cells lose their ability to respond to insulin in the blood