5.1.4- Hormonal Communication

Question 1

what are endocrine glands?

Answer 1

glands that secrete hormones directly into the blood.

Question 2

what is an example of an endocrine?

Answer 2

the pancreas (specifically the inslet of langerhans), as it secretes insulin and glucagon into the blood.

Question 3

what is endocrine communication detected by?

Answer 3

-target cells/tissues
-this is because the cells have a pacific receptor on their plasma membrane, which is complementary to the shape of the hormone molecule.

Question 4

what is the adrenal gland an example of?

Answer 4

an endocrine gland

Question 5

what are the two parts of the adrenal gland that releases hormones?

Answer 5

-cortex (secretes life-vital hormones)
-medulla (secretes non-life vital hormones)

Question 6

what 3 types of hormones and their examples, are released from the adrenal cortex?

Answer 6

-glucocorticoids, eg-cortisol
-mineralocorticoids, eg- aldosterone
-androgens, eg-sex hormones

Question 7

what is the secretion of hormones by the adrenal cortex controlled by?

Answer 7

the pituitary gland

Question 8

what are the two hormones, and their examples, that are released from the adrenal medulla?

Answer 8

-adrenaline, eg-adrenaline
-noradrenaline, eg-noradrenaline

Question 9

what is the secretion of hormones from the adrenal medulla controlled by?

Answer 9

when the sympathetic nervous system is stimulated

Question 10

what is the function of cortisol?

Answer 10

-regulates fat carbohydrates and protein metabolism
-stimulates liver to convert fat and protein to glucose

Question 11

what is the function of aldosterone?

Answer 11

-regulate mineral ion balance
-stimulates kidney and gut to uptake sodium ions to control blood pressure

Question 12

what is the function of sex hormones?

Answer 12

-smaller effect than oestrogen and testosterone

Question 13

what is the function of adrenaline?

Answer 13

-fight or flight response
-increased BR, MR, HR
-stimulates liver to hydrolyse glycogen and glucose
-inhibits peristalsis

Question 14

what is the function of noradrenaline?

Answer 14

-decreases HR, BR
-widens pupils and air passages in lungs
-narrows blood vessels in non-essential organs

Question 15

what does the histology of the pancreas consist of?

Answer 15

-islet of langerhans (made up of beta and alpha cells, endocrine), in the centre
-blood capillaries
-exocrine cells surrounding centre
-tubule/duct for enzymes in centre of enzyme-secreting cells

Question 16

what do the exocrine cells in the pancreas do?

Answer 16

secrete enzymes

Question 17

what is the role of the beta cells in the pancreas?

Answer 17

when there is a rise in blood glucose conc, beta cells detect this and secrete insulin

Question 18

what is the role of the alpha cells?

Answer 18

when there is a fall in blood glucose conc, alpha cells detect this and secrete glucagon

Question 19

how does insulin decrease blood glucose back to normal level?

Answer 19

-causes more glucose carriers placed in the plasma membrane so more glucose enters the cell
-stimulates glycogenesis (glucose to glycogen)

Question 20

how does glucagon increase blood glucose back to normal?

Answer 20

-stimulates gluconeogenesis (amino acids/fats to glucose
-glycogenolysis (glycogen to glucose)

Question 21

what are the 7 steps to insulin secretion by the pancreas, when blood glucose conc is too high?

Answer 21

-potassium ions diffuse out of open potassium channels
-glucose diffuses into beta cells when blood glucose conc is high
-glucose is used to make ATP in respiration
-ATP closes the potassium channels
-potassium ions accumulate inside the cell, creating a potential difference (cell is more negative inside)
-this change in pd causes calcium channels to open, so calcium ions diffuse into the beta cell
-calcium ions cause vesicles that contain insulin to fuse with plasma membrane, and so insulin is released via exocytosis.

Question 22

what is type 1 diabetes?

Answer 22

an autoimmune disease, when people are insulin dependent, as their beta cells are unable to produce insulin, due to being attacked by body cells.

Question 23

what is type 2 diabetes?

Answer 23

when people are unable to effectively use insulin and control their blood sugars.

Question 24

what causes type 1 diabetes?

Answer 24

-genetics
-family history

Question 25

what causes type 2 diabetes?

Answer 25

-obesity
-diet high in refined sugars
-family history
-ethnicity

Question 26

what is the treatment for type 1 diabetes?

Answer 26

daily insulin injection

Question 27

what is the treatment for type 2 diabetes?

Answer 27

-change in diet
-increased exercise
-tablets that slow down glucose absorption
-insulin rejection

Question 28

what is one alternative to using insulin injections to treat diabetes?

Answer 28

genetically modified bacteria through genetic engineering

Question 29

what are the 4 advantages of using insulin produced by genetically modified bacteria?

Answer 29

-produced in pure form, less allergic reaction
-produced in higher quantities
-cheaper to produce
-removes concerns over animal welfare/religious

Question 30

what are stem cells used for in diabetes treatment?

Answer 30

-promote differentiation into beta cells
-helps user create own insulin