Hormonal Communication

Question 1

what is the endocrine system made up of

Answer 1

endocrine glands which secrete chemicals called hormones which are released directly into the bloodstream

Question 2

compare nervous and endocrine system

Answer 2

endocrine is long lasting
slower and involves chemicals over electrical impulses

Question 3

what are hormones

Answer 3

they are chemical messengers which are secreted directly into the blood stream

Question 4

steroid hormones

Answer 4

lipid soluble
pass through cell membrane and bind to steroid receptor forming hormone receptor complex

Question 5

non steroid hormones

Answer 5

secreted directly

Question 6

hormonal vs nervous system

Answer 6

hormonal has communcation by hromones
nervous has communication by nerve impulses
h trabsmission by blood system
n transmission by neurones
h response is widespread and slow
n is fast
h is long lasting

Question 7

what is the adrenal gland made up of

Answer 7

the adrenal cortex
adrenal medulla

Question 8

what is the adrenal cortex

Answer 8

The adrenal cortex: this produces hormones such as cortisol and aldosterone (outer region)
Adrenal cortex: The production of hormones by the adrenal cortex is controlled by hormones released by the pituitary gland in the brain. There are 3 main types of hormones produced by the adrenal cortex ( glucocorticoids, mineralocorticoids, Androgens)

Question 9

what is the adrenal medulla

Answer 9

The adrenal Medulla : produces hormones such as adrenaline, it is the inner region of glands.
Adrenal Medulla : Hormones are released when the sympathetic nervous system is stimulated, occurs when the body is stressed. ( adrenaline and noradrenaline)

Question 10

what is the main role of the pancreas

Answer 10

to control blood glucose levels and to produce and secrete hormones

Question 11

hpw does the pancreas act as an exocrine gland and endocrine gland

Answer 11

produces enzymes and releases via duct into duodenum
endocrine gland, it produces hormones and releases into the blood

Question 12

exocrine gland

Answer 12

Exocrine Gland : This contains an exocrine glandular tissue which is responsible for producing digestive enzymes and the pancreatic juice.

Question 13

endocrine gland

Answer 13

Endocrine glands: Pancreas produces insulin and glucagon, these control blood glucose concentration. They contain islets of langerhans which are responsible for producing insulin and glucagon and secreting these hormones directly into the bloodstream.

Question 14

islets of langerhans

Answer 14

it is lightly stained and is large it is an endocrine tissue which produces and secretes hormones
it contains alpha cells which produce and secrete glucagon
beta cells which produce and secrete insulin

Question 15

acini

Answer 15

darker, small berry like, exocrine, produce and secrete digestive enzymes

Question 16

alpha cells

Answer 16

p and s glucagon

Question 17

beta cells

Answer 17

p and s insulin

Question 18

what are the main factors of blood glucose concentration increasing?

Answer 18

• diet
• glycogenolysis ( this is when glycogen is broken down into glucose and released into the bloodstream)
• gluconeogenesis ( this is the production of glucose from non carbohydrate sources which is released into the bloodstream)

Question 19

decreasing blood glucose concentration

Answer 19

• respiration
• glycogenesis (production of glycogen)

Question 20

where is insulin produced

Answer 20

beta cells of the islets of langerhans in the pancreas

Question 21

bgc levels is high

Answer 21

beta cells respond by secreting insulin directly into the bloodstream

Question 22

what happens when insulin binds to its glycoprotein receptor

Answer 22

there is a change in the tertiary structure of the glucose transport protein channels causing channels to open allowing more glucose to enter

Question 23

bgc levels low

Answer 23

insulin increases rate of absorption of glucose
increases respiratory rate
increases release og glucagon

Question 24

how is insulin broken down

Answer 24

by enzymes in the cells of the liver

Question 25

bgc returns to normal

Answer 25

b cells detect reduce secretion of insulin

Question 26

what is glucagon

Answer 26

it is produced by alpha cells of the islets of langerhans in the pancreas

Question 27

what cells have glucagon receptors

Answer 27

liver and fat cells

Question 28

how does glucagon raise blood glucose concentration

Answer 28

- glycogenolysis, liver breaks down glycogen store into glucose and releases into bloodstream - reducing glucose absorbed - increasing gluconeogenesis

Question 29

negative feedback system of insulin and glucagon

Answer 29

booklet

Question 30

control of insulin secretion mechanism

Answer 30

- Normal bgc levels, K channels in the plasma membrane of beta cells are open allowing potassium ions to diffuse out of the cell. There is a normal resting potential - BGC rises, glucose enters cells by a glucose transporter - Glucose is metabolised in the mitochondria and ATP production occurs ATP binds to the potassium channels causing them to close - Potassium ions no longer able to diffuse out of the cell, potential difference reduces and depolarization occurs - Depolarization causes the voltage gated calcium channels to open - Calcium ions enter cells and cause the secretory vesicles containing insulin to release via exocytosis

Question 31

what is diabetes

Answer 31

it is when the pancreas does not produce insulin or cannot effectively respond to insulin this means they have high blood glucose conc

Question 32

type 1 diabetes

Answer 32

Unable to produce insulin (beta cells in the islets of langerhans do not produce any insulin) Cause is unknown, cannot be prevented or cured Evidence suggests that it arises as a result of an autoimmune response where the body's own immune system attacks beta cells It normally begins at childhood Controlled by regular injections of insulin, it is insulin dependent, if they inject too much insulin their boody may experience hypoglycaemia They have to continuously check their blood glucose concentration

Question 33

type 2 diabetes

Answer 33

Patients with type 2 cannot use insulin or control their blood sugar levels Their beta cells do not produce enough insulin or do not react insulin This is because the glycoprotein insulin receptor on the cell membrane does not work. Cells lose response to insulin so do not take up glucose and leave it in the bloodstream It is typically due to excess body weight, physically inactivity, overeating of carbohydrate Control their intake of diet and exercising Drugs can be used which stimulate insulin production and slow down the rate at which the body absorbs glucose from the intestine.

Question 34

'fight or flight' response

Answer 34

booklet

Question 35

function of adrenaline

Answer 35

to trigger liver cells to undergo glycogenolysis allowing respiration to increase allowing muscle contraction

Question 36

why can adrenaline not pass through the cell membrane

Answer 36

it is hydrophillic so it binds with receptors on surface of liver cells

Question 37

second messenger model

Answer 37

Adrenaline binds to receptor, ADENYL CYCLASE is activated ADENYL CYCLASE triggers the conversion of ATP into cAMP Increase in cAMP level activates protein kinase which activate enzymes

Question 38

what controls heart rate

Answer 38

autonomic nervous system, in particular the medulla oblongata in the brain

Question 39

how does the medulla oblongata work

Answer 39

2 centres linked to san one centre increases heart rate by sending impulses through the sympathetic nervous system one centre decreases the heart rate by sending impulses through the parasympathetic nervous system

Question 40

what are the 2 types of receptors which provide info affecting heart rate

Answer 40

baroreceptors chemoreceptors

Question 41

baroreceptors

Answer 41

detect changes in blood pressure aorta, vena cava, cartoid arteries

Question 42

chemoreceptors

Answer 42

chemical receptors which detect the changes in particular chemicals in the blood eg co2 located in cartpid arteries medulla and aorta