Hormonal communication 5.4

Question 1

what are hormones

Answer 1

released into blood directly and travel around the whole body and bind to specific receptors on target cells to produce a response

Question 2

what are non-steroid hormones

Answer 2

proteins like insulin that cant pass through the cell membrane so bind to receptors on the cell surface of target cells

Question 3

what are steroid hormones

Answer 3

lipids that can pass through cell membrane of target cells
produced by adrenal cortex

Question 4

describe the secretion and detection of hormones

Answer 4

hormone is the first messenger and binds to specific receptors on cell surface

membrane of target cells

activates adenyl cyclase an enzyme

cAMP activates a cascade of enzyme controlled reactions

Question 5

what are the two parts of the adrenal gland

Answer 5

adrenal cortex

adrenal medulla

Question 6

describe the adrenal cortex

Answer 6

secretes steroid hormones - like cortisol when stressed

inc the uptake of Na+ and H2O by kidneys
- maintains blood pressure during stress
- prevents dehydration

suppress immune system
- prevent antibody production
- prevent histmaines and cytokinines production as this promotes inflammation
- prevents autoimmunity

• increased infection risk
• slower wound healing

Question 7

describe the adrenal medulla

Answer 7

secretes adrenaline- when stressed

inc. heart rate and breathing rate

breaks down glycogen into glucose

vasoconstriction so blood is diverted from brain and muscles

Question 8

describe the pancreas

Answer 8

made of Islets of Langerhans

B-cells: secrete insulin

a-cell: secrete glucagon

acinar cells: release hydrolytic enzymes

Question 9

what are acinar cells

Answer 9

produce digestive enzymes into the small intestine

Question 10

what does sodium hydrogencarbonate do

Answer 10

neutralise stomach acid in the pancreas

Question 11

when does blood glucose conc. increase

Answer 11

• ## eating food containing carbohydrates

Question 12

when does blood glucose conc. fall

Answer 12

after exercise , more glucose used in respiration during exercise to release energy

Question 13

when glucose conc. is too high what happens

Answer 13

insulin binds to specific receptors on liver and muscle cells

inc. permeability –> cells take up more glucose

glycogenesis - glucose to glycogen

glycogen stored as an energy source

inc. rate of respiration

Question 14

when glucose conc. is too low what happens

Answer 14

glucagon binds to receptors on liver cells only

glycogenolysis - glycogen to glucose

gluconeogenesis - glycerol and AA to glucose

for respiration

Question 15

how is insulin regulated

Answer 15

B-cells contain insulin in vesicles

when blood glucose conc. is high, more glucose enters the B-cells by facilitated diffusion

more ATP made, triggers K+ channels in plasma membrane to close

inside is more -ve than outside

depolarisation triggers Ca2+ channels to open, Ca2+ diffuse into B-cell

causes vesicles to fuse with B-cell plasma membrane releasing insulin via exocytosis

Question 16

what is Type 1 diabetes and who can get it

Answer 16

autoimmune disease where body cells attack B-cells
insulin not produced

young adults or children
higher risk with family history

Question 17

with type 1 diabetes what happens after you eat

Answer 17

blood glucose conc. stays high

Question 18

with type 1 diabetes what happens to the kidneys

Answer 18

cant reabsorb all glucose
excreted as urine

Question 19

symptoms of type 1 diabetes

Answer 19

thirsty

frequent urination

weight loss

Question 20

treatments for type 1 diabetes

Answer 20

insulin injections regularly

islet cells transplant

insulin pump

Question 21

what is type 2 diabetes and who can get it

Answer 21

B-cells dont produce enough insulin or body cells dont respond to insulin because insulin receptors dont work properly
blood glucose conc. is higher than normal

obesity or from african/asian ethnic groups or family history

Question 22

symptoms of type 2 diabetes

Answer 22

hypoglycemia - low blood sugar

hyperglycemia - high blood sugar

weight gain

frequent thirst and urination

Question 23

treatments for type 2 diabetes

Answer 23

low sugar and salt diet

exercise

medication like metformin

Question 24

what other ways can you obtain insulin from to cure diabetes

Answer 24

genetically modified bacteria or stem cells

Question 25

benefits of using GM bacteria to cure diabetes

Answer 25

cheaper make large amounts make human insulin instead of animals which for vegans/vegetarians or religious ppl they prefer this

Question 26

why is it beneficial that GM bacteria can produce human insulin

Answer 26

less likely to be rejected rather than animal insulin vegetarians and vegans prefer using human insulin religious reasons

Question 27

what are the benefits of using stem cells to cure diabetes

Answer 27

- pluripotent - produce B-cells

Question 28

describe the structure of the adrenal glands

Answer 28

1. adrenal medulla : . secretes adrenaline 2. adrenal cortex: Secretes aldosterone

Question 29

what does aldosterone help regulate

Answer 29

helps the kidneys regulate blood pressure

Question 30

exocrine gland

Answer 30

- Secrete substances into ducts that carry them to external surfaces Examples: - Salivary glands (secrete saliva into the mouth via ducts). - Sweat glands (release sweat onto the skin). - Pancreatic exocrine cells (secrete acinar cells into the small intestine Secretions: - Enzymes (e.g., amylase in saliva). - Mucus (e.g., from goblet cells).

Question 31

endocrine gland

Answer 31

- Secrete hormones directly into the bloodstream (no ducts involved). - Hormones travel in the blood to target organs/cells with specific receptors. Examples: - Pancreas (islets of Langerhans) – secretes insulin and glucagon. - Adrenal glands – secrete adrenaline. - Pituitary gland – releases FSH, ADH, growth hormone, etc.