hormonal communication

Question 1

endocrine def

Answer 1

a gland that secretes hormones directly into the blood

Question 2

exocrine def

Answer 2

a gland that secrets chemicals other than hormones into a duct

Question 3

what does adenyl cyclase do

Answer 3

converts ATP to cAMP (second messenger)

Question 4

give examples of protein, peptide or amino acid derived hormones (non steroid)

Answer 4

first messenger - adrenaline, insulin, glucagon, oxytocin

Question 5

give examples of steroid hormones

Answer 5

oestrogen, testosterone, progesterone

Question 6

what is bile for

Answer 6

alkaline to neutralise stomach acid

Question 7

name exocrine parts of pancreas

Answer 7

Duct cells (secrete NaHCO3), Acinar cells (secrete digestive enzymes), Bile duct

Question 8

name endocrine parts of a pancreas

Answer 8

Islets of Langerhans (insulin and glucagon)

Question 9

what do acinar cells do in the pancreas

Answer 9

produce digestive enzyme

Question 10

what do alpha and beta cells do in pancreas

Answer 10

alpha - glucagon insulin - beta

Question 11

what does pancrease juice contain

Answer 11

pancreatic amylase, trypsinogen, lipase, NaHCO3

Question 12

what is hypoglycaemia

Answer 12

low blood sugar, tiredness, confusion, death, impairment of brain function

Question 13

what is hyperglycaemia

Answer 13

high blood sugar, organ damage (due to raised blood pressure in capillaries -> high water potential so water drawing in and vol of blood increases)

Question 14

Regulating blood glucose if glucose too low

Answer 14

1) Receptors- alpha and beta cells in islets of langerhans
2) Co-ordination centre - B cells produce less insulin. A cells secrete more glucagon
3)Effector- liver and muscles - glycogenolyisis

Question 15

Process of glucagon being used in action (6 steps)

Answer 15

1) 1st messenger binds to complementary cell surface receptor on target cell (hepatocytes)
2) activates the G protein
3) activated g protein activates adenyl cyclase
4) adenyl cyclase converts ATP to cAMp (2nd messenger)
5) cAMP brings the response within the cell
6) glycogenolysis and gluconeogenesis)

Question 16

actions of insulin (4 points)

Answer 16

• target cells are liver muscles and brain
• binds to cell surface receptor –> activates tyrosin kinase. this phophorylated inactive enzymes to active enzymes
• then more glucose transporter proteins are placed in cell surface membrane –> more glucose enters cell
• increased glucose in cellleads to make glycogen, make fats, respiration

Question 17

what is glycogenolysis

Answer 17

conversion of glycogen to glucose

Question 18

what is gluconeogenesis

Answer 18

conversion of amino acids and fats to glucose

Question 19

what is glycogeneis

Answer 19

conversion of glucose to glycogen

Question 20

How is insulin secreted? (6 steps)

Answer 20

1) glucose enters B cell by faciliated diffusion
2) glucose is respired by B cell to produce ATP
3) Higher levels of ATP –> K+ ion channels close
4) K+ buildup so membrane depolarises
5) depolarisation causes Ca2+ volatage gated channels open so Ca2+ moves in
6)Ca2+ causes vesicles containing insulin to move & fuse w/ cell surface membrane. Insulin released by exocytosis

Question 21

what is type 1 diabetes?

Answer 21

autoimmune disease, body own immune system destroys the beta cells

Question 22

what is type 2 diabetes?

Answer 22

non insulin dependent. body’s reponse to insulin has declined and pancreas is unable to produce enough insulin