pancreas

Question 1

why is the pancreas an unusual gland ?

Answer 1

it functions as the endocrine + exocrine gland

Question 2

what is the exocrine function of the pancreas ?

Answer 2

secretion of pancreatic juice

the juice flows along the pancreatic ducts into the duodenum

> helps chemical digestion

Question 3

what is the endocrine function of the pancreas ?

Answer 3

the secretion of hormones

by groups of cells called the islets of langerhans

islets are scattered throughout the pancreas

Question 4

where do the hormones secreted by the pancreas go ?

Answer 4

the hormones they secrete pass directly into the bloodstream

Question 5

which cells are in the islet of langerhans ?

Answer 5

alpha cells

beta cells

Question 6

which hormone do the alpha cells secrete ?

Answer 6

glucagon

Question 7

which hormone do the beta cells secrete ?

Answer 7

insulin

Question 8

what are the functions of insulin/ glucose ?

Answer 8

both play a role in controlling the blood sugar level in the blood

Question 9

what is the normal glucose concentration in healthy humans ?

Answer 9

3,5 - 5,5 mmole/l

in the blood

Question 10

what is glucose ?

Answer 10

a simple sugar derived from digesting eaten carbohydrates

Question 11

what is glucose the primary source of ?

Answer 11

cellular energy

Question 12

how is glucose transported throughout the body ?

Answer 12

in the bloodstream

Question 13

what can glucose not enter cells without ?

Answer 13

the aid of insulin

Question 14

what does insulin do to blood sugar levels ?

Answer 14

lowers it

Question 15

what does glucagon do to the level of blood sugar ?

Answer 15

raises it

Question 16

what effects do glucagon and insulin have on each other ?

Answer 16

antagonistic effects

opposite

Question 17

how does insulin lower blood glucose levels ?

Answer 17

after a meal with carbohydrates

glucose from digested food is absorbed from the small intestine + moves into the blood stream

blood passes through pancreas
> beta cells detect raised glucose levels

respond by secreting insulin into the blood

Question 18

which cells detect the drop in glucose and what do they do ?

Answer 18

the insulin secreting cells

stop secreting insulin into the blood

Question 19

what are the main target cells of insulin ?

Answer 19

liver + muscles

Question 20

what are the effects of insulin on their target cells ?

Answer 20

1. makes cell l membranes more permeable to glucose
   > more glucose leave bloodstream + enter cells
2. increases rate that glucose is converted to glycogen
   >in cells, encourages more glucose to enter

Question 21

what can glucose be converted to and then stored ?

Answer 21

converted to fat

stored under skin

Question 22

what does the insulin process do ?

Answer 22

take glucose out of blood

> lowers blood glucose levels

Question 23

what is the insulin effect an example of ?

Answer 23

negative feedback control mechanism

Question 24

when are glucose levels low in a healthy person ?

Answer 24

waking up in the morning

after exercise

Question 25

how does glucagon increase the blood glucose level ?

Answer 25

1. as blood passes through the pancreas, glucagon secreting cells detect low glucose level > secrete glucagon into the blood (alpha cells) 2. glucagon affects liver cells (not muscle) > breakdown of stored glycogen into glucose 3. liver releases glucose into blood > increasing blood glucose level

Question 26

which cells detect the rise in glucose levels and what do they do ?

Answer 26

alpha cells when the blood flows though pancreas > stop secreting glucagon into blood

Question 28

what is the glycogen effect an example of ?

Answer 28

negative feedback control system