Signalling Between Cells 1

Question 1

Why do cells communicate?

Answer 1

process info e.g. stimuli
self preservation e.g. reflex
voluntary movement
homeostasis e.g. glucose

Question 2

define endocrine

Answer 2

single travels in blood to act on distant target cell

Question 3

define paracrine

Answer 3

signal acts on adjacent cell

Question 4

define autocrine

Answer 4

signal acts on same cell it was produced by

Question 5

Give an example of endocrine signalling

Answer 5

during hyperglycaemia insulin is secreted by the beta pancreas cells and travels to the liver, muscle an adipose tissue to increase glucose uptake and glycolysis

Question 6

Give examples of paracrine signalling

Answer 6

1) during hyperglycaemia insulin secrete by the beta cells of pancreas inhibit glucagon secretion by the alpha cells
2) osteoclast activating factors produced by osteoblasts

Question 7

Give an example of autocrine signalling

Answer 7

activated T-cell expresses interleukin 2 receptor on surface and also secretes interleukin 2 which binds to the receptors

Question 8

define signalling between membrane attached proteins

Answer 8

plasma membrane proteins on adjacent cells interact

Question 9

give an example of signalling between membrane attached proteins

Answer 9

hepatitis C is detected in blood stream by APC which digests the pathogen and expresses MHC class  molecule on surface 
T lymphocyte attaches to MHC class 2 molecule via receptor