Tissues 10- Signalling between cells I

Question 1

Why do cells need to communicate

Answer 1

process information:
Sensory stimuli

Self preservation:
Identify danger and take appropriate actions

Voluntary movement:

Homeostasis:

Question 2

What are the physiological responses to hypoglycemia

Answer 2

Glycogenlysis
glucogenesis

Process:
Glucagon secreted by alpha cells of the islets of langerhans (in pancreas)

glucagon travels out of pancreas in blood vessels

Glucagon stimulates glycongenolysis and glucogenesis within liver

Known as endocrine signalling

Question 3

What are the physiological responses to hyperglycemia

Answer 3

Glucose uptake
Reduces Glycogenlysis
Reduces glucogenesis

Process
Increased blood glucose -> increase levels of insulin secreted by beta cells in the islet langerhans
Insulin has a paracrine effect and inhibits glucagon secretion
Insulin also has endocrine effect on liver

Question 4

Describe signalling between membrane attached proteins in regards of the bodies viral response

Answer 4

Blood bounre virus detected within bloodstream by antigen presenting cell

APC digests pathogen expresses major histocompatablity (MHC) class II molecules on surface

Circulating t lmphocytes engages with MHC molecule through t cell receptor interaction

plasma membrane protiens on adjacent cells interacting

Question 5

What happens when the t cell is activated

Answer 5

IL-2 released

acts on its own cell

Autocrine effect