Wk 3 Physiology

Question 1

What are the categories of cell to cell communication

Answer 1

• Cell-cell contact
• Autocrine
• Paracrine
• Endocrine
• Neuroendocrine

Question 2

Explain electrical communication

Answer 2

• Adjacent cells only
• Through gap junctions
• Ions move across into connected cells
• Inducing synchonised activites (e.g. muscle contractions)

Question 3

Autocrine (chemical) signaling

Answer 3

• Cells speaks to itself
• Chemical binds to same cell that released it
• synthesis -> release -> recepto -> action
• E.g Interferon signalling in immune system

Question 4

Paracrine (chemical) signaling

Answer 4

• Cell speaks to its neighbour
• Cell synthesises release chemical which diffuses thorugh ISF to act on nearby target cells
• Sending cell: synthesis -> release
• Target/receiving cells: receptor -> action
• E.g. Synaptic signalling in nervous system

Question 5

Endocrine (chemical) signalling

Answer 5

• Cell speaks to many distant and diverse cells
• Chemical communicates over long distance (circulatory system)
• Endocrine secretory cell: synthesis -> release
• Hormone screted diffuses into leaky capillaries, circulates body
• E.g. Thyroids Hormones