Day 1. Cells - signalling, death and adaptation Flashcards
General cell communication
- Signalling cell releases ligand (messenger)
- Ligand binds to specific receptor
- receptor cell receives message
- signal transduction - signal conveyed into and through cell
- response - signal causes effect
Nerve signalling
- used exclusively by neurones
- Neurotransmitters (1 mark) sent through synapse (2 marks) to another neurone or receptor cell to regulate muscles or glands (3 marks)
Rapid and long distance action
specific routes of movement
If wrong: Parkinsons
Endocrine Signalling
Hormones
- Hormone - insulin
- released by endocrine gland - pancreas
- into the bloodstream
- hormone received by receptor cell to stimulate action - liver, fat and muscle cells increase uptake of glucose to reduce blood glucose levels
Slow acting
Diffuses around the entire body within bloodstream
Local Signalling
Inflammatory response (sprained ankle) and cancer
- signalling cell releases ligand to a cell close by
- to cause a local effect
Integration
Cells communicate to coordinate activity around the body and keep us disease free
Atrophy
Decrease in cell size
Hypertrophy
Increase is cell size
Hyperplasia
Increase in cell number
Metaplasia
Specific cell replaced with a less specific cell type
Dysplasia
Abnormal changes and variation in cell shape and size
Cell death
Apoptosis
Programmed cell death
1. The cell dies at the end of its life, controlling the population of cells
2. Cell shrinkage
3. Plasma membrane blebbing
4. Formation of apoptotic bodies
5. phagocytosis
Cell death
Necrosis
- Unplanned/ accidental cell death due to injury or damage to the cell
1. Increase in cell volume
2. Loss of plasma membrane integrity
3. Leakage of cellular contents
4. Inflammation
