Homeostasis

• What is homeostasis?


  The maintenance of a constant environment in the body
• What are some examples of homeostasis?

  Control of blood glucose

  Osmoregulation

  Feedback systems
• What does the sensor monitor?

  The factor being controlled
• What happens when a stimulus is detected?

  The coordinator is informed
• What does the co-ordination centre do when a stimulus is detected?

  Communicates with one or more effectors to carry out corrective procedures
• What happens once the correction is made?

  The response stops
• Are most of the systems in the body positive or negative feedback systems?


  Negative
• Name an example of positive feedback

  Action potential
• How do endotherms maintain body temperature?

  respiration generates heat and endotherms can change cellular and physiological processes
• How do ectotherms maintain body temperature?


  They can't, they rely on external heat energy
• 


  Ectotherm's body temperature are proportionate to the environmental temperature
• What hormone does the adrenal gland release?

  Adrenaline
• What hormones does the pancreas release?

  Insulin and glucagon
• What do exocrine glands do?

  Secrete chemicals outside the body
• What are the two types of gland?

  Endocrine and exocrine
• Where are hormones carried?

  In the circulatory system
• What is the benefit of hormonal responses?

  Slower, longer lasting and more widespread
• What is the pancreas's exocrine function?

  Secretes digestive enzymes: pancreatic amylase and lipase
• What is the pancreas's endocrine function?

  Secretes insulin
• What 3 main effects can hormones have on target cells?

  • Affect the permeability of the membrane
  • Cause the release of a 'second messenger' inside the cell
  • Diffuse into the cell and promote or inhibit transcription