P2. Homeostasis And Response

• What is the main focus of homeostasis?

  Regulation of internal conditions
• Why do cells require a constant temperature and pH?

  To maintain optimum conditions for function
• What are the components of control systems in the body?

  Receptors and effectors
• What is the role of receptors in control systems?

  To sense changes in the environment
• What is the function of effectors in control systems?

  To bring about changes restoring optimum levels
• What is homeostasis in the human body?

  • Regulation of internal conditions
  • Maintains optimal conditions for enzyme action
  • Controls blood glucose, body temperature, and water levels
• What does the nervous system enable humans to do?

  React to surroundings and coordinate behavior
• How does information from receptors travel to the CNS?

  As electrical impulses along neurones
• What does the CNS consist of?

  Brain and spinal cord
• What is the role of the CNS in response coordination?

  Coordinates the response of effectors
• What are reflex actions?

  Automatic and involuntary responses to a Stimulus.
• What are the components of a reflex arc?

  Sensory neurone, synapse, relay neurone, motor neurone
• Why are reflex actions important?

  They allow quick responses to stimuli
• What is the role of the thermoregulatory centre?

  To monitor and control body temperature
• How does the body respond to high temperature?

  glands under the skin secrete sweat onto the surface of the skin
• How does the body respond to low temperature?

  Blood vessels constrict and shivering occurs
• What is the human endocrine system?

  • Composed of glands secreting hormones
  • Hormones travel through the bloodstream
  • Effects are slower but longer-lasting than nervous system
• What is the function of the pituitary gland?

  Secretes hormones in response to body conditions
• How does insulin affect blood glucose levels?

  Causes glucose to move from blood into cells
• What characterizes Type 1 diabetes?

  Insufficient insulin production by the pancreas
• How is Type 1 diabetes treated?

  With insulin injections
• What characterizes Type 2 diabetes?

  Body cells no longer respond to insulin
• What are common treatments for Type 2 diabetes?

  Carbohydrate-controlled diet and exercise
• How does glucagon affect blood glucose levels?

  Causes glycogen to convert into glucose
• How do insulin and glucagon interact?

  In a negative feedback cycle to control levels
• What is a common treatment for obesity?

  Diet and exercise
• How does obesity relate to Type 2 diabetes?

  Obesity is a risk factor for Type 2 diabetes
• What should students be able to compare regarding diabetes?

  Type 1 and Type 2 diabetes
• What should students evaluate about obesity and diabetes?

  Relationship and social/ethical issues
• What data should students be able to interpret regarding insulin?

  Graphs showing insulin's effect on blood glucose
• What hormone does the pancreas produce when blood glucose is low?

  Glucagon
• What does glucagon do in the body?

  Converts glycogen to glucose
• How do glucagon and insulin interact?

  In a negative feedback cycle
• What happens to water during exhalation?

  Water leaves the body
• What substances are lost from the skin in sweat?

  Water, ions, and urea
• What is produced from the deamination of excess amino acids?

  Ammonia
• What is the main female reproductive hormone?

  Oestrogen
• What does testosterone stimulate?

  Sperm production
• What hormones are involved in the menstrual cycle?

  FSH, LH, oestrogen, and progesterone
• What does FSH do in the menstrual cycle?

  Causes egg maturation