B5: Homeostasis and response

• What does homeostasis regulate?

  The internal environments or conditions
• Why is it important to keep conditions constant in organisms?

  To ensure enzymes work effectively
• What are the three conditions that need to be kept constant in humans?

  Blood glucose concentration, water levels, body temperature
• What is a stimulus in the context of homeostasis?

  A change in the environment
• What detects a stimulus in the body?

  Receptor cells
• What is the role of a Coordination Center?

  To receive and process information
• Name two examples of Coordination Centers in the human body.

  Brain and pancreas
• What are the two types of effectors in the body?

  Muscles and glands
• What are the five main sense organs in the body?

  Eye, nose, tongue, ears, skin
• What does the eye detect?

  Light
• What does the nose detect?

  Chemicals by smell
• What does the tongue detect?

  Chemicals by taste
• What do the ears detect?

  Sound and balance
• What does the skin detect?

  Pressure and temperature
• What carries information from receptor cells to the CNS?

  Nerves
• What is the central nervous system made up of?

  Brain and spinal cord
• What are neurons?

  Individual nerve cells
• What is a nerve?

  A bundle of neurons
• What happens when a stimulus occurs?

  The receptor cell detects the stimulus
• What is the sequence of neurons involved in a response?

  Sensory neuron, relay neuron, motor neuron
• What is an example of a stimulus and response involving cold ice cream?

  Finger moves away from dripping ice cream
• What is a reflex action?

  An automatic and rapid response
• Why are reflex actions important?

  They protect an organism from harm
• What is the endocrine system composed of?

  Glands that secrete hormones
• How do hormones travel in the body?

  Through the bloodstream
• What is the master gland in the endocrine system?

  Pituitary gland
• What does the pituitary gland do?

  Releases hormones to other glands
• What hormone does the thyroid gland produce?

  Thyroxine
• What does thyroxine control?

  Basal metabolic rate
• What does adrenaline do to the body?

  Increases heart rate and oxygen supply
• What is negative feedback?

  A process to maintain constant hormone levels
• What happens when thyroxine levels increase?

  Less TSH is produced by the pituitary gland
• What happens when blood glucose levels are too high?

  The pancreas releases insulin
• What is the role of insulin?

  Allows glucose to enter cells for respiration
• What happens when blood glucose levels drop?

  The pancreas produces glucagon
• What does glucagon do?

  Turns glycogen back into glucose
• What are the two types of diabetes?

  Type 1 and Type 2 diabetes
• What is the cause of Type 1 diabetes?

  Pancreas doesn't produce insulin
• How is Type 1 diabetes treated?

  With insulin injections
• What is the main risk factor for Type 2 diabetes?

  Obesity