biology paper 2

• What does homeostasis regulate?

  Optimum internal environment conditions
• What are the three main things homeostasis controls in humans?

  Body temperature, blood glucose, water levels
• Why is maintaining homeostasis important?

  To ensure enzymes and cells function properly
• How is homeostasis controlled in the body?

  By the nervous and hormonal systems
• What is the first step in the homeostasis process?

  Receptors detect changes in the environment
• What are effectors in the homeostasis process?

  Organs that respond to the stimulus
• What is the central nervous system made up of?

  Brain and spinal cord
• What is the function of the nervous system?

  To react to surroundings and coordinate responses
• What do nerves transmit to send information?

  Electrical impulses
• What happens when a stimulus is detected by a receptor?

  Electrical impulses are sent to the coordinator
• What is a reflex action?

  An unconscious response to a stimulus
• How many neurons are involved in a reflex action?

  Three neurons
• What is the role of the sensory neuron in a reflex arc?

  Connects to a sense organ
• What is the function of the relay neuron?

  Connects sensory and motor neurons
• What is a synapse?

  The gap between two neurons
• How is an electrical impulse triggered across a synapse?

  A chemical diffuses across the gap
• What is the ruler drop test used for?

  Measuring reaction time
• What is the dependent variable in the ruler drop test?

  The distance the ruler falls
• Why is it important to control variables in the ruler drop test?

  To ensure accurate reaction time measurements
• What does a higher reaction time value indicate?

  Slower reactions
• What are the main functions of the brain?

  Controls behavior and processes information
• What part of the brain controls conscious thoughts?

  Cerebral cortex
• How is the brain studied?

  By studying brain damage and using scans
• What are the ethical issues with studying brain damage?

  Obtaining consent for studies
• What does the optic nerve do?

  Transmits electrical impulses to the brain
• What are rods and cones in the retina?

  Light receptors for vision
• How does the iris control light entering the eye?

  By contracting and relaxing muscles
• What is hyperopia?

  Long-sightedness
• How is hyperopia corrected?

  With a convex lens
• What is myopia?

  Short-sightedness
• How is myopia corrected?

  With a concave lens
• What regulates temperature control in the body?

  Thermoregulatory center in the brain
• What happens when the body is too cold?

  Vasoconstriction and shivering occur
• What happens when the body is too hot?

  Vasodilation and increased sweating occur
• What is the endocrine system?

  A system of glands secreting hormones
• What is the master gland of the endocrine system?

  Pituitary gland
• What hormone does the pancreas secrete to lower blood glucose?

  Insulin
• What is negative feedback in blood glucose control?

  Reversing changes in blood glucose levels
• What happens when blood glucose levels increase?

  The pancreas releases insulin
• What does insulin do in the body?

  Helps absorb glucose into cells