Homeostasis and Response

• What is homeostasis?

  Regulation of internal conditions
• Why is homeostasis important?

  It allows crucial chemical reactions to occur
• What three internal conditions does the body regulate?

  Blood glucose, temperature, water levels
• How does the nervous system help maintain homeostasis?

  By sending signals to effectors
• What does CNS stand for?

  Central Nervous System
• What does PNS stand for?

  Peripheral Nervous System
• What is the role of receptors in the nervous system?

  To detect changes due to stimuli
• What happens when a stimulus is detected?

  An electrical signal travels to the spine
• What is the gap between neurons called?

  Synapse
• How does a signal cross the synapse?

  By a neurotransmitter chemical
• What is a reflex arc?

  A signal bypassing the brain to act quickly
• What is the role of effectors?

  To produce responses to stimuli
• How do glands function as effectors?

  By producing specific chemicals as needed
• How can you investigate reaction times?

  By dropping a ruler and measuring distance
• What is the purpose of introducing an independent variable in reaction time experiments?

  To see how it affects reaction time
• What is the formula to calculate reaction time from distance?

  $S =$$\frac{1}{2} a t^2$
• What is the role of the brain in thermoregulation?

  It senses blood temperature and sends signals
• What are the three parts of the brain mentioned?

  Cerebral cortex, cerebellum, medulla oblongata
• What does the cerebral cortex control?

  Higher level functions like memory and speech
• What is the function of the cerebellum?

  Motor skills, movement, balance, coordination
• What does the medulla oblongata control?

  Unconscious actions like heart rate
• What is the purpose of MRI scans?

  To see brain activity safely
• What is accommodation in the eye?

  Changing lens shape to focus light
• How does the eye focus on distant objects?

  Ciliary muscles relax, lens becomes thin
• How does the eye focus on near objects?

  Ciliary muscles contract, lens becomes thick
• What is the function of the pupil?

  To change size based on light intensity
• What is the cornea?

  Transparent outer layer of the eye
• What are rod and cone cells responsible for?

  Responding to light intensity and color
• What is myopia?

  Shortsightedness
• What is hyperopia?

  Longsightedness
• How do glasses or contact lenses help vision?

  By converging or diverging light before entry
• What is the purpose of laser eye surgery?

  To change the shape of the cornea
• What is thermoregulation?

  Controlling internal temperature of the body
• How does the body respond when too hot?

  Sweat glands produce sweat to cool down
• What is vasodilation?

  Widening of blood vessels to increase heat loss
• What happens when the body is too cold?

  Vasoconstriction occurs to retain heat
• What is the endocrine system?

  A system of glands producing hormones
• What is the main gland in the endocrine system?

  Pituitary gland
• What does the pancreas produce?

  Insulin to regulate blood glucose levels
• What happens when blood glucose levels are too high?

  Pancreas secretes insulin to lower levels