bio paper 2

• What is homeostasis?

  Regulation of internal conditions despite external changes
• Why is homeostasis important?

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

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

  It sends signals to effectors to respond to changes
• What are the two main parts of the nervous system?

  CNS and PNS
• What does the CNS consist of?

  Brain and spinal cord
• What is the role of a receptor?

  Detects changes due to a stimulus
• What happens when a stimulus is detected?

  An electrical signal travels to the spine
• What is a synapse?

  The gap between neurons
• How does a signal travel across a synapse?

  By a neurotransmitter chemical
• What is a reflex arc?

  A pathway where signals bypass the brain
• What is the role of glands in the body?

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

  By dropping a ruler and measuring distance
• What is the effect of a stimulant on reaction time?

  It increases reaction time
• How can you calculate reaction time from distance?

  Using $s =$$\frac{1}{2} a t^2$
• What are the three parts of the brain?

  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?

  Controls motor skills, movement, and balance
• What does the medulla oblongata control?

  Unconscious actions like heart rate
• What is an MRI scan used for?

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

  Ability to change lens shape for focus
• 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 role of the pupil?

  Changes size based on light intensity
• What is the cornea?

  Transparent outer layer of the eye
• What do rods in the retina detect?

  Light intensity, not color
• What do cones in the retina detect?

  Color wavelengths of light
• What is myopia?

  Shortsightedness
• What is hyperopia?

  Longsightedness
• How do glasses correct vision?

  By converging or diverging light entering the eye
• What is thermoregulation?

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

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

  Widening of blood vessels to increase blood flow
• How does the body respond when too cold?

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

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

  The 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
• What happens when blood glucose levels are too low?

  Pancreas produces glucagon to raise levels
• What is type 1 diabetes?

  Pancreas can't produce enough insulin