PAPER 2 WHOLE

• What is homeostasis?

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

  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 is the role of receptors in the nervous system?

  They detect changes due to stimuli
• What is a reflex arc?

  A pathway that bypasses the brain for quick responses
• How do glands function as effectors?

  They produce specific chemicals needed by the body
• How can you investigate reaction times?

  Drop a ruler and measure the distance caught
• 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, 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 myopia?

  Shortsightedness, can't focus on distant objects
• What is hyperopia?

  Longsightedness, can't focus on near objects
• How do glasses correct vision?

  They converge or diverge light before entering the eye
• What is thermoregulation?

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

  Sweating and vasodilation occur
• How does the body respond when it is too cold?

  Shivering and vasoconstriction occur
• What is the endocrine system?

  A system of glands producing hormones
• What is the role of the pituitary gland?

  It produces hormones that regulate other glands
• What hormone does the pancreas produce?

  Insulin
• 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
• What is type 2 diabetes?

  Cells no longer absorb glucose effectively
• How do kidneys maintain water balance?

  They filter blood and adjust water reabsorption
• What is ADH's role in water balance?

  It causes kidneys to reabsorb more water
• What is negative feedback?

  Response that returns conditions to normal
• What is dialysis?

  A treatment for kidney failure
• What occurs during menstruation?

  Eggs mature and uterus lining thickens
• What does FSH do in the menstrual cycle?

  Stimulates egg maturation and oestrogen production
• What does estrogen do in the menstrual cycle?

  Thickens uterus lining and inhibits FSH
• What does LH do in the menstrual cycle?

  Triggers egg release from the ovary
• What is the role of progesterone in the menstrual cycle?

  Maintains uterus lining for potential pregnancy
• What are some contraception methods?

  Pills, injections, condoms, IUDs