paper 2 video

• What is homeostasis?

  The process by which the body maintains a stable internal environment despite external changes
• What are the main things that need to be regulated?

  • blood glucose concentration
  • internal temperature
  • water levels
• What two things make up the Nervous system?

  • CNS (central nervous system)
  • PNS (peripheral nervous system)
• How is an electrical signal passed through the body?

  1. Stimulus
  2. Detected by the receptor
  3. Travels through the spine through sensory and relay neurons
  4. Travels through the synapse by the neurotransmitter
  5. Reaches the brain
  6. Travels through the motor neuron
  7. Effector
• What neurons do reflex actions pass through?

  Reflex arc
• What are examples of effectors?

  • Hormone glands
  • Muscle
• What are the different parts of the brain?

  • Cerebral cortex
  • Cerebellum
  • Medulla Oblongata
  • Pituitary Gland
  • Hypothalamus
• What is the function of the Cerebral Cortex?

  • memory
  • speech
  • problem solving
• What is the function of the Cerebellum?

  • movement
  • balance
  • coordination
• What is the function of the Medulla?

  • unconscious actions
  • heart and breathing rate
  • releases adrenaline from glands
• What is Accommodation?

  The eyes ability to adjust its focus to see objects at different distances, achieved by changing the shape of its lens
• How does the eye adjust to focus on objects far away?

  • Ciliary muscles relax
  • Suspensory ligaments tighten
  • Thin lens
• How does the eye adjust to focus on objects nearby?

  • Ciliary muscles contract
  • suspensory muscles relax
  • thick lens
• What are the different parts of the eye?

  • Cornea
  • Pupil
  • Sclera
  • Iris
  • Suspensory ligaments
  • Ciliary muscles
  • Retina
• What are the roles of Retina Cells?

  Converts light into electrical signals, which are then sent to the brain for interpretation

  • detected red, blue and green lights
• What's another name for short-sightedness?

  Myopia
• Whats another name for long- sightedness?

  Hyperopia
• How does the body react to when you are hot?

  • Sweat glands produce water, which evaporates
  • Blood vessels dilate - vasodilation
• How does the body react to when youre cold?

  • Hairs stand on end to trap air - a layer of insulation
  • Shivering - muscles produce more heat
  • Blood vessels contract - vasoconstriction
• What is the endocrine system?

  A system of glands that secrete hormones to send signals to effectors, transported via blood
• What is the role of the Pituitary gland?

  • Master gland, which sends a signal to other glands
• What is the role of the Pancreas?

  Secreted insulin and glucagon to control blood sugar
• What is the role of the Thyroid gland?

  Controls growth, metabolism etc
• What is the role of the Adrenal Gland?

  Releases adrenaline
• What is the role of the Overies?

  Releases eggs and secretes hormones
• What is the role of the testes?

  Produces sperm
• How does the body respond to high blood glucose levels?

  1. The pancreas secretes insulin
  2. This causes glucose to move from the bloodstream into the cells used for respiration
  3. Excess glucose is converted into glycogen as energy store
• How does the body react to low blood glucose levels?

  1. The pancreas secretes glucagon
  2. This causes the liver and muscles to convert glycogen back into glucose
• What is type 1 Diabetes?

  When the pancreas cannot produce enough insulin

  • injections and medicine needed
• What is Type 2 diabetes?

  This is when cells do not absorb enough glucose as they should
• How is water lost from the body?

  • exhalation
  • sweating
  • urinating
• What does excess water cause the cells to do?

  Water moves into cells by osmosis, which make the cells turgid causing them to burst
• What does AHD do?

  causes the kidneys to reabsorb more water into the bloodstream, causing less to be lost through urine