B10 (Human Nervous System)

Question 1

Homeostatis (definition + example)

Answer 1

• regulation of internal conditions or organism to maintain function
  Eg. Temp (37), water, blood sugar, PH, CO2

Question 2

2 forms of communication

Answer 2

Nervous system, hormonal control

Question 3

Demand of the control system (3 steps)

Answer 3

• receptors detect changes internal/external conditions (from stimulus)
• coordination centres is where processes information. Send signals
• effectors are muscles/glands bring about response to maintain conditions

Question 4

3 parts of the nervous system

Answer 4

• brain
• spinal cord
• neurons

Question 5

How the nervous system works (2 stages)

Answer 5

• sensory neurone conduct electrical impulses and pass along

- the response to the stimulus is motor neurones (muscles or glands) to carry out the a action

Question 6

Reflex action (definition + example)

Answer 6

Reflex actions prevent harm to the body by responding rapidly
- eg. Blinking, withdrawal

Question 7

Route of reflect response (5 stages)

Answer 7

• receptor (stimulus activates)
• sensory neurone (signal to CNS)
• relay neurone (transmits signal to motor)
• motor neurone (transmits signal to muscle)
• effector (the response)

Question 8

How synapses work (3 stages)

Answer 8

• electrical impulses at end of neurone
• verticals contain chemicals (neurotransmitter) released
• neurotransmitter diffuses across binding with receptors and new electrical impulse

Question 9

Label parts of the eye (good notes)

Answer 9

Labelled correctly

Question 10

Adaptation in bright light

Answer 10

• circular muscles contract
• radial muscles relax
• pupil constricts
  Want least amount of light

Question 11

Adaptation in dim light

Answer 11

• circular muscles relax
• radial muscles contract
• pupils dilate
  You want as much light as possible

Question 12

Accommodation (far objects)

Answer 12

• lens less convex (flatter)
• ciliary muscles relax
• suspensory ligament pulled tight

Question 13

Accommodation (near objects)

Answer 13

• lens more convex (rounded)
• ciliary muscles contract
• suspensory ligaments relax

Question 14

Myopia (+ what lens to wear)

Answer 14

• short sighted
• image before retina meaning distant objects blurry
• lens too curved
• concave lens, light spread

Question 15

Hyperopia (+ what lens to wear)

Answer 15

• long sighted
• lens to flat and fin, ray focus behind retina
• wear convex lenses to bring light rays together

Question 16

3 new technology to help eye problems

Answer 16

• contact lenses: on surface of lens which either kept in sterile solution or reusable
• laser eye surgery: used for myopia to change curve of the cornea
• replacement lenses: cure myopia and hyperopia either by extra lens or artificial

Question 17

3 structures of brain (top down) + function

Answer 17

• cerebral cortex: consciousness, intelligence, memory, language
• cerebellum: coordination and activity (sensory and motor neurones)
• medulla: involuntary actions like breathing, heart beat, digestion

Question 18

3 ways finding out about the brain

Answer 18

• brain damage: matching changes in behaviour with damage area (map functions
• MRI: images of brain to link loss of function to damage region
• electrical impulses: stimulate areas to experience changes (hungry, angry, scared)

Question 19

How the eye works (5 stages)

Answer 19

• enters eye
• refracted by cornea
• refracted by lens
• lens changes thickness to focus
• image formed at the retina