B10 Nervous System
- Created by: Lucy Hart
- Created on: 09-02-20 16:08
View mindmap
- B10 Nervous System
- 10.1 Homeostasis
- regulation of the internal of a cell to maintain optimum conditions for function, in response to changes
- important for enzyme action
- body temperature
- glucose concentration
- water levels
- regulation of the internal of a cell to maintain optimum conditions for function, in response to changes
- 10.2 Structure + Function of Nervous System
- 1. receptors - detect stimulus (change)
- 2. Sensory neurones - carry impulse to CNS
- 3. central nervous system (CNS) or coordination centre - process information + send out signals for response
- 4. motor neurones - carry impulse to send out response
- 5. Effector (muscles + glands) - response
- nervous system uses electrical impulses to react quickly to surroundings + coordinate behaviour
- 10.3 Reflex Actions
- automatic + impulse bypasses the conscious areas of brain (reflex arc)
- synapses - junctions, diffusion of chemicals
- same as normal nervous system but relay neurones - connect sensory + motor neurone
- B10.4 The Brain
- structure
- cerebral cortex - consciousnes, intelligence, memory
- cerebellum - coordinating muscular activity + balance
- medulla - unconscious activities, heartbeat + breathing
- map regions of the brain by studying brain damage
- electrically stimulating
- MRI scans
- problems - delicate + complex, different chemicals easily damaged
- structure
- 10.5 The Eye
- iris controls the pupil, muscles contract + relax to change size of pupil + control amount of light reaching retina
- lens held in place by suspensory ligaments + ciliary muscles
- light hits retina + sends impulse to brain along sensory neurones in optic nerve
- light gets focused by refraction
- 10.6 Common eye problems
- accommdation - process of changing shape of lens of eye to focus on near or distant objects
- distant - ciliary muscles relax so suspensory ligaments pulled tight + lens pulled flat + thin. Light refracts light rays slightly
- near - ciliary muscles contract so the suspensory ligaments loosen + lens thicker + curved. Light refracts strongly
- myopia - distant objects blurred
- focused in FRONT of retina. Lens is too curved or long eyeball
- treated with concave lens - spread out the light
- focused in FRONT of retina. Lens is too curved or long eyeball
- hyperopia - close objects blurred
- Focused BEHIND the retina. Too flat + too thin or short eyeball
- convex
- Focused BEHIND the retina. Too flat + too thin or short eyeball
- new tech - laser eye surgery, contact lenses + replacement lenses
- accommdation - process of changing shape of lens of eye to focus on near or distant objects
- 10.1 Homeostasis
Comments
No comments have yet been made