B10 The Nervous System Flashcards
What does a sensory nueron do
Carries the electrical impulse to the central nervous system
What does the motor neuron do
Carries electrical impulses from the cns and is connected to the effector
What does the relay nueron do
Passes electrical impulses from the sensory nueron to the motor nuerone found in the spinal coord
State the sensory relay
Stimulus -> receptor -> sensory nuerone -> relay nuerone -> synapse -> motor neurone -> effector ->response
What is a synapse
A gap where two neurones connect
How do impulses travel across a synapse
Electrical impulses travel to one end of a nerve cell and causes a chemical to be released called a neurotransmitter. The neurotransmitter then diffuses across the gap slower than an electrical impulse would
Examples of reflex actions
Breathing, swallowing
Function of cerebral cortex
Involved in consciousness, language, thought, perception, memory, attention
Function of Hypothalamus
Links nervous system to the hormonal system, controls feeding fleeing fighting and mating
Function of pituitary gland
Involved In hormonal control
Function of cerebellum
Contributes to coordination precision and accurate timing
Function of medulla
Unconcious activity e.g heartbeat, breathing, vomiting, and blood pressure
What is the retina
The thin lsyer of tissue at the back of the eye that recieves light and converts it inro neural signals
What does the optic nerve do
Carries impulses from the retina to the brain
What is the sclera
The tough outer layer of the eye
What is the cornea
Transparent region of the sclera at the front of the eye that refracts light as it enters the eye
Iris
Has sets of muscles that control the size of the pupil and regulates the light reaching the retina
Cillary muscles and suspensory ligaments
Change the shape of the lens to focus light rays on the retina
When viewing a close object the ciliary muscles are contracted or relaxed
Contracted
When viewing a distant object the ciliary muscles are contracted or relaxed
Relaxed
When viewing a close object the suspensory ligaments are slack or taut
Slack
When viewing a distant object the suspensory ligaments are slack or taut
Taut
When viewing a close object what shape is the lense of the eye
Rounded and fat shaped
When viewing a distant object what shape is the lens
Flatter and thinner
What lens is used to treat long-sightedness
Convex lens
What lens is used to treat short-sightedness
Concave
