Nervous system and homeostasis Flashcards
What is the nervous system made up of
Central nervous system which compromises of the brain and the spinal cord
Give the pathway of a nervous response
Stimulus
Receptor
Coordinator
Effector
Response
What is the function of the nervous system
It enables organisms to react to their surroundings and coordinates behaviour
Why are reflex actions important
For survival and to prevent damage to the body
Why are reflex actions described as rapid and automatic
They do not involve the conscious part of the brain
What do neurones do
Carry electrical impulses around the body
Adaptions of a nerve cell
Branched endings (dendrites) make connection to other neurones
Myelin sheath insulates the axon increasing speed of electrical impulses
What is a synapse
Gap between two neurones allowing impulses to cross
Explain what happens at a synapse
Impulse arrives in neurone
Sacs containing chemicals
Chemicals are releases into the gap between neurones (synapse)
Chemicals attach to the receptor site of the next neurone and set up a new electrical impulse
Give the function of a cerebral cortex
Outer layer of the brain playing an important role in consciousness
Give the function of the medulla oblongata
Part of three brain above the spinal cord that controls breathing and heart rate
Give the function of the cerebellum
Part at the back of the brain involved in coordinating muscle activity
Why is it difficult to treat brain disorders
Brain is very complex and delicate
Why is treatment for brain damage and diseases difficult
It is not fully understood what each area of the brain does
Drugs do not always reach the brain through its membranes
Surgery can easily cause unintended damage
Function of the iris
Coloured part of the eye containing muscles that relax and contract changing the size of the pupil and allowing more or less light in