The Nervous System Flashcards
What is the CNS
Consists of the brain and spinal cord
What is the PNS
Consists of a vast network of nerves that carry messages between CNS and the rest of the body
To carry out a response to a stimulus what are the four processes
Reception
Transmission
Integration
Response
What is reception
Stimulus detected by neurons receptors snd sense organs
What is transmission
Message passes alone neurons
What is integration
Incoming messages are sorted snd processed and a response is decided
What is response
Carried out by effectors
What is the different between a motar neuron and a sensory neuron
Motar brings from CNS to muscle or gland
Sense brungs from organ to CNS
Whats the function of a nerve ending
Connects sensory neurons to receptor cells or sense organs
What are dendrites
Fibres that carry impulses towards body cells
What do axons do
Carry impulses away from cell bodies
What do schwann cells do
Produce myelin sheath
What does the myelin sheath do
Fat rich layer that insulates electrical impulses
What does the cell body do
Contains nucelus and mitochondria
What dies the axon terminal do
Carry impulse to a swelling
What do neruotransmitter swellings do
Release chemicals that carry impulses from one nerve to another
What is a ganglion
Group of cell bodies located outside the CNS
What are interneurons
Short neurons found between motar and sensory neurons
What us a resting neuron
A neuron not carrying an impulse
What is the threshold
Minimum stimulus needed to carry an impulse
What is the term for how a nerve does not carry an impulse unless threshold is met
All or nothing law
What is a refractory period
Is a short time span after a neuron has carried an impulse during which a stimulus fails to cause a response
What is a synapse
Region where two neurons come into contact
What is the synaptic cleft
Tony gal between two neurons
Name two neurotransmitters
Noradrenalin
Dopamine
What happens to meurotransmitters
Carry impulse to post synaptic neuron and is broken down by enzymes snd are reabsorbed back into neurotransmitter swellings
What are the functions of the synapses
Transmit impulses
Control direction of impulse
Prevent overstimulation
Impulse can be blocked by chemicals
What is the name for the membrane which covers the spinal chord and brain
Meninges - there sre 3
What is in between the two inner meninges
Cerebrospinal fluid
Shock absorber snd exchange medium between blood snd braim
What is the largest part if brain
Cerebrum
What are the two halves of the cerebrum called
Right and left cerebral hemisphere
What are the functions of the cerebrum
Controlling voluntary movement Receiving and interpreting impulses from sense organs Thinking Intelligence Memory Language Emotions Judgement Personality
What does the right hemisphere control and what does the left hemisphere control
Right hem - left side of body
Left hem - right side of body
What is left and right hem more dominant for
Left - hand use
Right - art music shape recognition and emotional response
What oart if the brain is heavily folded
Cerebellum
What does the cerebellum control
Muscular coordination
Involuntary responses when learned eg walking
Balance
What does the medulla oblongota do
Connects spinal chord to rest of brain
Controls involuntary movements eg breathing swallowing salvation sneezing blood pressure coighing vomiting
What gland is located in cerebrum
Thalamus - acts as sorting centre eg incoming impulses
Whats belo the thalamus
Hypothalamus - regulates internal environment by monitoring blood pressure and body temo and appetite and thirst
Os the pituitary gland part of the brain
No
How is parkinsons caused
Failed production of dopamine
What are sympotoms of parkinsons
Trembling hands
Stiff and rigid muscles
Shuffling
Unblinking stare
Prevention to parkinsons
None
Treatment to parkinsons
Physio and special excercises
Where is the spinal chord located
Neural canal
What does the spnial chord do
Transmits impulses to and from brain and controls reflex actions
What is the outer rung and inner h section of a spinal chord
Outer - white matter AXONS ONLY
H- grey matter CELL BODIES
What root carries
1 motar neurons out
2 sensory neurons in
1 ventral
2 dorsal
What is reflex action
Involuntary action automatic in response to stimulus
What are reflex actions
Knee jerk
Breathing
Blinking
What reflex arc
Pathway taken by nerve impulse in a reflex action
