Nervous system Flashcards
What are the 2 main sections of the nervous system?
Central and peripheral
What is the peripheral nervous system made up from
Cranial nerves, spinal nerves and sensory organs
What are the main components of the central nervous systems?
Brain and spinal cord
What is the main function of the Cns
Processes and integrates information
What is the main function of the PNS
Carries impulses between the CNS and the rest of our body
How many pairs of spinal nerves are there? Name them?
31: 8 cervical nerves, 12 thoracic nerves, 5 lumbar, 5 sacral, 1 coccygeal
How many pairs of cranial nerves are there?
12
Which spinal nerves form the cervical plexus?
C1-4
Which spinal nerves form the brachial plexus?
C5-8 and T1
What is the difference between the somatic and autonomic nervous systems
Both part of PNS: somatic is voluntary _ control of skeletal muscles, autonomic is involuntary and controls smooth muscle, cardiac muscle and glands
In the autonomic nervous system, what is the sypathetic and parasympathetic systems
Sympathetic takes control during fight or flight and stimulates activity, parasympathetic inhibits activity mostly and is rest and relax stage
List some functions of sympathetic nerves
Dilate pupils, vasodilation, raise heart beat, increase respiration rate, inhibit digestion, inhibit urination and salivation
List some functions of the parasympathetic nerves
Constrict pupils, stimulate saliva, decrease heartbeat, vasoconstriction, stimulate digestion and urination
What are the two types of processes emanating from the neuron?
Axons and dendrites
What is the function of axons and dendrites
Axons conduct impulses away from cell body, dendrites are short and receive impulses from other neurons and transmit them to cell body
What is the function of the Myelin sheath
Protects, insulates the axon of the neuron and speeds up transmission of nerve impulses
What are efferent neurons?
MOTOR OR DESCCENDING neurons which carry nerve impulses from the CNS to the PNS - muscles, glands and organs
What are afferent neurons
SENSORY neurons which carry nerve impulses from the PNS to the CNS
What is a synapse
The site where axons connect to other cells
How do nerve impulses travel?
Chemicals called neurotransmitters are released at the end of axons, there is a gap or cleft between the neurons called the synaptic cletf - these neurotransmitters pass across this gap into the reception site of another neuron
Which part of the neuron do the neurotransmitters pass into.?
The receptor site in the dendrites of the post synaptic neuron
Name 3 examples of neurotransmitters
Dopamine, adrenaline, acetylcholine
What is the place where bundles of neurotransmitters can be found in the axons called
Synaptic vesicle
How does the action potential move down the axon?
When one segment of thr axon becomes demoralised, it causes the next section to be demoralised so the wave of decolonisation moves down the axon
