Flashcards in Nervous System Deck (72):
Classify the nervous system according to structure
Central - brain and spinal cord
Peripheral - cranial nerves, spinal nerves
What are the two divisions within the PNS?
Sensory and motor
How many pairs of cranial nerves are there?
Where do cranial nerves enter and leave via?
How many pairs of spinal nerves are there and where do they arise from?
Which division of the PNS is involved in voluntary and involuntary actions?
The motor division
Classify the nervous system according to function
Somatic and autonomic
In relation to the somatic nervous system which divisions and muscles are involved?
Motor - skeletal muscle
Sensory - pain, temperature, touch, pressure, proprioception, special senses (internal changes in muscular activity)
What 2 divisions can the autonomic system be divided into
Sympathetic - fight or flight
Parasympathetic - rest and digest
Describe the midbrain
Consists of nuclei and nerve fibres (tracts) which connect the cerebrum with lower parts of the brain and spinal cord. The nuclei act as relay stations for the ascending and descending nerve fibres.
How is the anatomical structure of the pons different to that of the cerebrum?
Cell bodies (grey matter) lie deeply and the nerve fibres (white matter) lie on the surface in the pons.
What does the pons consist mainly of?
Nerve fibres (white matter) that form a bridge between the 2 hemispheres of the cerebellum and of fibres passing between the higher levels of the brain and the spinal cord.
Nuclei in the pons act as what 2 different things?
Some associated with cranial nerves
Others for pneumotoxic and apnoustic centres that operate in conjunction with the respiratory centre in the medulla.
Describe the structure of the medulla
Outer aspect is composed of white matter, centre is grey matter.
What does the medulla contain?
Vital centres, consisting of groups of cell bodies associated with autonomic reflex activity such as cardiovascular centre, respiratory centre and reflex centres of vomiting, coughing, sneezing and swallowing.
What do some cells in the medulla constitute?
Relay stations for sensory nerves passing from the spinal cord to the cerebrum.
Describe the cerebrum
Largest part of the brain, divided by a deep cleft called the longitudinal cerebral fissure into the right and left cerebral hemispheres. Divided into 4 lobes which control different areas of the body.
Name the 4 lobes of the cerebrum
Frontal, temporal, parietal, occipital.
What is the cerebellum the control centre for?
Coordination, posture, balance and voluntary muscular movement.
What does the frontal lobe control?
Planning, intellect, mood, social judgement.
What does the temporal lobe control?
What does the parietal lobe control?
General sensation and taste
What does the occipital lobe control?
Name the 5 regions of the spine
Cervical, thoracic, lumbar, sacrum, coccyx
How many vetebrae and spinal nerves are in the cervical region?
8 spinal nerves
How many vertebrae and spinal nerves are in the thoracic region?
How many vertebrae and spinal nerves are in the lumbar region?
How many vertebrae and spinal nerves are in the sacrum?
5 fused vertebrae, 5 nerves
What are the protective membranes of the spinal cord and brain from inside to out?
Pia mater, arachnoid mater, dura mater.
Where is CSF produced?
In the ventricles which are interconnecting chambers
Where is CSF found?
Inbetween the pia mater and arachnoid mater surrounding the brain in an area called the subarachnoid space.
What is the function of CSF?
Protects the brain by creating a cushion between nerve tissues and bony cavities. Also carries away waste and toxins.
What is the purpose of the dendrites in the neurone?
Receive and carry incoming impulses towards cell bodies, form part of synapses in motor neurones and in sensory neurones form receptors that respond to a stimuli.
What are groups of cell bodies called in the CNS?
What are groups of cell bodies called in the PNS?
What do cell bodies form in none nervous system?
What is the purpose of the axon?
Carry nerve impulses away from the cell body.
What does the myelin sheath consist of?
Consists of Schwann cells and a fatty substance.
Define a neurone?
Nerve cell which relays information
Where do afferent nerves travel from and too
From receptors to the CNS
Where do efferent nerves travel from and to
From the CNS to receptors
What are the tiny gaps inbetween the myelin sheath called?
Nodes of ranvier
What are the 3 different classes of neurones?
Bipolar, unipolar and multipolar
What is the cell called when it's at it's resting state?
Is the cell negative or positive at its resting state?
Which electrolytes and substance are inside and outside the cell during polarization?
Inside - protein, potassium
Outside - sodium
What happens during depolarization?
Sodium channels open, sodium moves in, cell becomes positive.
What happens during repolarization?
Potassium channels open, potassium moves out, sodium channels close. Cell becomes negative again.
Explain what happens at the synapse
Neuro- transmitters are transported from neurone to neurone and act on specific receptor sites
Name 7 common neurotransmitters released from the brain and spinal cord
Noradrenaline, adrenaline, dopamine, histamine, serotonin, gamma aminobutynic acid (GABA), acetycholine.
In the sympathetic nervous system the ore ganglionic neurone is?
In the sympathetic nervous system the post ganglionic neurone is?
What are the neuro- transmitters involved in the sympathetic nervous system?
In the parasympathetic nervous system the preganglionic neurone is what and the postganglionic neurone is what?
Preganglionic - long
Postganglionic - short
What are the neuro transmitters involved in the PNS?
What are the neuro transmitters involved in the SNS cholinergic neurones?
Acetylcholine - acetylcholine
What are the neuro transmitters involved in the sympathetic splanchnic nervous system?
Acetylcholine, (adrenal medulla) - adrenaline and noradrenaline
Where are the alpha 1 adrenoceptors located and what is there effect?
Peripheral vascular smooth muscle - vasoconstriction
Where are the alpha 2 adrenoceptors located and what is there effect?
Per synaptic membrane, inhibit transmitter release
Where are the beta 1 adrenoceptors located and what is there effect?
Heart, increase force of contraction, increase heart rate.
Where are the beta 2 adrenoceptors located and what is there effect?
Bronchial smooth muscle, vascular smooth muscle, dilates bronchioles, vasodilation
Where are the beta 3 adrenoceptors located and what is there effect?
Adipose tissue, lipolysis.
What is the thalamus?
An important relay station for nervous information
What supplies blood to the brain?
Internal carotid arteries and vetebral arteries
What is it called where the spinal cord ends?
What does viscera mean?
Organs with body cavities
What is in the diencephalon?
The thalamus and hypothalamus
How many ventricles are there?
Where are the 2 lateral ventricles?
Where is the third ventricle?
Lateral walls formed by hypothalamus
What is he cerebral aqueduct?
Connects 3rd to 4th ventricle