Nervous System 2- Organisation Flashcards
What is innervation
The nerve supply of
What does a motor neurone do
Cause movement
What does a sensory neurone do
Responds to a stimulus
What does afferent mean
Towards
What does efferent mean
Away from
What does the somatic nervous system do
Controls the contraction of skeletal muscles of the body
What are somatic motorneurones
Efferent neurones sending nerve impulses (action potentials) which cause muscle contractions
What is voluntary muscle action
Intentional
Why is involuntary muscle action
Unintentional (e.g. postural muscles)
Muscle actions controlled by the somatic nervous system are either
Sterotyped or non-stereotyped
What are stereotyped muscle actions
Simple, repetitive
What are non-stereotyped muscle actions
Complex and individual to each person
What exerts control over motor neurones
The CNS
What 2 functional divisions is the autonomic nervous system made up of
Parasympathetic and sympathetic
What is the parasympathetic nervous system
‘rest and digest’
What is the sympathetic nervous system
‘fight or flight’
What are the actions of the sympathetic and parasympathetic nervous system on the eye
Sympathetic = dilates pupil. Parasympathetic = contracts pupil
What are the actions of the sympathetic and parasympathetic nervous system on the tear glands
Sympathetic= no action. Parasympathetic = stimulates tear secretion
What are the actions of the sympathetic and parasympathetic nervous system on the heart
Sympathetic = speeds up heart rate. Parasympathetic = slows down heart rate
What are the actions of the sympathetic and parasympathetic nervous system on the lungs
Sympathetic = dilates bronchi. Parasympathetic = constricts bronchi
What are the actions of the sympathetic and parasympathetic nervous system on the intestine
Sympathetic = inhibits peristalsis. Parasympathetic = stimulates peristalsis
What are the actions of the sympathetic and parasympathetic nervous system on the bladder
Sympathetic = inhibits urination. Parasympathetic = stimulates urination
What are the actions of the sympathetic and parasympathetic nervous system on the liver
Sympathetic = stimulates glucose production. Parasympathetic = stimulates bile production
What exerts control over the autonomic motor neurones
The central nervous system
What happens in the control the ANS has on the CNS is damaged
A rapid rise in blood pressure that can causes a stroke or even be fatal
What are the 4 main parts of the CNS
- Cerebral hemisphere 2. Cerebellum 3. Brainstem 4. Spinal chord
What is the name of the membranes that surround the entire nervous system
Meninges
What is the space between the meninges and CNS filled with
Cerebro spinal fluid
What is the function of cerebro spinal fluid
To allow the brain to float, protecting the brain physically. To maintain a stable chemical environment. Allowing the brain to float means it is weightless. Brain tissue is very soft so blood can only flow if the brain is weightless
What are the 4 main parts of the cerebral hemisphere
- Cerebral cortex 2. Motor nuclei 3. Thalamus 4. Hypothalamus
Describe the cerebral cortex
The sensory region where pathways end
Describe the motor nuclei
They control movement of messages down the spinal chord
Describe the thalamus
It is a big area made up of individual neurones lumped together
Describe the hypothalamus
A collection of neurones underneath the thalamus with 2 functions: 1. controlling the endocrine system 2. Controlling the ANS
What are the 3 main parts of the brainstem
- Midbrain 2. Pons 3. Medulla
Describe the midbrain
Connected to the cerebral hemisphere
Describe the pons
Major connections with the cerebellum
Describe the medulla
Connected to the spinal chord, has motor and sensory autonomic roles
Describe the cerebellum
It is called the ‘little brain’ and is involved in the co-ordination of motor function and balance
What is the CNS divided into
Grey and white matter
What is grey matter in the CNS
Neurone cell bodies grouped into nuclei
What is white matter in the CNS
Myelinated axons which form tracts
What is the spinal chord protected by
The vertebral column (spine)
Where are the somatic and autonomic motor neurones of the peripheral nervous system (PNS) located
In the spinal chord
What is the PNS connected to and what is is controlled by
Connected to and controlled by the CNS
What does the PNS control
The body from the neck down
What two parts is a spinal flex arc composed of
Dorsal root and ventral root
Describe the position and function of the dorsal root
Posterior (back) and function is sensory
Describe the position and function of a ventral root
Anterior (front) and function is motor
What is a spinal chord made up of
Repeating units of roots
Which ordinary sensations can be detected by a spinal relfex arc
Touch, pressure, pain, temperature
What are the 4 functional components of a spinal nerve
GSE (general sensory efferent) GVE (general visceral efferent) GVA (general visceral afferent) GSA (general sensory afferent)
What does the general sensory efferent (GSE) do
Motor neurones -> skeletal muscles. Somatic
What does the general sensory afferent (GSA) do
Discriminative touch, pain, temp from skin, joints, muscle. Somatic
What does the general visceral efferent (GVE) do
Motor neurone -> viscera. Visceral
What does the general visceral afferent (GVA) do
Detects sensation in the viscera
What are the 5 special sense
- Vision 2. Hearing 3. Smell 4. Taste 5. Balance
What are the special senses controlled by
Cranial nerves
What two types on neurones make up the peripheral nervous system
Somatic and visceral
Where are the cerebral cortex, cerebellum, brainstem and spinal chord located
