What is a ganglion?
Collection of nerve cell bodies
What are dendrites?
Extensions from the body that allow us to increase the surface area of a cell
What is the difference between a single axon an a named nerve?
Single axons only transmit a single fibre type (motor/sensory) but named nerves are a collection of axons so can transmit several fibre types
What are the 6 functions of a single nerve fibre(axon)?
1) Somatic sensory
2) Somatic motor
3) Special sensory
4) Visceral afferent
5) Sympathetic
6) Parasympathetic
What is the somatic sensory function?
It gives sensation and tells the spinal cord/brain about a pain somewhere on the body wall
What is the somatic Motor function?
It causes something to move/twitch and tell a skeletal muscle to contract
What is the special sensory function?
Tells the brain about a “special” sensation: sight, smell,taste,sound,balance
What is the visceral afferent function?
Tells the spinal cord/brain about a pain from an organ
What is sympathetic/ parasympathetic function?
Part of the autonomic nervous system and tells cardiac or smooth muscle to contract or a gland to secrete
What are the components of the central nervous system?
Brain and spinal cord
What makes up the peripheral nervous system?
What nerve supplies the soma (body wall)?
Spinal nerves
What does the posterior ramus do?
Supplies the back (posterior part of the body wall) with sensation and motor supply
What does the anterior ramus do?
Supplies the rest of the body walls (anterolateral part of the body wall)
What is the function of the nervous system?
Allows us to sense our environment and to effect an appropriate response
What are the 2 categories of the nervous system?
- autonomic nervous- internal environment
What does the somatic nervous system do and where are the neurones found?
Supplies the soma and responds to external environment.
-The neutrons are found in spinal nerve branches i.e intercostal/phrenic
What is the functions autonomic nervous?
Senses and responds to internal environment i.e heart rate and is involuntary as we dont need to think about it
What is ‘flight or flight’ controlled by?
Sympathetic nervous system
Describe the sympathetic supply to the soma?
What thoracolumbar outflow?
Action potentials conducted into T1-L2 spinal nerves
How do sympathetic access head / neck and organs?
What do sympathetic connections (rami communications) connect?
Spinal nerves T1 to L2 and the paravertebral ganglia of the sympathetic trunk
What neurotransmitter lies in all paravertebral ganglia as part of the sympathetic system?
noradrenaline