PNS Flashcards
(20 cards)
Extensively classify the PNS
Motor and sensory
Motor - somatic and autonomic
Autonomic- sympathetic and parasympathetic nervous system
What are a bundle of individual axons called?
Fascicles
How are axons packed?
Single- endoneurium
Fascicles- perineurium
External vascular layer- Epineurium
How many pairs of cranial and spinal nerves
12 pairs of cranial
31 pairs of spinal
Where do somatic afferent neurones take information form
Skeletal muscles, skin, joint
Where do somatic efferent nerves take information to?
Skeletal muscles
Contrast dermatome and myotome
Dermatome- skin area supplied by a single spinal nerve
Myotome- group of muscles (unit) supplied by a single spinal nerve.
Classify peripheral nerves in terms of speed
A-C conduction velocity
I-IV- diameter
How can sensory receptors be classified ?
Source of stimulus or mode of detection
Give examples of internal receptors
Proprioceptors-= movement and joint position
Enterorecptors- Blood pH and movement through gut
Give examples of external receptors
Exteroreceptors- pain, temperature, touch and pressure
Give types of receptors by mode of detection
Chemoreceptors- molecules Themoreceptors- heat Photoreceptors- light Mechanoreceptros- pressure And touch on skin Noiciceptors- tissue damage
Explain proprioceptors
Muscle spindles- detect muscle length
Golgi tendon organs- change in tension in tendons
Joint receptors- start and end of movement.
What is the position of the white ramus communicans
Between ventral rami and transverse foramina, nerve comes back and can move up or down
What is the position of the gray ramus communicans
Between mixed spinal nerves and transverse foramina.
Where do sympathetic fibres to skin and heart synapses
In spinal cord.
The ones to the heart form a Cardiac plexus
Where do sympathetic fibres to visceral synapse?
In the pre-aortic ganglia.
I.e. the ventral root synapse in pre aortic ganglia before forming the pre ganglionic SNS fibres
What are the nerves in parasympathetic nervous system?
3,7,9 and 10
S2-S4 through pelvic splanchic nerve.
Synapse in effector.
What are the nerves of the sympathetic nervous system
T1-L2
What is supplied by the following: Otic ganglion Ciliary ganglion Pterygopalatine ganglion Submandibular ganglion
Otic- 9 to parotid
Ciliary - 3 to pupils
Pterygopalatine- 7 to lacrimal
Submandibular- 7 to salivary glands
