Neuro Flashcards
what is the sixth cranial nerve
Abducens
which nucleus does the sixth cranial nerve arise from
abducens nucleus
What is the anatomical course of the abducens nerve?
Enters subarachnoid space
pierces dura mater
travels through the carvernous sinus
Eters the orbit through the superior orbital fissure
where does the abducens nerve terminate
The Lateral Rectus
What effect does the Lateral rectus have on the eye
it abducts the eye
Where does the Lateral rectus originate from
Common tendinnous ring
Where does the Lateral rectus originate from
Common tendinnous ring
Which 2 paired arteries supply the arterial blood of the brain
Vertebral
Internal carotid
Where does the external carotid supply
Supplies the face and scalp
Not that thought box of yours
What is the function of the circle of Willis
If one of the cerebral arteries becomes blocked blood supply of the whole brain is not completely effected
Where does your internal common carotid originate from
Arch of aorta
Common carotid bifurcates into the internal and external branches
Name 3 branches of the vertebral arteries
Meninggeal
Anterior and posterior spinal
Posterior inferior cerebral
What are the terminal branches of the interval carotid arteries
Arteries cerebral
The posterior cerebral arteries are the terminal branches of what?
Vertebral arteries
Define Axonal Transmission
Transmission of information from location A to location B
Define Synaptic transmission
Integration and processing of infomration.
where does cerebral spinal fluid run through?
with regards to the spinal cord!
The central canal
Define Fassiculi
Bundles of nerve axons which run up and down the spinal cord.
contain axons which are going from or to similar locations.
what does the Dorsal column convey?
Fine touch and Proprioception
What are the Four nerve ending whcih sense finetouch
Meisners Corpuscles
Pacnian Corpuscles
Ruffini Endings
Merkel Endings
What type of neurons are located in the dorsal root ganglion
Pseudounipolar neurons - because they have an axon which runs in two directions.
Describe the course of the Dorsal Column
3 main points
Project from body to spinal cord
Ascends through brain stem
Synapses at the Cuneae ad Gracile nuclei - in the Medulla Oblongata
Decussates in medulla
synpases in the thalamus at the Ventral posterolateral nucleus
sends info to the post central gyri (primary sensory area of the brain)
What are the 3 neurons of the Dorsal Column
1) Dorsal root ganglion
2) Cuneate/Gracile Nucleus
3) Ventral posterolateral nucleus of the thalamus.
Is the Dorsal Column Ascending or descending? And therefore is it a motor or sensory tract
Ascending Tract
Sensory
Always smile dont moan
Name the fascilulus that the upper limb neurons travel through (dorsal column)
Cunate Fasciculis
Gracile Fasciluls contains neurons from where?
Lower Limb of the Dorsal Column
What does the spinothalamic Tract convey?
Conveys sensation of Pain Temperature and Crude Touch
What neurons are in the Spinothalaic tract?
pseudounipolar neurons
Is teh Spinothalamic tract Sensory or Motor?
Ascending or descending?
Sensory and Ascending
How many times to the Spinothalamic tract Synapse? where does the spinothalamic tract synpase?
2 times …
In the Spinal cord at the dorsal Horn of the spinal column
In the thalamus
What is the role of the Lissauers Fasciculus in the Spinothalamic tract?
where the tract ascends up through for 1/2 levels before it decussates.
How many neurons are in the pathway of the Spinothalamic tract and name each one
3 neurons
1) Dorsal Root Ganglion
2) Dorsal horn of the spinal cord
3) Thalamus
Where does the Spinothalamic tract decussate
At the anterior white commisure in the spinal cord:
Important as has strong clinical relevance.
What does the Corticospinal Tract Convey
Motor Control of Limb and Axial
Brain controlling movement of muscles
Where does the CorticoSpinal Tract begin
PRE central gyri in the cortex
This is the primary Motor Cortex
Describe the path of the Corticospinal tract
Descends through Brainstem
75-90% decussate in the medulla
down spina cord to target level.
Synapse and the innervate the muscles directly
Which nerves decussate in the medulla and what % is it
The Nerves which innervate the limbs decussate in the medulla. 75-90% of the fibres decussate here
The lateral corticospinal tract
Where does the anterior Cortico Spinal tract decussate
In the Spinal cord, at the level it is targetting in the anterior white commisure. It then synapses in the anterio horn of the grey matter
