Neurology 1 Flashcards
Label this to show the divisions of the PNS.
Make a table to describe the pathways of somatic sensory & somatic motor spinal nerves.
Make a table to describe the pathway of sympathetic efferent (excluding splanchnic nerves).
-Pre-ganglionic to post-ganglionic = Ach
-Post-ganglionic to large tissues = noradrenaline
Make a table to describe the pathway of a sympathetic splanchnic efferent.
-Pre-ganglionic to post-ganglionic = Ach
-Post-ganglionic to large tissues = noradrenaline
Make a table to describe the pathway of parasympathetic efferent sacral outflow.
-Pre-ganglionic to post-ganglionic = Ach
-Post-ganglionic to large tissues = Ach
Make a table to describe the pathway of parasympathetic efferent cranial outflow.
-Pre-ganglionic to post-ganglionic = Ach
-Post-ganglionic to large tissues = Ach
Label this spinal cord & spinal nerve.
What is the ANS associated with?
Viscera
Does the ANS contain both sensory & motor components?
Yes
What are the motor components of the ANS divided into?
-Sympathetic = left
-Parasympathetic = right
What is the outflow of the sympathetic NS?
Thoracolumbar - T1-L2(or L3)
What is the outflow of the parasympathetic NS?
Craniosacral - S1(or S2)-S4 OR dorsal nucleus of vagus nerve
What is the enteric NS?
-NS of the gut - has sensory & motor neurons
-Capable of autonomous control of gut peristalsis
-Contains sensorimotor circuits that can function independently of CNS input - BUT are regulated by ANS - parasymp & symp
How is the enteric NS regulated by the sympathetic & parasympathetic NSs?
To slow down or speed up peristalsis because if have fight or flight response want to slow down peristalsis so more blood flow to skeletal muscles
Where do parasympathetic and sympathetic pre-ganglionic fibres exit the spinal cord?
Ventral root - as motor/efferent neurons
Where are the neuronal cell bodies of the sympathetic NS?
Lateral horn of grey matter of spinal cord
Where are the neuronal cell bodies of the parasympathetic NS?
Ventral horn of grey matter of spinal cord
Describe the sympathetic chain aspect of the sympathetic efferent pathway.
-Axons of pre-ganglionic motor/efferent symp neurons enter sympathetic chain - via white rami - as pre-ganglionic axons = myelinated
-Synapse (of pre & post) in paravertebral ganglia = now have post-ganglionic fibres
-Exit sympathetic chain via grey rami - as post-ganglionic axons = unmyelinated
OR
-Axons of pre-ganglionic motor/efferent symp neurons enter sympathetic chain - via white rami - as pre-ganglionic axons = myelinated
-Synapse (of pre & post) in prevertebral ganglia - outside of sympathetic chain
= for splanchnic nerves
What is the missing label?
What can the ANS be controlled/regulated by?
Hypothalamus - signals to brainstem & spinal cord
Label the spinal cord & spinal nerve
Label the spinal cord & spinal nerve.
Mnemonic to remember the cranial nerves in order.
Mnemonic to remember which cranial nerves are sensory, motor or both (mixed).
Label the cranial nerves on this ventral view of the brain.
What are the 2 division of the PNS?
-Somatic (left)
-Visceral (right)
How do the spinal cord & vertebrae grow in relation to one another?
-Initially in 1st trimester - spinal cord & vertebral column are similar lengths
-In 3rd trimester - as embryo grows - vertebral column grows faster than spinal cord
-Spinal nerves pulled out between vertebrae (intervertebral foramen) due to difference in growing rates & spinal cord effectively shrinks relative to vertebral column
***Cauda equina!!!
-S1 nerve not at level of S1 vertebrae
–> instead S1 nerve leave spinal cord @ T12/L1 & runs down & exits @ S1 level
–> spinal nerves are named based on where they exit not where they originate!
Describe the clinical consequences of a lumbosacral cord lesion.
= LMN lesion
-Muscle atrophy - as actual neurons which supply the muscles = not getting there (to muscles)
-Flaccid paralysis
-Normal/no plantar response -> as no signals are arriving @ muscles
-Absent tendon reflexes
-Can see visible fasciculations -> where single muscle fibres are still stimulated - as still some transmission - some signals from LMNs that aren’t fully injured
Describe the clinical consequences of a thoracic cord lesion.
= lesion to UMN
-Little/no muscle atrophy (if is any = due to muscle disuse)
-Will only be muscle weakness - as other neurons from other areas can still help with muscle movement
-Deep tendon reflexes e.g., patellar = hyper-reflexive
–> as spinal level = unaffected -> so reflexes = amplified - as no use of UMN regulating reflex @ that level
-Diminished/absent superficial reflex - show +ve Babinski’s sign - scrape sole of foot = causes dorsiflexion & fanning of toes = abnormal - shown in image
-Spastic paralysis
What is the dual blood supply to the brain?
Dual blood supply into circle of Willis from:
-Internal carotid arteries
-Vertebrobasilar system (= x2 vertebral arteries into basilar artery into circle of Willis)
Where does the circle of Willis receive blood supply from?
-Internal carotid artery
-Basilar artery
What does the circle of Willis supply - in terms of arterial branches?
The 3 cerebral arteries:
-Anterior cerebral arteries
-Middle cerebral arteries
-Posterior cerebral arteries
Label.
How can examination inform diagnosis after a stroke in terms of arterial supply to the brain?
-Legs/trunk - anterior cerebral artery (ACA)
-Face/hands - middle cerebral artery (MCA)
-Both legs/trunk & face/hands = anterior circulation/internal carotid
-Visual field - posterior cerebral artery (PCA)
-Brainstem symptoms - loss/weakness of sensation or motor activity in whole body (as brainstem contains axon tracts travelling to/from cortex)
How do the premotor cortices (BA 6) control the primary motor cortex (M1 or BA 4)?
Intention of motor activity (motor activity generated by primary motor) is controlled in:
-Supplementary motor area - involved in internally generated movements
-Premotor area - involved in responses to external changes
What are association areas of the cortex?
= parts of cerebral cortex that receive inputs from multiple areas; association areas integrate incoming sensory information & also form connections between sensory & motor areas
-Aspects of the human brain & primates - not seen in any other species
-Enables connecting of ideas - to formulate complex ideas
What are the regions of the premotor cortices that are specialised in homo sapiens?
-Frontal eye field
(upper circle, in BA8)
= directs eye movement
-Broca’s area (lower circle, BA44 and BA45, & usually predominantly in left hemisphere)
= specifically associated with language production/speech
What is Wernicke’s area?
= involved in language processing
-Understood in patients with deficit in understanding language
(= U14W2)
What is the cortical areas 2.0?
Classification using machine learning to integrate modern data has now yielded 360 different functional areas based on 210 young healthy volunteers in the Human Connectome Project.
Which of these 3 colours represents the anterior, middle and posterior cerebral arteries?
