Neuro 1 Flashcards
What is the falx cerebri?
A fold of dura mater separating the L & R cerebral hemispheres
What is the fold of dura mater found between the cerebellum & cerebrum?
Tentorium cerebelli
What is the grey matter?
Surface, cerebral cortex
Cell bodies
Associated with processing & cognition
What is the white matter?
Bulk of cerebrum, deeper
Glial cells & myelinated axons
What separates the two hemispheres?
Longitudinal fissue
Explain the concept of dominance?
One hemisphere as greater control over some neurological functions than the other
Broca’s & Wernicke’s areas only in dominant hemisphere
What is the dorsal brainstem?
Tectum
What is the ventral brainstem?
Tegmentum
What does the pineal gland secrete?
Melatonin (circadian rhythm)
What is a fontanelle?
2 areas at either end of saiggital suture where other sutures meet
What supplies the medial surface of the brain?
Anterior carotid artery
What supplies the lateral surface of the brain?
Middle carotid artery
What supplies the posterior surface of the brain?
Posterior carotid artery
Where does the falx cerebri attach anteriorly?
Crista galli
Where does the superior sagittal sinus run?
In thee attachment of the falx cerebri to cranial cavity roof
Where does the inferior sagittal sinus run?
Free border of falx cerebri
Where does the straight sinus run?
Attachment between falx cerebri & tentorium cerebelli
What sinuses form the convergence of sinuses?
Superior sagittal
Straight
Transverse
What continues on from the transverse sinus?
Sigmoid sinus
What 3 layers is the blood brain barrier made out of?
Astrocyte foot processes
Basement membrane
Capillary epithelium
What is a Berry aneurysm?
A sac forming at a bifurcation of arteries
What is a stroke?
Where blood fails to reach a portion of the brain for long enough to cause damage
What are the symptoms of a stroke?
Headache Muscle weakness/paralysis Speech disturbances Sensory problems Memory loss Confusion FAST
What are the risk factors for a stroke?
High BP
Diabetes
High cholesterol
Family history
What is a TIA?
Transient ischaemic attack
Minutes/hour long mini stroke
Could be sign of actual stroke
What joins the body & transverse process of a vertebral bone?
Pedicle
What joins the spinous process & transverse process of a vertebral bone?
Lamina
How many of each vertebra are there?
7C 12T 5L 5S (fused) Coccyx
What are the differences between the vertebrae?
Cervical - transverse foramen, C1 no body, C2 has superior projection
Thoracic - larger, downwards pointing spinous processes, circular shaped vertebral foramina
Lumbar - largest, triangular vertebral foramina
What are the 2 main parts of the intervertebral discs?
Nucleus pulposus - hydrated gel with proteoglycan, collagen, cartilage cells
Annulus fibrosus - surrounds nucleus, 10-12 concentric layers of collagen
What is the conus medullaris?
Lower part of spinal cord, tapered
Where does the spinal cord end?
L1/2
What is the filum terminale?
A projection of pia mater extending from the coonus medullaris to the coccyx
What is the cauda equina?
Bundle of spinal nerves L2-5 & S1-5
What do the dorsal and ventral horns of the grey matter carry?
Dorsal - sensory (terminations)
Ventral - motor (cell bodies)
What do the dorsal, lateral & ventral columns of the white matter carry?
Ascending & descending tracts
What are the anterior spinal arteries a branch of?
The vertebral arteries (circle of Willis)
What do the paired posterior spinal arteries arise from?
The posterior inferior cerebellar arteries (PICA) (circle of Willis)
How many spinal nerves are there?
31 bilateral paired
Where are the cell bodies of motor neurons in the spinal cord?
Ventral horn
Where do the spinal nerves love the intervertebral foramen?
C1-7 from above respective (named) vertebra
C8 from foramen between C7 & T1
Subsequent arise from below respective vertebra
Why is the caudal equina formed?
Spinal cord shorter than vertebrae - gets increasingly superior to foramen
What is the frontal lobe responsible for?
Initiation of movement Personality Higher intellect/consious thought Social conduct Mood Language
What is the temporal lobe responsible for?
Auditory processing
Memory
Language
Olfactory processing
What is the parietal lobe responsible for?
Sensory processing (most)
What is the occipital lobe responsible for?
Visual processing
Where is the primary motor cortex?
Pre-central gyrus in frontal lobe
Fibres extend down internal capsule
Betz cells
Where is the primary somatosensory cortex?
Post-central gyrus in parietal lobe
What is the motor & sensory homunculi?
Representation of inputs & outputs from/to different parts of body
(legs in middle - ACA stroke)
What is Broca’s area?
Brodmann’s 44 & 45
Posterior inferior frontal lobe
Production of fluid speech
(lesion = understand, no fluid speech)
What is Wernicke’s area?
Brodmann’s 22
Posterior superior temporal lobe
Comprehension & understanding language
(lesion = incomprehensible fluid speech, no understanding)
What are the main sulci of the cerebrum?
Central - frontal & parietal
Lateral/sylvian - frontal & parietal & temporal
Lunate - occipital & parietal
What are the ventricles lined by?
Ependymal cells
Make up choroid plexus
What are the 4 ventricles?
Lateral (x2)
Third
Fourth
How do the lateral ventricles communicate with the third ventricle?
Via the foramen of Monro
How does the third ventricle communicate with the fourth ventricle?
Cerebral aquaduct
How does the CSF leave the fourth ventricle?
2 lateral foramina of Luschka
Medial foramen of Magendie
What are the 3 main functions of CSF?
Protection
Buoyancy
Chemical stability
How is CSF drained into venous blood?
Arachnoid granulations protrude out into dural venous sinuses
What is the corpus callosum?
qBundle of white matter fibres
Connects hemispheres
Allows communication between hemispheres
What are the 5 sections of the corpus callosum?
Rostrum Genu Body Isthmus Splenium
What do the fibres of the forceps anterior & posterior do?
Connects frontal lobes (anterior)
Connects occipital lobes (posterior)
Which cranial nerve originates from the posterior midbrain?
Trochlear
Is the fasciculus gracilis or cuneatus more lateral?
Cuneatus - upper limbs
What are the 3 cranial fossa & what do they contain?
Anterior - frontal lobe
Middle - parietal, temporal, occipital lobes
Posterior - cerebellum, brainstem
What are the 11 main cranial foramina?
Ethmoidal Optic canal Superior orbital fissure Rotundum Ovale Spinosum Lacerum Internal acoustic meatus Jugular Hypoglossal canal Magnum
What passes through the ethmoidal foramina?
Olfactory CNI
What passes through the optic canal?
Optic CNII
What passes through the superior orbital fissure?
Oculomotor CNIII
Trochlear CNIV
Ophthalmic CNV1
Abducens CNVI
What passes through the foramen rotundum?
Maxillary CNV2
What passes through the foramen ovale?
Mandibular CNV3
What passes through the internal acoustic meatus?
Facial CNVII
Vestibulocochlear CNVIII
What passes through the jugular foramen
Glossopharyngeal CNIX
Vagus CNX
Accessory spinal CNXI
Internal jugular vein
What passes through the hypoglossal canal?
Hypoglossal CNXII
What passes through the foramen spinosum?
No nerves
Middle meningeal blood vessels
What passes through the foramen magnum?
Spinal cord
Vertebral arteries
Anterior & posterior spinal arteries
What are the 3 meninges from superficial to deep?
Dura
Arachnoid
Pia
What are the two laters of the dura mater?
Periosteal (outer)
Meningeal (inner)
Where is the CSF contained?
Subarachnoid space
What does the internal carotid artery split into at the circle of Willis?
Middle cerebral artery
Anterior cerebral artery
What are the anterior cerebral arteries joined by?
Anterior communicating artery
What are the internal carotid and posterior cerebral arteries joined by?
Posterior communicating artery
What are small arteries coming off from the basilar artery?
Pontine
Where is the superior cerebellar artery found?
Between the posterior cerebral artery and the basilar artery
What is a long branch from the basilar artery?
Labyrinthine artery
What is between the basilar artery and the vertebral arteries?
Anterior inferior cerebellar artery
What are two branches of the vertebral arteries?
Posterior inferior cerebellar arteries
Anterior spinal artery
What does the cavernous sinus contain?
Oculomotor
Trochlear
Ophthalmic
Maxillary
Carotid artery (internal)
Abducens
T
What is the acronym ‘standing room only’ used for?
Superior orbital fissure - ophthalmic
Rotundum - maxillary
Ovale - mandibular
What of the cranial nerves contain parasympathetic fibres?
1(o)973 CNX - vagus CNIX - glossopharyngeal CNVII - facial CNIII - trigeminal
Which of the cranial nerves have purely sensory fibres?
Olfactory CNI Optic CNII Ophthalmic CNIII1 Maxillary CNIII2 Vestibulocochlear CNVIII
What does the oculomotor nerve do?
Innervates 4/6 of the extra-ocular muscles
Parasympathetic controls smooth muscle in eyeball
What does the trochlear nerve do?
Innervates the superior oblique muscle
What does the trigeminal nerve do?
Sensation from face/head
Mandibular also muscles of mastication & tensor tympani
What does the abducens nerve do?
Lateral rectus muscle
What does the facial nerve do?
Taste from anterior 2/3 of tongue, floor of mouth & palate, cutaneous sensation from part of external ear
Muscles of expression, posterior belly of digastric
Parasympathetic to submandibular & sublingual glands
What does the vestibulocochlear nerve do?
Vestibular for balance
Cochlear for hearing
What does the glossopharyngeal nerve do?
Cutaneous sensation from pharynx, post 1/3 of tongue, eustachian tube & middle ear, taste from posterior 1/3 tongue & pharynx, chemo & baroreceptors of cartif
Stylopharyngeus
Parasympathetic to parotid gland
What does the vagus nerve do?
Cutaneous sensation from pharynx, larynx, oesophagus, external auditory meatus, tympanic membrane, taste sensation from epiglottis, chemoreceptors & baroreceptors of aorta
Muscles of pharynx, soft palate, larynx, upper oesophagus
Parasympathetic throughout thoracic & abdominal viscera
What does the accessory spinal nerve do?
Sternocleidomastoid & trapezius
What does the hypoglossal nerve do?
Intrinsic & extrinsic muscles of tongue except palatoglossus
Which of the cranial nerves have purely motor fibres?
Oculomotor CNIII Trochlear CNIV Abducens CNVI Accessory spinal CNXI Hypoglossal CNXII
Which of the cranial nerves have both sensory & motor fibres?
Trigeminal CNV
Facial CNVII
Glossopharyngeal CNIX
Vagus CNX
What sensations do the DCML pathway convey?
'nice' Fine touch Two-point discrimination Vibration Proprioception
What conveys sensation from below T6 & above T6? (DCML)
Above - gracile fasciculis medially
Below - cuneate fasciculus
Where do the neurons of the DCML pathway decussate?
Medulla
What sensations do the spinothalamic pathway convey?
'nasty' Crude touch (ventral/anterior) Pressure (ventral/anterior) Pain (lateral) Temperature (lateral)
Where do the neurons of the spinothalamic pathway decussate?
1-3 segments above where they enter the spinal cord
Substantia gelatinosa
What does the corticospinal tract do?
Cosnious motor innervation of the muscles of the body
Where do the neurons of the corticospinal pathway decussate?
75-90% in medulla - lateral
At level of exit - ventral
What do the lateral & ventral corticospinal tracts innervate?
Lateral - limbs
Ventral - trunk
What is the floor of the fourth ventricle known as?
Rhomboid fossa
What is the stria medullaris?
Fibres that run laterally along the floor of the 4th ventricle, dividing it into a superior pontine half & inferior medullary half
What are the 2 main types of memory?
Working/short-tern
Long-term
What are the 2 main types of long-term memory?
Explicit - facts & events
Implicit - skills, conditioned reflexes & emotions
What are the 2 main types of explicit memory?
Episodic - events & experiences
Semantic - facts, ideas & concepts
Where are the types of implicit memory remembered?
Skills & habits = cerebellum & basal ganglia
Conditioned reflexes = cerebellum
Emotional memory = amygdala
Where do the DCML & spinothalamic tracts terminate?
Thalamus, VPL nucleus
What is in the internal capsule?
Projection fibres
Axons from motor cortex to deep brain structures