Neuro Flashcards
3 main sulci of the brain?
Longitudinal fissure
Lateral/ Sylvian fissure
Central sulcus
What structures make the brainstem?
Midbrain
Pons
Medulla
What is the operculum?
Lines the lateral sulcus
What does the precentral gyrus contain?
Motor cortex
What does the postcentral gyrus contain?
Somatosensory cortex
What are the meninges?
Dura
Arachnoid
Pia
What forms the venous sinuses?
Ares where the endosteal and meningeal layers of dura are separated
What does the falx cerebri do?
Sits between L&R hemispheres
Whats does tentorium cerebelli do?
Sits between occipital lobe and cerebellum
What does falx cerebelli do?
Sits between two lobes of cerebellum
How is CSF reabsorbed? (2)
- Through subarachnoid granulations/ villi and into venous circulation
- Drains along nerves into lymphatics
Functions of the dura?
Mechanical: stops brain moving around in skull
Forms venous sinuses
What a are the 3 main cranical fossa?
- anterior cranial fossa
- middle cranial fossa
- posterior cranial fossa
What drains into the confluence of the sinuses?
Superior sagittal sinus
Straight sinus
What is the straight sinus a continuation of?
Inferior sagittal sinus
Great cerebral vein
What is the path of the sinuses from the confluence of sinuses?
Transverse sinus
Sigmoid sinus
Internal jugular vein
What structures does the cavernous sinus contain?
[O TOM CAT] Oculomotor nerve Trochlear nerve Ophthalmic division of trigeminal Maxillary division of trigeminal Carotid (Internal) Abducens
Why is the cavernous sinus important?
It’s a potential route of infection into the brain
A stroke in which circulation (ant./post.) can cause cranial nerve involvement?
Posterior circulation (supplies the brainstem)
Which arteries supply the cerebellum?
SuCA - superior cerebellar artey
AICA - anterior inferior cerebellar artery
PICA - posterior inferior cerbellar artery
What passes through the ethmoid foramen? (3)
Ethmoidal artery
Ethmoidal vein
Olfactory nerve
What passes through the optic canal? (2)
Ophthalmic artery
Optic tract
What passes through the superior orbital fissure? (5)
CN's 3, 4, 5.1, and 6 Oculomotor nerve Trochlear nerve Ophthalmic division of trigeminal nerve Abducens nerve Superior ophthalmic vein
What passes through foramen rotundum? (1)
Maxillary division of trigeminal nerve
What passes through foramen ovale? (1)
Mandibular division of trigeminal nerve
What passes through foramen spinosum? (1)
Middle meningeal artery
What passes through internal acoustic meatus? (3)
Facial nerve
Vestibulocochlear nerve
Labyrinthine artery
What passes through the jugular foramen? (4)
Glossopharyngeal nerve
Vagus
Accessory nerve
Internal jugular vein
What passes through foramen magnum? (1)
Vertebral arteries
What passes through the hypoglossal canal? (1)
Hypoglossal nerve
Where does the anterior horn of the lateral ventricles sit?
In frontal lobe
Where does the posterior horn of the lateral ventricles sit?
In occipital lobe
Where does the inferior horn of the lateral ventricles sit?
In temporal bone
What connects the lateral and 3rd ventricles?
Interventricular foramen (of Monro)
What connects the 3rd and 4th ventricle?
Cerebral aqueduct
What’s contained in the anterior cranial fossa? (3 - bone, lobe)
Frontal lobe
Frontal bone
Lesser wing of sphenoid
What’s contained in the middle cranial fossa? (3 - bone, lobe)
Temporal lobe
Temporal bone
Greater wind of sphenoid
What’s contained in the posterior cranial fossa? (3 - bone, lobe)
Cerebellum
Occipital bone
Squamous part of temporal bone
What are the two parts of the temporal bone?
Petrified part (rock-like) Petrous part (squamous)
What’s the central ridge on the ethmoid bone called?
Crista galli
What is the sella turcica? (2)
Depression in middle cranial fossa (sphenoid bone)
Where pituitary gland lies
Where does the facial nerve exit the skull?
Stylo-mastoid foramina
Which artery supplies the skull, dura, skin and muscles on the superficial tissues of the skull?
Middle meningeal artery
Superior oblique
- action
- innervation
Action: intorsion
Innervaton: trochlear nerve (CN 4)
Lateral rectus
- action
- innervation
Action: Abducts the eye
Innervation: Abducens nerve (CN 6)
What is intorsion?
Clockwise rotation
What is extorsion?
Anti-clockwise rotation
Inferior rectus
- action
- innervation
Action: extorsion
Innervation: oculomotor nerve (CN 3)
Inferior oblique
- action
- innervation
Action: extorsion
Innervation: oculomotor nerve (CN 3)
Medial rectus
- action
- innervation
Action: adduction
Innervation: oculomotor nerve (CN 3)
Superior rectus
- action
- innervation
Action: intorsion
Innervation: oculomotor nerve (CN 3)
Levator palpebrae superioris
- action
- innervation
Action: raises eyelid
Innervation: oculomotor nerve (CN 3)
What does the midbrain consist of? (2)
- Tectum (superior & inferior colliculi)
- Crus cerebri (tegmentum [red nucleus], substantia nigra, cerebral peduncles)
What does the medulla contain? (3)
- Pyramids
- Olive
- Inferior cerebellar peduncle
What does the pons contain?
Middle cerebellar peduncle
What supplies the macula?
PCA
Also believed to be the MCA too
Why is the olfactory nerve different to the other CN’s?
Doesn’t go to the thalamus so only has 1st and 2nd order neurons
What does the 3rd ventricle sit between?
Two thalamus
What runs through the midbrain?
Cerebral aqueduct
Where does the 4th ventricle sit?
Behind the pons and in front of the cerebellum
Describe the tracts of the optic nerve
Optic nerve
Optic tract
Optic radiation
What field of vision does Meyer’s loop contribute to?
Upper quadrants
What field of vision does Baum’s loop contribute to?
Lower quadrants
What lobe does Meyer’s loop pass through?
Temporal lobe
What lobe does Baum’s loop go through?
Parietal lobe
What CN arises from the interpeduncular fossa?
Oculomotor nerve (CN 3)
What CNs arise from the pons?
Trigeminal nerve (CN 5) Abducens nerve (CN 6) - bulbopontine sulcus Facial nerve (CN 7) - bulbopontine sulcus Vestibulocochlear nerve (CN 8) - bulbopontine sulcus
What nerves arise from the medulla?
Glossopharyngeal nerve (CN 9) - lateral sulcus Vagus (CN 10) - lateral sulcus Accessory nerve (CN 11) - ventrolateral sulcus Hypoglossal nerve (CN 12) - ventrolateral sulcus
What CNs enter the midbrain?
Olfactory nerve (CN 1) Optic nerve (CN 2)
What nerve arises from the back of the brainstem and travels around the cerebral peduncles?
Trochlear nerve (CN 4)
What does the primary fissure separate?
Anterior and posterior lobes of cerebellum
What is the vermis?
Central worm-like structure
What are the deep cerebellar nuclei? (3)
- Dentate nucleus
- Fastigial nucleus
- Interpose nucleus
How would you identify the dentate nucleus?
Largest nuclei
Zig-zag edged
What are the tonsils and where are they found?
Rounded swellings on either side of the vermis (anteriorly)
What is the flocculus and where are they found?
Ovoid swellings posterior to foramen of Luschka
What is the nodule continuous with?
With the flocculus via peduncle of whiter matter
Flocculonodular lobe receives what type of information?
Vestibular information
Which peduncle does corticopontocerebellar tract travel through?
Middle cerebellar peduncle
What information does the corticopontocerebellar tract carry?
Motor plan
Which peduncles does spinocerebellar tract travel through?
Superior cerebellar peduncle
Inferior cerebellar peduncle
What information does the spinocerebellar tract carry?
Balance and position sense
Which peduncle does the vestibulocerebellar tract travel through?
Inferior peduncle
What is the floor of the 4th ventricle called?
Rhomboid fossa
What lines the rhomboid fossa? (laterally and posteriorly)
Laterally: cerebellar peduncles
Posteriorly: gracile and cuneate tubercles
What is the name of the sulcus that divides the rhomboid fossa?
Median sulcus
What are the medullary striae?
Pontocerebellar fibres that divide rhomboid fossa into caudal and rostral
What is the locus coeruleus and where is it located?
Bluish-grey pigmented noradrenergic cells in rostral part of rhomboid fossa
Locus coeruleus functions in?
Stress responses
Arousal
What is the obex?
Inferior apex of the rhomboid fossa
Which area is associated with nausea control?
Area postrema
What is the facial colliculus and where is it located?
- bumps where facial nerve runs over abducens nerve nuclei
- rostral part of area postrema
What is the vestibular trigone?
Lateral swelling formed by vestibulocochlear nerve nucleus
What is the hypoglossal trigone?
Medial swelling formed by hypoglossal nerve nucleus
What is the vagal trigone?
Swelling formed by vagus nerve nucleus
What separates the anterior horns of the lateral ventricles?
Septum pellucidum (double-membrane)
What connects the two thalami?
Interthalamic adhesion
Where is the calcarine sulcus and why is it important?
Occipital lobe - primary visual cortex lies here
What sulcus forms a Y shape with the calcarine sulcus?
Parieto-occipital sulcus
What is the corpus callosum?
Largest white matter tract, connects the two hemispheres
Describe the regions of the corpus callosum
Rostrum
Genu
Body
Splenium
What is the fornix?
White matter structure that connects hippocampus to the diencephalon
What is the paracentral nodule?
U-shaped gyrus that surrounds the medial part of the central sulcus
What is the stria of Gennari?
White band running in the primary visual cortex in the middle of the grey matter
Where does the cingulate gyrus lie?
Above the corpus callosum
What does the olfactory tract divide into?
Lateral olfactory stria
Medial olfactory stria
Describe the Papez circuit of the limbic system (8)
Amygdala Uncus Hippocampus Fornix Mammillary bodies Thalamus Cingulate gyrus Parahippocampal gyrus
What makes up the corpus striatum?
Caudate
Putamen
What makes up the lentiform nucleus?
Putamen
Globus pallidus
What are the white matter tracts of the basal ganglia?
Extreme capsule
External capsule
Internal capsule
Wha is the nucleus accumbens?
Brain’s reward centre
What is forceps minor?
Anterior curve of the fibres of the corpus callosum
What is forceps major?
Posterior curve of the fibres of the corpus callosum
What nerve sits between the PCA and the SuCA?
Oculomotor nerve (CN 3)