Neuroscience Anatomy Flashcards
What are the four lobes of the brain?
Frontal
Temporal
Parietal
Occipital
Where is the primary motor cortex and prefontal cortex?
The frontal lobe
Where is the primary auditory cortex, auditory association cortex, hippocampus and amygdala?
The temporal lobe
Where is the primary somatosensory cortex and association cortex?
The parietal lobe
Where is the primary visual and visual association cortex?
The occipital lobe
What are the roles of the cerebellum?
Motor control of equilibrium, posture and muscle-tone and movement co-ordination
Where are the ascending and descending tracts, cranial nerve nuclei and the reticular formation?
The brainstem
What are gyri?
The rolls of cerebral cortex
What are sulci?
The grooves between the gyri
What is the central sulcus?
A large fissure separating the frontal from the parietal lobe
What is the lateral sulcus?
A large fissure that separates the temporal lobe from the parietal and frontal lobes
Where is the insula?
Forming the floor of the lateral sulcus
Where are the opercula?
The parts of the temporal, frontal and parietal lobes that overlie the insula
What is the corpus callosum?
A large bundle of white matter connecting the two hemispheres
Where are the olfactory tracts?
Running on the inferior surface of the frontal lobes
What is the path of the optic nerves?
Passing backwards and medially on the underside of the brain. They converse in the midline to form the optic chiasma, and then pass laterally as the optic tracts
Where are the mammillary bodies?
Two rounded eminences behind the optic chiasma
Where is the hypothalamus?
Behind the optic chiasma up to and including the mammillary bodies (only part of the diencephalon is visible on the outside of the brain)
Where are the crura cerebri of the cerebral peduncles?
Two large masses of white matter emerging, behind the mammillary bodies on each side, from the cerebral hemisphere.
What is the path of the crura cerebri of the cerebral peduncles?
Passing backwards behind the mammillary bodies, converging in the midline at the upper border of the pons
Where is the interpenduncular fossa?
The space between the crura roofed over by the arachnoid
Where is the pons?
Immediately behind the point where the crura meet in the midline. It forms a bridge of neural tissue between the midbrain and the medulla oblongata.
Where is the cerebellum?
The little brain on the underside of the brain. There are two lobes, one on either side of the medulla and a central vermis joining the two hemispheres
Where is the medulla oblongata?
Running from the caudal border of the pons to where the spinal cord was cut when the brain was removed.
Which is normally the dominant parietal lobe?
The left
What are the roles of the dominant parietal lobe?
Perception, interpretation of sensory information and the formation of the idea of a complex, meaningful motor response
What are the roles of the supramarginal and angular gyrus of the dominant parietal lobe?
Language and mathematical operations
What is the role of the non-dominant parietal lobe?
Visuospatial functions
What are the roles of the frontal lobe?
Motor function, problem solving, spontaneity, memory, language, judgement, personality, impulse control, social and sexual behavior
What is the importance of the anterior portion of the frontal lobe/prefrontal cortex?
Higher cognitive functions and determination of personality
What is the importance of the posterior portion of the frontal lobe?
Motor and premotor areas
Where is Broca’s area?
The inferior frontal gyrus
What is the importance of Broca’s area?
Language producuction and comprehension
What is contained within the temporal lobe?
Primary auditory cortex, hippocampus, amygdala, and Wernicke’s area
Where is Wernicke’s area?
The superior temporal gyrus of the left hemisphere
What is the importance of Wernicke’s area?
Understanding with the spoken word
Where is the auditory cortex?
The lateral (sylvian) fissure in the temporal lobe
Where is the occipital lobe?
The posterior aspect of the brain
What is contained within the occipital lobe?
The primary visual and visual association cortex
Where is the limbic lobe?
The medial margin of the hemisphere
What is the importance of the limbic system?
Emotion, memory, behaviour, and olfaction.
What is the importance of the hippocampus?
Long term memory function
What is the importance of the amygdala?
Motivationally significant stimuli such as those related to reward and fear
How does the limbic system operates?
By influencing the endocrine system and the autonomic nervous system
What are the two layers of the dura mater?
The outer endosteal layer
The inner meningeal layer
What is the outer endosteal layer?
The layer of dura mater lining the interior of the skull, adhering to, and sending blood vessels and fibrous processes into the cranial bones
What is the inner meningeal layer?
The layer of dura mater enveloping the central nervous system. It continues as a tube of dura seen around the spinal cord, and provides tubular sheaths for the cranial nerves.
Where are the dural venous sinuses?
Where the dural folds attach to the skull. These are a system of communicating blood filled spaces.
What is the falx cerebri ?
An arched crescent of dura lying in the longitudinal fissure between the cerebral hemispheres
Where is the superior sagittal sinus?
Where the falx cerebri attaches to the cranium
Where is the inferior sagittal sinus?
At the free border of the falx cerebri
What is the tentorium cerebelli?
Dura forming a thick fibrous roof over the posterior cranial fossa and the cerebellum
Where is the straight sinus?
Within the tentorium cerebelli at its attachment to the falx cerebri
What is teh tentorial inscisure?
A horseshoe-shaped space between the free concave border of the tentorium and the dorsum sellae of the sphenoid
Where is the cavernous sinus?
Lying laterally to the body of the sphenoid
Where is the trigeminal cave?
Lying next to the apex of the petrous part of the temporal bone and enveloping the roots of the trigeminal nerve
What is the diaphragma sellae?
A small, circular, horizontal fold of dura mater which forms the roof of the pituitary fossa
What is the falx cerebelli?
A small, vertical, sickle-shaped reflection of dura separating the two lobes of the cerebellum
What are the layers of mater from skull to brain?
Dura
Arachnoid
Pia
What is the foremen of magdie?
A midline communication between the IVth ventricle and the subarachnoid space
What is the foramen of luschka?
A lateral communication between teh IVth ventricle and the subarachnoid spac e
Where is the cerebellomedullary cistern?
Lying in the angle formed by the dorsal surface of the medulla and the inferior surface of the cerebellum
Where is the pontine cistern?
On the ventral surface of the pons
Where is the Circle of Willis?
Contained within the interpenduncular cistern
Where is the middle cerebral artery contained?
The cistern of the lateral fissure
Where are the great cerebral vein and the pineal gland found?
The superior cistern
Where is the superior cistern?
Found between the posterior end of the corpus callosum and the superior surface of the cerebellum
What is the cisterna ambiens?
A group of subarachnoid cisterns which completely encircle the midbrain
Which layer of mater plays an important role in the blood-brain barrier?
Pia mater
What is the blood brain barrier?
A combination of features, unique to the brain and spinal cord, that limit the ability of molecules to pass between the blood and the CNS. This has the effect of protecting tissue from toxic substances.
What are the features of the blood brain barrier?
The edges of adjacent endothelial cells that line blood vessels are bonded closely together by tight junctions to prevent molecules passing between them
The basement membrane of CNS blood vessels lack fenestrations
Pericytes are present in the basement membrane
Astrocytes extend processes that envelop CNS capillaries and restrict the flow of molecules into the CNS parechyma
What is an extradural haemorrhage?
Blood between the skull and dura mater. It strips the dura from the bone and compresses the brain, typically after head injury. Haemorrhage is from the memingeal arteries
What is a subdural haemorrhage?
Blood between the dura and arachnoid. It appears as a crescent on CT head. Typically after high impact injury. Haemorrhage is typically as a result of tears in the bridging veins. (chronic subdural haematoma occurs 4-8 weeks following mild/moderate head injury in the elderly)
What is a subarachnoid haemorrhage?
Blood between the arachnoid and pia mater. Occurs after head injury. ( traumatic sub arachnoid haemorrhage or after rupture of a berry aneurys- blood surrounds the brain and fills the sulci, predominantly near the site of injury/ aneurysm. Sudden headache and high mortality rate)
What is an intracerebral haemorrhage?
Rupture of small vessels and microaneurysms in perforating vessels, leading to bleeding within the brain tissue- classic location: internal capsule following rupture of the lenticulostriate artery do to high blood pressure
What is meningitis and meningism?
Inflammation of the meninges, typically caused by infection. Meningism is the triad of headache, neck stiffness, and photophobia. Nausea/ vomiting and fever are also preset. Viral meningitis is often mild and self-limiting, bacterial meningitis requires urgent treatment or will lead to brain damage/ death.
What is amaurosis fugax?
Temporary loss of vision to one eye. Part of a carotid plaque breaks off and occludes the central retinal artery. Warning of thrombosus of the internal carotid artery, which is a potential for an impending stroke.
What is the arterial blood supply to the brain?
Two pairs of vessels- the internal carotid and vertebral arteries
What percentage of the blood do the vertebral arteries provide to the cerebrum?
About 20% of total supply, and supply the posterior cerebrum
What percentage of the blood do the internal carotid arteries supply to the cerebrum?
80% of the total supply, supplying the anterior and middle parts, and the diencephalon
Where does the internal carotid artery arise from?
The bifurcation of the common carotid at the level of the upper border of the thyroid cartilage.
What are the terminal branches of the internal carotid artery?
The anterior and middle cerebral arteries
What does the anterior cerebral artery supply?
The corpus callosum and the aspects of the hemispheres
What does the middle cerebral artery supply?
The majority of the lateral surface of the hemisphere and the deep structures of the anterior part of the cerebral hemisphere via its anterior perforating branches
What is the anterior communicating artery connecting?
The two anterior cerebral arteries
What does the posterior communicating artery connect?
The internal carotid and vertebro-basilar systems via the posterior cerebral artery
What percentage of brains show the “normal” pattern of the Circle of Willis?
60%
Where does the vertebral artery arise from?
The first part of the subclavian artery
How does the vertibral arteries enter the skull?
The foramen magnum
What is the basilar artery?
The united two vertebral arteries. It lies in the anterior median fissure on the PONS
What is a berry aneurysm?
A congenital sac-like out pouching of an intercranial artery. They progressively enlarge until then suddenly rupturing, resulting in a subarachnoid or intracerebral haemorrhage. They most commonly occur on the branching points around the circle of willis particularly the anterior communicating artery which lies in the subarachnoid space.
What is a stroke?
Can be ischaemic or haemorrhagic. Rapid onset of focal neurological deficit lasting more than 24 hrs. Third most common cause of death worldwide
Where are the internal cerebral veins?
Running within the substance of the brain tissue, and they end when they reach the surface of the brain where they become external cerebral veins
Where are the external cerebral veins?
These run on the surface of the brain crossing the subarachnoid space to drain into the Dural venous sinuses. There are four named groups which drain into different dural sinuses.
What are the four groups of external cerebral veins?
Superficial cerebral veins
Superior anastomic vein
Superficial middle cerebral vein
Inferior anastomic vein
Where is the inferior sagittal sinus?
The inferior margin of the falx cerebri
Where is the superior sagittal sinus?
The superior border of the falx cerebri
Where is the straight sinus?
In the midline of the tentorium cerebelli
Where is the transverse sinus?
In the posterior fixed margin of the tentorium cerebelli
Where is the sigmoid sinus?
A deep groove in the mastoid part of the temporal bone
Where is the cavernous sinus?
Beside the body of the sphenoid bone
Where is the superior petrosal sinus?
In the attached lateral margin of the tentorium cerebelli
Where is the inferior petrosal sinus?
In the groove between the petrous temporal bone and the basal part of the occipital bone
What is the major clinical significance of the cavernous sinus?
It houses five cranial nerves and the internal carotid artery
What are the causes of venous sinus thrombosis?
Rare complication of childbirth, clotting disorders and ear infection.
Where is the majority of the CSF produced?
The lateral ventricles of the choroid plexus
What is the route of the CSF from the lateral ventricles to subarachnoid space?
- Lateral ventricles
- IIIrd ventricle via the interventricular foramen
- IV ventricle via the cerebral aqueduct
- subarachnoid space via the media foramen of magendie and lateral foramina of luschka
What is the choroid plexus?
A vascular fold of pia mater covered by epithelium devided from the ependymal lining of the ventricle.
How is CSF reabsorbed into venous drainage of the brain?
Via tufts of arachnoid mater called arachnoid villi
What are arachnoid granulations?
Calcifications of arachnoid villi
What is the medial ventricular aperture?
The magendie foramen
What is the lateral ventricular apeture?
The luschka foramen
Where is the longitudinal fissure?
Seperating the left and right hemispheres
Describe the ethmoid bone
Has cribriform plate and crista galli (central ridge) – falx cerebri attaches to crest of crista galli. The olfactory foramina are on the cribriform plate.
What does the superior orbital fissure contain?
Oculomotor nerve (CN III) Trochlear nerve (CN IV) Ophthalmic division of trigeminal nerve (V1) Abducens nerve (CN VI) Ophthalmic veins`
What does the inferior orbital fissure contain?
Zygomatic branch of maxillary nerve
Inferior ophthalmic vein
Sympathetic nerves
What does the optic canal contain?
Contains optic nerve (CN II) and ophthalmic artery
What is the sella turcica?
Bony prominence in sphenoid bone behind chiasmatic groove and tuberculum sellae. Covered by diaphragma sellae. The pituitary fossa is the most inferior part of the sella turcica.
What is contained within the foramen rotundum?
Maxillary branch (V2) of the trigeminal nerve (CN V)
What is contained within the foramen ovale?
OVALE
Optic ganglion V3 cranial nerve (mandibular division of trigeminal – both sensory and motor) Accessory meningeal artery Lesser petrosal nerve Emissary veins
What is contained within the foramen lacerum?
Closed in life – no structures go completely though Internal carotid artery emerges through
Also has pterygoid canal, nerve of pterygoid canal and emissary veins
What is contained within the foramen spinosum?
Middle meningeal artery
Middle meningeal vein
Meningeal branch of mandibular nerve
What is contained within the foramen magnum?
VAMPires Sing AT Midnight Vertebral arteries Anterior spinal artery Meningeal branches of cervical nerves Posterior spinal arteries Spinal parts of accessory nerve Alar and Apical ligaments of the dens Tectorial membrane Medulla oblongata
What is contained within the internal acoustic meatus?
Vestibular cochlear nerve and facial nerve
What is contained within the hypoglossal canal?
Hypoglossal nerve
Meningeal branch of pharyngeal artery
Venous plexus of hypoglossal canal
What is contained within the jugular foramina?
9,10,11 crainial nerve pass out
Jugular vein passes out
What are the attachments of the levator palpebrae superioris?
Lesser wing of sphenoid bone
superior tarsal plate of upper eyelid
What is the action of the levator palpebrae superioris?
Elevates upper eyelid/ open eye
What is the nerve supply to the levator palpebrae superioris?
Oculomotor nerve (CN III)
What are the attachments of the superior rectus?
Superior part of CTR
superior/ anterior aspect of sclera
What is the action of the superior rectus?
Elevation
Also, adduction/ medial rotation of eyeball
What is the nerve supply to the superior rectus?
Oculomotor nerve (CN III)
What are the attachments of the inferior rectus?
Inferior part of CTR
Inferior/ anterior aspect of sclera
What are the actions of the inferior rectus?
Depression
Also, adduction and lateral rotation of eyeball
What is the nerve supply to inferior rectus?
Oculomotor nerve (CN III)
What are the attachments of the medial rectus?
Medial part of CTR
Anteromedial aspect of sclera
What is the action of the medial rectus?
Adducts eyeball
Medial rotation
What is the nerve supply to the medial rectus?
Oculomotor nerve (CN III)
What are the attachments of the lateral rectus?
Lateral part of CTR
Anterolateral aspect of sclera
What is the action of the lateral rectus?
Abducts eyeball
Lateral rotation
What is the nerve supply to the lateral rectus?
Abductens nerve (CN VI)
What are the attachment of the superior oblique?
Body of sphenoid bone, tendon passes through trochlear, attaches to sclera posterior to superior rectus
What is the action of the superior oblique?
Depresses, and medially rotates eyeball
What is the nerve supply of the superior oblique muscle?
Trochlear nerve (CN IV)
What is the attachment of the inferior oblique?
Anterior aspect of orbital floor
Sclera of eye, posterior to lateral rectus
What is the action of the inferior oblique?
Elevates, and laterally rotates eyeball
What is the nerve supply to the inferior oblique?
Oculomotor nerve (CN III)
What are the three ear ossicles?
Stapes
Malleus
Incus
Which of the ear ossicles is the smallest?
Stapes
Which of the ear ossicles is the largest?
Malleus
What is the order of ear vibrations between the tympanic membrane to the oval window?
Tympanic membrane Malleus Incus Stapes Oval Window
