Week 4 - Brain, Spinal Cord & Cranial Nerves Flashcards
What is the difference between white and grey matter ?
White matter is more myelinated.
In the brain, where is white and grey matter positioned in relation to one another ?
White more interior than grey.
What are gyri ?
Elevations in brain surface.
What are sulci ?
Infoldings in brain surface.
What are fissures ?
Clefts in brain surface.
What is the function of corpus callosum and what cells is it formed by ?
Links two cerebral hemispheres.
Formed by myelinated axons, so white matter.
Cross horizontally to allow for communication between hemispheres (horizontal pathway) - forms corona radiata.
What separates the left and right cerebral hemispheres ?
Longitudinal sulci.
What are folia ?
Ridges in cerebrum.
What is the function of the cerebrum ?
Balance.
What is the distinct difference between the cerebellum and cerebrum’s control ?
Cerebellum - contralateral.
Cerebrum - ipsilateral.
What are the three divisions of the brainstem ?
Midbrain, pons, medulla.
What cranial nerves are associated with the midbrain ?
Occulomotor CNIII and trochlear CNIV.
What cranial nerves are associated with the pons ?
Trigeminal CNV.
What cranial nerves are associated with the medulla ?
Glossopharyngeal CNXI, vagus CNX, hypoglossal CNXII.
What is the pontomedullary junction ?
Junction between pons and medulla.
What cranial nerves are associated with the pontomedullary junction ?
Abducens CNVI, facial CNVII, vestibulocochlear CNVIII.
What is diencephalon composed of and what does it form ?
Epithalamus, thalamus, hypothalamus.
Central core of the brain.
Is the corpus callous formed by white or grey matter ?
White matter - myelinated axons.
What exits the skull via the supra-orbital foramen ?
Supra-orbit nerve and vessels.
What exits the skull via the infra-orbital foramen ?
Infra-orbital nerve and vessels.
What exits the skull via the mental foramen ?
Mental nerve and vessels.
What exits the skull via the foramina of the cribriform plate ?
Olfactory nerve (CNI).
What exits the skull via the optic canal ?
Optic nerve (CNII) and ophthalmic artery.
What 4 cranial nerves and blood vessels exit the skull via the superior orbital fissure ?
Oculomotor nerve (CNIII), trochlear nerve (CNIV), ophthalmic division of trigeminal nerve (CNV1), abducens nerve (CNVI) and superior ophthalmic vein.
What cranial nerves exit the skull via the internal acoustic meatus ?
Facial nerve (CNVII) and vestibulocochlear nerve (CNVIII).
What is the exit point in the skull for the hypoglossal nerve (CNXII) ?
Hypoglossal canal.
What foramen does the maxillary division of trigeminal nerve exit the skull from ?
Foramen rotundum.
What foramen does the mandibular division of trigeminal nerve exit the skull from ?
Foramen ovale.
What foramen does the ophthalmic division of trigeminal nerve exit the skull from ?
Superior orbital fissure.
What blood vessel passes through foramen spinosum ?
Middle meningeal artery.
What nerves and blood vessels pass through the jugular foramen ?
Internal jugular vein.
Glossopharyngeal nerve (CNIX).
Vagus nerve (CNX).
Spinal accessory nerve (CNXI).
What nerves and blood vessels pass through foramen magnum ?
Spinal cord.
Vertebral arteries.
Roots of spinal accessory nerve, travelling superiorly from spinal cord to jugular foramen.
Facial nerve passes through what two foramina ?
Internal acoustic meatus and stylomastoid foramen.
Name the foramina.
Name the foramina (left arrows).
Name the foramina (right arrows).
What cranial nerves have sensory function ?
Olfactory (CNI).
Optic (CNII).
Trigeminal (CNV).
Facial (CNVII).
Vestibulocochlear (CNVIII).
Glossopharyngeal (CNIX).
Vagus (CNX).
What cranial nerves have motor function ?
Oculomotor (CNIII).
Trochlear (CNIV).
Trigeminal (CNV).
Abducens (CNVI).
Facial (CNVII).
Glossopharyngeal (CNIX).
Vagus (CNX).
Accessory (CNXI).
Hypoglossal (CNXII).
What cranial nerves have special sensory function ?
Olfactory (CNI).
Optic (CNII).
Facial (CNVII).
Vestibulocochlear (CNVIII).
Glossopharyngeal (CNIX).
Vagus (CNX).
What is the central connection for the 3 branches of the trigeminal nerve ?
Pons.
Where is the trigeminal ganglion located ?
Meckel’s cave.
What is the central connection for the olfactory nerve (CNI) ?
Olfactory bulb.
What is the central connection for the optic nerve (CNII) ?
Thalamus.
What 2 cranial nerves’ central connection is the midbrain ?
Oculomotor (CNIII) and trochlear (CNIV).
What 3 cranial nerves’ central connection is the pontomedullary junction ?
Abducens (CNVI), facial (CNVII) and vestibulocochlear (CNVIII).
What 4 cranial nerves’ central connection is the medulla oblongata ?
Glossopharyngeal (CNIX), vagus (CNX), accessory (CNXI), hypoglossal (CNXII).
What are the two main sources of arterial supply to the brain ?
Vertebral arteries and internal carotid artery.
What are the two main sources of arterial supply to the brain ?
Vertebral arteries and internal carotid artery.
What artery supplies the anterior aspect of the brain ?
ICA.
What arteries supply the posterior aspect of the brain ?
Vertebral.
What is the vertebral artery a branch of ?
Subclavian, second branch of the aortic arch.
What route does the vertebral artery take ?
Travel through vertebral foramen of the 1st 6 vertebrae and then through the foramen magnum into the base of the brain.
What is the main blood supply to the meninges ? And the main branches ?
ECA.
Occipital, ascending pharyngeal and middle meningeal.
Contralateral hemiparesis.
Hemisensory loss involving mainly leg and foot.
Inability to identify objects correctly.
Personality changes.
Stroke has likely affected what artery ?
Anterior cerebral - distal to anterior communicating artery.
Affecting frontal and parietal lobes.
Contralateral hemiparesis.
Hemisensory loss involving mainly face and arm.
Aphasia.
Contralateral hemianopia.
Stroke has likely affected what artery ?
Middle cerebral.
Pre and post-central gyri affected.
Contralateral hemianopia with degree of macular sparing.
Visual agnosia.
Impairment of memory.
Stroke has likely affected what artery ?
Posterior cerebral artery.
Ischemia of occipital lobe.
Damage to medial aspect of temporal lobe.
Where do ALL venous sinuses drain into ? And what foramen does this exit the skull ?
IJV via jugular foramen.
What are dural venous sinuses ?
Spaces between periosteal and meningeal layers of dura, for drainage of blood and resorption of CSF from the brain.
What are arachnoid granulations ?
Balloons of arachnoid which extend into venous sinuses and are responsible for resorption of CSF.
Where is CSF made ?
Choroidal epithelial cells of choroid ventricles. Modified ependymal cells.
What is the name for the invagination of dura matter into longitudinal fissure between left and right hemispheres ?
Falx cerebri.
What 4 cranial nerves are associated with the cavernous sinus ?
Oculomotor.
Trochlear.
Abducens.
Trigeminal (CNV1 and CNV2).
What is clinically significant about the cavernous sinus with respect to dentistry ?
Slow blood flow so infection and thrombosis risk - can be from maxillary dental infection. Swollen eye and fever - common symptoms.
What is the most common cause of extra-dural haematoma ? And how will symptoms present ?
Trauma.
Quickly unconscious as arterial damage - higher blood flow.
What is the most common cause of subdural haematoma ? And how will symptoms present ?
Elderly.
Slower symptoms as venous damage - slower blood flow.
What is the most common cause of subarachnoid haematoma ?
Aneurysm.
What is the function of the hypothalamus ?
Controls blood glucose, body temperature, controls release of hormones from pituitary, growth, sleep-wake cycle.
What is the pituitary stalk (or infundibulum) ?
Connection between pituitary gland and hypothalamus.
Where is the pituitary gland located ?
In middle cranial fossa at sella turcica.
What is diaphragma sellae ?
Dura mater covering pituitary gland leaving opening for hypothalamus connection.
What are examples of hormones released from pituitary gland ?
GH, TSH, FSH.
What are the 3 cortexes of the frontal lobe ?
Pre-frontal.
Pre-motor.
Primary motor.
What is the function of the pre-frontal cortex ?
Problem solving, complex planning, decision making, personality.
What is the function of the pre-motor cortex ?
Supplementary to primary motor cortex for planning, control and execution of voluntary movement.
Broca’s area is associated with which part of the brain ?
Left hemisphere of frontal lobe.
What is Broca’s area responsible for ?
Production of speech.
What are the two cortexes associated with the parietal lobe ?
Primary somatosensory cortex.
Posterior parietal cortex.
How is the primary somatosensory cortex position in relation to the central gyrus ?
Behind.
How is the primary motor cortex position in relation to central gyrus ?
In front.
What is the function of the primary somatosensory cortex ?
Tactile sensation.
What is the function of the posterior parietal cortex ?
Integration of sensory information, spatial perception and attention, cognitive function.
What image represents “specific areas of body are mapped to specific areas of the cortex” linked to somatosensory and motor cortex ?
Sensory homunculous.
What lobe is responsible for visual processing ?
Primary visual cortex in occipital lobe.
What is the function of the temporal lobe of the brain ?
Processing sensory information, long term memory, visual perception and recognition, processing olfactory stimulus.
What is Wenicke’s area responsible for ?
Language comprehension.
The cerebral aqueduct connects what two ventricles ?
Mid-line 3rd and 4th.
The inter ventricular foramen joins what ventricles ?
Lateral and 3rd midline.
Where is the brainstem located ?
Posterior cranial fossa.
The cervical enlargement between C4-T1 contributes to ?
Brachial plexus.
Grey matter is deep to white matter where ?
Spinal cord.
White matter is deep to grey matter where ?
Brain.
Dorsal horns relay what kind of nerve fibres/rootlets ?
Afferent sensory so info from PNS to CNS.
Ventral horns relay what kind of nerve fibres/rootlets ?
Efferent motor so info from CNS to PNS.
Dorsal and ventral roots converge to form ?
Mixed motor and sensory spinal nerve.
Dorsal and ventral roots divide into rami after exiting ?
Intervertebral foramen of vertebral column.
How many pairs of spinal nerves emerge from spinal cord ?
31
C1 spinal nerve emerges between what two bones ?
Occipital bone and C1.
What are the 3 meningeal layers of the spinal cord ?
Dura - outermost.
Arachnoid - middle.
Pia - innermost.
Where is CSF fluid located in spinal cord ?
Subarachnoid space.
