Anatomy - Brain and Spinal Cord Flashcards
Which cranial fossa does the brainstem lie in?
Posterior
Embryologically, which two vesicles of the neural tube gives rise to the brainstem?
Mesencephalon (midbrain) and rhomebencephalon (hindbrain)
What are the cavities of ventricular system lie within the brainstem?
Cerebral aqueduct and 4th ventricle
What nerves emerge from the pontomedullary junction?
Facial, abducens, glossopharyngeal and vestibulocochlear nerve
What part of the brain lies immediately superior to the midbrain?
Thalamus (part of diencephalon)
What part of the midbrain lies immediately inferior to the midbrain?
Pons
What kind of fibres make up the cerebral peduncles and where are they destined for?
Centrifungal –> outgoing (most motor) fibres to spinal cord and peripheral from the cerebellum
What 2 features are found on the surface of the midbrain?
- Cerebral peduncles
* Inferior and superior colliculi
What is the diencephalon made up of?
Thalamus and hypothalamus
What part of the hypothalamus is visible from the surface?
Mammillary bodies
What is the name of the midline structure connecting the two cerebellar hemispheres?
Vermis
To what part of the brain are the pentacles anatomically connected to?
Pons (middle), midbrain (superior) and medulla (inferior)
Which ventricular space lies immediately anterior to the cerebellum?
4th ventricle
What is cerebellar coning?
When the cerebellar tonsils herniate through the foramen magnum in instances where there is a sudden drop in intracranial pressure
What is the name of the large fissure separation the two cerebral hemispheres in the mid-saggital line?
Longitudinal fissure
What structure connects the two cerebral hemisphere and what fibres does it contain?
Corpus callous and commissural fibres
What fissure separates the frontal and parietal lobes from the temporal lobe?
Lateral sylvan fissure
What fissure separates the frontal from the parietal lobe?
Central sulcus
What fissure separates the parietal from the occipital lobe?
Parieto-occipital sulcus
What does the calcimine sulcus separate in the brain?
Located on the medial surface of the occipital lobe and divides the visual cortex into two
What lobe contains the primary motor cortex?
Frontal lobe
What lobe contains the primary visual cortex?
Occipital lobe
What lobe contains the primary sensory cortex?
Parietal lobe
What lobe lobe contains the primary auditory cortex?
Temporal lobe
What is removed in a laminectomy?
The lamina of the vertebra and therefore the spinous process
At what level foes the spinal cord terminate in an adult and a new born?
- Adult - L1/2
* Child - L2/3
When does the dura and arachnoid mater end?
Both S2
What happens as the Pia mater inferior to the spinal cord?
Becomes film terminale at the conus medularis
At what vertebral level would a lumbar puncture be performed on an adult?
L3/4
What are upper motor neurone lesions characterised by?
Spasticity, increased muscle tone and complex sensory syndrome
What are lower motor neurones characterised by?
Global sensory changes and/or flaccid paralysis
Which artery do the right and left vertebral arteries arise from?
Subclavian arteries
At what vertebral level so the left and right internal carotid arteries arise?
C4
How is the basilar artery formed and which part of the brainstem is it most closely related to?
Joining of vertebral arteries and is related to pons
In what fissure does the anterior cerebral artery travel?
Longitudinal fissure
In what fissure does the posterior cerebral artery travel?
Calcarine sulcus
In what fissure does the middle cerebral artery travel?
Lateral sylvian sulcus
Which cerebral arteries supply the primary motor cortex?
Anterior and middle
Which cerebral arteries supply the primary sensory cortex?
Anterior and middle
Which cerebral arteries supply the primary visual cortex?
Posterior
Which cerebral arteries supply the primary auditory cortex?
Middle
Which cerebral arteries supply the area for olfaction?
Posterior
What parts of the brain does the vertebro-basilar system supply?
Superior surface of cerebellum and midbrain
Which cranial nerve emerges just above the superior cerebellar artery?
Oculomotor nerve (CN III)
What is the carotid sinus?
Dilatation in the terminal part of the common carotid - it is a pressure receptor which monitors the flow of blood to the head
Sensory nerves from the carotid sinus run in the glossopharyngeal and vagus nerve
What is the carotid body?
Area on the posterior wall of the terminal part of the common carotid artery in the neck which contains chemoreceptors which are sensitive to low oxygen level (anoxia)
Sensory nerves run in the glossopharyngeal nerve
Detection of anoxia will stimulate increase HR, RR and BP
What three sensory and motor mechanisms which control blood flow to the brain?
Carotid sinus, carotid body and sympathetic motor nerve
Where are the sympathetic motor nerves, that control blood glow to the brain, located?
Come from to the superior cervical ganglion and forms a plexus around in the ICA. The plexus enters the skull, with the artery through the carotid canal, and continues along the main branches of the ICA
Describe the venous drainage of the brain
Drained by a series of veins which drain into dural venous sinuses which are present between the periosteum and the cranial dura
Into which vein in the neck do these dural venous sinuses drain into?
IJV
What is the clinical significance of the connections between intracranial venous sinuses and extra cranial sinuses?
Potential routes of infections and they do not contain valves
Name and describe three important connections between intracranial venous sinuses and extra cranial sinuses?
- Superior ophthalmic vein drains into cavernous sinus inside the cranial cavity, and then with the facial vein outside of it
- Emissary veins which are small veins that connect cranial venous sinuses with diploe of the skull containing the blood sinuses in the bone marrow, which in turn are continuous with the veins in the superficial fascia overlying skull and scalp
- Inferior petrosal sinuses lie at the base of the brain and join each other via the basilar sinus and also connects inferiorly to internal vertebral sinus
What vein drains into the cavernous sinus?
Ophthalmic veins
What fluid circulates in the subarachnoid space?
CSF
Which structures does the falx cerebri separate?
Two cerebral hemispheres
What bony structure does the falx cerebri attach to?
Crista gali of ethmoid bone
Which dural venous sinus runs within the upper border of the falx cerebri?
Superior sagittal sinus
Which dural venous sinus runs along the lower border of the falx cerebri?
Inferior sagittal sinus
What structures lie on either side of the tentorium cerebelli?
Occipital lobe and cerebellum
What bony structures does the anterior edge of the tentorium cerebelli attach to?
Anterior and posterior crinoid processes of sphenoid bone
Which dural venous sinus runs along the attachment of the falx cerebri to the tentorium?
Straight sinus
What dural fold separated the two cerebellar hemispheres?
Falx cerebelli
What is the fold of dura that surrounds the pituitary stalk?
Sellar diaphragm
Name the clinically important artery that supplies the dura mater
Middle meningeal artery (branch of the maxillary artery)
Through which foramen does the middle meningeal artery enter the skull?
Foramen spinosum
Which artery is the maxillary artery a terminal branch of and within which gland is it given off?
ECA and parotid gland
What embryological structure forms the ventricles?
Neural tube vesicles
Which parts of the brain do the different parts of the lateral ventricle lie in?
Anterior horn - frontal lobe
Posterior horn - occipital lobe
Body - parietal lobe
Inferior horn - temporal lobe
Where in the brain is the interventricular foramen located?
Temporal lobe
Where in the brain is the 3rd ventricle located?
Within the diencephalon
Where in the brain is the cerebral aqueduct located?
Midbrain
Where in the brain is the 4th ventricle located?
Dorsal to brainstem and anterior to cerebellum
Which structure in the ventricles generates CSF?
Choroid plexus
How does CSF pass into the subarachnoid space from the 4th ventricle?
Via apertures (3 small holes)
At which location is the cerebrospinal fluid finally reabsorbed back into the general circulation?
Arachnoid villi into sagittal sinus