MRI & CT anatomy of the brain Flashcards
Out of grey and white matter, which is located in the periphery and which Is deep?
Grey matter is in the periphery
White matter is deep
Grey matter deep within the brain is called?
Basal ganglia
In the spinal cord which is located centrally and what forms the bulk of the superficial parts?
Grey matter is located centrally.
White matter forms bulk of superficial parts.
What are the elevated ridges in the brain?
Gyri
What are the small grooves dividing the ridges of the brain?
Sulci
What does the central sulcus divide?
Frontal lobe from the parietal
What’s the name of the groove that divides the cerebral hemispheres?
Longitudinal fissure
What groove separates the cerebrum from the cerebellum?
Transverse fissure
What groove divides the temporal lobe from the parietal and frontal lobes?
Sylvian fissure
What 2 structures does the sylvan fissure accommodate?
Middle cerebral arteries
Insular cortex
What shape does the parietal-occipital fissure have when it joins the calcarine sulcus ?
Letter Y placed sideways
What is the parietal lobe bounded by anteriorly and posteriorly?
- Ant. central sulcus
- post. parietal-occipital sulcus
What structure does the occipital lobe overly?
Tentorium cerebelli.
How many gyri does the insult have?
5
What separates the nasal cavity from the brain?
Cribriform plate of ethmoid bone
What’s the order of the brainstem?
1 midbrain
2 pons
3 medulla oblongata
What does the midbrain connect?
Pons & cerebellum to diencephalon
Where does the midbrain lie?
In the gap in the tentorium cerebelli.
How many colliculi does the post. surface of the midbrain have?
4
What rests between the 2 superior colliculi?
Pineal gland
What is located internally In the midbrain? (2)
Substantia nigra & red nucleus.
What is the largest part of the hindbrain called?
Cerebellum.
What are the 4 components of the cerebellum?
- 2 lateral cerebellar hemispheres
- median vermis
- horizontal fissure
- tonsils
What do the tonsils of the cerebellum overhand?
They overhang the foramen magnum on each side of the medulla oblongata.
What does the cerebellum control? (3)
Balance, regulation of posture & muscle tone.
What is a cerebellar peduncle?
It’s a nerve tract that permits communication between the cerebellum & other parts of CNS.
What are the 3 cerebellar peduncles?
Superior, middle, inferior.
What does the diencephalon consist of?
It comprises of the hypothalamus & thalamus.
What ventricle does the diencephalon surround?
3rd Ventricle.
Where is the thalamus situated?
Lateral wall of 3rd ventricle, it extends from the inter ventricular foramen rostrally to the midbrain caudally.
Below the thalamus.
What type of nuclei is the thalamus composed of?
Relay nuclei.
Where is the hypothalamus situated?
It forms the floor of the 3rd ventricle.
What does the hypothalamus include? (3)
Optic chiasma, infundibular stalk,
maxillary bodies.
What type of nerve activity is the hypothalamus associated with?
Autonomic.
Which is the largest? Hypothalamus or thalamus?
Thalamus.
What does the hypothalamus control?
Body temp, emotion, ANS.
What is the infundibular stalk also known as?
Pituitary stalk.
What do the basal ganglia consist of? (2)
Corpus striatum and Claustrum
What is the corpus striatum composed of? (3)
Caudate nucleus
Putamen
Globus Pallidus
What nucleus do the putamen and globes pallidus form?
Lentiform nucleus.
What is the globus pallidus involved in?
Regulation of voluntary movement.
What are the 4 white matter tracts?
- Corpus collosum,
- Fornix,
- Internal capsule,
- Anterior & posterior commissures.
What are the 4 areas of the corpus collosum?
Genu, rostrum, body & splenium.
What are the most anterior and posterior portions of the corpus collosum?
Anterior: genu
posterior: splenium
The fornix carries signals from where to where?
From the hippocampus to the hypothalamus.
Why is the internal capsule one of the most important parts of the cerebral white matter?
It contains nerve fibres which pass to and from the cerebral cortex and lower levels of neuraxis.
What is the anterior commissure?
Bundle of nerve fibres connecting the 2 cerebral hemispheres across the midline.
What is CSF secreted by?
Epithelium
Where does the CSF cover?
Choroid plexus in the lateral, 3rd & 4th ventricles.
Where does the CSF drain into?
Subarachnoid space from the roof of the 4th ventricle before being reabsorbed.
What structure does the CSF pass through from the 3rd ventricle to the 4th ventricle?
Cerebral aqueduct (of sylvius)
What shape is the 4th ventricle when viewed from above and from the side?
Above: diamond
Side: tent.
What 3 parts do the lateral ventricles have?
Anterior horn
Body
Posterior horn
What is the septum pellucidum (lucidum)?
Thin triangular, vertical membrane separating the anterior horns of the right and left lateral ventricles of the brain.
Where does the septum pellucidum run?
Runs as a sheet from corpus collosum down to fornix.
Name the 5 basal cisterns.
- Cisterna magna
- prepontine (anterior to pons)
- interpeduncular (basal)
- ambient
- suprasellar
Where does the cisterna magna lie?
Between the cerebellum and dorsum of medulla.
Where does the cisterna magna receive CSF from?
Foramen of magendie/ median aperture of 4th ventricle.
What artery does the prepontine cistern contain?
Basilar
Where does the prepontine cistern receive CSF from?
Foramen of luschka / lateral aperture of 4th ventricle.
What structure does the interpeduncular cistern contain?
Circle of willis.
Where is the interpeduncular cistern located?
Between paired temporal lobes of brain, between 2 cerebellar peduncles.
What 2 structures does the ambient cistern contain?
Great cerebral vein & pineal gland.
What are 2 other names for the ambient cistern?
superior cistern/ quadrigeminal cistern.
Where is the ambient cistern located?
Occupies the space between the splenium of corpus collosum and superior aspect of cerebellum.
Where is the suprasellar cistern located?
Above the sella turcica, under hypothalamus.
What 3 structures does the suprasellar cistern contain?
Optic chiasma, pituitary stalk & polygons of Willis.
Name the 4 folds of the dura mater and what they separate
- Falx cerebri: cerebral hemispheres
- Falx cerebelli: cerebellar hemispheres
- Tentorium cerebelli: divides cranial cavity into supra & infra tentorial compartments
- Diaphragm sellae: covers sella turcica and forms roof over pituitary fossa
