External features of the brain Flashcards
What is the role of the superior and inferior sagittal sinuses
To drain blood
What is the falx cerebri
Attached to the crista galli of the ethmoid bone anteriorly and posteriorly attached to the tentorium cerebelli
What is falx cerebelli
Dips between cerebral hemispheres, splitting the right and left
What is tentorium cerebelli
Dips between cerebrum and cerebellum, running horizontally
What is Diaphragma sellae
A hole in the dura that allows the pituitary stalk to pass through
where is the cavernosus sinus located
In a cavity between the sphenoid and temporal bone. It contains venous structures and cranial nerves
What characteristic does the arachnoid mater have
It is translucent
What are arachnoid granulations
Projections into the dura to allow CSF to return the venous blood
What is the choroid plexus
Pia mater folded back on itself
What is the space between the arachnoid and the pia mater
The subarachnoid space, it is sealed off by tight junctions and contains veins and arteries of the brain and spinal cord.
What is a gyri
A fold in the cerebral cortex
What is a sulci
A groove/fissure in the cerebral cortex
What separates the parietal and frontal lobes and the primary motor and primary sensory cortex
The central sulcus/ fissure of ronaldo
What divides the frontal and parietal lobes from the temporal. (forcing it apart would reveal the insula)
The lateral sulcus
What separates the right and left hemispheres (forcing apart reveals the corpus callosum)
The longitudinal fissure
which lobe houses the primary motor cortex
Frontal
Which lobe processes auditory input and high level visuals
Temporal
Which lobe houses the primary sensory cortex
Parietal
What lobe contains the primary visual cortex
Occipital
What is the job of CSF
Acts to keep the brain buoyant, protects the tissue, clear it of waste, as well as preventing ischemia and chemical disturbances
What produces CSF
Choroid plexus (ependymal cells) of the lateral and fourth ventricle
What is the path of CSF
Lateral and fourth ventricle. Then flows through the interventricular foramen to the third ventricle. Then flows via the cerebral aquaduct into the fourth ventricle. CSF then escapes via the lateral and median apertures. It diffuses around the brain in the sub arachnoid space and returns venous blood through arachnoid granulations which project into the dura.
What is hydrocephalus
The abnormal accumulation of CSF in the brain
What are the two types of hydrocephalus
1) Communicating - caused by impaired CSF reabsorption
2) non-communicating - caused by CSF flow obstruction
What is the most common cause of hydrocephalus
Aqueductal stenosis - narrowing of the cerebral aqueduct
What will hydrocephalus cause
Increased intracranial pressure and progressive enlargement of the head
What structure joins the two cerebellar hemispheres
The vermis
What are the highly convoluted structures of the surface of the cerebellum
The folia
What is the cerebrocerebellum
Lateral part of the hemispheres and regulaes motor output
What is the spinocerebellum
Vermis and intermediate parts of the hemispheres. Adapts body to circumstances
Vestibulocerebellum
In the flocculonodular lobe (tucked behind the cerebellum) regulates balance and eye movement, and muscle tone
