The Human Brain Flashcards
What does failure of the spinal cord closing cause?
Spina bifida or anencephaly
What prevents most neural tube defects?
Folic acid
What are the primary brain vesicles?
Prosencephalon
Mesencephalon
Rhombencephalon
Spinal cord
What are the secondary brain vesicles?
Telencephalon Diencephalon Mesencephalon Metencephalon Myelencephalon Spinal cord
What does a dorsal fold in the rhombencephalon make?
Metencephalon
Myelencephalon
What does the prosencephalon become?
Telencephalon
Diencephalon
What are the adult derivatives of the telencephalon?
Olfactory lobes
Hippocampus
Cerebrum
What are the adult derivatives of the diencephalon?
Retina (optic vesicle)
Epithalamus
Thalamus
What are the adult derivatives of the mesencephalon?
Midbrain
What are the adult derivatives of the metencephalon?
Cerebellum
Pons
What are the adult derivatives of the myelencephalon?
Medulla
Meninges of the spinal cord
Dura mater (outermost) Arachnoid Pia mater (innermost)
Where is most of the cerebrospinal fluid formed?
Cerebral ventricles
Sites of origin of CSF?
Choroid plexus
Ependyma
Parenchyma
What is the function of CSF?
To act as a buffer/cushion for the brain’s cortex providing basic mechanical and immunological protection to the brain
Where does CSF occupy?
Subarachnoid space
Ventricular system around the inside of the brain and spinal cord
What does it mean if CSF pressure is elevated?
Cerebral blood flow may be constricted
What is hydrocephalus?
Abnormal accumulation of CSF in the brain ventricles
What causes hydrocephalus?
Impaired flow of CSF
Impaired reabsorption or excessive production of CSF
What is a lumbar puncture?
CSF is extracted through a needle between the 3rd and 4th lumbar vertebrae
What is aqueductal stenosis?
Narrowing of the aqueduct of Sylvius which blocks the flow of CSF in the ventricular system
Life threatening in a short period of time
Restricts blood flow to the brain
What is an ependymal cell?
A type of neuronal support cell that forms the epithelial lining of the ventricles of the brain and central canal of the spinal cord
Structure of a ependymal cell
Have cilia on their surface
Influence the flow of CSF, bringing nutrients to neurons and filtering harmful molecules
What is the function of the layer of ependymal-derived cells surrounding the blood vessels of the choroid plexus?
To produce CSF through selective uptake of water and other molecules from blood into cells
Then transported across cells
Secreted into lateral ventricles as CSF
Where are tanycytes found?
The lining of the floor of the third ventricle of the brain