FC Y2B4

Regarding the meninges:

• The subarachnoid space is a true space between the arachnoid mater and the pia mater.

• The epidural space is a true space containing cerebrospinal fluid (CSF).

• The periosteal and meningeal layers of dura mater are separated at dural venous sinuses.

• The subdural space contains major blood vessels and trabeculae.

• Both the arachnoid mater and pia mater are referred to as the leptomeninges

Regarding the dural folds:

• They are formed by reflections of the periosteal layer of the dura mater.

• The falx cerebri is a vertical dural fold between the two cerebral hemispheres.

• The tentorium cerebelli extends between the occipital lobes and the cerebellum.

• The falx cerebelli separates the cerebrum from the cerebellum.

• The diaphragma sellae forms a roof over the pituitary gland.

Regarding the basal ganglia:

• They are deep grey matter structures.

• The head of caudate nucleus lies lateral to the third ventricle.

• The tail of caudate nucleus is continuous inferiorly with the putamen.

• The lentiform nucleus includes the putamen and the globus pallidus.

• The globus pallidus externus is located lateral to the putamen.

Regarding the basal ganglia motor pathways:

• The direct pathway decreases the thalamic output to the cortex.

• The indirect pathway promotes motor activity.

• The substantia nigra modulates the basal ganglia by exciting the direct pathway and inhibiting the indirect pathway

• Huntington disease is a hyperkinetic disorder resulting from degeneration of striatal neurons.

• Parkinson’s disease is caused by loss of dopaminergic input from the substantia nigra.

Regarding the diencephalon:

• It is located between the cerebral hemispheres and the brainstem.

• It includes the thalamus, hypothalamus, epithalamus, and substantia nigra.

• The thalamus is the largest component of diencephalon.

• The hypothalamus contains the pineal gland.

• The epithalamus is the most dorsal part of the diencephalon.

Regarding the thalamus:

• It is a paired, egg-shaped mass of white matter.

• It forms the wall of the lateral ventricle.

• The anterior tubercle marks the anterior end of the thalamus.

• It is connected to the opposite side by the interthalamic adhesion.

• The internal medullary lamina covers the lateral surface of the thalamus.

Regarding the thalamic nuclei:

• The internal medullary lamina divides the thalamus into anterior, medial, and lateral nuclear groups.

• The ventral anterior and ventral lateral nuclei relay motor signals from the basal ganglia to the motor cortex.

• The ventral posterolateral (VPL) nuclei relay facial and gustatory sensory input to the primary somatosensory cortex.

• The lateral geniculate body sends auditory signal transmission to the primary auditory cortex.

• The intralaminar nuclei is located within the internal medullary laminar.

Regarding the midbrain:

• The cerebral peduncles contain descending motor tracts.

• The interpeduncular fossa is an anterior midline depression that is perforated by blood vessels.

• The inferior colliculi are part of the visual reflex pathway.

• The trochlear nerve (CN IV) emerges just below the inferior colliculus.

• The oculomotor nerve (CN III) emerges from the lateral surface of the midbrain.

Regarding the pons:

• The basilar sulcus lodges the basilar artery.

• The trigeminal nerve (CN V) emerges at the pontomedullary junction.

• The abducent, facial and vestibulo-cochlear nerves (CN VI, VII, and VIII) emerge at the cerebellopontine angle.

• Its dorsal surface forms the upper two-thirds of the floor of the fourth ventricle.

• A lesion at the facial colliculus level can impair both facial and abducens nerve functions.

Regarding the medulla:

• The pyramids contain descending corticopontine fibers.

• The olives are produced by the underlying inferior olivary nuclei.

• The gracile and cuneate tubercles are found on the ventral surface of the medulla.

• The hypoglossal nerve (CN XII) emerges between the pyramid and olive.

• The superior part of the dorsal medulla forms part of the floor of the fourth ventricle.