Anatomy Of The Brainstem Flashcards
The brainstem is the part of the brain that connects the
Cerebrum with the spinal cord
Brainstem site
lies in the posterior cranial fossa
Brainstem parts
Mid brain
Pons
Medulla oblongata
Brainstem is connected to Cerebellum by
cerebellar peduncles
Brainstem function
- Pathway of tracts between cerebral cortex & spinal cord.
- Site of origin of nuclei of cranial nerves (from 3rd to12th)
Brainstem is responsible for
control of level of consciousness
perception of pain
regulation of CV & resp systems.
Divides the medulla into 2 halves
Ventral median fissure
An elevation, lies on either side of ventral median fissure
Pyramid
Pyramid produced by
corticospinal tract
An elevation, lies lateral to the pyramid
Olive
Olive is produced by
inferior olivary nucleus
Nerves emerging from Medulla _______ from
sulcus lateral to olive
Hypoglossal
Glossopharyngeal
vagus
accessory
divides the closed medulla into 2 halves
Dorsal median sulcus
on either side of dorsal median sulcus
Fasciculus gracilis
an elevation produced at the upper part of fasciculus gracilis
Gracile tubercle
on either side of fasciculus gracilis.
Fasciculus cuneatus
an elevation produced at the upper part of fasciculus cuneatus
Cuneate tubercle
marks the site of cuneate nucleus
Cuneate tubercle:
marks the site of gracile nucleus
Gracile tubercle
( Open medulla )4th ventricle on either side, an inverted V-shaped sulcus divides the area into 3 parts
Hypoglossal triangle
Vagal triangle
Vestibular area
overlies hypoglossal nucleus
Hypoglossal triangle
overlies dorsal vagal nucleus.
Vagal triangle
overlies vestibular nuclei
Vestibular area
Divides the pons into 2 halves
Basilar sulcus
occupied by basilar artery
Basilar sulcus
connect the pons to cerebellar hemisphere
Middle cerebellar peduncle
Nerves emerging from pons (ventral surface)
Trigeminal (5th)
Abducent (6th)
Facial (7th)
Vestibulocochlear (8th)
In dorsal surface of the pons On either side of median sulcus, it divides into 2 parts (from medial to lateral):
Medial eminence ( overlies abducent nucleus)
Vestibular area (overlies vestibular nuclei)
On the ventral surface of the mid brain large column of descending fibers (crus cerebri) , on either side, separated by a depression called the
Interpeduncular fossa
Nerves emerging from midbrain
Dorsal: Oculomotor (3rd) (from median aspect of crus cerebri)
Ventral: trochlear (4th) (caudal to inferior colliculus)
The only cranial nerve emerging from dorsal surface of brain stem)
Trochlear (4th)
