ventricles and gross anatomical features of the brainstem/forebrain

ventricles

chambers in the brain that produce and/or conduct cerebral spinal fluid

lateral ventricle

interventricular foramen

third ventricle

cerebral aqueduct

fourth ventricle

ventricles part of the internal ventricle system

lateral ventricle

paired; located in all parts of the cerebral cortex

interventricular foramen

paired; connects the lateral ventricles with the third ventricle

third ventricle

unpaired, located on the midline in diencephalon

cerebral aqueduct

unpaired; connects the third ventricle located in midbrain and rostral pons

fourth ventricle

unpaired; located dorsal to pons and rostral medulla; has openings that allow the movement of CSF to the outside of brain and spinal cord

choroid plexus

secretes CSF; filters substances from the vascular system (through epithelial cells to the ventricular space)

• a rise from tuft of cells within the walls of the ventricles

protein

potassium

calcium

CSF has lower levels of these substances compared to serum

lateral ventricles

third ventricle

cerebral aqueduct

fourth ventricle

medial and lateral foramen

subarachoid space

flow of CSF:

arachnoid granulation

outgrowth of arachnoid into the superior sagittal sinus - allows for the CSF to enter the venus system

medulla

pons

midbrain

diencephalon

brainstem consists of:

anterior median fissure

pyramid decussation

pyramid

olivary eminence

preolivary sulcus

postolivary sulcus

medulla (ventral features)

pyramid decussation

axons of the medulla pyramid cross over at this location

cranial nerves 6-12

cranial nerves associated with the medulla

cranial nerve 12

associated with the pre-olivary sulcus

cranial nerves 9 and 10

associated with the post-olivary sulcus

cranial nerve 11

associated with the foramen magnum

4th ventricle

OBEX

gracle tubercle

cuneate tubercle

trigeminal tubercle

posterior median fissure

medulla (dorsal features)

cerebellar peduncles

fiber tracts that connect the cerebellum to the brainstem; they are made of

1. axons entering the cerebellum that originated in the spinal cord or other parts of the brainstem

2. axons leaving the cerebellum that are destined for brainstem targets

ICP

MCP

SCP

cerebellar peduncles:

inferior cerebellar peduncles

connect the cerebellum to the medulla

middle cerebellar peduncles

connect the cerebellum to the pons; THE ONLY ONE YOU CAN SEE

superior cerebellar peduncles

connect the cerebellum to the midbrain

middle cerebellar peduncle

cranial nerve 5

cranial nerve 4

pons (ventral features)

cerebral peduncle

interpeduncular fossa

cranial nerve 3

midbrain (ventral components)

tectum

roof located dorsal to the midbrain; this is where the superior and inferior colliculi are located

superior colliculus

inferior colliculus

cranial nerve 4

midbrain (dorsal components)

mamillary bodies

infundibulum

cranial nerve 2

optic chaism

optic tract

diencephalon (ventral components)

thalamus

hypothalamus

corpus callosum

fornix

diencephalon (sagittal components)

lateral sulcus

central sulcus

parieto-occipital sulcus

major sulci of the lateral cortex

insular cortex

buried deep in lateral sulcus; covered by gyri of temporal, parietal and frontal lobes

• contains gustatory, autonomic, pain and vestibular areas

cingulate sinus

pareito-occiptal sulcus

calcarine sulcus

major sulci of medial cortex

calcarine sulcus

splits the occipital lobe into 2 parts