Brainstem Flashcards
brainstem
1) midbrain
2) pons
3) medulla
midbrain derives from?
mesencephalon
pons derives from?
metencephalon
medulla derives from?
myelencephalon
borders of midbrain
mammilary bodies (of diencephalon)
isthmus of brainstem (aka pontomesencephalic junction)
anatomy of midbrain
1) tectum
2) tegmentum
3) cerebral aqueduct
4) cerebral peduncles
tegmentum
contains grey matter which contains nuclei and white matter which contains fibre tracts
nuclei of midbrain
1) CN III nuclei
- oculomotor nuclei
- Edinger-Wespinal (EW)
2) CN IV nuclei
3) CN V nuclei
- part of mesencephalic nuclei
4) red nucleus - cerebellar circuitry
5) substantia nigra - basal ganglia (dopamine circuit)
tectum
- pretectal area
- corpora quadrigemini
pretectal area
junction of midbrain and diencephalon
corpora quadrigemini
2 superior colliculi (eyes) and 2 inferior colliculi (ears)
CN V nuclei in brainstem
1) mesencephali nuclei (midbrain and ponds)
2) main sensory nuclei and motor nuclei (pons)
3) spinal nuclei (pons and medulla)
fibres/tracts of midbrain
1) corticospinal tract
2) medial lemniscus
3) spinothalamic tract
- medial longitudinal fasciculus
- decussation of sup. cerebellar peduncles
cerebral aqueduct
separates tectum and tegmentum
cerebral peduncles
separated by interpeduncular fossa
nerves emerging from midbrain
CN III - emerges ventrally from interpeduncular fossa
CN IV - emerges dorsally, caudal to inferior colliculi
borders of pons
isthmus of brainstem (between midbrain and pons)
pontomedullary junction (between pons and medulla)
fourth ventricle
anatomy of pons
1) tegmentum
2) basal pons
3) part of fourth ventricle
4) cerebellar peduncles
pontine nuclei
1) CN V
- part of mesencephalic nucleus
- main sensory nucleus
- motor nucleus
- part of spinal nucleus
2) CN VI
3) CN VIII
- motor nucleus
- part of sensory nucleus
4) CN VIII
5) basal pontine nuclei - specific to basal pons
6) superior olivary nucleus
pontine fibres
1) corticospinal tract
2) medial lemniscus
3) spinothalamic tract
4) pontocerebellar fibres
cerebellar peduncles
connect brainstem to cerebellum
superior cerebellar peduncles (SCP)
middle cerebellar peduncles (MCP)
inferior cerebellar peduncles (ICP)
nerves that emerge from the pons
CN V
CN VI
CN VII
CN VIII
boundaries of the medulla
pontomedullary junction (between the pons and the medulla)
foramen magnum - contines as spinal cord
pontomedullary junction
imaginary line connecting inferior aspects of middle cerebellar peduncles