69 Brain development (incomplete) Flashcards
During 4 weeks, what are the primary brain vesicles?
- Forebrain = prosencephalon
- Midbrain = Mesencephalon
- Hindbrain = Rhombencephalon
What are the secondary vesicles of forebrain? They will become?
- Telecephalon: cerebral hemisphere
2. Diencephalon > thalamus etc
What is the secondary vesicle of mesencephalon? It will become?
mesencephalon;
midbrain
What are the secondary vesicles of hindbrain (rhombencephalon)? They will become?
- Metencephalon > pons + cerebellum
2. Myelencephalon > medulla
Lateral ventricles derived from which secondary brain vesicle?
Lateral ventricles derived from which secondary brain vesicle? Telencephalon
Third ventricle derived from which secondary brain vesicle?
Diencephalon
Aqueduct derived from which secondary brain vesicle?
mescenphalon
Upper part of 4th ventricle derived from which secondary brain vesicle?
Metencephalon
Lower part of 4th ventricle derived from which secondary brain vesicle?
Myelencephalon
What is the midbrain flexure/ cephalic flexure?
4th-5th week, forebrain rotates ventrally and then posteriorly around midbrain region >under midbrain region.
What is the cervical flexure?
Ventral flexion between hindbrain and spinal cord. (4th-8th week)
What is pontine flexure of the brain?
Dorsal flexion at the hindbrain, dividing it into mesencephalon and myelencephalon
Deepening of pontine flexure folds the mesencephalon back onto myelencephalon.
5-8th week
Which of the following is true about the development of the myelencephalon?
A. Ala plates lie medial to the basal plates
B. Neuroblasts of alar plates form afferent sensory nuclei
C. Neutroblasts of basal plates from efferent motor nuclei
D. Rostral part: some neuroblasts from alar places form the olivary nuclei
E. Caudally, neuroblasts from basal plates form gracile nuclei and caudate nuclei.
All except A
A: Alar plate is more lateral to basal plate
D:Neuroblasts from the alar plates migrate into the marginal zone and form
isolated areas of gray matter: gracile nuclei medially and cuneate nuclei laterally
Divergence of lateral walls causes the stretching and thinning of the ___________. Neural lumen forms the ______________.
Ependymal roof;
lower part of 4th ventricle
Vascular pia mater together with ependymal roof forms the?
Tele choroidea
Tela choroidea invaginates into
4th ventricle & differentiates into
____________ to produce
cerebrospinal fluid.
choroid plexus
Myelencephalon:
Basal plate (motor)
1. Medial somatic efferent group: neurons of _____ nerve?
2. Intermediate special visceral efferent group: Neurons of ____________ nerve?
3. Lateral group general visceral efferent group: motor neurons of?
- CN 12
- CN9,10
- of CN10, CN9 that supple involuntary musculature of the respiratory tract, intestinal tract, hear
Myelencephalon:
Alar plate (sensory)
1. Somatic afferent group (most lateral) ?
2. Special visceral afferent group (intermediate)?
3. General visceral afferent group?
- 1 General somatic afferent group: receives general sensation from surface of head and neck and from mucosa of oral and nasal cavities and pharynx
- 2 special somatic afferent: hearing and balancing
- impulses from taste buds and tongue, palate, oropharynx and epiglottis
- interoceptive information via CN10 from gastrointestinal tract and heart
Of the metencephalon, specialization of the alar plate develops into?
cerebellum
Some neuroblasts of the alar plate and the metecephalone form _________ nuclei, and migrate to ventral side
Pontine nuclei
