Neurodevelopment Flashcards
What layer does the nervous system develop from?
Ectoderm
What do neural crest differentiate into?
cranial nerve sensory ganglion cells, dorsal root ganglion cells, postganglionic autonomic ganglion cells (parasympathetic and sympathetic), chromaffin cells of the adrenal medulla, schwann cells, and melanocytes
What cells form alongside the neural tube and what do they form?
mesodermal cells, which form somites, which form skeletal muscle, vertebrae, and the dermis
What are the derivatives (secondary vesicles, regions, and ventricles) of the prosencephalon?
=forebrain
- –> telecephalon –> cerebral cortex, basal ganglia, amygala, hippocampus –> lateral (foramen of Monro)
- –> diencepalon, thalamus, hypothalamus, pituitary, pineal gland –> 3rd ventricle
What are the derivatives (secondary vesicles, regions, and ventricles) of the mesencephalon?
=midbrain
mesencephalon –> midbrain –> cerebral aqueduct
What are the derivatives (secondary vesicles, regions, and ventricles) of the rhombencephalon?
=hindbrain
- –> metencephalon –> pons, cerebellum –> 4th ventricle
- –> myelencephalon –> medulla –> central canal
What are the important flexures in the brain?
Cephalic flexure, pontine flexure, and cervical flexure
Neurocytes migrating dorsal to the sulcus form the –?
Alar plate
Neurocytes migrating ventral to the sulcus form the —?
Basal plate
Which plates contribute to which neural pathways?
Alar= sensory
Basal=motor
The alar plate contains what kind of fibers?
GSA and GVA
What kind of fibers doe the basal plate contain?
GSE and GVE
What is Hirschprungs disease?
Defective formation or migration of neural crest cells, resulting in bowel issues and an absence of autonomic ganglia cells int he colon
What causes anencphaly?
Failure of closure of the rostral neuropore
What causes spina bifida?
Failure of closure of the caudal neuropore
In the brainstem, where is the alar plate located?
Lateral to the basal plate
What is the foramen of Luschka?
a pair of foramina that develop in the roof of the medulla laterally, also known as lateral aperatures
What is the foramen of magendie?
A foramen medial to the foramen of luschka, also known as the medial aperature
What are the types of Spina bifida?
Spina bifida occulta: “hidden”, split in bone of the spine, often just a small part of vertebrae missing in low back
Spina bifida cystica (meningocele and meningomyelocele): either the meninges protrudes through an opening causing a sac or a portion of the cord protrudes through as well
Rachischisis: spinal cord is exposed, frequently neural tissue becomes necrotic or fails to form
What are the three cranial defects involving protrusion of the skull?
meningocele, meningoencephalocele (brain tissue protusion), and meingohydroencephalocele (brain tissue and ventricle protrusion)
What is exencephaly?
Failure of the cephalic (rostral) neural tube to close, leaving malformed brain exposed –> necrosis
What is hydrocephaly?
abnormal accumulation of CSF within the ventricular system, frequently due to blockage or narrowing of aqueduct of sylvius
What is Dandy walker syndrome?
congenital abnormality of the fourth ventricle with failure of foramens luschka and magendie to form, resulting in enlarged fourth ventricle, complete absense of cerebellar vermis, and cyst formation near base of skull
What is an arnold-chiari malformation?
a caudal displacement and herniation of the posterior cranial fossa structures, namely the cerebellum, through the foramen magnum
What is microphaly?
a smaller than normal cranial vault normally caused by lack of brain development (Associated with Zika)
What are nuclei and components for the midbrain?
Oculomotor nuclei = GSE
Edinger-Westphal nuclei=GVE
Trochlear nuclei = GSE
Mesencephalic nucle and tr. of V = GSA
What are the nuclei and components of the Pons?
- Abducens nuc = GSE
- Sup. salivatory nuc = GVE
- Motor trigemnial nuc = SVE
- Motor facial nuc= SVE
Principle sensory nuc of V = GSA - Spinal trigeminal nuc = GSA
