CNS Embryogenesis Flashcards
1
Q
Somatic ns
A
- Innervates skin and most skeletal muscle
2
Q
Visceral (autonomic) ns
A
- Innervates viscera smooth muscle and glands
- Sympa and parasympa divisions
- Both have pre and post ganglionic fibers
3
Q
Neural tube closure
A
- Neural plate thickens and elongates
- Lateral folding occurs
- Neural groove
- Median hinge point
- Lateral hinge point
- Fusion of opposing neural folds and seperation from overlying ectoderm
- Neural crest cells
4
Q
What initiates brain development and what establishes sensory and motor regions
A
- Molecular signals at neural plate initiate
- BMP for sensory
- SHH for motor
5
Q
Primary CNS segmentation
A
- Brain segments/vesicles
- Prosencephalic (forebrain)
- Mesencephalic (midbrain)
- Rhombencephalic(hindbrain)
- Spinal cord
- Flexures
- Cephalic
- Cervical
6
Q
Regulation of rhombomeres
A
Differentiation of rhombomeres is regulated by HOX genes
7
Q
Secondary CNS segmentation
A
- Prosencephalon
- Telencephalon
- Diencephalon
- Mesencephalon
- Rhombencephalon
- Metencephalon
- Myelencephalon
- Neural canal in each segments forms a primitive ventricle
- Spinal cord
- Flexures
- Mesencephalic (cranial)
- Cervical
- Pontine
8
Q
Proliferation in neural tube
A
- Consists of Pseudostratified epithelium
- External limiting membrane (BM)
- DNA synthesis
- Lumen
- Mitotic division
- External limiting membrane (BM)
9
Q
Neurite Outgrowth
A
- Axons and dendrites
- Growth cones
- Numerous filopodia (small spindle like feet)
- Filopodia regularly extend and retract to test enviroment
10
Q
Later changes of brain vesicles
A
- Telencephalon–> cerebrum
- Diencephalon–> Thalamus, hypothalamus, oineal gland, pituitary, eyes
- Mesencephalon–> Auditory colliculi
- Metencephalon–> Pons and cerebellum
- Myelencephalon–> Medulla oblongata
11
Q
Peripheral nevers development
A
- Outgrowth of axons from motor neuroblasts in basal plate
- Neural crest cells form spinal ganglion
- Dendrites grow towards periphery
- Axons grow towards dorsal horn
- Interneurons form btw sensory neuron termination and motor neurons
- Reflex arc is formed
- Sensory information–>motor response
12
Q
What forms the sympathetic and parasympathetic ganglion
A
ALL are formed from neural crest cells
13
Q
Stabilization
A
- Interaction between neuron and target structure influence connection type and number
- Spoptosis
- Eliminates axons that fail to reach normal target
- Reduces size of neuronal pool to match target or presynaptic input
- Elinates connection errors
14
Q
Neural crest cells differntiation
A
- Hypothesis
- Equal developmental potential
- Differntiation exclusvly determined by enviroment
- Preprogrammed before migration
- Diff exclusively determined by internal factors
- Equal developmental potential
- Both are true
- Factors
- Origin
- time of migration
- proximity to inducing tissue
- Factors
15
Q
Cranial NCC
A
- Leave before neural tube closure
- Origin specifies destination (unlike trunk ncc)
- Responsible for facial tissues
