Neuroembryology Flashcards
What is nueroembryology
- Development of the nervous system (CNS & PNS)
How does nueroembryology begin?
- Fertilized egg begins to divide shortly after conception —> forming the blastula (hollow ball of cells)
The blastula infolds, forming what 3 germinal layers?
- Ectoderm
- Mesoderm
- Ectoderm
The ___ forms skin and nervous system
Ectoderm
What does the mesoderm do?
- forms skeletal system, bones, muscles, and
circulatory system
What does the endoderm do?
- forms digestive system, respiratory tract, viscera
The thickened plate known as the ____ lies in between two strips of ____
- neural plate
- neural crest
How is the neural groove formed?
At 20-22 days the neural plate sinks in the middle forming the neural groove
The neural groove eventually fuses and forms the ____
neural tube
What does the neural tube form?
CNS & ventricles
What does the neural crest form?
PNS (including cranial and spinal nerves)
How is the PNS developed?
- Somites lie in close proximity to spinal cord and are eventually innervated by spinal nerves —> innervated areas are called dermatomes
- Somites go on to form muscles; thus somites and their corresponding spinal nerve establish connections with peripheral structures
How is the CNS developed?
By days 30-50, the spinal cord is marked by an enlarged ventral portion which will become the ventral horn (motor) and conduct efferent (exiting) nerve impulses to peripheral structures (the muscles).
- The smaller dorsal region becomes the dorsal/sensory horn and will conduct afferent (approaching) nerve impulses from various sensory terminals.
Neural tube becomes ___
CNS
What are the two major cell types?
- Neurons (“functional” cells)
- Gray matter: somata, dendrites, axon terminals
- Glia (supporting cells)
- Myelinate axons, metabolic support, cleanup crew, toxin removal, etc.
