Lecture 18 - Development of the nervous system Flashcards
What are the 3 germ layers of the embryo
- Ectoderm
- Mesoderm
- Endoderm
Describe the ectoderm
- outer layer
- forms tissues associated with outer layers: skin, hair, sweat glands, epithelium.
- The brain and nervous system develop from the ectoderm.
Describe the Mesoderm.
- middle layer
- forms structures associated with movement and support (skeleton and muscles): body muscles, cartilage, bone, blood, and all other connective tissues.
- Reproductive system organs and kidneys form from mesoderm.
Describe the endoderm.
- inner layer
- forms tissues and organs associated with the internal organs (digestive and respiratory systems).
- form the thyroid and parathyroid glands, the liver, pancreas, and gall bladder
What are the changes that occur in the human development between day 17 and day 23 (as en embryo)?
- Formation of neuro groove which becomes a neural tube
- Formation of CNS from the neural tube cells
What is the name of the cells that make up the peripheral nervous system?
Neural crest
How is the neural tube formed?
- part of the ectoderm forms the neural plate
- formation of the neural groove
- The walls of the groove (neural fold) come together and form the neural tube
- As neural folds come together some ectoderm is pinched off becomes the neural crest
What does the neural canal evolve in?
The ventricular system
- there are 4 ventricals in the brainstem
Which cells evolve into the skeletal system and skeletal muscles?
somites
What are the differences between anencephaly and spina bifida on a neurobiological level?
- Anencephaly - failure to close the neural tube at the rostal end
- Spina bifida - failure to close the neural tube at the caudal end
What is hydrocephalus?
Accumulated CSF during development resulting in brain compression
What are the three primary vesicles?
- Prosencephalon (forebrain)
- Mesencephalon (midbrain)
- Rhombencephalon (hindbrain)
Which vesicle splits into two?
- Prosencephalon (forebrain)
The neurons of the telencephalon wall proliferate to form which 3 distinct regions:
1) Cerebral cortex
2) Basal telencephalon
3) Olfactory bulb
The diencephalon differentiates into what?
- thalamus
- hypothalamus