Development of the Nervous System Flashcards
What does the endoderm layer in embryology become?
- Digestive system
- Liver
- Pancreas
- Lungs (inner layers)
What does the mesoderm layer in embryology become?
- Circulatory system
- Lungs (epithelial layer)
- Bone
- Muscles
What does the ectoderm layer in embryology become?
- Skin
- Hair
- Nails
- Nervous system
What is neurulation?
The process where the neural tube forms.
When does neurulation occur?
Weeks 3-4
What does the neural tube eventually form in the adult?
CNS
What is gastrulation?
The formation of the three primary germ layers - endoderm, mesoderm, ectoderm by the primitive streak.
What does the notochord form later in life?
The notochord becomes the nucleus pulposus
How does the neural plate change in week 3?
The neural plate changes shape forming the neural folds and neural grooves. Eventually the two neural folds fuse together forming the neural tube.
How does the mesoderm around the neural tube change?
The mesoderm around the the neural tube thickens and subdivides producing somites.
What are somites precursors for?
The axial musculature and skeleton
What does the neural crest form?
Peripheral nervous system
Dorsal root ganglia of spinal nerves
Cranial Nerves
What does the notochord do?
Stimulates the neurulation process
What does the alar plate give rise to?
Sensory afferent neurones
What does the basal plate give rise to?
Motor efferent neurones
What is the sulcus limitans?
The boundary between the alar and basal plate.
What does each somite give rise to?
Dermatome
Myotome
Sclerotome
What does a dermatome give rise to?
Skin and epithelia
What does a myotome give rise to?
Muscle and connective tissue
What does a sclerotome give rise to?
Vertebral column
What are the three primary brain vesicles of the neural tube?
Prosencephalon
Mesencephalon
Rhombencephalon
What does the prosencephalon become in the adult brain?
Cerebrum and thalamus
What does the mesencephalon become in the adult brain?
The midbrain
What does the rhombencephalon become in the adult brain?
The pons
Medulla
Cerebellum
A thickening of the ectoderm in week 3 of gestation leads to what?
Formation of the neural plate
What two secondary brain vesicles does the prosencephalon develop into?
Telencephalon
Diencephalon
What two secondary brain vesicles does the rhombencephalon develop into?
Metencephalon
Myelencephalon
In which germ layer do somites form?
Mesoderm
What does the telencephalon develop into?
Cerebral hemispheres
Lateral ventricles
What does the diencephalon develop into?
Thalamus
Hypothalamus
Epithalamus
Where does the CNS come from?
Neural tube
Where does the PNS come from?
Neural crest
How does the notochord form?
The notochord forms through invagination of the mesoderm at the region of the primitive streak.
What does the alar plate give rise to?
Dorsal neurons (sensory)
What does the basal plate give rise to?
Ventral neurons (motor)
What does the neural tube differentiate into initially?
Alar plate
Basal plate
What happens to the neural crest cells in the neural tube?
The neural crest cells undergo epithelial mesenchymal transition. This allows them to move out of the neural tube and migrate into the embryo.
Which cells in the embryo undergo epithelial mesenchymal transition?
Neural crest cells
What do proprioreceptors sense?
Sense of self e.g position of the limb in space
What are the autonomic nervous system neurons derived from?
Neural crest cells
What type of outflow does the sympathetic nervous system have?
Thoraco-lumbar outflow
What type of outflow does the parasympathetic nervous system have?
Cervical-sacral outflow
What controls the development of the vertebrae?
Sclerotomes
What neuropeptide causes nerve tissue to grow and develop?
NGF - nerve growth factor
What does sonic hedgehog do?
Stimulate development of the neural tube
What releases sonic hedgehog?
The notochord
Where do the thalamus, hypothalamus and epithalamus develop from?
The diencephalon
At what point is the neural tube formed?
When gastrulation gives rise to the third germ layers the endoderm.
What develops into the peripheral system neurons?
Neural crest cells
From what germ layer does the digestive system form?
Endoderm
From what germ layer does the circulatory system form?
Mesoderm
From what germ layer does the nervous system form?
Ectoderm
From what germ layer does the skin form?
Ectoderm
From what germ layer do muscles and bones form?
Mesoderm
What is the primitive streak?
The primitive streak is a transient structure whose formation, on day 15 of human development, marks the start of gastrulation. The process in which the inner cell mass in converted into the trilaminar embryonic disc, which is comprised of the three germ layers (ectoderm, mesoderm and endoderm).
From what vesicle of the brain do the thalamus and cerebrum originate?
Prosencephalon
From what vesicle of the brain does the midbrain come from?
Mesencephalon
From what vesicle of the brain do the pons, the medulla oblongata, and cerebellum form from?
Rhombencephalon
When does gastrulation occur in embryological development?
Day 15
From what germ layer does the neural plate form?
Ectoderm
