Development of the nervous system Flashcards
The function of the nervous system is underpinned by a circuit, what is the main roles of this circuit?
- sensing changed in the external environment
- deciding what to do based on instinct and experience
- responding
Label the nervous system


Define Neurogenesis ?
Neurogenesis is the process by which new neurons are formed in the brain
Define differentiation?
Cellular differentiation is the process in which a cell changes from one cell type to another
What is formed in the first 18 days of neurogenesis?
- The notochord which is formed at the midline
- the 3 layers:
Outside
Ectoderm
Mesoderm
Endoderm
inside
- Neural plate develops from overlying ectoderm (neuroectoderm)
- Neuroectodermal percursor cells: neurulation

What happens in the first 18-20 days of neurogenesis?
- The neural plate folds inwards and forms the neural groove
- the floor plate is above the notochord and here the neural tube/plate closes

What happens in days 20-22 of neurogenesis?
- Neural cells present above the neural tube
- Anterior neural fold
- Neural tube closes completely which forms the central canal

What happens in day 22-24 or neurogenesis?
- Somites form all the way around the central canal
- this closes the area and produces the spinal cord
- Rhombenecephalon present on spinal cord
- sensory ganglion develop around spinal cord under rhombencephalon

What structures are essential for instructung nervous system formation?
Notochord
Floorplate
Roofplate
What is the anterior end of the nervous system?
The brain
What does the neural crest seperate?
Separated from neural tube and is a major component of PNS
All the development covered occurs in the first 24 days but over a 4 day span of time, when does the PNS form?
The PNS is later formed from plate opening a few days after day 24
Which structure is the precursor that gives rise to the entire nervous system?
The Neural plate
There is a high degree of patterning in the neural tube. Tell me some of these distinct features?
- Anterior/ Posterior (rostral/ Caudal) along the length of the tube
- dorsal ventral in cross section
- patterning is instructed by morphogens
Tell me about the anterior-posterior patterning?
Proliferation and segmentation generate the early spinal cord and 3 primary vesicles: brainstem, midbrain and forebrain
Name transient structures that instruct nervous system formation (sources of morphogens)?
Roofplate
Floorplate
Notochord
Which structure gives rise to the PNS?
Neural crest
label these 2 developments of the nervous system…


At 25 days development of the brain, what is present?
Neural tube

At 40 days development of the brain, what is present?
Midbrain
Hindbrain
Spinal cord
Forebrain

At 100 days development of the brain, what features start to develop?
Cerebellum
Pons
Medulla

At what age does the brain take form as we know it?
9 months

What part of the brain distinguishes humans from animals?
Why is this the case?
The size of the cortex, particuarly the frontal lobe.
The brain determine the person and makes us who we are.
The frontal lobe is where our personality is determined as it’s where we judge risk/ reward

What determines a neurons ultimate fate?
When and were its born














