Week 1 Terms Flashcards
What is Convergence?
- when many pre-synaptic neurons converge on any single post synaptic neuron
- single cell receiving inputs from multiple sources
What is Divergence?
a single sell projecting/ sending out signals to multiple cells
On what day after conception does the neural tube of an embryo form?
~Day 23
What influences and interactions cause neuronal differentiation?
- Morphology
- Gene expression
- Neurotransmitters
- Axon projections & connections
What are the 2 Types (Directions) of Neuronal Migration?
1) Radial - moving OUT
2) Tangential - moving UP
What are 2 Methods of Migration?
1) Somal Translocation- extension develops in direction of migration
2) Glial-mediated - cells move along a radial-glial network
How many spinal nerves are there?
31
Through what structure do spinal nerves leave the vertebra?
through the corresponding intervertebral foramen
At which vertebra does the spinal cord end?
L1-L2
What is the cauda equina?
- The bunch of nerve roots at the lower end of the spinal cord
- cauda equina = horses tail
- located from ~L3
What parts of the brain are included in the Hindbrain?
1) Cerebellum
2) Pons
3) Medulla
What is the oldest part of the brain?
The Hindbrain
Where is the Diencephalon located and what are the 4 main parts?
- Location = top of brain stem
- Thalamus, Subthalamus, Hypothalamus, Epithalamus
What are the 4 Main Lobes of the Brain?
1) Frontal
2) Parietal
3) Temporal
4) Occipital
What are cortical ascending connections?
1) Somatosensory - from the Thalamus
2) Auditory -from Thalamus (inputs from cochlea)
3) Visual - from Thalamus (inputs from retina)
4) Smell - from Olfactory
5) Taste - from taste buds via thalamic nuclei
What is the most primative of all of our senses? (hint: and is the only sense that doesn’t go through the Thalamus?)
Smell
What are Descending Cortical Connects?
- Motor to spinal cord
- Motor to brain stem motor nuclei
- Motor to motor control centers
- to the Limbic system
What are Commissures?
pathways that connect one side of the brain with the other
they cross the midline to reach both hemispheres
What are Association Fibers?
a type of white matter tract that connects different areas in the same hemisphere
What are the 3 Major Classes of Neurons connecting Cortical Structures?
1) Association
2) Commisural
3) Projection
During development, cells of the nervous system differenciate into what 2 cell types:
1) Neurons - come in many forms, specialized based on function
2) Glia - support neurons
What are some of the Glial Subtypes?
- Ependymal cells
- Astrocytes
- Microglia
- Oligodendrocytes
What are Astrocytes and what are their functions?
Astrocytes are Glial Cells.
Functions include:
- scaffolding (for entire CNS)
- distribute nutrients from the blood supply to neurons
- function as glycogen reserve
- proliferate & migrate to area of injury (tissue repair)
- regulation of synaptic activity (clear out synapses as needed)
- new evidence suggest they can sense and respond to neuronal activity. they respond by raising intracellular calcium which can induce LTP.
What are the functions of Microglial cells?
- resident immune cells of brain
- clear debris –> can also degrade synapses (essential for pruning)
- recruit other cells to sites of damage
- aid in tissue repair