Week 1 Terms

Question 1

What is Convergence?

Answer 1

• when many pre-synaptic neurons converge on any single post synaptic neuron
• single cell receiving inputs from multiple sources

Question 2

What is Divergence?

Answer 2

a single sell projecting/ sending out signals to multiple cells

Question 3

On what day after conception does the neural tube of an embryo form?

Answer 3

~Day 23

Question 4

What influences and interactions cause neuronal differentiation?

Answer 4

• Morphology
• Gene expression
• Neurotransmitters
• Axon projections & connections

Question 5

What are the 2 Types (Directions) of Neuronal Migration?

Answer 5

1) Radial - moving OUT

2) Tangential - moving UP

Question 6

What are 2 Methods of Migration?

Answer 6

1) Somal Translocation- extension develops in direction of migration
2) Glial-mediated - cells move along a radial-glial network

Question 7

How many spinal nerves are there?

Answer 7

31

Question 8

Through what structure do spinal nerves leave the vertebra?

Answer 8

through the corresponding intervertebral foramen

Question 9

At which vertebra does the spinal cord end?

Answer 9

L1-L2

Question 10

What is the cauda equina?

Answer 10

• The bunch of nerve roots at the lower end of the spinal cord
• cauda equina = horses tail
• located from ~L3

Question 11

What parts of the brain are included in the Hindbrain?

Answer 11

1) Cerebellum
2) Pons
3) Medulla

Question 12

What is the oldest part of the brain?

Answer 12

The Hindbrain

Question 13

Where is the Diencephalon located and what are the 4 main parts?

Answer 13

• Location = top of brain stem

- Thalamus, Subthalamus, Hypothalamus, Epithalamus

Question 14

What are the 4 Main Lobes of the Brain?

Answer 14

1) Frontal
2) Parietal
3) Temporal
4) Occipital

Question 15

What are cortical ascending connections?

Answer 15

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

Question 16

What is the most primative of all of our senses? (hint: and is the only sense that doesn’t go through the Thalamus?)

Answer 16

Smell

Question 17

What are Descending Cortical Connects?

Answer 17

• Motor to spinal cord
• Motor to brain stem motor nuclei
• Motor to motor control centers
• to the Limbic system

Question 18

What are Commissures?

Answer 18

pathways that connect one side of the brain with the other

they cross the midline to reach both hemispheres

Question 19

What are Association Fibers?

Answer 19

a type of white matter tract that connects different areas in the same hemisphere

Question 20

What are the 3 Major Classes of Neurons connecting Cortical Structures?

Answer 20

1) Association
2) Commisural
3) Projection

Question 21

During development, cells of the nervous system differenciate into what 2 cell types:

Answer 21

1) Neurons - come in many forms, specialized based on function
2) Glia - support neurons

Question 22

What are some of the Glial Subtypes?

Answer 22

• Ependymal cells
• Astrocytes
• Microglia
• Oligodendrocytes

Question 23

What are Astrocytes and what are their functions?

Answer 23

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.

Question 24

What are the functions of Microglial cells?

Answer 24

• 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

Question 25

What are the fuctions of Oligodendrocytes?

Answer 25

- secrete lipid myelin to create myelin sheath - myelin sheath increases speed of neuronal signalling - provide metabollic support

Question 26

How does Multiple Sclerosis prevent the brain from communicating with the body properly?

Answer 26

It causes degredation of the myelin sheath

Question 27

What are Progenitor cells?

Answer 27

Descendants of stem cells that further differentiate to become a mature, specialized cell.

Question 28

Describe Human Development (fertilization to 3 months):

Answer 28

``` Day 0= Fertilization Day 0-6= cleaves to form Blastocyte Day 7= Implantation of Blastocyte & formation of 2 layer disc. Day 14= Gastrulation Day 21= Neurulation Day 28-35= Tailbud Stage Day 28-56= Embryonic Period 3 Months to Birth = Fetal ```

Question 29

Describe the process of Neurulation:

Answer 29

Occurs during Week 3 1. Notochord starts/stimulates the process 2. Ectoderm thickens to become neural plate 2. Lateral edges of neural plate become elevated —> neural folds. Depressed region = neural groove. 3. Neural folds fuse together and form neural tube (becomes brain & spinal cord). 4. Neural crest forms above & becomes PNS.

Question 30

Describe the Organization of the Nervous System

Answer 30

1) CNS 2) PNS - Somatic —Sensory —Motor - Autonomic —Sympathetic —Parasympathetic

Question 31

What are 3 unique key features of Neurons?

Answer 31

1) High energy demand mainly from ATP pump 2) Need to transport cargo long distances for signaling or recycling 3) Limited capacity to generate new neurons

Question 32

What is transcription?

Answer 32

Photocopying DNA into mRNA via RNA polymerase enzyme

Question 33

What is translation?

Answer 33

Literal translation of the genetic code on the mRNA into a protein. Read by ribosomes in cytoplasm of the cell.

Question 34

What are Microglia and what are their functions?

Answer 34

Microglia are small glial cells of CNS. They have a resting and active form. Functions: - look for dead & damaged areas - when they sense inflammation from injury or infection they change to active form - they secrete cytotoxic factors causing bacteria to turn into debris which they eat (phagocytosis)

Question 35

What are Neuronal Substructures and their Functions?

Answer 35

1) Nucleus- stores genetic info 2) Endoasmic Reticulum- produces, sorts, and processes new proteins 3) Mitochondria- energy generator 4) Golgi Apparatus- additional processing & packaging of lipids & proteins 5) Lysosomes- contains digestive enzymes break down excess & worn out cell parts 6) Cell membrane- lipid bilateral