Lecture 1 (applied Neuroscience, Corticospinal Tracts, Motor System Activation)

Question 1

What are the principal roles of the NS?

Answer 1

-cognitive functions
-sensory-motor functions
-motivation and emotion
-regulatory function and homeostasis (autonomic NS)

Question 2

What is the functional unit of NS? What does it consist of?

Answer 2

Neuron; soma, dendrites, axon and presynaptic terminals

Question 3

What are the four different types of neurons?

Answer 3

-Motor
-Sensory
-Interneuron

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Question 4

What does gray matter contain?

Answer 4

cell body/soma, nuclei or ganglia

Question 5

What does white matter contain?

Answer 5

axons with myelin

Question 6

Where is gray and white matter found in the brain? Spinal cord?

Answer 6

Brain - gray outside and white inside
SC - gray inside and white outside

Question 7

What are fasciculi/fasciculus?

Answer 7

white matter pathways or tracts

Question 8

What is a nucleus?

Answer 8

group of functionally related nerve cells

Question 9

What is ganglia?

Answer 9

group of multiple nerve cells

Question 10

What is a column or tract? Examples?

Answer 10

group of nerve cell bodies and their axons that are related in function

Ex. cerebral cortex and spinal cord

Question 11

What does the CNS consist of?

Answer 11

spinal cord and brain

Question 12

What does the PNS consist of?

Answer 12

-autonomic NS (parasympathetic and sympathetic)
-peripheral nerves -> cranial nerves (exception CN II)

Question 13

Posterior root ganglion (ganglia)

Answer 13

group of nerve cell bodies lying in a peripheral nerve root (forms visible knot)

Question 14

Root or ramus

Answer 14

peripheral structure w/ parallel axons

Question 15

Afferent vs efferent

Answer 15

Afferent: input, going towards the brain and spinal cord
Efferent: output

Question 16

What is the sequence sensory info travels?

Answer 16

sensory neuron, posterior root and ganglion -> synapses and dendrites in SC -> anterior horn cell -> motor neuron, anterior root -> nerve root

Question 17

What is the parasympathetic NS know as? What type of nerves?

Answer 17

“rest and digest”; cranial and sacral

Question 18

What is the sympathetic NS known as? Where do the nerves come from?

Answer 18

“fight or flight”; thoracic and lumbar

Question 19

What are glial cells? What does glial mean?

Answer 19

Glial cell: support cells, provide critical support network for neurons

Glial = “glue”

Question 20

What are the four types of glial cells?

Answer 20

Astrocytes “star”, oligodendrocytes, ependymal cells, microglia cells

Question 21

What are the purposes of astrocytes? What % of brain cells?

Answer 21

-signal clean up crew, nutrition for neurons, involved in memory, release neurotransmitters
-30-65%

Question 22

What is the purpose of oligodendrocytes?

Answer 22

provide myelin in CNS

Question 23

What are the purposes of ependymal cells?

Answer 23

produce cerebrospinal fluid, waste clearance

Question 24

What is the purpose of microglial cells? What % of brain cells?

Answer 24

function as immune system in NS
10%

Question 25

What mediates neuroinflammation?

Answer 25

microglia and astrocytes

Question 26

**What conditions are abnormal microglia found in?

Answer 26

Alzheimer’s, MS, Parkinson’s, head injury

Question 27

What NS are satellite cells found? Functions?

Answer 27

PNS
-surround neuron cell bodies in ganglia
-regulate O2, CO2, nutrient and neurotransmitter levels around neurons in ganglia

Question 28

What NS are Schwann cells found? Functions?

Answer 28

PNS
-myelination of peripheral axons
-participate in repair process after injury

Question 29

What cells are found in CNS?

Answer 29

oligodendrocytes, astrocytes, microglia, ependymal cells

Question 30

How does MS occur? What NS does it impact?

Answer 30

immune system attacks oligodendrocytes; CNS disease

Question 31

What happens in Alzheimer’s disease?

Answer 31

microglial increase neuroinflammation (release of cytokines and free radicals) which lead to beta Amyloid plaques

Question 32

What are the three planes a brain can be cut?

Answer 32

sagittal, brain coronal, brain horizontal

Question 33

What areas of the brain are known as the “planning area”?

Answer 33

supplementary motor area and premotor cortex

Question 34

What area of the brain is the “initiator”?

Answer 34

primary motor cortex

Question 35

How many lobes are in the brain? What are they?

Answer 35

4; frontal, parietal, occipital, temporal

Question 36

How many layers or lamina are in the motor cortex?

Answer 36

6

Question 37

What is a Betz cell? Where do most originate from? What do they synapse w/?

Answer 37

-type of pyramidal neuron; connects to axon and descend to spinal cord via corticospinal tract
-over 50% from primary motor cortex, from lamina V and VI
-anterior horn cells

Question 38

Pathway for motor impulses

Answer 38

primary motor cortex -> through brain -> brainstem (midbrain, pons, medulla) -> through spinal cord

Question 39

What are the two corticospinal tracts?

Answer 39

lateral corticospinal tract and anterior corticospinal tract

Question 40

Lateral vs anterior corticospinal tract

Answer 40

-Lateral: crosses at cervicomedullary junction (decussation); right side of the brain controls left side

-Anterior: doesn’t split, goes to both sides and ends at mid thoracic

Question 41

**What are the four areas of the motor system?

Answer 41

1. Posterior cortex (primary somatosensory and parietal association cortex)
2. Prefrontal cortex
3. Premotor cortex
4. Primary motor cortex

Question 42

What are functions of the four