Neurons Fuction and dysfuction

Question 1

Name the speeds for each fiber type

Fiber 1: Myelinated from spindle or golgi tendon organ

Fiber 2: myelinated from spindles and some tactile receptors

Fiber 3: Myelinated conduct crude touch, temperature, and pain

Fiber 4: Unmeylinated, carry pain and temperature

Answer 1

1. Fast
2. medium fast
3. relatively slow
4. slowest

Question 2

Name five types of glia and function

Answer 2

1. astrocytes: provide support for neurons, insulate;buffer impulses
2. oligodendrocytes: produce myelin in the CNS
3. Microglia: immune response
4. Ependmal: Absorbtive, transport of hormones to a secretion of CSF fluid
5. Schwann Cells-Produce myelin in perphery

Question 3

Identify each type of neuron.

Answer 3

Yellow: Bipolar

( 2 axons with cell body in center, usually do sensory information, Ex: can be found in retina)

Green: Unipolar

(dendrites arise in axon, very rare, both ends have axon characteristics Ex:dorsal root ganglion cells)

Purple: Multipolar

( most common, 3 or more dendrites, one long axon in brain and cord, ex. alpha motor neuron)

Question 4

What ending and fibers are considered sensory(afferent)?

Answer 4

Endings: receptors that begin transduction

Fibers: Dendrites

Question 5

What ending and fibers are considered efferent(motor)?

Answer 5

Endings: terminal bouton, connect to effector organ,

Fibers: axons(conduct info away from cell body towards an effector [muscle or gland])

Question 6

Describe Guillain-Barre

Answer 6

Auto-immune response linked with prior infection or inflammation

Demyelination of peripheral axons

Progressive motor weakness, sensory loss

May affect face, limbs, trunk, diaphram

Treatable

Question 7

Describe Multiple Sclerosis (MS)

Answer 7

Autoimmune disease with inflammatory characteristics

Demyelination of CNS axons

Scar formation interferes with signal conduction

Fibers degenerate

Central damage to white matter (cord, cerebellum, and basal ganglia)

Symptoms: tingling, pain, numbness, visual distrubances, speech disturbances, tremor, lack of coordination and unsteady gait

Question 8

What area of the neuron does each of the following diseases/ toxins damage?

1. Alzheimer’s
2. Myasthenia Gravis
3. Botulin Toxin

Answer 8

1. dendrites and cell bodies (loses receptive and info processing parts)
2. damage to termonal axon and loss of receptors to specific neurotransmitters
3. Prevents depolarization and neurotransmitter release pre-synaptically

Question 9

Where is the degenearation in Wallerian degeneration?

Answer 9

Axon degneration is distal to site of damage

Ex: if damage to axon near cell body, the rest of the axon to the terminal bouton is damaged

Question 10

Where is the degeneration occur in Anterograde degeneration?

Answer 10

Damage to one neuron causes degeneration to target cell because the target cell does not get any input from the damaged cell

Question 11

Where does degeneration occur in retrograde degeneration?

Answer 11

Degeneration of sending neuron when receiving neuron is damaged

Question 12

When does the CNS begin to develop?

Answer 12

3 weeks post-conception

Question 13

When does the brain begin to specialize?

Answer 13

6 to 7 weeks post conception

Question 14

Explain the difference between spina bifida oculta and cystica

Answer 14

Oculta: Characterized by hair tuffed, no neurologica consequences

Cystica: Protrusion of cord and spine which is observed by a cyst. Meningocele and mylomeningocele

Question 15

Give 2 examples of developmental sensory stimulation that is affected by a “critical period”

Answer 15

Lazy eye correction

Cochlear implants: more affective in younger clients

Question 16

Name the order of myelination in the brain from first to occur to last

Motor areas

Higher order association areas

Sensory processing areas

Answer 16

1. sensory processing areas
2. motor areas
3. higher order association areas

Question 17

Where is CSF located?

Answer 17

Between pia and arachnoid mater