Lec 1: Neurohistology and Neuroanatomy

Question 1

Principe Roles of Nervous System

Answer 1

1. Cognitive functions (e.g. declarative, implicit, memory)
2. Sensory-motor functions (e.g catching a ball, grabbing an object): Perception, vision, motor and sensory receptors
3. Motivation and emotion (e.g. hunger, sexual drive, fear, love)
4. Regulatory function and homeostasis (e.g. regulatory= gastrointestinal, cardiovascular adaptation to environment and body system changes)= autonomic NS

Question 2

Types of Neurons

Answer 2

1. Motor neuron= multipolar
2. Sensory neuron= unipolar
3. Interneuron/Bipolar= multipolar: receives and transmits abundant amount of information

Question 3

Gray matter and white matter contain…

Answer 3

Gray matter= cell body/soma (ganglia/nuceli: groups of cells)
White matter= axons which contain myelin (pathways: groups of axons)

Question 4

Structural definitions: Pathways (fasciculi and tracts/columns), Nucleus and Ganglia

Answer 4

Fasciculi/Fasciculus: white matter pathways or tracts (lemniscus, tract, bundle within brain)
Tracts or Columns: in cerebral cortex and spinal cord are groups of nerve cell bodies and axons
Nucleus: group of functionally related nerve cells
Ganglia: group of multiple nerve cells

Question 5

Definitions Peripheral Nervous System (posterior root ganglion and rami)

Answer 5

Root or ramus (rami): peripheral structure with parallel axons
Posterior root ganglion (ganglia): a group of nerve cell bodies lying in a peripheral nerve root (visible knot)

Question 6

Grey matter and white matter distribution in SC and brain

Answer 6

Brain= grey matter outside + white matter inside
SC= grey matter inside + white matter outside

Question 7

Glial cells or support cells in CNS

Answer 7

provide critical support network for neurons and are found in CNS
*involved in pathogenisis is of disease: alzheimer’s, multiple sclerosis

Question 8

Types of Glia

Answer 8

1. Astrocytes
2. Oligodendrocytes
3. Ependymal cells
4. Microglial cells

Question 9

Astrocytes

Answer 9

-direct role in signaling (release neurotransmitters= glutamate (E))
-scavengers (clean up extracellular space)
-nutrition for neurons
-involved in memory
-make up 30-65% of glial cells

Question 10

Oligodendrocytes

Answer 10

-provide myelin in CNS

Question 11

Ependymal cells

Answer 11

-produce CSF
-waste clearance

Question 12

Microglial Cells

Answer 12

-immune system in CNS (activated in disease, infection, injury)
-attracted by a dying neuron’s protein secretion
-10% of brain cells

Question 13

Neuroinflammation cascade

Answer 13

injury —> microglial and astrocyte activation —> pro inflammatory elements —> neuronal death

Question 14

Abnormal glial activity in… because…

Answer 14

1. Alzheimer’s
2. Multiple Sclerosis
3. Parkinson’s Disease
4. Head Injury

d/t loss of protective control and increased stimulation of cellular breakdown

Question 15

Neuroglia types in PNS

Answer 15

1. Satellite cells (surround cell bodies, similar to astrocytes in CNS)
2. Schwann cells (surround axons, similar to oligodendrocytes in CNS)

Question 16

Multiple Sclerosis Demyelination

Answer 16

Microglia (immune system) attacks oligodendrocytes in MS
—> degeneration and destruction of myelin in CNS (SC and brain)
—> plaques form over time
—> microglial work to regenerate oligodendrocytes

Question 17

Alzheimer’s Disease

Answer 17

1. microglia increase neuro-inflammation (M1)
   release of cytokines and free radicals —> amyloid plaques
2. **Dual role of microglia= also work to reduce inflammation (M2)