Histology - Nervous Tissue

Question 1

choroid epithelial cells

Answer 1

involved in cerebral spinal fluid

Question 1

White Matter

Answer 1

Myelin is lipid-rich, and on gross inspection appears white. Thus, in the ‘white matter’ of the brain and spinal cord, myelinated axons are the predominant neuronal component, whereas ‘gray matter’ contains relatively more neuronal and glial perikarya and non-myelinated (e.g. dendritic) processes.

Question 2

bipolar neurons

Answer 2

retina, cranial nerve I, cranial nerve VIII

Question 2

ependymal cells

Answer 2

cells line ventricular spaces (spinal fluid)

Question 2

Dorsal Root Ganglia

Answer 2

Contain the cell bodies of sensory neurons.

The neuron cell bodies belong to large, pseudounipolar sensory neurons that have a single “T-shaped” process; these are the afferent fibers carrying sensory information from the periphery (sensory receptors in the skin, joints and muscles that respond to touch, temperature, pain, stretch) to the dorsal horn, where they synapse on neurons in the spinal cord.

NOTE: these sensory neurons are an exception to the typical neuron, in that they do not have separate dendrites and an axonal process, but rather one branched process that serves both functions.

Question 3

sensory ganglia

Answer 3

pseudounipolar neurons, high neuron density, large # of satellite cells, and NO synapses.

Question 4

axonal retrograde transport

Answer 4

uses microtubules and dynein, how viruses can spread between neurons.

Question 5

oligodendrocytes

Answer 5

Branched processes that myelate CNS axons. Has multiple internodal segments on multiple axons. . Involved in MS.

Question 6

multipolar neurons

Answer 6

99% of all neurons

Question 6

autonomic ganglia

Answer 6

motor, multipolar, low neuron density, fewer satellite cells, synapses. Takes two neurons to get to target.

Question 7

neural crest

Answer 7

origin of PNS: neurons, Schwann cells, satellite cells.

Question 9

epimeirium

Answer 9

the outermost layer of dense irregular connective tissue surrounding a peripheral nerve.

Question 10

endoneurium

Answer 10

a layer of delicate connective tissue that encloses the myelin sheath of a nerve fiber.

Question 11

perineurium

Answer 11

protective sheath that surrounds nerve fasciles.

Question 11

Answer 11

CNS Neurons - spinal cord

Question 12

Answer 12

Parasympathetic ganglia located in the organ that is being innervated.

Question 13

pseudounipolar sensory neurons

Answer 13

Afferent fibers carrying sensory information from the periphery (sensory receptors in the skin, joints and muscles that respond to touch, temperature, pain, stretch) to the dorsal horn, where they synapse on neurons in the spinal cord.

NOTE: these sensory neurons are an exception to the typical neuron, in that they do not have separate dendrites and an axonal process, but rather one branched process that serves both functions.

Question 14

oligodendrocytes

Answer 14

A type of glial cell responsible for myelination of CNS axons.

Question 15

axodendritic

Answer 15

axon synapses on a dendrite

Question 16

major dense lines

Answer 16

(dark line) formed by the closely apposed cytoplasmic faces of the plasma membrane, and measuring 2.5nm thick, in myelin sheath.

Question 17

meningeal cells

Answer 17

connective tissue layes lay outside CNS, protection.

Question 19

dendrites

Answer 19

contains same organelles as cell body except nucleus, Nissl bodies and Golgi complexes only in proximal portion.

Answer 20

glial cells that produce myelin in peripheral nerves.

Question 21

axosomatic

Answer 21

axon of one neuron synapses with cell body of a second neuuron

Question 22

cell body (perikaryon/soma)

Answer 22

contains nucleus, nucleolus, Nissl bodies, Golgi complexes, mitochondria, neurofilaments, microtubules.

Question 23

pseudounipolar neurons

Answer 23

sensory ganglia

Question 25

neuropil

Answer 25

meshwork of processes of neurons and glia in gray matter of CNS

Question 26

Answer 26

Axon and Nissl bodies. Characteristic clusters of ribosomes and rough ER termed Nissl bodies or substance scattered in the cytoplasm

Question 27

axonal anterograde transport

Answer 27

uses microtubules and kinesin

Question 28

Answer 28

perikarya of large somatic motor neurons - innervate the skeletal muscles of the limbs and trunk, which are embryologically derived from somites (hence, “somatic” muscles).

Question 29

astrocyte

Answer 29

star-shaped glial cells regulating ionic environment of extracellular space, guiding of neuron migration during early development, proliferation at sites of injury. the most abundant cell of the human brain.

Question 31

axoaxonic

Answer 31

one axon synapses on another axon.

Question 32

neural tube

Answer 32

origin of CNS: neurons, astrocytes, oligodendrocytes, ependymal cells

Question 34

Glioblastoma multiforme

Answer 34

most common and most aggressive malignant primary brain tumor in humans, involving glial cells

Question 35

myelin sheath

Answer 35

up to 50 lipoprotein lamellae/Pligodendrocytes in CNS, Schwann cells in PNS. Internodal segnment and node of Ranvier.

Question 36

Answer 36

Dorsal Root Ganglia, near, but outside of the spinal cord. Afferent fibers carrying sensory info from perifery to dorsal horn, where they synapse with neurons in the spinal cord.

Question 37

axon

Answer 37

contains mitochondria, neurofilaments and microtubules, but NO protein making machinery.

Question 38

Neurolemmocytes

Answer 38

myelination of PNS axons, a single internodal segment. Basal lamina guides regenrating axons, allows for better regeneration/recovery than CNS.

Question 39

microglial cells

Answer 39

resident macrophages of the brain and spinal cord, and thus act as the first and main form of active immune defense in the central nervous system (CNS).

Question 40

Meningeal cells

Answer 40

consist of three layers: the dura mater, the arachnoid mater, and the pia mater that are membranes which envelop and protect the central nervous system. CNS is unique in that it has NO internal connective tissue.

Question 41

Schwann cells

Answer 41

Peripheral equivalent of the oligodendrocytes. Mylenate PNS axons, basal lamina guides regeberating neurons. Single Schwann cell mylenates a single internodal segment.