Nervous Tissue

Question 1

What anatomical division of the nervous system are cranial nerves a part of?

Answer 1

Peripheral nervous system

Question 2

What are the two basic types of neural cells?

Answer 2

Neurons and glial cells

Question 3

What are the two types of human tissue that exhibit excitability?

Answer 3

Neurons and muscle cells

Question 4

What is the term for the collection netwrol of cellular processes of neruons and glial cells?

Answer 4

Neuropils

Question 5

What types of glial cells are found within the central nervous system?

Answer 5

Oligodendrocytes, astrocytes, ependymal cells, microglial cells

Question 6

What types of glial cells are found within the peripheral nervous system?

Answer 6

Schwann cells, satellite cells

Question 7

Which part of the neruon carriers impulses to the other neurons or effector organs?

Answer 7

The axon

Question 8

What structure serves as the beginning of the axon?

Answer 8

Axon hillock

Question 9

What are other names for the neuron cell body?

Answer 9

Soma or perikaryon

Question 10

What are nissl bodies? What part of the neuron will these bodies not be found in? What color will they stain?

Answer 10

Nissl bodies are aggregations of rER and free ribosomes; NOT found in the axon hillock or axon; stains dark blue

Question 11

What are most intermediate filament in a neuron called?

Answer 11

Neurofilaments

Question 12

What structures are found at the very end of axons?

Answer 12

Terminal buttons

Question 13

What part of the neuron is typically myelinated?

Answer 13

Axons

Question 14

What cells provide myelination of neurons in the peripheral nervous system?

Answer 14

Schwann cells

Question 15

What area of neuron(s) will be myelinated by one Schwann cell?

Answer 15

One Schwann cell forms myelin around a segment of one axon

Question 16

What is the general term for Schwann cells and oligodendrocytes?

Answer 16

Neurolemmocytes

Question 17

What is the functino of myelin?

Answer 17

Serves to insulate nerve fibers, increasing conduction speed

Question 18

What are the small areas of axon not covered by myelin found in between myelinated segments?

Answer 18

Nodes of Ranvier

Question 19

What are the major dense lines in myelin sheaths that periodically separate to allow transient movement of cytoplasm?

Answer 19

Schmidt-Lanterman clefts

Question 20

True or false: Even unmyelinated peripheral axons are enveloped by Scwann cells?

Answer 20

True

Question 21

What is the resting membrane potential?

Answer 21

The voltage differenc across te cell membrane when the cell is at rest

Question 22

What are the major ions involved in generating the membrane potential?

Answer 22

Na+, K+, Cl-, A-

Question 23

What is the approximate resting potential in neurons?

Answer 23

~-70mV

Question 24

At rest where is the greatest concentration of Na+? K+?

Answer 24

Na= outside; K=inside the cell

Question 25

What is the activity of the Na+/K+ ATPase pump?

Answer 25

Maintains resting membrane potential by pumping out 3Na+ and takes in 2 K+ using ATP

Question 26

What ion movement is responsible for neural depolarization?

Answer 26

Na+ influx

Question 27

What is the approximate threshold potential for neurons?

Answer 27

~-55 mV

Question 28

What events are responsible for repolarization of the neuron?

Answer 28

Closure of the Na+ channels and openind of voltage-gated K+ channels, allowing K+ efflux

Question 29

What causes hyperpolarization of neurons? What is the physiologic importance of this phase?

Answer 29

Slow closing of the K+ channels; Creates a refractory period (cell cannot refire)

Question 30

What are the two mechanisms of action potential propagation? Which method is faster?

Answer 30

Saltatory and continuous conduction; Saltatory is faster

Question 31

What kind of neurons synapse in the dorsal root ganglion?

Answer 31

None

Question 32

In what kind of neurons does continuous conduction of action potentials occur?

Answer 32

Unmyelinated axons

Question 33

What is the anatomical basis of saltatory conduction?

Answer 33

Na+ channels are concentrated at Nodes of Ranvier

Question 34

What kind of cells can serve as post-synaptic cells?

Answer 34

Another neuron, muscle, or myoepitheial (gland)

Question 35

What are the two types of synapses?

Answer 35

Chemical and electrical

Question 36

What structures are used to form electrical synapses?

Answer 36

Gap junctions

Question 37

By what process are neurotransmitters released into the synaptic cleft?

Answer 37

Exocytosis

Question 38

What is the approximate size of the synaptic cleft?

Answer 38

20-30 nm

Question 39

What type of synapse are between the axon of one neuron and the dendrites of another neuron?

Answer 39

Axodendritic

Question 40

What are axosomatic synapse? Axoaxonic?

Answer 40

Axosomatic= axon to soma; axon to axon synapse

Question 41

What is the most common structural classification of neurons?

Answer 41

Mutlipolar neuron

Question 42

What types of neurons are typicaly multipolar?

Answer 42

Motor and interneurons

Question 43

Where can bipolar neurons be found?

Answer 43

The retina, CN I, CN VIII

Question 44

What type of neuron has one stem that splits near the cell body into 2 long processes?

Answer 44

Pseudounipolar neurons

Question 45

What functional type of neuron are pseudopolar neurons typically?

Answer 45

Sensory

Question 46

What is the layer of connective tissue that surround an entire nerve?

Answer 46

Epineurium

Question 47

What kind of connective tissue surrounds a fascicle?

Answer 47

Perineurium

Question 48

What kind of connective tissue surround individual nerve fibers?

Answer 48

Endoneurium

Question 49

What is the name given to collection of cell bodies in the peripheral nervous system?

Answer 49

Ganglia

Question 50

What distinctive feature does the dorsal root ganglion have surrounding it?

Answer 50

A distinctive connective tissue capsule

Question 51

What is the function of satellite cells?

Answer 51

Provide structural and metabolic support

Question 52

What structural class of neuron cell bodies are typically found within the dorsal root ganglion?

Answer 52

Pseudounipolar neurons

Question 53

Where are parasympathetic ganglia typically located?

Answer 53

Generally found in or near the tissues they innervate

Question 54

Where is gray matter located in the brain? In the spinal cord? What neural structures make up the grey matter?

Answer 54

The cortex; the inner portion; cell bodies and neuropil

Question 55

How many layers make up the cerebral cortex?

Answer 55

6

Question 56

What is the most prominent cell type within the cerebral cortex?

Answer 56

Pyramindal neurons

Question 57

What are the layers of the cerebellar cortex?

Answer 57

Outer- Molecular layer; Central- Purkinje neurons; Inner- Granular layer

Question 58

What cells are responsible for myelination within the CNS?

Answer 58

Oligodendrocytes

Question 59

Except for location, what is the difference in the function of oligodendrocytes and Schwann cells?

Answer 59

Oligodendrocytes can myelinate sections of many neurons

Question 60

What is the most numerous glial cell in the CNS?

Answer 60

Astrocytes

Question 61

Bundles of what kind of filament reinfornce larger processes of all astrocytes?

Answer 61

Glial fibrillary acid protein (GFAP)

Question 62

What part of astrocytes completely encolse all capillaries and contribute to the blood brain barrier?

Answer 62

Perivascular feet

Question 63

What is the main structural component of the blood-brain barrier?

Answer 63

Capillary endothelium

Question 64

What feature of the brain endothelial cells prevent paracellular movement of molecules?

Answer 64

Continuous tight junctions

Question 65

What is the typical shape of ependymal cells?

Answer 65

Cuboidal or low columnar cells

Question 66

Where are ependymal cells located?

Answer 66

Lining the ventricles of brain and central canal of the spinal cord

Question 67

What apical specializations do ependymal cells commonly have?

Answer 67

Cilia and microvilli

Question 68

Ependymal cells of what structure function in the production of CSF?

Answer 68

Choroid plexus

Question 69

What cells serves as the macrophages of the CNS?

Answer 69

Microglia

Question 70

What is the simpest form of sensory receptor?

Answer 70

Free nerve endings

Question 71

What are the small, encapsulated receptors in the dermis of skin which respond to light discriminatory touch?

Answer 71

Meissner's corpuscles

Question 72

What are the large, encapsulated receptors in depper layers of skin, ligaments and joint capsules that sense pressure, vibration and tension?

Answer 72

Pacinian corpuscles