TBL 3 (Module II)

Question 1

What are cell bodies called in the central nervous system?

Answer 1

Ganglia

Question 2

What are cell bodies called in the peripheral nervous system?

Answer 2

Nuclei

Question 3

What are axons called in the central nervous system?

Answer 3

Tracts

Question 4

What are axons called in the peripheral nervous system?

Answer 4

Fibers

Question 5

What 2 groups of cell types exist in nervous tissue?

Answer 5

Glial cells (support), neurons

Question 6

What are Nissl bodies?

Answer 6

Rough endoplasmic reticulum of neurons

Question 7

What are nodes of Ranvier?

Answer 7

Gaps between segments of myelin sheath (increase speed of action potential propagation)

Question 8

What is the role of interneurons, generally?

Answer 8

To connect sensory and motor neurons

Question 9

Which component (organelle) present in neuron cell bodies is not present in dendrites

Answer 9

Golgi apparatus

Question 10

What 2 pigments are common to the substantia nigra?

Answer 10

Lipofuscin and melanin

Question 11

What protein is involved in antegrade transport (along an axon)?

Answer 11

Kinesin

Question 12

What protein is involved in retrograde transport (along an axon)?

Answer 12

Dynein

Question 13

What viruses enter neurons via membrane fusion?

Answer 13

HSV, VZV, PRV

Question 14

What viruses enter neurons via endocytosis?

Answer 14

RABV, poliovirus, VSV

Question 15

What are the 4 types of glial cells present in the central nervous system?

Answer 15

Astrocytes, oligodendrocytes, microglia, and ependymal cells

Question 16

What are the 2 types of glial cells present in the peripheral nervous system?

Answer 16

Schwann cells and satellite cells

Question 17

What are astrocytes responsible for? What is their function?

Answer 17

Astrocytes connect neurons to capillaries and Pia mater, thus they are involved in the transfer of metabolic products from blood to neurons

Question 18

What is the role of astrocytes with respect to brain injury?

Answer 18

Proliferation to form scar tissue

Question 19

What 4 structures are associated with the blood-brain barrier?

Answer 19

Tight junctions, basal lamina, astrocytes, [squamous] epithelia

Question 20

What is the primary site of HIV-1 infection in the central nervous system?

Answer 20

Microglia

Question 21

What is the role/function of microglia?

Answer 21

Phagocyte of the central nervous system

Question 22

Where are ependymal cells found?

Answer 22

Lining the ventricles and central canal of the spinal cord

Question 23

What is the function of ependymal cells?

Answer 23

To form a barrier between the brain and cerebrospinal fluid

Question 24

What are the myelinating cells of the central nervous system?

Answer 24

Oligodendrocytes

Question 25

What are the myelinating cells of the peripheral nervous system?

Answer 25

Schwann cells

Question 26

What is the function fo satellite cells?

Answer 26

To cluster around and provide support for cell bodies in peripheral ganglia

Question 27

What is white matter composed of?

Answer 27

Myelinated axons, few unmyelinated axons, glial cells but no neurons

Question 28

What is gray matter composed of?

Answer 28

Neurons, dendrites, glial cells (also "initial portion" of unmyelinated axons)

Question 29

What is neuropil?

Answer 29

The non-neuron component of the nervous system; composed of unmyelinated axons, dendrites and glial cells with relatively low numbers of cell bodies. Remember that it is synaptically dense, and the brain has neuropil-concentrated regions.

Question 30

What carries motor innervation to the muscularis externa of the esophagus?

Answer 30

Auerbach's (myenteric) plexus

Question 31

What carries secretory (parasympathetic) innervation to goblet cells in the intestinal epithelia and motor innervation to the muscularis mucosa? Where is it located?

Answer 31

Meissner's (submucosal) plexus; lamina propria

Question 32

List the characteristics of dorsal root ganglia

Answer 32

Peudounipolar neurons; Cell bodies are spherical in shape but vary in size (large and small); Nuclei tend to be central in location; Numerous satellite cells; Nerve cell bodies located mainly in periphery with fibers traveling in bundles; Axons are heavily myelinated; Connective tissue capsule present

Question 33

List the characteristics of sympathetic ganglia

Answer 33

Multipolar neurons; Cell bodies are rather uniform in size; Nuclei tend to be peripheral in location; Few satellite cells; Arrangement of nerve cell bodies in ganglion is haphazard; Axons are lightly myelinated; No connective tissue capsule

Question 34

What nervous system is associated with the lateral horn (in the spinal cord)?

Answer 34

Sympathetic

Question 35

What histologic cell type is dura mater?

Answer 35

Dense irregular connective tissue

Question 36

What histologic cell type is arachnoid mater?

Answer 36

Simple squamous epithelia

Question 37

What histologic cell type is Pia mater?

Answer 37

Loose (areolar) connective tissue. Highly vascular.

Question 38

What is the function of the choroid plexus?

Answer 38

Production of CSF

Question 39

What is endoneurium composed of?

Answer 39

Loose (areolar) connective tissue; type IV collagen

Question 40

What are the two types of muscle tissue?

Answer 40

Striated (including skeletal and cardiac) and smooth

Question 41

Where would you find cardiac muscle?

Answer 41

Walls of heart, bases of large veins and aorta

Question 42

Where would you find smooth muscle?

Answer 42

Walls of blood vessels, viscera, arrector pili

Question 43

What protein is associated with thin filaments?

Answer 43

Actin

Question 44

What protein is associated with thick filaments?

Answer 44

Myosin

Question 45

What is sarcolemma?

Answer 45

Muscle cell plasma membrane

Question 46

Describe the process of myogenesis by satellite cells

Answer 46

Satellite cells get activated to transform into myoblasts, which then proliferate and differentiate into myotubes, which then further transform into my-fibers ("CD34" and "MyoD" associated with this process)

Question 47

How are skeletal muscle fibers held together?

Answer 47

Connective tissue, NOT cell junctions

Question 48

What histologic cell type is epimysium?

Answer 48

Dense irregular connective tissue

Question 49

In what layer (epimysium, endomysium, perimysium) is most of the vascular and nerve supply to muscle tissue housed?

Answer 49

Epimysium

Question 50

What protein is associated with thick filaments specifically in striated muscle?

Answer 50

Myosin II (line up "tail-to-tail" for bipolar appearance)

Question 51

What proteins are associated with thin filaments specifically in striated muscle?

Answer 51

F-actin, tropomyosin, troponin

Question 52

What features do myosin heads possess?

Answer 52

Actin and ATP binding sites

Question 53

What is the function of tropomyosin?

Answer 53

To mask the myosin binding sites

Question 54

What filaments are associated with the A band?

Answer 54

Thick filaments

Question 55

What filaments are associated with the I band?

Answer 55

Thin filaments only

Question 56

What filaments are associated with the H band?

Answer 56

Thick filaments only

Question 57

What is the function of dystrophin in muscle fibers?

Answer 57

Links actin filaments to endomysium through glycoprotein complex, in order to shorten my-fibers (which leads to contraction)

Question 58

What 2 diseases are associated with mutations in the gene encoding for dystrophin?

Answer 58

Duchenne muscular dystrophy, Becker muscular dystrophy

Question 59

What changes to the A, I, H and Z bands are associated with contraction?

Answer 59

I band shortens, H band narrows, Z lines brought closer together, A band remains unchanged

Question 60

Describe the cause of rigor mortis

Answer 60

Lack of ATP prevents dissociation of actin and myosin (In normal state ATP binding causes reduced affinity of actin-myosin connection)

Question 61

Describe the process of muscle contraction initiation

Answer 61

Action potential arrives, synaptic transmission at NMJ occurs, AP propagates along sarcolemma, leading to hypo polarization of T tubules, which causes a conformational change of voltage-sensor proteins, in turn causing calcium channels to open, calcium release into sarcoplasm from SER, calcium then binding to troponin C to allow actin-myosin interaction

Question 62

Describe the cause and one symptom of myasthenia gravis

Answer 62

Autoantibodies against ACh receptor on post-synaptic sarcolemma (at NMJ). Causes ptosis (among other sx).

Question 63

Where are muscle spindle cells located? What is their function?

Answer 63

Between muscle fascicles; sensory cells to detect changes in length

Question 64

What is epineurium composed of?

Answer 64

Dense irregular connective tissue

Question 65

What is perineurium composed of?

Answer 65

Specialized connective tissue, layers of flattened epithelial-like cells