Histo Lab: Muscle and Nervous Tissue

Question 1

smooth muscle contains what two filaments?

Answer 1

Contains actin and myosin filaments- but they are not organized in sarcomeres

Question 2

is smooth muscle organized in a sarcomere?

Answer 2

no!

Question 3

smooth muscle contains dense bodies which are similar to what in striated muscle sarcomere?

Answer 3

dense bodies are similar to Z-DISCS

Question 4

smooth muscle cells do not contain troponin but do contain____?

Answer 4

tropomyosin (binds to and stabilizes actin filaments)

Question 5

calmodulin

Answer 5

binds to Ca2+ in cytosol
activates myosin light-chain kinase

*smooth muscle

Question 6

myosin light-chain kinase is responsible for…

Answer 6

responsible for the Ca2+ sensitivity of the contractile fibers in smooth muscle

Question 7

Do Ca2+ ions that initiate contraction derive from outside the cell OR from the sarcoplasmic reticulum?

Answer 7

outside the cell

Question 8

steps in smooth muscle contraction

Answer 8

Question 9

myosin light chain kinase: control of smooth muscle contraction occurs principally on the ____

Answer 9

thick filament

Question 10

smooth muscle contraction occurs via _____

Answer 10

dense bodies

Question 11

during contraction of smooth muscle, filaments pull on ___ causing shortening of fiber

Answer 11

dense bodies

Question 12

cardiac muscle contracts to…

Answer 12

reduce the volume of heart chambers
propel the blood

Question 13

smooth muscle contracts to…

Answer 13

-propel food along the gut tube
-reduce the diameter of blood vessels and airways
-propel urine from the kidneys to the bladder
-give you goosebumps

Question 14

skeletal muscle contracts to move…

Answer 14

skeleton
larynx and tongue for speech
facial features for nonverbal communication
upper esophagus for swallowing
thoracic diaphragm for breathing

Question 15

most muscle tissues are derived from the____

Answer 15

mesoderm

Question 16

comparison of muscle tissues appearance

Answer 16

Question 17

skeletal muscle characteristics

Answer 17

striated
very large cells
multinucleated
peripheral nuclei

Question 18

smooth muscle characteristics:

Answer 18

not striated
spindle-shaped cells
smallest cells
single, central nucleus

Question 19

cardiac muscle characteristics:

Answer 19

typically branched
linked together via intercalated disks
1-2 centrally located nuclei

Question 20

size of muscle cells ranked

Answer 20

skeletal > cardiac > smooth

Question 21

compare cardiac and smooth muscle

Answer 21

Question 22

skeletal muscle epimysium

Answer 22

• a dense connective tissue sheath that surrounds the entire muscle
• lots of collagen I
• thickens and merges with the tendons at the ends of the muscle

Question 23

skeletal muscle perimysium

Answer 23

• skeletal muscle is divided into fascicles (bundles of fibers)
• comprised of dense connective tissue, but with collagen III > collagen I

Question 24

skeletal muscle endomysium

Answer 24

• surrounds each myofiber
• myofibrils appear as small pink dots filling the entire muscle cell
• occcasional connective tissue nuclei and capillaries visible

Question 25

skeletal muscle fiber (myofiber, muscle cell)

Answer 25

Question 26

skeletal muscle fascicle

Answer 26

skeletal muscle is divided into fascicles (bundles of fibers)

Question 27

myofibrils are composed of ___ , ___ , & ___

Answer 27

Myofibrils are composed of actin (thin filaments), myosin (thick filaments), and support proteins

Question 28

sarcomere organization

Answer 28

Question 29

identify

Answer 29

nucleus myofiber
myofiber
endomysium
perimysium

Question 30

cardiac muscle intercalated disks

Answer 30

• specialized junctions that are characteristic of cardiac muscle
  —– consist of adherens junctions, desmosomes and gap junctions
  —– mutations in components of those junctions result in heart arrhythmias
• visible as dark lines running perpendicular to the cell’s long axis, marking where two cells join end-to-end
• might also run parallel when connecting branches

Question 30

cardiac muscle myocytes

Answer 30

branched
striations are sometimes seen

Question 31

smooth muscle enteric ganglion (plexus)

Answer 31

middle “?”

Question 32

smooth muscle neuronal cell bodies

Answer 32

?

Question 33

golgi stain

Answer 33

precipitation of silver salts in cells

Randomly fills some cells entirely, turning them black so they can be seen clearly against the background of other cells in which no precipitation occurs

Question 34

nissl stain

Answer 34

• basic stain for DNA in nuclei and to RNA in ribosomes (RER)
• useful for seeing shapes of neuronal cell bodies (abundant RER)
• strongest stain close to cell body
• in some cases, stains dendrites and the initial segment of axon

Question 35

glial cells

Answer 35

comprise most cell bodies in the white matter, as well as many of the small cell bodies in the gray matter (oligodendrocytes and astrocytes)

Question 36

what does white/grey matter look like under microscope?

Answer 36

Question 37

what matter is left “?” and right “?”

Answer 37

Left “?”: grey matter
Right “?”: white matter

Question 38

Purkinje neuronss

Answer 38

lie in the middle layer, with theor large, complex dendritic fans extending through the upper molecular layer to the surface of the cerebellum

Question 39

what doe astrocytes look like?

Answer 39