Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

28 Cards in this Set

  • Front
  • Back
muscle cells: char
multinucleate (peripheral nuclei)

from a single myoblast

polygonal shape in x-section

one cell can be as long as whole muscle
damage to muscle fiber
will die

myoblasts still present and will regenerate missing fibers
skeletal muscle in tongue: char
multidirectional fasciculi
between fasciculi
sarcomere bands
Z: disc (thin line): connections of actin (alpha actinin binds it to z disc)
A: dark: thick myosin fibers and overlap of actin
I: light: actin only
myosin components
heavy and light meromyosin chains:

two alpha helices of rod light make up light

heavy is just the end, includes some light parts and the heavy heads
light meromyosin
won't complex with actin

will form filaments
heavy meromyosin
ATPase activity

won't form filaments
sliding filament theory of contraction
ADP form of light chain has affinity for thick filament

power stroke: when no ADP is present

with just ADP will cause state of rigor (mortis): cross linking betw. actin and myosin filaments
calcium dependent reg. of contraction
tropomyosin: chain that holds troponin

troponin: no Ca2+ will hold actin filament awy from actin head

w/ Ca will expose binding site for contraction
t-tubules and sarc. reticulum
SR encloses myofibril

t-tubule triad (system) links SRs together

t-t is depaolarized and Ca channels open up to fill cytoplasm around myofibril->contraction->free Ca recovered to shut down contraction
a t-tubule and the ends of two adjacent SRs makes up the t-t triad
type 1
-slow twitch
-resistant to fatigue
-lots of myoglobin
-smaller diameter->gen. less force
-contract slowly
-aerobic resp. dep.<-^mitochon.
-have smaller nerve fibers
type II
fast twitch
-low myoglobin->white muscle
-larger diam.
-rapid contraction
-anaerobic, glycolysis, few mito., fatigue quickly
-inn. by large diam. nerve fibers
muscle fiber typing (I or II)
number of mitochondria (TCA assay)

slow: stain darkly b/c of more mito.

fast: stain lighter

denervation renervation will cause you to lose checkerboard pattern of fast/slow-> prblem
Duchenne Musc. Dystrophy
prob in dystrophin (just beneath membrane)

linking actin cytoskeleton to EC matrix

round or swollen m. fibers
macrophages present
central nuclei (newly formed cells)
muscle spindles
sensory structures in muscle fibers


relays info about muscle movement
golgi in muscle
sensory organs in tendons

tell about stretch
cardiac muscle: char
centrally placed single nucleus


intercalated discs connecting cells
cardiac muscle: histology
variability in diameter (because of branching)

central nucleus obvious in cross section

striations seen in EM
intercalated discs
complex of cell/cel connections

fascia adherens: like zonula adherens

desmosome: spot welds

gap jxns: electrical/metab. conxtn
intercalated disc: histology
darks spot is desmosome

actin filament is adhered to adherens

where memb. is very close, where gap jxns are
atrial granules
only in atrial walls


contain peptide to reg. BP
purkinje fibers: char
conducting cells that keep heart beating in rythm

signal begins at SA node and propagates out to AV node->purkinje cells

make up AV node and bundle of His, etc.
purkinje fibers: histo
large diam fibers with few contractile fibers

stain lightly, look empty
smooth muscle: char
large ducts, uterus

spindle shaped

orthogonal fasicles: multidirectional

actin and myosin throughout cytoplasm, no bands
smooth muscle: histo: EM
-oval shaped nucleus
-round in cross section
-perimysium between fasicles
-actin and myosin random in cytoplasm
-desmosome jxn also where actin attached
-gap jxns for e- coupling
separates fasicles