Muscle Tissue Flashcards
why is connective tissue needed in skeletal muscle?
for transduction
where is smooth muscle found?
intrinsic muscles of the eye
arrector pili muscles of the skin
viscera of the vascular system
where are the nuclei in skeletal muscle fibers located?
in the cytoplasm immediately beneath the plasma membrane (or sarcolemma)
what are the 3 connective tissue coverings associated w/ skeletal muscle?
endomysium
perimysium
epimysium
what type of fibers make up the endomysium?
reticular
what are the fibers that make up the perimysium?
fascicles
how are skeletal muscle fibers visualized?
histochemical reactions specifically NADH-TR reactions
what do fibers have that are characterized as oxidative metabolism?
large amounts of myoglobin and mitochondria
what are the 3 types of skeletal muscle fibers?
type 1 (slow oxidative fibers) type 2a (fast oxidative fibers) type 2b (fast glycolytic fibers)
Type 1 (slow oxidative fibers) have what % of mitochondria and myoglobin?
lots of mitochondria
lots of myoglobin
Type 1 fibers have what physical properties?
slow twitch fatigue resistant
great resistance to fatigue but generate little tension
Type 2a (fast oxidative fibers) have what % of myoglobin and mitochondria?
many mitochondria
high myoglobin
lots of glycogen
what physical properties do type 2a have?
fast twitch fatigue resistant
high peak muscle tension
what % of myoglobin, mitochondria and glycogen do type 2b have ?
few mitochondria
little myoglobin
lots of glycogen
physical properties of Type 2b?
fast twitch fatigue prone
high peak muscle tension
more precise neural control
what are myofilaments made of?
actin and myosin
what other proteins are associated w/ the actin?
troponin and tropomyosin
what makes a triad in skeletal muscle?
two terminal cisternae and 1 t-tubule
what neurotransmitter is in the presynaptic vesicles w/in the axon terminal?
acetylcholine
what prevents continued stimulation of the muscle cell at the motor end plate?
acetylcholinesterase
what is myasthenia gravis?
autoimmune disease where acetylcholine receptors are blocked by anitbodies to the receptor protein
EXTREME MUSCLE WEAKNESS
what forms a diad in cardiac muscle?
1 terminal cisternae + 1 t tubule
what are the 3 specialized cell junctions in cardiac muscle?
fasciae adherentes
desmosomes
gap junctions
what is in the granules found in atrial cells?
diuretics
Atrial natriuretic factor (ANF)
brain natriuretic factor (BNF)
what cells initiate, regulate, and coordinate heart beat?
cardiac conducting cells
how is death to cardiac muscle cells repaired?
fibrous connective tissue
what do the cytoplasmic dense bodies in smooth muscle cells contain?
alpha actinin
what type of collagen is in smooth muscle?
type 4 and type 3
what special fibers are also found in the smooth muscle of the blood vessels and the uterus?
type 1 collagen and elastin
the cytoskeleton of smooth muscle has thick, thin and intermediate filaments. what are each made of?
thin- actin, tropomyosin, caldesmin + calponin
thick- myosin II
intermediate- desmin + vimentin
