Muscle tissue

What is the fundamental property of muscle

Contractility

three types of muscle tissue

skeletal, cardiac, smooth

Muscle term for cell

muscle fiber

Muscle term for plasma membrane

sarcolemma

Muscle term for cytoplasm

sarcoplasm

Muscle term for smooth er

sarcoplasmic reticulum

which muscle tissue

skeletal muscle

which muscle tissue

cardiac muscle

which muscle tissue

smooth muscle

what is inside a muscle cell

contractile machinery, calcium storage/release, electrical signaling, and energy

skeletal muscles provide the clearest example of what (give 3)

muscle organization

sarcomeres

striations

excitation-contraction coupling

neuromuscular transmission

skeleton muscle fibers have…

very long, cylindrical, multinucleated, peripheral nuclei fibers packed with myofibrils

sarcomere

thin filament

thick filament

What are the accessory proteins

a-actinin, titin, nebulin, myomesin

function of sarcomere

permits actin-myosin interaction / muscle contraction and shortening

what are the red, blue, and green parts

T-tubule, terminal cisterna, sarcoplasmic reticulum

what is this, and what is #1

acetylcholine (ACh) is released, due to nerve impulse, from the synaptic knob into the synaptic cleft. ACh then attaches to the ACh receptors in the neuromuscular junction, initiating a muscle impulse inn the sarcolemma of the muscle fiber.

what is #2

Muscle impulses spreads from the sarcolemma via T-tubules, which causes calcium ions to release from terminal cisternae into the sarcoplasm.

what is this

cross-bridge cycle

what are the 4 things that happen in the cross-bridge cycle

attachment

power stroke

detachment

reactivation

what happens before the attachment stage

calcium binds with troponin to move tropomyosin away to expose active binding sites on actin (thin) filaments so that the myosin heads (thick) bind to them

attachment stage

myosin heads of thick filaments bind to the exposed active sites on actin filaments

power stroke stage

myosin heads bend strongly to slide thin actin filaments past the thick filaments to shorten muscle fibers and generate force

detachment stage

ATP is used up to attach tot he myosin head and detach from the actin filaments

reactivation stage

ATP is hydrolyzed to ADP + P, which reactivates the myosin head for it to bind and pull again

what does calcium reuptake need to be pumped back into the sarcoplasmic reticulum

It needs ATP

what is being shown here

neuromuscular transmission and neuromuscular junction

what is the green part?

motor unit

what is being represented in this picture?

proprioception

How does the central nervous system (cns) know what the muscle is doing?

due to muscle spindles and golgi tendon organ

what composes the muscle spindle?

capsule, intrafusal muscle fibers, and stretch receptor

What is being shown besides the tendon?

golgi tendon organ

skeletal muscle fiber types

type I, type IIa, and type IIb

what characteristics does type I skeletal muscle fibers have?

slow, oxidative, and fatigue resistant

what characteristics does type IIa skeletal muscle fibers have?

fast, oxidative-glycolytic, and intermediate

what characteristics does type IIb skeletal muscle fibers have?

fast, glycolytic, and fatigues rapidly

histochemical differences of type I and type II skeletal muscle fibers

Type I: high oxidative activity, many mitochondria, high myoglobin, and rich capillary supply

Type II: greater glycolytic activity, faster contraction, and different myosin ATPase properties

what is being shown?

cardiac muscle

what characteristics does cardiac muscles have?

striated, branched, central nucleus, involuntary, and rhythmic

differences between cardiac muscle and skeletal muscle

Skeletal: has striations, many nuclei, nuclear position (peripheral), no branching
Cardiac: has striations, usually 1 nuclei, nuclear position (central), has branching

what is being shown here?

intercalated discs (in the heart)

two mechanical junctions that hold the heart cells together?

fascia adherens (anchor thin actin filaments of sarcomeres), and desmosomes (anchoring intermediate cytokeratin filaments with high tensile strength)

electrical coupling that allows the heart to beat rhythmically and involuntarily

gap junction (allows action potentials to spread rapidly across the myocardium, allowing for a synchronized, rhythmic contraction)

what is being shown here?

cardiac muscle ultrastructure

when cardiac muscle acts as an endocrine tissue, what makes up the muscle cell walls of the heart’s atria, and what does this produce?

atrial cardiomyocytes, and atrial natriuretic factor (ANF)

two primary actions that occur when ANF regulates fluid balance and blood pressure when released

increase in sodium excretion, and lowers blood volume and pressure by promoting sodium and fluid loss

what do these images show?

smooth muscle

difference between skeletal/cardiac muscles and smooth muscles?

skeletal/cardiac: have sarcomeres = organized striated contraction

smooth: no sarcomeres = flexible, sustained contraction

contents of smooth muscle

fusiform, single nucleus, central nucleus, no striations, and involuntary

smooth muscle locations

blood vessels, gastrointestinal tract, respiratory tract, urinary tract, and reproductive tract

what is being shown here?

smooth muscle ultrastructure

contents of the smooth muscle ultrastructure (not sure dito)

actin, myosin, intermediate filaments, dense bodies, caveolae, no sarcomeres, no t-tubules

what is being shown here?

dense bodies

functions of dense bodies?

actin anchoring sites, and functional analogue of z discs

this is a dense body when a smooth muscle ____(not sure dito)

contracts

what does this show?

smooth muscle innervation

what are the capacity for regeneration for each muscle

skeletal: limited, involving satellite cells mainly

cardiac: very poor

smooth: good, involving mitotic activity of muscle cells

what does this show?

skeletal muscle regeneration

what is being shown here?

cardiac muscle injuries

what kind of cardiac muscle injury?

viable

what kind of cardiac muscle injury?

necrotic

what kind of cardiac muscle injury?

granulation tissue

what kind of cardiac muscle injury?

scar

what is being shown here?

smooth muscle regeneration