muscular system part 1

what are the main functions of muscle tissue

produce movement, maintain posture, stabilize joints and generate heat

what are the functional characteristics/properties of muscle tissue

excitability/irritability, contractility, extensibility and elasticity

what does excitability/irritability mean

ability of muscle tissue to respond to stimuli (responsiveness)

what does contractility mean

ability of muscle tissue to shorten

what does extensibility mean

ability of muscle tissue to stretch

what does elasticity mean

ability of muscle tissue to recoil to original shape

what are the three types of muscle tissue

skeletal, cardiac and skeletal

skeletal muscle has what kind of control

voluntary by somatic nervous system

does skeletal muscle have striations and how many nuclei?

striated with multinucleated fibers

what is the location of skeletal muscles and what does it provide

attached to bones and provide movement and posture

cardiac muscle has what kind of control

involuntary by ANS and endocrine

does cardiac muscle have striations and how many nuclei?

striated with intercalated discs, branching and uni-nucleated

what is the function and location of the cardiac muscle

heart and pumps blood

smooth muscle has what kind of control

involuntary (ANS and endocrine)

does smooth muscle have striations and how many nuclei?

non-striated with spindle shaped single nucleus

what is the function and location of smooth muscle

walls of hollow organs (intestines, esophagus) and moves substances (peristalsis)

what are the two layers found in the smooth muscle

longitudinal layer and circular layer

what layer of the smooth muscle is the deepest layer (seems as if the cells are coming at you); allows for pushing of food in GI tract

longitudinal layer

what layer of the smooth muscle is the superficial layer; squeezes the food

circular layer

when a nerve impulse reaches a NMJ, what is released

ACH

a stimulus reaches the axon that sends an electrical signal to the NMJ, allowing for what to occur

contraction

what is NMJ

neuromuscular junction; physical site where neuron synapses with skeletal muscle fiber that elicits a response

can a neuron synapse at multiple locations and why?

yes, will allow for quick response (if we had only one it would be harder to have response)

all muscle types are vascularized which means

arteries are present to deliver oxygen and nutrients while veins help remove metabolic wastes in order for contraction remain efficient

what is unique about skeletal muscle NMJ compared to smooth and cardiac

each skeletal muscle fiber is supplied with its own nerve ending that controls its activity

muscle fibers are surrounded and bundled by that do what

connective tissue sheaths help support and reinforce muscle as a whole

what are the layers of the connective tissue sheaths that surround the muscle fibers, internal to external

endomysium, perimysium and epinysium

which layer wraps around a single muscle fiber

endomysium

which layer surrounds fasicles

perimysium

what is a fasicle

bundles of muscle fibers

which layer surrounds entire muscle

epimysium

what is the epimysium composed of

Dense Irregular CT

what is the fascia made of and where it is found

dense irregular CT, located on the outside of the epimysium (most superficial and easily susceptible to infection)

what is a condition associated with fascia (flesh eating disease caused by bacterial infection)

necrotizing fascitis

all layers are made of connective tissue and

continuous with one another and with tendons that join muscle to bone