Ch.9 Flashcards
what is a function of muscles
pumping blood, generate heat, movement
What is the epimysium
outermost layer connective tissue surrounding skeletal muscle
What is endomysium made of
loose connective tissue
Myofibrils are composed primarily of
myosin and actin
What causes the striated appearance of skeletal muscle fibers
orgainization of sarcomeres
Sacromere description
segment of muscle fiber
Function of transverse tubules
transmits electrical impulses to interior of the cell
A tendon is blank, whereas an aponeurosis is blank
cordlike that connects muscle to bone ; sheet that connects muscle to muscle
Unlike smooth muscle cells, the blank of skeletal and cardiac muscle cells are well developed
Transverse tubules and sarcoplasmic reticulum
List these structures in order from smallest to largest: fascicle, filament, muscle fiber, myofibril, muscle
filament, myofibril, muscle fiber, fascicle, muscle
List structures in order from deepest to most superficial: perimysium, epimysium, endomysium, fascia
endomysium, perimysium, epimysium, fascia
What is the functional unit of muscle contraction
Sarcomere
Many muscles are names for their location, particularly in relation to bones. In what body region would you expect to find the frontal muscle?
cranium
Muscle fibers generally have only one motor end plate, bu a single motor neuron can innervate many different muscle fibers in a group. How does this arrangement affect muscle contraction
generates more force
The characteristic reddish brown color of skeletal muscle is due to the presence of what
myoglobolin
How do skeletal muscles help maintain body temp
muscle contraction releases heat
What is a myogram
graph recording of muscle contraction
The term ____ refers to an increase in the number of motor units activated as a results of more intense stimuation
recruitment
What features are not present in smooth muscle
striation and transverse tubules
What happens in a muscle as it undergoes atrophy in response to disuse
size of actin and myosin filaments decrease - atrophy
How does smooth muscle compare to skeletal
smooth contracts slower and relax slower
Muscle cells that are short in length and have centrally located nuclei are what kind of cells
smooth
What neurotransmitter can stimulate smooth muscle cells
acetylcholine and norepinepherine
What has happened in someone with myasthenia graves that causes them to have muscle weakness
decrease in each receptors on muscle fibers
What happens to the fibers of muscle whose motor neurons have been severed
Muscle fibers become smaller, Mose mitochondria, myosin and actin
Recruitment refers to
increasing number of motor units
Troponin, tropomyosin and actin are all pars of the blank
thin filaments
what structure within a skeletal muscle cell extends from z line to z line
sarcomere
main component of thin filaments
actin
what are fascicles
bonded unit of muscle fibers
