CHAPTER 7 Flashcards
3 TYPES OF MUSCLES
SKELETAL
CARDIAC
SMOOTH
attached to bones
striated
voluntarily controlled
skeletal
located in the heart
striated
involuntarily controlled
cardiac
located in blood vessels, hollow organs
non-striated
involuntarily controlled
smooth
MUSCULAR SYSTEM FUNCTIONS (7)
- movement
- maintain posture
- respiration
- production of body heat
- communication
- heart beat
- contraction of organs and vessels
Properties of muscles
contractility
excitability
extensibility
elasticity
the ability of muscle to shorten forcefully or contract
contractility
the capacity of muscle to respond to a stimulus
excitability
the ability to be stretched beyond it normal resting length and still be able to contract
extensibility
ability of the muscle to recoil to it original resting length after it has been stretched
elasticity
constitutes about 40 precent of body weight
skeletal muscles
also called as striated muscles because of transverse bands or striations, can be seen in the muscles under the microscope
skeletal muscles
Individual muscles are
biceps
brachii
a skeletal muscles subdivided into groups of muscle cells
fascicles
each skeletal muscles is surrounded by a connective tissue sheath called the
epimysium
each fascicles is surrounded by a connective tissue covering
perimysium
each skeletal muscle cell (fiber) is surrounded by a connective tissue covering
endomysium
a single cylindrical cell with several nuclei located at its periphery
muscle fiber
range in length 1cm to 30 cm and are generally 0.15 mm in diameter
muscle fiber
contain several nuclei that are located at the periphery of the fiber
skeletal muscle fiber
has many tubelike inward folds,called transverse tubules or T tubules
sarcolemma (CELL MEMBRANE)
occur at regular intervals along the muscles fiber and extend into the center of the muscle fiber
T tubules
The T tubules are associated with enlarged portions
of the smooth endoplasmic reticulum
sarcoplasmic reticulumm
The enlarged portions are called
terminal cisternae
T tubules connect the sarcolemma to the terminal
cisternae to form a
muscle triad
The cytoplasm of a muscle fiber is called
sarcoplasm
bundles of protein filaments are called
myofibrils
the myofibrils consists of
myofilaments, actin and myosin
is a nerve cell stimulates muscle cells
motor neuron
is a synapse where a
the fiber of a nerve connects with a muscle fiber.
neuromuscular junction
refers to the cell-to-cell junction between a nerve cell and either another nerve cell or an effector cell such as in a muscle or a gland
synapse
is a group of muscle fibers that a motor neuron stimulates
motor unit
is the end of neuron cell axon fiber
presynaptic terminal
is the space between the presynaptic terminal and postsynaptic membrane
synaptic celft
is the muscle fiber membrane (sarcolemma)
postsynaptic membrane
is a vesicle in the synaptic terminal that stores and releases neurotransmitter chemical
synaptic vesicle
are chemicals that stimulate or inhibit postsynaptic cells
neurotransmitter
is the neurotransmitter that stimulates skeletal muscles
acetylcholine
are very energy demanding cells wether at rest or during any form of exercise
muscle fibers
is derived from four processes in skeletal muscle
ATP
production of ATP during most exercise and normal conditions
aerobic
production of ATP during intensive short-term work
Anaerobic
called creatine phosphate to ATP
conversion of molecules
is a temporary state of reduced work capacity
fatigue
4 types of contractions
isometric
isotonic
concentric
eccentric
contraction has an increase in
muscle tension, but no change in length.
isometric
contraction has a change in
muscle length with no change in tension.
isotonic
contractions are isotonic
contractions in which muscle tension increases
as the muscle shortens.
concentric
contractions are isotonic contractions
in which tension is maintained in a muscle, but
the opposing resistance causes the muscle to
lengthen.
Eccentric
is the constant tension produced by
body muscles over long periods of time.
muscle tone
Each whole muscles is subdivided into numerous visible bundles called
MUSCLE FASCICLES
cell membrane of the muscle fiber
SARCOLEMMA
separate one sarcoomere from the nest
Z DISK
is a network of protien fibers that forms a stationary anchor from actin myofilaments to attach
Z DISK
Light straining bands
I BANDS
central dark staining band
A BAND
contains only myosin myofilaments
H ZONE
consists of fine proteins filaments that anchor the myosin myofilaments in place
M LINE