HPP LEC CHAP 7 Flashcards
attached to bones
striated
voluntarily controlled
skeletal muscle
located in the heart
striated
involuntarily controlled
cardiac muscle
located in blood vessels, hollow organs
non-striated
involuntarily controlled
smooth muscle
Functions of muscular system
- Movement
- Maintain posture
- Respiration
- Production of body heat
- Communication
- Heart beat
- Contraction of organs and vessels
4 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
ability to be stretched beyond it normal resting length and still be able to contract
extensibility
ability of the muscle to recoil to its original resting length after it has been stretched
elasticity
Skeletal muscle, or striated muscle, with its
associated connective tissue, constitutes
approximately how many percent of the body weight?
40%
a connective tissue sheath that surround each skeletal muscle
epimysium
a skeletal muscle is subdivided into groups of muscle cells
fascicles
surround the fassicle
perimysium
surround each skeletal muscle cell
endomysium
fiber is a single cylindrical cell, with
several nuclei located at its periphery.
muscle fiber
The muscle fibers range in what length and in diameter?
1cm - 30 cm
0.15 mm
Skeletal muscle fibers contain several nuclei that are located where?
periphery
has many tubelike inward folds
sarcolemma (cell membrane)
what do you call the tubelike in sarcolemma? It also occur at regular intervals along the muscle fiber and extend into the center of the muscle fiber.
Transverse tubules/ T tubules
the t tubules are associated with enlarged portions of the smooth endoplasmic reticulum
sarcoplasmic reticulum
what do you call the enlarged portions
terminal cisternae
t tubules connect the sarcolemma to the terminal cisternae to form a?
muscle triad
The sarcoplasmic reticulum has a relatively high
concentration of?
Calcium
the cytoplasm of a muscle fiber which contains many bundles of protein filaments
sarcoplasm
are bundles of protein filaments
myofibrils
myofibrils consists of
myofilaments, actin, myosin
a nerve cell stimulates muscle
cells.
motor neuron
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
a group of muscle fibers that a
motor neuron stimulates.
motor unit
is the end of a neuron cell
axon fiber.
presynaptic terminal
is the space between the
presynaptic terminal and postsynaptic membrane.
synaptic cleft