The Muscular System Flashcards
myo-, mys-, and sarco- is latin for ____
Little Mouse
Approximately how many muscles in the human body?
Approx 700
Muscles account for ___% of total bjody weight
40-50%
Elongated cells packed with contractile proteins
Myosin and Actin
Muscles contract on ________
conscious command OR reflexive response
4 Muscle Characteristics
Excitability, Contractility, Extensibility, Elastin
Excitibility
Responds to external stimuli
Contractility
Actively shortens along longitudinal axis
Extensibility
Can stretch beyond original length, without tearing
Elastin
Stretches out and recoils back to original length
The complete action of the organ is the result of the action ____
of the individual cell
This is filled with muscle fibers, connective tissue, nervous tissue, and epithelial tissue
Muscle Organ
Muscle Function
To change chemical energy into mechanical energy
The chemical energy for a cell is ___
ATP
ADP breaks down into
ADP, inorganic phosphate, and energy
When mechanical energy is produced, it allows us to:
Produce skeletal/skin movement, maintain posture, supports soft tissue, regulating incoming and outgoing material along a tract, and maintains body temperature
A lot of organs are anchored/supported by ____
connective tissue
Doors of smooth muscles moving substances throughout the body
Sphincter Muscles
Smooth muscles have ____ & ____, but no _____.
Have actin and myosin, but no sarcomeres (so no striations)
-soma
body
Skeletal muscles have _______, which indicate that there are sarcomeres
striations
Skeletal muscles have _____ fibers, ________ nuclei, voluntary/involuntary control, can/can’t divide, will ___ over time, and is attached to the _____
cylindrical fibers, multiple/peripheral nuclei, voluntary control, cannot divide, will fatigue over time, and are attached to skeleton and skin
Every muscle ORGAN has at least one ____, one___ and one ___.
Artery, vein, nerve
Muscle cells are ______that may be > ___ft long and lay _____ to each other.
fibers; 1ft; parallel
Bundles of muscle cells (fibers) are called
fascicles
_____ wraps the muscle organ into multiple tubes within tubes within tubes
Connective Tissue
-peri
around
-endo
within
-epi
upon / on
endomysium
links the cells (fibers) together
Endomysium fibers blend in to form
Tendons
Individual skeletal muscle cells formed by a fusion of multiple _____
myoblasts
_____ bring their own organelles (including nuclei)
Myoblasts
some myoblasts remain as ____
myosatellite cells
Myosatellite cells may be activated with ___, ___ , and ____. Also helps with ______ of muscle cells
exercise, disease, and damage; repair/regeneration
Every muscle fiber is surrounded by a plasma membrane or __________
sarcolemma
The sarcolemma invaginations to the center
Transverse Tubules
T-Tubules lay next to the ________, store and release _______, and wraps around the ______
SR, calcium ions, myofibrils
Myofibrils contain organized _____, which are ____ proteins, containing ____ & ______
myofilaments; contractile proteins; actin and myosin
A muscle cell (fiber) consists of many ______ arranged side-by-side along the length of the myofibrils. So when you look at it, you see_____
Sarcomeres; striations
Stimulus travels down the motor neuron to the ___
neuromuscular junction
Motor neuron releases _____
Ach
The connection between the neuron synapse and muscle cell
Neuromuscular Junction
If there is not enough Ach, ______________
the Ach esterase will eat it all up (we need enough for threshold and contraction)
The sliding filament theory starts at the ______
motor neuron
Myofilaments consist of _______
Actin & myosin (contractile proteins)
Actin is THICK / THIN? Myosin is THICK / THIN?
Actin = Thin Myosin = Thick
Stimulus (AP) is transferred to the SR & _____ are released. These bind to proteins on ______ filaments, causing the exposure of cross-bridge binding sites on these filaments.
Calcium ions; actin (thin)
