Muscular system Pt. 1 Flashcards
Muscle Function (5)
-Produce Movement
-Maintain Posture and Body Position
-Stabilize Joints
-Generate Heat
-Additional Functions
____ are packaged into organs called skeletal
muscles that attach to the skeleton.
Skeletal muscle fibers
cover our bone and cartilage framework, they help form the
smooth contours of the body.
Skeletal muscle
are large, cigarshaped, multinucleate
cells
Skeletal muscle fibers
Skeletal muscle is also known as ___muscle and as
___muscle
striated; voluntary
no striations and is
involuntary; found mainly in the walls of
hollow (tubelike) organs
Smooth Muscle
______ are
spindle-shaped, uninucleate,
and surrounded by scant
endomysium and are
arranged in two layers
(___ and __)
Smooth muscle fibers;
circular and longitudinal
is striated,
uninucleated and under involuntary control
cardiac muscle
The cardiac cells are cushioned by
small amounts of ____and are
arranged in spiral or figure 8–shaped
bundles
endomysium;
Cardiac muscle fibers are branching
cells joined by special gap junctions
called ___
intercalated disc
attached to bones or for some facial muscles to skin
skeletal muscles
single, very long, cylindrical, multinucleate cells wwith very obvious striation
skeletal muscles
walls of hollow organs (except heart); single, fusiform, uninucleate, no striations
smooth muscle
walls of the heart; branching chains of cellls; uninucleate, striations; intercalated discs
cardiac muscles
are the structural and functional units of
skeletal muscle.
Sarcomeres
___are the precise arrangement of even smaller
structures within sarcomeres – __ and ___
Myofilaments; Thick and Thin Myofibrils
____interconnecting tubules and sacs
that is used for store calcium and to release it on demand
when the muscle fiber is stimulated to contract
Sarcoplasmic reticulum
Skeletal Muscle Fiber
Activity (4)
irritability
contractility
extensibility
elasticity
, also called responsiveness, which is the ability to
receive and respond to a stimulus.
Irritability
, is the ability to forcibly shorten when
adequately stimulated.
Contractility
is the ability of muscle fibers to stretch
Extensibility
is their ability to recoil and resume their
resting length after being stretched
elasticity
____ (nerve cell) may stimulate a few muscle
fibers or hundreds of them, depending on the particular
muscle and the work it does
One motor neuron
A ___ consists of one neuron and all the skeletal
muscle fibers it stimulates
motor unit
_____, contain synaptic vesicles filled with
neurotransmitter which stimulates skeletal muscle fibers is
____
Neuromuscular junctions;
Acetylcholine or Ach
states that a “muscle fiber will contract
to its fullest extent when it is stimulated adequately;
it never partially contracts.
Muscle Law
the whole muscle reacts to stimuli with
graded responses, or different degrees of shortening,
which generate different amounts of force.
Muscle Law
Graded Muscle Contraction
is generated by: 2
(1) by changing the frequency of muscle
stimulation
(2) by changing the number of muscle fibers
being stimulated at one time
What fuels muscle contraction (3)
Direct phosphorylation
Aerobic pathway
Anaerobic pathway
Types of Muscle
Contraction (2)
Isotonic contractions
Isometric contractions
- the myofilaments are successful in
their sliding movements, the muscle shortens, and movement
occurs.
Isotonic contractions
Bending the knee, lifting weights, and smiling are all
examples of ___
isotonic contractions.