MOVEMENT AND MUSCLE CONTROL Flashcards
composed of differentiated cells containing contractile proteins, which have the special ability to shorten or contract to move the body parts
Muscle tissue
Muscle tissues are derived from the?
mesodermal layer of
embryonic germ cells
Muscle cells contain protein filaments of ____, producing a contraction that changes both the length and the shape of the cells
actin and myosin
that slide past one another
4 Characteristics of a Muscle
excitability
contractility
extensibility
elasticity
ability to respond to stimuli
Excitability/irritability
ability to contract
Contractility
ability of a muscle to be stretched.
Extensibility
ability to recoil and return to its normal shape
after stretch
Elasticity
5 Muscle Functions
- 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
Skeletal muscle cover our bone and cartilage framework, they help form the ____
smooth contours of the body
are large, cigarshaped, multinucleate
cells
Skeletal muscle fibers
also known as striated muscle and as
voluntary muscle
Skeletal muscle
connective tissue that wraps entire muscle
epimysium
tissue wrapped by fascicle
perimysium
tissue wrapped in perimysium
fascicle
muscle fiber wrapped in ___
endomysium
no striations and is
involuntary
Smooth Muscle
found mainly in the walls of
hollow (tubelike) organs
Smooth Muscle
spindle-shaped, uninucleate, and surrounded by and are arranged in two layers (____)
scant endomysium
circular and longitudinal
striated, uninucleated and under involuntary control
Cardiac Muscle
The cardiac cells are cushioned by small amounts of endomysium and are arranged in ____
spiral or figure 8–shaped
bundles
Cardiac muscle fibers are branching
cells joined by special gap junctions
called
intercalated discs
connective tissue components: skeletal muscle
epimysium
perimysium
endomysium
connective tissue components: smooth muscle
endomysium
connective tissue components: cardiac muscle
endomysium attached to the fibrous skeleton of the heart
regulation of contraction: voluntary, via nervous system controls
skeletal muscle
speed of contraction: skeletal muscle
slow to fast
regulation of contraction:involuntary, internal heart pacemaker, nervous system, controls, hormones
cardiac muscle
regulation of contraction: involuntary, nervous system controls, hormones, chemicals, stretch
smooth muscle
speed of contraction: cardiac muscle
slow
speed of contraction: smooth muscle
very slow
no rhythmic contraction
skeletal muscle
rhythmic contraction, yes, is some
cardiac, smooth
are the structural and functional units of skeletal muscle
Sarcomeres
are the precise arrangement of even smaller
structures within sarcomeres – _______
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
also called responsiveness, which is the ability to
receive and respond to a stimulus.
Irritability
the ability to forcibly shorten when
adequately stimulated
Contractility
the ability of muscle fibers to stretch,
whereas elasticity is their ability to recoil and resume their
resting length after being stretched
Extensibility
____ motor neuron (nerve cell) may stimulate a few muscle
fibers or hundreds of them, depending on the particular
muscle and the work it does.
One
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 Acetylcholineor Ach
Neuromuscular junctions
Muscle Law
“muscle fiber will contract
to its fullest extent when it is stimulated adequately;
it never partially contracts.
However, the whole muscle reacts to stimuli with
graded responses, or different degrees of shortening,
which generate different amounts of force.
Graded Muscle Contraction
is generated by:
- (1) by changing the frequency of muscle
stimulation - (2) by changing the number of muscle fibers
being stimulated at one time
What Fueled Muscle Contraction?
direct phosphorylation
aerobic pathway
anaerobic pathway
direct phosphorylation
energy source?
oxygen use?
products:
duration of energy provision?
- creatine phosphate CP
- none
- 1 ATP per CP, creatine
- 15 secs
aerobic pathway
energy source?
oxygen use?
products:
duration of energy provision?
- glucose; pyruvic acid; free fatty acids from adipose tissue; amino acids from protein catabolism
- with oxygen
- 32 ATP per glucose, CO2, H2O
- Hours
anaerobic pathway
energy source?
oxygen use?
products:
duration of energy provision?
- glucose
- no oxygen
- 2 ATP per glucose, lactic acid
- 40 secs or more
Types of Muscle
Contraction
isotonic contractions
isometric contractions
the myofilaments are successful in
their sliding movements, the muscle shortens, and movement
occurs
isotonic contractions
examples of isotonic contractions
bending knee, lifting weights, smiling
the myosin filaments are “spinning
their wheels,” and the tension in the muscle keeps increasing.
They are trying to slide, but the muscle is pitted against some
more or less immovable object
isometric contractions
example of isometric contractions
when you push
the palms of your hands together in front of you, your arms
and chest muscles are contracting isometrically.
