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.
____ - the myosin filaments are “spinning
their wheels,” and the tension in the muscle keeps increasing
Isometric contractions
They are trying to slide, but the muscle is pitted against some
more or less immovable object.
Isometric contractions
For example, when you push
the palms of your hands together in front of you, your arms
and chest muscles are contracting ____
isometrically
is the maintenance of partial
contraction of a muscle, important for generating
reflexes, maintaining posture and balance, and
controlling proper function of other organ systems
Muscle tone
(muscle) Tone is controlled by the ____,
which measures muscle stretch.
sensory muscle spindle
The continuous and passive partial contraction of
the muscles, which helps maintain posture
(muscle) Tone
results in stronger,
more flexible muscles with greater resistance to fatigue.
Aerobic exercise, or endurance exercise
helps us reach a steady rate of ATP
production and improves the efficiency of aerobic
respiration.
Aerobic exercise
___require very little time and little or no
special equipment
Resistance exercises
Some muscles are named in reference to
some imaginary line, usually the ___ of
the body or the ___ of a limb bone.
midline; long axis
When a muscle’s name includes the term
____, its fibers or whole structure
run parallel to that imaginary line.
rectus (straight)
the term ___in a muscle’s
name tells you that the muscle fibers run (at a slant) to the imaginary line
oblique
largest= __
smallest= ___
long=___
maximus;
minimus
longus
the ____is
the largest muscle of the
gluteus muscle group
gluteus maximus
the ____muscle is roughly triangular
(means “triangular”), like the Greek letter delta (Δ)
deltoid;
Arrangement of the
Fascicles (4)
Circular pattern
Convergent muscle
Parallel arrangement
Pennate pattern
Fascicles are arranged in concentric rings
Circular pattern
____muscles are typically found surrounding external
body openings which they close by contracting, creating a
valve. A general term for such muscles is ___
Circular;
sphincters
(“squeezers”)
example of circular pattern:
_____surrounding the eyes
and mouth
orbicularis muscles
fascicles converge toward a
single insertion tendon
Convergent Muscle
____ is triangular or fan-shaped, such as
the ___muscle of the anterior thorax
convergent muscle;
pectoralis major
____, the length of the fascicles run
parallel to the long axis of the muscle, as in the ___ of
the anterior thigh.
Parallel arrangement; sartorius
These muscles are straplike
Parallel arrangement
____, short fascicles attach obliquely to a
central tendon
Pennate pattern
In the _____ muscle of the leg,
the fascicles insert into only one side of the tendon, and the
muscle is ___
extensor digitorum; unipennate
fascicles insert into opposite sides of the tendon, the
muscle is ___
bipennate
fascicles insert from several different sides, the
muscle is ___
multipennate
Types of Muscle
Movement (6)
Flexion
Extension
Rotation
Abduction
Adduction
Circumduction
movement, generally in the sagittal plane, that
decreases the angle of the joint and brings two bones
closer together
Flexion
___is typical of hinge joints (bending the knee or
elbow), but it is also common at ball-and-socket joints
(for example, bending forward at the hip).
Flexion
___is the opposite of flexion, so it is a movement that
increases the angle, or distance, between two bones or parts of
the body (straightening the knee or elbow)
Extension
___is movement of a
bone around its
longitudinal axis
Rotation
____is a common
movement of ball-and-socket joints and
describes the movement
of the atlas around the
dens of the axis.
Rotation
___is moving a limb
away (generally in the
frontal plane) from the
midline, or median plane, of
the.
Abduction
The terminology also
applies to the fanning
movement of your fingers
or toes when they are
spread apart
Abduction
___is the opposite
of abduction, so it is the
movement of a limb
toward the body midline
Adduction
Think of ___as
“adding” a body part by
bringing it closer to the
trunk
adduction
___is a
combination of flexion,
extension, abduction, and
adduction commonly seen
in ball-and-socket joints,
such as the shoulder
Circumduction
The proximal end of the
limb is stationary, and its
distal end moves in a
circle
Circumduction
special movements (7)
Dorsiflexion and plantar flexion;
Inversion and Eversion;
Supination and Pronation;
Opposition;
Lifting the foot so that its superior surface approaches the
shin (pointing your toe toward your head) is ___,
whereas pointing the toes away from your head is ____.
dorsiflexion; plantar
flexion
____of the foot corresponds to extension and
hyperextension of the hand at the wrist, whereas ___ of the foot corresponds to flexion of the hand.
Dorsiflexion; plantar flexion
To ___the foot, turn the
sole medially, as if you
were looking at the bottom
of your foot. To ___the
foot, turn the sole
laterally.
invert; evert
___“turning backward” and ___“turning
forward” refer to movements of the radius around the ulna
supination; pronation
____occurs when the forearm rotates laterally so that
the palm faces anteriorly (or up) and the radius and ulna are
parallel, as in anatomical position
Supination
____occurs when the forearm rotates medially so that
the palm faces posteriorly (or down).
Pronation
___brings the
radius across the ulna so that the two bones form an X
Pronation
___= radius rotates over ulna
___= radius and ulna are parallel
Pronation
Supination
