Movement and Muscle control Flashcards
____is composed of differentiated cells containing ___, which have the special ability to shorten or contract to move the body parts.
Muscle tissue; contractile proteins
Muscle tissues are derived from the
mesodermal layer of embryonic germ cells.
Muscle cells contain protein filaments of ____that slide past one another, producing a contraction that changes both the length and the shape of the cells.
actin and myosin
Characteristics of a Muscle (5)
-Specialized cells:
-Excitability/irritability:
-Contractility:
-Extensibility:
-Elasticity:
elongated, high density of myofilaments or cytoplasmic filaments of actin and myosin.
Specialized cells:
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:
Muscle Function (5)
• Produce Movement
• Maintain Posture and Body Position
• Stabilize Joints
• Generate Heat
• Additional Functions
Skeletal muscle fibers are packaged into organs called ___that attach to the skeleton.
skeletal muscles
cover our bone and cartilage framework; help form the smooth contours of the body.
Skeletal Muscle
are large, cigarshaped, multinucleate cells.
Skeletal muscle fibers
is also known as striated muscle and as voluntary muscle
Skeletal muscle
Connective Tissues wrapping:
Wraps entire muscle- __
Wraps muscle fibers-___
Wraps fascicle-__
Wraps entire muscle- epimysium
Wraps muscle fibers- endomysium
Wraps fascicle- perimysium
muscles that have no striations and is involuntary,
Smooth Muscle
muscles found mainly in the walls of hollow(tubelike) organs
Smooth Muscle
spindle-shaped, uninucleate, and surrounded by scant endomysium
and are arranged in two layers (___ and ___)
Smooth muscle fibers; circular and longitudinal
muscle is striated, uninucleated and under involuntary control.
Cardiac Muscle
are cushioned by small amountsof endomysiumand are arranged in spiral or figure 8–shaped bundles
cardiac cells
___are branching cells joined by special gap junctions called __
Cardiac muscle fibers; intercalated discs
Microscopic Anatomy of Muscle (3)
Sarcomeres
Myofilaments
Sarcoplasmic reticulum
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; used for store calciumand to release it on demand when themuscle fiberisstimulated tocontract
Sarcoplasmic reticulum
Contractile Apparatus (8)
alpha- actinin
troponin
myosin
actin
myomesin
My-PB-C
Tropomyosin
Titin
Muscle fibers have several special functional properties that enable them to perform their duties (3)
-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, whereas ___ is their ability to recoil and resume their resting length after being stretched.
Extensibility; elasticity
Skeletal muscle fibersmust be stimulated by ___
nerve impulses.
___ may stimulate a few muscle fibers or hundreds of them, depending on the particular muscleand theworkit does.
One motor neuron (nerve cell)
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.
Mechanism of Muscle Contraction is explained by
SLIDING FILAMENT THEORY
___ states that a “muscle fiber will contract to its fullest extent when it is stimulated adequately; it never partially contracts.
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 onetime.
What Fuels Muscle Contraction? (3)
-Direct phosphorylation
-aerobic pathway
-anaerobic pathway
Types of Muscle Contraction (2)
Isotonic contractions
Isometric contractions
Type of muscle contraction where the myofilaments are successful in their sliding movements, the muscle shortens, and movement occurs.
Isotonic contractions
examples of isotonic contractions. (3)
Bending the knee,
lifting weights,
smiling
Type of muscle contraction where the myosin filaments are “spinning theirwheels,” 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
