68WM6 Muscles

Description:	68WM6 Muscles
Category:	Nursing
Created by:	NurseMaryK on 2009-09-10

Question	Answer
Actin:	contractile protein found in the thin myofilaments of skeletal muscle.
All or None:	when stimulated, a muscle fiber will contract fully or not at all; whether a contraction occurs depends on whether the stimulus reaches the required threshold.
Antagonist:	those having opposing actions; for example, muscles that flex the upper arm are antagonists to muscles that extend it.
Aponeuroses:	broad fibrous sheets of connective tissue.
Atrophy:	wasting away of tissue; decrease in size of a part; sometimes referred to as disuse atrophy.
Bursa:	saclike, fluid-filled structure, lined with synovial membrane, near a joint.
Hypertrophy:	increase in size, structure, or function.
Isometric:	type of muscle contraction in which muscle does not shorten.
Isotonic:	of the same tension or pressure.
Sacromere:	contractile unit of muscle; length of a myofibril between two Z bands.
Synergist:	muscle that assist the prime mover.
Tenosynovitis:	inflammation of the tendon sheath.
Three types of muscle tissue:	-Skeletal-Cardiac-Smooth
Skeletal Muscle	Striated / Voluntary
40-50% of body weight is____muscle.	Skeletal Muscle
Contractions can be voluntary with this type of muscle.	Skeletal Muscle
When looking at skeletal muscle under a microscope you will see....	Microscope reveals crosswise stripes or striations
Cardiac Muscle	Bulk of the Heart, Unique dark bands called intercalated disks, Allows heart to contract as a unit.
Smooth Muscle	Movement is involuntary, Found in walls of hollow visceral structures, Lacks cross-stripes or striations under microscope.
Origin:	attachment to the bone that remains relatively stationary.
Insertion	point of attachment to the bone that moves when a muscle contracts.
Body:	main part of the muscle.
Muscles attach to the bone by	tendons (fascia).
Sacromere:	separated from each other by dark bands called Z-lines.
Functions of the Skeletal Muscle	Movement. (Opposing muscles)Posture or muscle tone.Heat Production.
Groups of muscles usually contract to produce	a single movement
Prime mover:	muscle whose contraction is mainly responsible for producing a given movement.
Synergist:	muscle whose contractions help the prime mover produce a given movement.
Antagonist:	muscle whose actions oppose the action of a prime mover in any given movement.
Enables us to maintain body position	Specialized muscle contractions called tonic contractions.
Tonic contraction	Only a few of a muscle’s fibers shorten at one time, Produce no movement of body parts.
Good posture reduces strain on	muscles, tendons, ligaments, and bones.
Poor posture causes	fatigue and may lead to deformity.
Fever:	an elevated body temperature (often a sign of illness).
Hypothermia:	a reduced body temperature.
Contraction of muscle fibers produces most of the _____ required to maintain normal body temperature.	heat
If muscle cells are stimulated repeatedly without adequate periods of rest	the strength of the muscle contraction decreases, resulting in fatigue.
Contraction in the absence of adequate oxygen produces...	lactic acid, which contributes to muscle soreness.
Oxygen debt:	term used to describe the metabolic effort required to burn excess lactic acid that may accumulate during prolonged periods of exercise; the body is attempting to return the cells’ energy and oxygen reserves to pre-exercise levels.
Motor neuron	the specialized nerve that transmits an impulse to a muscle, causing contraction.
Neuromuscular junction	is the specialized point of contact between a nerve ending and the muscle fiber it innervates.
Acetylcholine	Specialized chemicals are released by the motor neuron in response to a nervous impulse.
Threshold Stimulus	the minimal level of stimulation required to cause a muscle fiber to contract.
Twitch:	contractions are laboratory phenomena and do not play a significant role in normal muscular activity; they are a single contraction of muscle fibers caused by a single threshold stimulus.
Tetanic:	contractions are sustained and steady muscular contractions caused by a series of stimuli bombarding a muscle in rapid succession.
Isotonic:	contraction of a muscle that produces movement of a joint.
Isometric:	contractions that do not produce movement, muscles as a whole does not shorten.
Facial muscles:	lie beneath the skin of the face and scalp and used to communicate feelings through facial expression.
Mastication	closes mouth and produce chewing movements.
Sternocleidomastoid	flexes head
Trapezius	elevates shoulder and extends head
Pectoralis Major	flexes the upper arm
Latissimus Dorsi	extends the upper arm
Deltoid	abducts the upper arm
Biceps brachii	flexes the forearm
Triceps brachii	extends the forearm
Abdominal Muscles	External obliqueInternal obliqueTransversus abdominisRectus abdominis
Respiratory Muscles two types are:	IntercostalDiaphragm
Hamstring muscles	SemimembranosusSemitendinosus*Biceps femoris
Quadricepts femoris group	Rectus femorisVastus lateralisVastus medialisVastus intermedius
Flexion:	movement that decreases the angle between two bones at their joint: bending.
Extension:	movement that increases the angle between two bones at their joint: straightening.
Aponeuroses	Connective tissue in a muscle that forms broad fibrous sheets.
Fascicles	Bundles of skeltal muscle fibers.
myo-	(muscle)
calat-	(something inserted)
erg-	(work) ex: synergist
Laten-	(hidden)
sarco-	(flesh)
tetan-	(stiff)
troph-	(well fed)
I Bands	(light bands) composed of thin actin filaments.
Threshold Stimulus	Minimal strength required to cause a contraction.
Muscle Tone	a response to nerve impulses that originate repeatedly from the spinal cord and stimulate a few muscle fibers.
Peristalsis	wavelike motion that occurs in certain tubular organs, such as the intestines, and helps force the contents of these organs along their lengths.
Where are smooth muscles found?	Walls of hollow viscera, peristalsis, and vasoconstriction.