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Flashcards in Myscular System Deck (24):

What three things determine muscle tissue characteristics?

Whether it's voluntary verse in voluntary.
Whether it striated vs. smooth or unstriated.
Whether it's somatic vs. visceral.


What are the three muscle types?

Skeletal striated muscle.
Cardiac striated muscle.
Smooth muscle.


What are the differences between the three muscle types?

Skeletal striated muscle:
voluntary somatic muscle, makes exoskeletal muscles, move and stabilize bones and other structures.

Cardiac striated muscle: involuntary visceral muscle, forms most of the walls of the heart and adjacent parts of the great vessels, pumps blood.

Smooth muscle:
involuntary visceral muscle, forms part of the walls of most vessels and hollow organs (viscera), moves substances through using coordinated sequential contractions (peristalsis)


What portions of the contractile skeletal muscle are fleshy and reddish?

Heads or bellies


White noncontractile portions composed mainly of organized collagen that provide a means of attachment?



What is aponeurosis?

Flat sheet formed by some tendons that anchor the muscle to the skeleton and/or the fascia, May also anchor to the aponeurosis of another muscle.


What are the different classifications of muscles?

Flat, fusiform, pennate muscles, quadrate, circular or sphincteral, multi-headed or multi-bellied.


What are the different types of contraction of muscles?

Reflexive contraction, tonic contraction, phasic contraction.


What is an example of a reflex contraction?

Contraction of thoracic diaphragm is controlled reflexively by oxygen and carbon dioxide levels in blood. Can control this within limits.


Movement of a muscle after a stretch to tendon has been induced by tapping with the hammer?

Myotatic reflex


What is a tonic contraction and what are the causes of such a contraction? Or lack thereof?

Slight contraction present in muscles even when relaxed creating muscle tone.

Does not produce movement or active resistance.

Gives muscle a certain firmness to stabilize joints maintain posture.

Keeps muscles ready to respond.

Absent when a deep sleep, under anesthesia and after paralysis.


What are the two main types of phasic contraction?

Isometric and isotonic.


What is considered an isometric contraction? Give an example.

Muscle length remains the same or another words no movement occurs.
An example is maintaining upright posture.


Muscle changes length in relationship to production of this movement. What is this contraction type?

Isotonic contraction.


What are the two types of isotonic contractions? Briefly explain each one.

Concentric contraction is a movement that occurs as a result of muscle shortening.
Eccentric contraction is a lengthening of a contracting muscle. In this contraction a controlled and gradual relaxation occurs while continually exerting a diminishing force.


What are the different terms describing muscle function?

Prime mover or agonist, fixator, synergist, antagonist.


What does a prime mover do?

Main muscle responsible for producing a specific movement, contracts concentrically to produce movement, usually a single prime mover, under certain circumstances gravity maybe prime mover.


What is a fixator muscle do?

Steadies proximal parts of a limb.

It's an isometric contraction in other words no shortening lengthening occurs.


What does a synergist muscle do?

Complements actions of the prime mover which performs same movements as the prime mover and may act as a fixator of an intervening joint. This is a concentric contraction and usually has several synergist helping prim mover.


What does an antagonist muscle do?

It opposes action of another muscle.
It is an eccentric contraction relaxing progressively to produce a smooth movement.
A primary antagonist directly opposes the prime mover. Secondary antagonist opposes synergists.


In which plane does flexion and extension of a muscle occur and what is its axis?

Sagittal plane around a transverse axis.


What plane and axis does adduction and abduction occur in?

In the frontal plane and around and anteroposterior axis.


What classifies a circumduction action?

Any muscle performing all four movements such as sequential flexion, abduction, extension and adduction.


What is radial/ulnar deviation?

Terms used for abduction and adduction at the wrist.