Anatomy 2.1 Muscular Flashcards
Skeletal striated muscle
Voluntary somatic muscle that makes up the gross skeletal muscles that compose the muscular system (eyeballs)
Cardiac striated muscle
Involuntary visceral muscle that forms most of the walls of the heart and adjacent parts of the great vessels (aorta)
Smooth muscle
Involuntary visceral muscle that forms part of the walls of most vessels and hollow organs (peristaltic contractions)
(Unstriated)
Pennate muscles
Parallel fibers often with an aponeurosis
Aponeuroses
When tendons of a muscle form flat sheets
Fusiform muscles
Spindle shaped with a round thick belly and tapered ends
Convergent muscles
Arise from a broad area and converge to form a single tendon
Circular muscles
Surround a body opening, constricting it when contracted
Digastric muscles
Have two bellies
What do tonic contractions provide?
The muscle with a certain firmness, assisting the stability of joints and maintenance of posture (keeping muscle ready to respond to stimuli)
What are the two types of Phasic contractions?
Isotonic contractions
Isometric contractions
Isotonic contraction
Muscles changes length in relationship to the production of movement
Isometric contraction
Muscle length remains the same (resist movement)
What are the two types of isotonic contraction?
Concentric
Eccentric
Concentric contraction
Muscle shortening (create movement)
Eccentric contraction
Muscle lengthening (control movement)
Prime mover
Main muscle responsible for producing a movement of the body
Fixator
Steadies the proximal parts of a limb through isometric contraction while movements are occurring in distal parts
Synergist
Complements the action of the prime mover
Antagonist
Muscle that opposes the action of another muscle
Motor unit
Consist of a motor neuron and the muscle fibers it controls
What does muscle testing help do?
Diagnose nerve injuries
What are the methods of muscle testing?
Person performs movements that resist those of the examiner
Examiner performs movements that resist those of the person
Electromyography (EMG)
Absence of muscle tone
An antagonist muscle may cause a limb to assume an abnormal resting position
What type of workout causes most muscle soreness?
Eccentric (more likely to produce microtears or periosteal irritation)
What happens when there is a pulled muscle?
When a muscle elongates more than 1/3 of its resting position
How are new skeletal muscles formed?
Through satellite cells (fuse with each other to form new skeletal muscle fibers)
What happens to the muscle after traumatic injury?
It is composed of a disorganized mixture of muscle fibers and fibrous scar tissue
When does hypertrophy of the myocardium occur?
When cardiac striated muscles are damaged (myocardium gets bigger to help supply heart with more blood)
Endomysium
Surrounds muscle fibers
Perimysium
Surrounds muscle fascicles
Epimysium
Surrounds whole muscle
What are examples of impairments?
Fracture, tear, severed nerve
What are examples of activity limitations?
Activities of daily living (self care)
What are examples of participation restrictions?
Stuff you do outside of home (weight lifting)
Single joint muscles
Only crossing one joint
Multi joint muscles
Crossing two joints
Active insufficiency
Multi joint muscle shortens over both joints simultaneously and creates so much slack that muscle tension is lost
Passive insufficiency
Multi joint muscle is lengthened to its fullest extent at both joints so it cannot stretch any further
What is the role of connective tissue layers in muscle function?
Limits lateral expansion of muscles during contraction
What does moving joints closer together create?
More slack
What does moving joints further apart create?
More tension
Gross screening
Typically isometric
General appraisal of muscle strength
Manual muscle testing
Typically isometric
Appraisal of strength of specific muscle
Reflexive contraction
Automatic involuntary contractions
