Week 3: Muscles Flashcards
How many muscles are there?
> 650
What are the roles of the muscular system?
Strength, survival, function, stability, endurance, movement, blood flow, bodily function, fight or flight
What is the compostion of a muscle?
7% salts, 23% protein and 70% water
What are the 3 body compostions?
Ectomorph, mesomorph and endomorph
What are the 3 types of muscle?
Cardiac, smooth and skeletal (striated)
Where is cardiac muscle found?
In the heart
Where is smooth muscle found?
Digestive system
Which two types of muscle are involuntary?
Cardiac and smooth
Where do muscles attach?
Bony landmarks
How do muscles attach to the bony landmarks?
Via tendons
Where does the muscle have to attach to make the joint move?
Above and below the joint line
What is the origin?
Fixed end, usually proximal to attachment, usually closest to midline
What is the insertion?
Moving end, usually distal attachment, usually furthest from midline
What is a uni axial muscle?
Muscles that only cross one joint
What is a bi axial muscle?
Muscles that cross more than one joint
What is an agonist/prime mover?
Muscle responsible for producing the desired movement
What is an antagonist?
The opposing muscle to the agonist wgich has the power to control and stop movement when innervated
What is a synergist?
Othe muscles that assist the agonist
What is the fixator/stabilser?
Muscles that aid joint stability to allow the agonist to work
What does it mean if there are a lot of motor units activated?
Higher force produced
What are the two types of muscle fibres?
Slow and fast twitch
What are the three types of fast twitch fibres?
Type IIa, IIb (fast oxidative glycoly) and IIc
What are the two types of isotonic muscle actions?
Concentric and eccentric
Define Concentric muscle action
Muscle shortens during contraction
Define eccentric muscle action
Muscle lengths during contractions
Define static contraction (isometric)
Muscle stays the same length under contraction
Define isokinetic muscle action
Muscle changes length at a constant speed
Define hypotrophy
An increase in size of skeletal muscle
Define atrophy
A wasting away of skeletal muscle
Define hyperplasia
The enlargement of an organ
Define strength
The ability of a muscle to tolerate load
Define endurance
The ability of a muscle to tolerate load over a period of time
What are the catagories of skeletal muscle?
Fusiform, parallel, pennate, orbicular and convergent
Define fusiform muscles
Central muscle belly which converges into a tendon at one or both ends. Can be one, two or three headed muscle
Define parallel muscle
Formed by muscle fibres which lie parallel to each other, usually flat and straight or strap like
Define pennate muscles
Muscle fibres attached obliquely to a central tendon, resembles a leaf or feather, increases explosive capacity, can be uni pennate, bi pennate or multi pennate
Define orbicular muscle
A sphincter like sheet of muscle that encircles an orifice, results in a narrowing of an orifice
Define convergent muscle
Triangular muscle that emient from a large area and converge onto one attachment
