L04 - Muscle and movement Flashcards
What are the different classifications of striated muscle ?
- Flat muscles
- Pennate muscles
- Fusiform muscles
- Convergent muscles
- Quadrate muscles
- Circular muscles
- Multiheaded/ Multibellied muscles
On what basis are striated muscles classified?
Depends on the direction of their fibres and their shape
Appearance of flat muscles?
Parallel fibres often with an aponeurosis
Example of a flat muscle
External oblique (broad flat muscle) - The sartorius (narrow flat muscle with parallel fibres)
Appearance of pennate muscles?
Feather-like in the arrangement of their fasicles
- May be unipennate, bipennate or multipennate
Example of unipennate muscle?
Extensor digitorum longus (wrist and finger extensor)
Example of bipennate muscle?
Rectus femoris
Example of multipennate muscle?
Deltoid
Appearance of fusiform muscles?
Spindle-shaped with a roung, thick belly (or bellies) and tapered ends
Example of fusiform muscle?
Biceps brachii
Appearance of convergent muscles?
Arises from a broad area and converge to form a single tendon
Example of a convergent muscle?
Pectoralis major
Appearance of quadrate muscles?
Has four equal sides
Example of quadrate muscle?
Rectus abdominis between its tendinous intersections
Appearance of circular (sphincteral) muscles?
Surrounds a body opening or orifice, constricting it when contracted
Example of circular muscle?
Orbicularis oculi (closes eyelids)
Appearance of mult-headed muscle
Has more than one head of attachment or more than one contractile belly
Example of multiheaded muscles?
- Biceps muscles have two heads of attachment (biceps brachii)
- Triceps muscles have three heads of attachment (triceps brachii)
What are the different functions of muscles?
- Prime mover (agonist)
- Fixator
- Synergist
- Antagonist
Function of prime mover muscle?
- Main muscle responsible for producing a specific movement of the body
- Contracts concentrically to produce the desired movement
