Muscles Flashcards
What are the 4 functions of muscles?
Production of movement
Production of heat
Maintenance of posture
Stabilization of joints
If muscles cross a _______, it can create ___________.
Joint; movement
What are the 4 characteristics of muscle?
Contractility
Excitability
Extensibility
Elasticity
Contractility
Muscle can produce force (concentric, isometric, and eccentric contractions)
Excitability
Muscles are stimulated by nerves
Extensibility
Muscles can be shortened and lengthened
Elasticity
When stretched, can be returned to original length
What are the 3 types of muscle
Smooth
Cardiac
Skeletal
Origin of a muscle is __________ and usually has higher/greater _______.
Proximal; inertia
Insertion is _________ and has ______ inertia, thus more likely to ________.
Distal; less; move
Uniarticular
Muscle crosses only 1 joint
(Ex. Vasti muscles, brachialis)
Biarticular
Muscle crosses 2 joints
(Ex. Rectus femoris, hamstrings)
Multiarticular
Muscle crosses multiple joints
(Muscles of the hands, feet and spine)
Muscle structures: Biceps
2 heads
Muscle structures: triceps
3 heads
Muscle structures: quadriceps
4 heads
Muscle structures: Digastric
2 bellies
Muscle structure: Multigastric
Many bellies
Muscle structure: Radial
Sphincters
What are the 3 types of tendon structures?
Cord
Fleshy
Aponeurotic
What is the most common type of tendon structure
Cord
What are the 2 types of muscle fiber orientation?
Longitudinal (fusiform) orientation
Pennated orientation
What are the 3 types of pennated orientation of muscle fibers?
Unipennate
Biden ate
Multipennate
Which muscle fiber orientation is beneficial for large excursions, fast velocities?
Longitudinal (fusiform) orientation
In longitudinal orientation, shorting of _________ = shortening of _________
Fibers; muscle
Which muscle fiber orientation has more fibers packed into a given area?
Pennated orientation
Pennated orientation of muscle fibers if beneficial for ________
Force!
What are the 4 functions of CT coverings?
Strength
Allow sliding of muscle fibers without friction
Attach muscle fiber to tendon
Wall of infection or tissue damage/injury
What are the 3 CT coverings within muscle from deep to superficial
Endomysium (covers muscle fiber)
Perimysium (covers fascicle)
Epimysium (covers muscle)
Draw the muscle CT coverings
Myofibril
Muscle fiber
Fascicle
Muscle
Myotendinous junction
Junction between the muscle and the tendon
Bursae
Fibrous sacs, lined with synovial membrane and containing synovial fluid
Bursae function (2)
Reduce frictional stress: lubrication
Increased contact area (Stress = force/area)
