Muscles & Tendons Flashcards
What are the types of muscles
- Skeletal muscle
- smooth muscles
- cardiac muscles
skeletal muscles
produces joint movement and support
smooth muscles
organs and blood vessels
cardiac muscles
heart muscles
what is the structure of muscles
muscle belly>bundle of muscle fiber (fasciculus)>single muscle fiber>myofibrils>sarcomere
what structure provides movement for myofibrils and how do they move
the sarcomere (shorten and lengthen themselves)
fascia
connective tissue that surrounds organs, muscles, bones, vessels, and nerves within the body (will change shape depending on the placement of the tissue)
can respond to stress
whats the role of fascia
to support, separate, reduce friction between, and interconnect structures of the body
what does the fascia form
forms intermuscular septa (muscle separators) that compartmentalize muscles and support nerves
tendons
connect between muscles and bones
- muscles have a tendon at each end
ligaments
connect between bones
true or false:
the fascia of tendons do not blend into the tendon structure
false
the fascia of tendons do blend into the tendon structure
true or false:
the tissues of the tendon do not interweave with the fiber of the bone
false
the tissues of the tendon do interweave with the fibers of the bone
true or false:
the ligament fibers interweave into bone fibers at either end
true
origin
- where a muscle’s tendon joins a relatively stable skeletal structure
- usually is the proximal or the closest to the midline
insertion
- the point where the distal muscle tendon attaches to the moving bone
- opposite to the origin
what’s the function of the muscle
when the muscle moves its insertion towards its origin
concentric
muscle shortening causes joint movement
eccentric
muscle lengthens while still developing tension
isometric
muscle length does not change but keeping tension through the muscle
which is concentric, eccentric, and isometric in a squat
joint action
the movement that occurs at the joint itself
(flexion/extension)
muscle action
the muscle contraction that is occurring
(concentric, eccentric, isometric)
agonist muscles
the main muscle in the movement
antagonist muscle
the muscle that opposes the movement
synergist muscle
helps apply the movement by creating a supplemental force
fixator muscle
the muscles that help stabilize the body in a movement
- minimizes any extra movement
how can muscles be differentiated
by their fiber orientation and shape
what can determine the muscles function
placement of origin and insertion
fascicles
a bundle of muscle fibers
what are the muscle shapes
- parallel
- pennate
- convergent
- circular
how to determine a parallel muscle
fascicles run parallel to one another
what the types of parallel muscles
- parallel non-fusiform (strap muscles)
- parallel fusiform
parallel non-fusiform
muscles that have a consistent diameter throughout
parallel fusiform
muscles mid belly has the largest diameter the tapers at both ends
how to determine pennate muscles
the tendon runs the length of the muscle and fascicles pull on the tendon at varying angles
unipennate
all fascicles are on the same side of the tendon
bipennate
fascicles lie on either side of the tendon
multipennate
if the central tendon splits/more than one central tendon with pennation. (multiple muscles)
can parallel or pennate muscles undergo quicker muscle contractions, and why
- parallel muscles can undergo quicker muscle contractions than pennate muscles
- because parallel muscles pull longer along the axis of the muscle, while pennate pulls at an angle
can parallel or pennate muscles generate greater force, and why
- pennate muscles can generate greater force than parallel muscles
- because they have a greater number of fascicles per unit area
how to determine convergent muscles
they are triangular-shaped muscles with a common point of attachment
(not all fascicles run parallel to each other)
how to determine circular muscles
fascicles are orientated concentrically around an opening. Muscle contraction shrinks the opening while relaxing widens it
state the following for the biceps brachii (two heads):
- origin
- insertion
- function
origin:
- long head: superior glenoid
- short head: coracoid process (scapula)
insertion:
- anterior, proximal radius
function: elbow flexion
state the following for the triceps brachii (three heads):
- origin
- insertion
- function
origin:
- long head: inferior glenoid
- medial head: posteromedial humerus
- lateral head: posterolateral humerus
insertion:
- olecranon
function: elbow extension
state the following for the tibialis anterior:
- origin
- insertion
- function
origin:
- anterolateral tibial surface
insertion:
- dorsal surface of foot
function: dorsiflexion
state the following for the gastrocnemius (two heads):
- origin
- insertion
- function
origin:
- medial head: posteromedial femoral condyle
- lateral head: posterolateral femoral condyle
insertion:
- posterior calcaneus
function: plantar flexion
