Muscular system part 2 (1-44) Flashcards
smooth muscle characteristics
- no striations
- spindle-shaped
- uninucleated
- involuntary
smooth muscles are found mainly in the walls of hollow visceral organs of
- respiratory
- digestive
- urinary
- reproductive systems
- blood vessels
- and iris and dermis of skin
the smooth muscle propel substances along a definite pathway which is known as
peristalsis
what is peristalsis
the wave like movement that propels the food down the esophagus, intestine and ureters
cardiac muscle characteristics
- striated
- uninucleated
- involuntary
- branched
- intercalated discs
cardiac fibers are branched cells joined by special junctions called
intercalated discs to form a syncytium
cardiac fibers are arranged in
spirals or figure 8-shaped bundles
what are the 3 parts of the skeletal muscle
- origin
- body/belly
- insertion
skeletal muscles are attached to at least two points known as
- origin
- insertion
what is an origin
attachment of the muscle to an immovable or less movable part of the bone
what is an insertion
attachment of the muscle to a moveable part of the bone
some muscles have more than one origin or insertion. How many origins does a bicep brachii have
two origins
what is flexion
- decreases the angle of the joint
- brings bones closer together
what are flexors
group of muscles which cause flexion
what is extension
- increases angle between two bones
- straightening the elbow or knee
what are extensors
group of muscles which cause extension
for a particular body movement to occur a person must do
more than contracting a single muscle
what is agonist or prime mover
a muscle with the major responsibility for a certain movement
what is synergist
a muscle that contracts and assists the prime mover in a movement
what is antagonist
muscle that opposes or reverses the prime mover
- these muscles resist a prime mover’s action and cause movement in the opposite direction
what is rotation
movement of a bone around its longitudinal axis
- move your head from shoulder to shoulder (180 degrees)
what is circumduction
combination of flexion, extension, abduction, and adduction
- shoulder joint at 360 degrees
what is abduction
movement of a limb away from the midline
what is adduction
movement of a limb towards the midline
what is dorsiflexion
lifting the foot so that the superior surface approaches the shin of the tibia
what is plantar flexion
moving the foot toward the sole
what is inversion
turn the sole of the foot medially
what is eversion
turn the sole of the foot laterally
what is supination
rotate the forearm laterally so that the palm is facing upwards
what is pronation
rotate the forearm medially so that the palm is facing downwards
- radius and ulna cross each other like an x
what is opposition
move thumb to touch the tips of other fingers on the same hand
what are the combinations of name convention
- direction of muscle fibers
- relative size of muscle
- location of muscle
- number of origins
- location of origin and insertion
- shape of the muscle
- action of the muscle
what are the muscles of facial expression
- frontalis muscle
- orbicularis oculi
- orbicularis oris
- buccinator
- zygomaticus
- platysma
Frontalis function
- raises eyebrows
orbicularis oculi function
-closes eye, squints, blinks, and winks
orbicularis oris function,
- closes mouth and protrudes lips
buccinator function
- compresses cheeks inward
zygomaticus function
- raises corner of mouth
platysma function
- depress jaw and lower lip to turn the mouth downwards
what are the muscles of mastication
- Masseter
- Temporalis
- Buccinator
masseter function
- closes jaw, and elevates mandible
temporalis function
- closes jaw
buccinator function mastication
- draws corner of mouth laterally
muscles that move the head
- sternocleidomastoid
- trapezius
sternocleidomastoid function
- flexes head and rotates head
trapezius function neck
- extends and adducts scapula
muscles of swallowing
- stylohyoid
- sternohyoid
stylohyoid function
- elevate and retract hyoid bone
- styloid process of temporal bone
sternohyoid function
- depresses the larynx and hyoid bone if mandible is held stationary
what are the muscles of the trunk
- serratus anterior
- deltoid
- pectoralis major
- trapezius
- latissimus dorsi
serratus anterior function
- depresses scapula and pulls it forward
deltoid function
- abducts arm to horizontal
pectoralis major function
- flexes and adducts arm
trapezius function
- extends the head, rotates and adducts scapula, elevates or depresses the scapula
latissimus dorsi function
- extends, adducts, and medially rotates the shoulder
rotator cuff muscles
- supraspinatus
- infraspinatus
- teres minor
- subsacpularis
supraspinatus function
abduction at the shoulder
infraspinatus function
lateral rotation at the shoulder
teres minor function
lateral rotation and adduction at the shoulder
subscapularis function
medial rotation at the shoulder
trunk muscles moving the vertebral column
- Erector spinae (Iliocostalis, longissimus, spinalis)
function of the erector spinae
extends and laterally rotates the vertebral column; extends neck
muscles of respiration
- external intercostals (second to main muscle)
- internal intercostals
- diaphragm
external intercostals function
elevate rib cage for inspiration
internal intercostals function
depress rib cage for forced expiration
diaphragm function
main muscle of respiration
muscles of the abdominal wall
- external oblique
- internal oblique
- transverse abdominus
- rectus abdominus
external oblique function
flexes vertebral column; rotates trunk and bends it laterally
internal oblique function
flexes vertebral column; rotates trunk and bends it laterally
transverse abdominus function
tenses abdominal wall
rectus abdominus function
flexes and rotates the vertebral column, and bends it laterally; compresses abdominal contents (defecation, childbirth, forced breathing)
