Muscular System Part 2 Flashcards
the attachment of
muscle tendon to a
stationary bone
origin
attachment of muscle
tendon to a movable
bone
insertion
a rigid structure that moves around a fixed point
fulcrum
lever (fulcrum)
causes movement
effort
- opposes movement
Load (resistance)
when does Motion occurs
when effort exceeds the load
acts as lever during movement
bone
acts as fulcrum during movement
joints
acts as effort during movement
muscle contraction
acts as load during movement
Weight of body part moved or resistance of
body part
the load is closer to the fulcrum and the effort
farther from the fulcrum
mechanical advantage
The load is father from the fulcrum and the
effort is closer to the fulcrum
mechanical disadvantage
The fulcrum is between the effort and the load
first class lever (f)
The load is between the fulcrum and the effort
second class lever (l)
The effort is between the fulcrum and the load
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third class lever (e)
most common lever in the body
third class lever (e)
uncommon lever in the body
second class lever (l)
Affects muscle’s power and range of motion
fascicle arrangement
The longer the muscle fibers, the
greater the range of motion
parallel muscles
The greater the total cross-sectional
area of a muscle, the greater power it
produce
pennate muscles
Fascicles parallel to
longitudinal axis of
muscles
parallel
Fascicles nearly parallel
to longitudinal axis of
muscles
fusiform
Fascicles in concentric circular arrangements form sphincter muscles that enclose an orifice (opening).
circular
Fascicles spread over
broad area converge at
thick central tendon
triangular
Fascicles arranged on
only one side of the
tendon
unipennate
Fascicles arranged on
both sides of centrally
positioned tendons
bipennate
Fascicles attach
obliquely from many
directions to several
tendons
multipennate
Contracts to cause the action
prime mover (agonist)
Stretches and yields to the effect of prime
mover (relaxes)
antagonist
Usually needed when a prime mover crosses
other joints before it reaches the primary joint
where action is produced
synergist
Stabilizes the origin of the of the prime mover
fixator
A group of skeletal muscles with their associated vessels (artery and vein), and nerves, all of which have common function
compartment
where does the muscles of facial expression lie?
Lies within the subcutaneous layer
what muscles is responsible for Look of surprise
Occipitofrontalis
what muscles is responsible for Closes lips (kissing)
Orbicularis oris
Draws angle of mouth superiorly and laterally (smiling
Zygomaticus major
Elevates upper lip, exposing upper
tee
Zygomaticus minor
Raises upper lip
Levator labii superioris
Depresses lower lip
Depressor labii inferioris
Presses cheeks against teeth and
lips (whistling, blowing, sucking
Buccinator
Closes eye (wink)
Orbicularis oculi
Draws eyebrows inferiorly, wrinkles the forehead (frowning)
Corrugator supercilii
Draws the angle of the mouth
laterally (Grimace)
risorius
Unilateral paralysis of
the muscles of facial
expression
BELL’S PALSY
Are muscles that move the eyeball
EXTRINSIC EYE MUSCLES
A condition where two eyeballs are not properly
aligned
STRABISMUS
The eyes are in LATERAL position at rest
External strabismus (EXOTROPIA)
The eyes are in MEDIAL position at rest
Internal strabismus (ESOTROPIA)
- moves the
mandible from side to side
Pterygoid
what divides the muscles in the tongue into lateral halves?
median fibrous
septum
Originates outside the tongue and
inserts to the tongue
EXTRINSIC TONGUE MUSCLES
Originate and insert within the tongue
INTRINSIC TONGUE MUSCLES
what helps by inserting the tube through
the laryngopharynx to the trache
intubation
Elevates the hyoid bone, floor of the oral
cavity and tongue during deglutition
SUPRAHYOID MUSCLES
Depress the hyoid bone and move the
larynx during swallowing and speech
INFRAHYOID MUSCLES
An oblique passage through the lower part
of the anterior abdominal wall
INGUINAL CANAL
external oblique
aponeurosis and origin of internal
oblique
Anterior wall
conjoint tendon
(medially) and transversalis fascia
(laterally)
Posterior wall
lowest fibers of
internal oblique and transversus
abdominis
Superior wall (roof)
lower edge of
inguinal ligament and lacunar ligament
Inferior wall (floor)
protrusion of an organ through a
structure that normally contains it
HERNIA
thoracic cavity increases in size
inhalation
thoracic cavity decreases in size
exhalation
Main muscle of respiration
diaphragm
Allows passage of aorta, thoracic
duct, and azygos vein
aortic hiatus
Largest and most important muscle of
the pelvic floor
levator ani
The region of the trunk inferior to the pelvic
diaphragm
perineum
Happens during CHILDBIRTH that induces URINARY STRESS
INCONTINENCE
iNJURY TO LEVATOR ANI
connects your upper limbs to the bones
along the axis of your body
PECTORAL GIRDLE
Stabilizes the scapula so that it can
function as a steady origin for most of
the muscles that move the humerus
PECTORAL GIRDLE
Are tendons of certain muscles that circle
around the shoulder joint
ROTATOR CUFF
Strain or tear in the rotator cuff muscles
rotator cuff injury
skeletal muscles with their associated blood
vessels and nerves grouped together by a
fascia
compartments
Functions to provide support and locomotion
INTRINSIC MUSCLES OF THE FOOT
● Biceps femoris
● Semitendinosus
●Semimembranosus
These are collectively called?
HAMSTRING
the great extensor leg
Quadriceps
femoris
Stabilizes vertebral column and provides
proprioceptive feedback
SEGMENTAL MUSCLE GROUP
extends the
vertebral column and rotate the head
Semispinalis muscles
Produces weak but intricate and precise
movement of the hand
INTRINSIC MUSCLES OF THE HAND
lateral aspect of the palm
thenar
(medial aspect of the palm)
hypothenar
midpalmar
intermediate
Structures under the carpal tunnel (esp. Median
nerve) are vulnerable to compression
CARPAL TUNNEL
SYNDROME
Extends the head and laterally flex and
rotate the head
SPLENIUS MUSCLES
Largest muscle of the back
erector spinae
Flex, laterally flex, and rotate the head and Assist in deep inhalation
scalenes
