Skeletal muscle gross anatomy I Flashcards
origin vs insertion of muscle
origin: end attached to more stationary bone
insertion: end attached to bone with greatest movement
very broad tendon
aponeurosis
muscles that work together to cause a movement
SYNERGISTS
- PRIME MOVERS: major role in accomplishing movement
- FIXATORS: stabilize joints crossed by prime mover
belly of the muscle
largest portion of muscle between origin and insertion
In general, characteristics of muscles that cause flexion/extension/lrotation in neck
Flexion
- deep
- attached to anterior side of vertebral bodies
Extension
- posterior
- attached to occipital bone and mastoid process
Rotation/Lateral flexion
- lateral and posterior groups
prime movers in neck
- STERNOCLEOMASTOID (lateral/anterior, forward flexion, rotate)
- TRAPEZIUS (posterior, extension, lateral flexion)
types muscles that move vertebral column
Deep group
- vertebrae to vertebrae
Superficial Group
- vertebrae to ribs
prime movers of back extension
ERECTOR SPINAE
3 subgroups
- SPINALIS (medial)
- LONGISSIMUS (intermediate)
- ILIOCOSTALIS (lateral)
4 groups of thoracic muscles
SCALENES: 3 muscles that elevate first two ribs during inhalation
EXTERNAL INTERCOSTALS: elevate the ribs
INTERNAL INTERCOSTALS: depress ribs during expiration
TRANSVERSUS THORACIS: depress ribs during expiration (originate on sternum, insert on costal cartilages)
DIAPHRAGM:
which thoracic muscles depress the ribs
internal intercostals
transversus thoracis
which thoracic muscles elevate the ribs
external intercostals
scalenes
centre line of connective tissue on abdomen
linea alba
muscles of abdomen (superficial to deep) and their movements
all muscles compress
- external oblique: flexion, rotation, compression
- internal oblique: flexion, rotation
- transversus: compression
- rectus abdominis: flexion
muscles involved in scapular movement
- trapezius (elevate, depress, rotate, retract)
- levator scapulae (elevate, rotate)
rhomboideus (elevate, retract) - serratus anterior (hold scapula in place on rib cage, protract, rotate)
- pectoralis minor (depress)
another word for muscle origin
head
aponeurosis
very broad tendon
agonist vs antagonist muscle
agonist: muscle that, when contracted, causes an action
antagonist: muscle working in opposition to agonist
muscles are named based on…
location
size (maximus, minimus)
shape (deltiod)
action/function
orientation of fibres (rectus, transverse, oblique)
origin and insertion
number of heads (biceps, triceps)
sternocleidomastoid origin, insertion, classification, function
Origins:
- clavicular head (clavicle)
- sternal head (manubrium of sternum)
Insertion: mastoid process
Classification: lateral neck muscle
Function: neck flexion
trapezius origin, insertion, classification, function
Origin: broadly along vertibrae
Insertions
- spine of scapula
- clavicle, comes over shoulder
classification: posterior neck muscle
Function: extension and lateral flexion of neck, elevate/depress/rotate scapula
How do muscle fibres run in external and internal intercostals?
EXTERNAL
- “hands in your pockets” direction
- Tilt rib below up and out to help create room for inspiration
INTERNAL
- perpendicular to external intercostals
- move ribs downa dn in
muscles involved in scapular movement
- trapezius (elevate, depress, rotate)
- levator scapulae
- rhomboideus (retract, elevate)
- serratus anterior (protraction, rotation)
- pectoralis minor (depress)
levator scapulae origin, insertion, function
origin: cervical vertebrae
insertion: top portion of scapula
rhomboideus origin, insertion, function
rhomboid major (inferior) and minor (superior)
Origin: thoracic vertebrae
Insertion: medial border of scapula
Function: retract scapula
