17 Muscles For Class Flashcards
Functional Groups
- Prime Movers
Provide the major force for producing a specific movement
- Antagonists
Oppose or reverse a particular movement
- Synergists - help the prime mover
add force to movement
reduce undesirable or unnecessary movement
- Fixator
Synergists that immobilize a bone or muscle’s origin
Naming Skeletal Muscles
- Location
- Shape
- Relative size
- Direction of fibers or fascicles
- Number of origins
- Location of attachments
- Action
Muscles of the posterior view
2 Groups of Muscles in the Head
- Muscles of facial expression
- Muscles of mastication and tongue movement
Muscles of Facial Expression
Where are they inserted?
Why are they important?
How are they innervated?
Insert into the skin
Important in nonverbal communication
All innervated by cranial nerve VII (facial nerve)
What is Epicranius (occipitofontalis)?
Bipartite muscle consisting of
frontalis
occiptalis
galea aponeurotica - cranial aponeurosis connecting above muscles
The two muscles have alternate actions of pulling the scalp forward and backward
What is the frontalis?
Where does it orginate and insert?
What does it do?
- Covers forehead, no boney attachments
Origin-cranial aponeurosis
Insertion - skin of eyebrows, root of nose
Action: raises eyebrows
Orbicularis oris
Where is it?
Origin and insertion?
Action?
Encircles the mouth
Origin-maxilla and mandible
Insertion - muscles and skin at the angles of the mouth
Action - closes mouth, purses, and protrudes the lips
Kissing and whistling muscle
Buccinator
Where is the origin?
Where is the insertion?
What does it do?
Origin - molar region of maxilla and mandible
Insertion - orbicularis oris
Action - hold food between teeth when chewing, compresses cheeks as in whistling
Muscles of Mastication and Tongue Movement
Which two go together?
Name all 4
Four pairs involved in mastication
Prime movers of closure
Temporalis and masseter
Grinding movements
Medial and lateral pterygoids
Masseter
Origin, insertion, action
Origin - zygomatic arch and maxilla
Insertion - mandible
Action - elevates the mandible
Sternocleidomastoid
Origin, insertion, action
Origin - sternum and clavicle
Insertion - mastoid process of temporal bone
Action - major head flexion
What are the Deltoids?
Origin, insertion, action
Rounded top of shoulder, commonly used for injections
Origin - clavicle and scapula
Insertion - deltoid tuberosity of humerus
Action
prime mover of arm abduction (if all fibers contract)
flexion and medial rotation of humerus (if anterior portion is active)
extension and lateral rotation of humerous (if posterior fibers only active)
Biceps Brachi
Origin, insertion, action
Origin - scapula 2 locations short head coracoid process, long head glenoid tubercle of scapula
Insertion - into radial tuberosity
Action: flexes elbow, supinates forearm
Triceps Brachii
Origin, insertion, action
Large fleshy muscle, only muscle of posterior arm, 3 heads so 3 origins
Origin - scapula and 2 locations on posterior shaft of humerus
Insertion - olecranon process of ulna
Action: prime mover of forearm extension
Pectoralis Major
Origin, insertion, action
Fan shaped muscle covering anterior chest
Origin - clavicle, sternum cartilage of ribs 1 - 6
Insertion - humerus
Action - prime mover of arm flexion, rotates arm medially, aducts arm against resistance
Muscles of the Thorax
What do they do?
Where are they
Muscles of respiration
External intercostals - more superficial muscles that elevate ribs for inspiration
Internal intercostals - deeper muscles that aid forced expiration
Diaphragm
Partition between thoracic and abdominal cavities
Most important muscle in inspiration
Innervated by phrenic nerves
External intercostals
Origin, insertion, action
11 pairs of these muscles lie between the ribs
Origin - inferior border of the rib above
Insertion - superior border of rib below
Action - elevates rib cage by pulling each rib toward each other aids the diaphragm in inspiration
Muscles of the abdominal wall
Internal obliques
External obliques
Transversus abdominis
Rectus abdominis
Rectus abdominus
Purpose, origin, insertion, action
Covers the abdomen - six pack muscle
Origin - pubic crest and symphysis
Insertion - xiphoid process of sternum and costal cartilage of ribs 5 - 7
Action - flexes and rotates lumbar region of vertebral column, compresses abdomen, stabilizes the pelvis during walking
External Obliquies
Most superficial of the lateral abdominal muscles, run the directions of your fingers if you were placing your hands in your pockets
Origin - lower 8 ribs
insertion - iliac crest and linea alba
Action - flex verebral column and compress abdomen
Superficial Muscles of the Posterior Thorax
Trapezius
Levator scapulae
Rhomoids (major and minor)
Latissimus dorsi
Trapezius
Posterior trunk, triangular
Origin - occipital bone, spinous process of cervical vertebrae 7 and all thoracic vertebrae
Insertion - clavicle and scapula
Action - stabilizes, raises, rotates, and retracts the scapula (shrugs shoulders)
Latissimus Dorsi
Muscle of lower back
Origin - iliac crest, T7 sacrum, lower 8-12 ribs
Insertion - humerus
Action - prime mover of arm extension, adduction and medial rotation
Muscles Crossing Hip and Knee Joint
Most anterior muscles flex the femur at the hip and extend the leg at the knee (foreswing of walking)
Most Posterior muscles extend the thigh and flex the leg (backswing of walking)
Medial muscles all adduct the thigh
All three groups are enclosed by the facia lata
Gluteus Maximus
Buttocks
Origin - illium, sacum, and coccyx
Insertion - femur
Action - major extensor of the thigh, laterally rotates and abducts the thigh
Rectus Femoris
Anterior thigh, rectus - straight
One of the 4 quadricepts muscle group
Only one to cross the hip joint
Origin - illium and acetabulum
Insertion - patella and tibial tuberosity
Action - extends the knee and flexes the hip
Gastrocnemus
Posterior calf, part of the triceps surae group which includes the soleus muscle, come together to form the achilles tendon, largees tendon in the body
Origin - femur - 2 heads from medial and lateral condyles
Insertion - calcaneus
Action - plantar flexes the foot when knee extended and flexes knee when foot is dorsiflexed
Which muscles make the achilles tendon?
Triceps surae group
Gastrocnemius
Soleus
1 more?
