Skeletal Muscle Groups

Skeletal Muscle Groups

Ready or not, here we go!

A. Muscles of Facial Expression

1. Frontalis A: elevates eyebrows O: occipital bone I: skin of eyebrow

2. Occipitalis A: pulls scalp posterior O: mastoid process of occipital bone I: galea aponeurotica

3. Orbicularis oculi A: closes eyelid O: frontal & maxillary bones I: skin around eyelid

4. Orbicularis oris A: closes lips

Kissing, speaking O: facia surrounding lips I: corners of mouth

5. Zygomaticus Major/Minor A: Retracts & elevates corners of mouth

smiling O: zygomatic bone I: corner of mouth/upper lip

6. Buccinator- “kissing muscle” A: compresses cheeks

Sucking, whistling, blowing O: mandible & maxillary bones I: orbicularis oris

7. Depressor anguli oris A: Depresses corner of mouth O: Anterolateral surface of mandibular

body I: Skin at corner of mouth

Muscles of Facial Expression

B. Muscles of Mastication

1. Masseter- strongest jaw muscle A: elevates the mandible

Closes mouth O: zygomatic arch I: mandibular ramus

2. Temporalis A: elevates mandible O: temporal bone I: coronoid process of mandible

Muscles of Mastication

C. Muscles of the Neck1. Platysma

A. Depresses mandible, tenses neck O: Upper thorax between cartilage of

2nd rib & acromion process I: Mandible & skin of cheek

2. Sternocleidomastoid A: flexes head, turns head side to side O: clavicle & manubrium I: mastoid process of temporal bone

3. Omohyoid A. Depresses hyoid & larynx O: Central tendon attaches to clavicle &

1st rib I: 2 bellies:

Superior- hyoid bone Inferior- superior margin of scapula

4. Sternohyoid A: Depresses hyoid & larynx O: Clavicle & manubrium I: Hyoid bone

Muscles of the Neck

Quiz Tomorrow!Head & Neck Muscles

D. Muscles of the Pectoral Girdle

1. Trapezius A: extends head & elevates scapula

Look up & shrugs shoulders O: occipital bone & thoracic & cervical

vertebrae I: clavicle & scapula

2. Serratus Anterior A: Abduction, upward rotation,

protracts shoulder O: Anterior & superior margins of ribs

1-9 I: Anterior surface of medial border of

scapula

3. Rhomboid Major/Minor A: Adduction, downward rotation O:

Major: Spinus processes of upper thoracic vertebra

Minor: Spinus processes of cervical vertebrae

I: Vertebral border of scapula

4. Pectoralis Minor A: elevates ribs (breathing) & depresses

shoulders O: ribs 3-5 I: coracoid process of scapula

E. Muscles of the Shoulder & Upper Arms

1. Pectoralis Major A: adducts & flexes humerus, rotates

arms medially O: clavicle, sternum, & costal cartilage I: greater tubercle of humerus

2. Deltoid A: abducts humerus O: clavicle & scapula I: deltoid tuberosity of humerus

(Rotator Cuff Muscles)3. Supraspinatus

A: Abduction, stabilization O: Supraspinous fossa of scapula I: Greater tubercle of humerus

4. Infraspinatus A: Adduction, outward rotation O: Infraspinous fossa of scapula I: Greater tubercle of humerus

(Rotator Cuff Muscles)5. Teres Minor

A: Adduction, outward rotation O: Inferior angle of scapula I: Medial lip of intertubercular groove

of humerus

6. Subscapularis A: Adduction, inward rotation O: Subscapular fossa of scapula I: Lesser tubercle of humerus

7. Teres Major A: Adduct, inward rotation, extension O: Inferior angle of scapula I: Medial lip of intertubercular groove

of humerus

8. Latissimus Dorsi A: extends, adducts, & rotates arms

medially O: spines of T7-sacrum, iliac crest, &

ribs 9-12 I: intertubercular groove of humerus

9. Biceps Brachii- “two heads” A: flexes arm @ elbow, supinates

forearm O: scapula I: radial tuberosity

10. Triceps Brachii- “three heads” A: extends arm (antagonist to biceps

brachii) O: scapula & humerus I: olecranon process of ulna

11. Coracobrachialis A: Adduction, flexion O: Coracoid process I: Medial margin of shaft of humerus

F. Muscles of the Forearm

1. Brachioradialis A: flexes arm @ elbow, supinates

forearm O: lateral epicondyle of humerus I: styloid process of ulna

2. Brachialis A: Flexion O: Anterior distal surface of the

humerus I: Tuberosity of ulna

(mentioned previously)3. Biceps Brachii

A: Flexion, supination O: scapula I: radial tuberosity

4. Triceps Brachii A: extends arm O: scapula & humerus I: olecranon process of ulna

G. Muscles of the Hand & Wrist

1. Flexor Carpi Radialis A: Flexion & abducts wrist & hand O: Medial epicondyle of humerus I: Base of 2nd & 3rd metacarpals

2. Palmaris Longus A: Flexion of the wrist and hand O: Medial epicondyle of humerus I: Palmar aponerosis & flexor

retinaculum

3. Flexor Carpi Ulnaris A: Flexion & adduction of wrist & hand O: Medial epicondlye of humerus,

medial surface of olecranon, anteromedial part of ulna

I: Pisiform & hamate bones & 5th metacarpal

4. Extensor Carpi Radialis Longus A: Extension & abduction of wrist &

hand O: Lateral supracondylar ridge of

humerus I: 2nd metacarpal

5. Extensor Digitorum A: Extension of the fingers & hand O: Lateral epicondyle of humerus I: Posterior surfaces of phalanges 2-5

6. Extensor Carpi Ulnaris A: Extension & adduction of wrist &

hand O: Lateral epicondyle of humerus,

dorsal surface of ulna I: Base of 5th metacarpal

Flexors

Extensors

Quiz TomorrowShoulder, Arm, Forearm, Wrist & Hand Muscles

G. Muscles of the Abdomen1. Rectus Abdominis

A: depresses rib cage & flexes vertebral column

O: pubic symphysis I: costal cartilage of ribs 5-7 & xiphoid

process

2. External Oblique A: compresses abdomen, flexes

vertebral column & lateral rotation O: ribs 5-12 I: iliac crest & linea alba

3. Internal Oblique A: same as external oblique O: iliac crest I: costal cartilage of ribs 8-12 & linea

alba

4. Transversus Abdominis A: compresses abdomen O: iliac crest & costal cartilage of ribs

7-12 I: pubis, linea alba, & xiphoid process

3. Diaphragm- separates thoracic & abdominopelvic cavities A: expands thorax O: costal cartilage of ribs 7-12 &

xiphoid process I: central tendon of diaphragm

Quiz TomorrowAbdominal Muscles

H. Muscles of the Hip & Thigh

1. Iliacus A: Flexion, outward rotation O: Iliac fossa I: Distal femur

2. Psoas Major A: Flexion, outward rotation O: Anterior surfaces of vertebrae T12-

L5 I: Lesser trochanter of femur

3. Rectus Femoris (part of Quadriceps) A: Flexion O: Anterior inferior iliac spine &

superior rim of acetabulum I: Tibial tuberosity via patellar ligament

4. Sartorius A: Flexion, outward rotation O: Anterior, superior iliac spine I: Medial tibia

5. Gracilis A: Adduction O: Inferior ramus of pubis I: Medial surface of tibia inferior to

medial condyle

6. Pectineus A: Flexion, adduction O: Superior ramus of pubis I: Inferior to lesser trochanter of femur

7. Adductor Longus A: Adduction, flexion O: Inferior ramus of pubis I: linea aspera of femur

8. Gluteus Maximus A: extends & laterally rotates thigh O: iliac crest, sacrum, & coccyx I: femur

(Hamstrings Group)9. Semitendinosus

A: Extension O: Ischial tuberosity I: Proximal, medial surface of tibia

10. Semimembranosus A: Extension O: Ischial tuberosity I: Posterior surface of medial condyle of

tibia

(Hamstrings Group)11. Biceps Femoris

A: Extension O: Ischial tuberosity and linea aspera of

femur I: Head of fibula, lateral condyle of tibia

12. Tensor Fasciae Latae A: Flexion, stabilizes knee O: Iliac crest & anterior superior iliac

spine I: Iliotibial tract

13. Gluteus Medius A: Abduction O: Anterior iliac crest I: Greater trochanter of femur

I. Muscles of the Knee Joint

1. Sartorius- mentioned previously A: Flexion

2. Gracilis- mentioned previously A: Flexion

3. Gastrocnemius A: Flexion O: lateral & medial epicondyles of

femur I: calcaneus

(Quadriceps Group)4. Rectus Femoris- mentioned

previously A: Extension

5. Vastus Lateralis A: Extension O: Anterior & inferior to greater

trochanter & linea aspera I: Tibial tuberosity

(Quadriceps Group)6. Vastus Medialis

A: Extension O: Entire length of linea aspera of

femur I: Tibial tuberosity

7. Vastus Intermedius A: Extension O: Anterolateral surface of femur &

linea aspera I: Tibial tuberosity

(Hamstrings Group)8. Semitendinosis- mentioned

previously A: Flexion

9. Semimembranosus- mentioned previously A: Flexion

10. Biceps Femoris- mentioned previously A: Flexion

J. Muscles of the Ankle Joint

1. Tibialis Anterior A: dorsiflexes ankle, inverts foot O: lateral epicondyle & body of tibia I: 1st metatarsal

2. Fibularis (Peroneus) Longus A: Everts and plantar flexes foot,

supports arch O:lateral condyle of tibia, head of fibula I: base of 1st metatarsal, medial

cuneiform bone

3. Gastrocnemius- mentioned previously A: Plantar flexes foot

4. Soleus A: plantar flexes foot O: posterior fibular & tibia I: calcaneus

Next Week We will start dissecting the fetal pigs

Friday. I would like you to work in these pairs: Sara & Alyssa Kelly & Jamie Cecily & Travis Megan will be

working Bethany & Jordan on a special

project for Andrew & Renee me on her

own. Max & Amanda Emma & Jacob

Dissection Details I will assign each pair a specific muscle

group to start with, and if your group completes that dissection, you may go on to dissect the rest of the pig.

You must dress appropriately for the lab: Close-toed shoes No loose clothing/jewelry (unless you want pig

juice on them!) Hair must be tied back (ditto to the above

comment- I hear it’s a great conditioner!) No food or drink while we’re dissecting

Grading for the Dissection

Each day we dissect you will receive a participation grade.

You will also be graded on how well you dissect/identify your assigned muscle group.

I may look into giving some extra points for dissecting more than just your assigned muscles.

You will lose participation points if you are gone for a lab day (we’ll talk if it’s excused).