Lab Activity 11 Group I Muscles Martini Chapter
Lab Activity 11: Group I Muscles Martini Chapter 11 Portland Community College BI 231
Origin and Insertion • • Origin: The place where the fixed end attaches to a bone, cartilage, or connective tissue. Insertion: The site where the movable end attaches to another structure. 2
MUSCLES OF THE HEAD
Frontalis • • • Epicranial Aponeurosis Origin: Epicranial aponeurosis Insertion: Skin over forehead Action: Elevates eyebrows and wrinkles skin of forehead 4
Occipitalis • • • Origin: Occipital and temporal bones Insertion: Epicranial aponeurosis Action: Fixes epicranial aponeurosis and pulls scalp posteriorly 5
Orbicularis Oculi • • • Origin: Medial orbital margin and zygomatic bone Insertion: Skin surrounding eye Action: Closes eyelids and depresses skin of forehead 6
Temporalis • • • Origin: Temporal fossa Insertion: Coronoid process of mandible Action: Elevates and retracts mandible 7
Masseter • • • Origin: Zygomatic process and arch Insertion: Angle and ramus of mandible Action: Elevates mandible 8
Orbicularis Oris • • • Origin: By muscular skips to surround muscles Insertion: Muscles interlace to surround mouth Action: Closes and purses lips 9
Zygomaticus Major • • • Origin: Zygomatic arch Insertion: Corner of mouth Action: Elevates corner of mouth 10
Risorius • • • Origin: Fascia of masseter Insertion: Corner of mouth Action: Draws corner of mouth laterally 11
SUPERFICIAL MUSCULATURE OF THE NECK
Omohyoid • Origin: Medial tip of suprascapular notch • Insertion: Body of hyoid bone • Action: Depresses hyoid bone 13
Sternohyoid • • • Origin: Posterior surface of manubrium, and medial clavicle Insertion: Hyoid bone Action: Depresses hyoid bone 14
Mylohyoid • • • Origin: Mylohyoid line of mandible Insertion: Hyoid bone Action: Elevates hyoid bone and floor of mouth, depresses mandible 15
Digastric Anterior Belly • • • Origin: Lower border of mandible near midline Insertion: Intermediate tendon on the hyoid bone Action: Elevates hyoid bone and base of tongue, depresses mandible 16
Digastric Posterior Belly • • • Origin: Mastoid notch of temporal bone Insertion: Intermediate tendon on the hyoid bone Action: Moves hyoid bone back 17
MUSCLES OF THE NECK & BACK
Sternocleidomastoid • • • Origin: Manubrium and medial third of clavicle Insertion: Mastoid process Action: Rotates head to opposite side, extends head, and flexes vertebral column 19
Trapezius • • • Origin: External occipital protuberance, superior nuchal line and spinous process of C 7 -T 12 Insertion: Anterior border of scapular spine, acromion process, lateral third of clavicle Action: Elevates, adducts, and depresses scapula 20
Latissimus Dorsi • • • Origin: Spinous processes of lower 6 thoracic vertebrae, thoracolumbar fascia, crest of ilium Insertion: Intertubercular groove of humerus Action: Extends, rotates humerus medially, draws shoulder down and backward 21
Levator Scapula • Origin: Transverse processes of C 1 -4 • Insertion: Superior angle spine of scapula • Action: Elevates scapula 22
Rhomboid Major • • • Origin: Spinous process of T 1 -5 and supraspinous ligament Insertion: Medial border below spine of scapula Action: Adducts scapula and performs downward rotation 23
Rhomboid Minor • • • Origin: Spinous process of C 7 -T 1 Insertion: Medial border of scapula at base of spine Action: Adducts scapula and performs downward rotation 24
Serratus Anterior • • • Origin: Lateral surface of upper 8 ribs Insertion: Anterior lip of medial border of scapula Action: Holds scapula to chest wall, medially rotates scapula in abducting or extending humerus 25
Erector Spinae • • • Origin: Sacrum, iliac crest, spinous processes of lumbar vertebrae and T 11, 12 Insertion: Angles of the ribs. Spinous & Transverse processes of vertebrae Action: Extension of vertebral column 26
Quadratus Lumborum • • • Origin: Iliolumbar ligament and iliac crest Insertion: Lower border of 12 th rib, transverse process of upper lumbar vertebrae Action: Depresses rib cage inferiorly and laterally flexes trunk 27
Scalenes Anterior • • • Origin: Transverse processes of C 3 -C 6 Insertion: 1 st rib Action: Elevates 1 st rib, flexes neck forward and laterally, rotates neck 28
Scalenes Middle • • • Origin: Transverse processes of C 2 -C 7 Insertion: 1 st rib Action: Elevates 1 st rib, flexes neck forward and laterally, rotates neck 29
Scalenes Posterior • • • Origin: Transverse processes of C 4 -C 6 Insertion: 2 nd rib Action: Elevates 2 nd rib, flexes neck laterally, slightly rotates neck 30
MUSCLES OF THE THORACIC WALL
External Intercostal • • • Origin: Inferior border of rib above Insertion: Superior border of rib below Action: Elevates rib cage during inspiration 32
Internal Intercostal • • • Origin: Superior border of rib below Insertion: Inferior border of rib above Action: Depresses rib cage during expiration 33
Pectoralis Major • • • Origin: Medial half of clavicle, sternum, costal cartilages, aponeurosis of external abdominal oblique Insertion: Intertubular groove of humerus Action: Flexes, adducts, and medially rotates humerus, draws body upward in climbing 34
Pectoralis Minor • • • Origin: Anterior surface of ribs 3 to 5 Insertion: Coracoid process of scapula Action: Draws scapula down and forward and elevates ribs 35
MUSCLES OF THE ANTERIOR ABDOMINAL WALL
Rectus Abdominus • • • Origin: Pubic symphysis and crest of pubis Insertion: Xiphoid process and cartilages of ribs 5 to 7 Action: Tenses abdominal wall and flexes vertebral column 37
External Abdominal Oblique • • • Origin: External surface of lower 8 ribs Insertion: Anterior half of iliac crest and linea alba Action: Compresses abdomen, contralaterally rotates and flexes vertebral column 38
Internal Abdominal Oblique • • • Origin: Lateral half of inguinal ligament, anterior iliac crest and thoracolumbar fascia Insertion: Lower four ribs, linea alba and by conjoined tendon to pubis Action: Compresses abdomen, ipsilaterally rotates and flexes vertebral column 39
Transverse Abdominis • • • Origin: Lateral third of inguinal ligament, anterior iliac crest, and thoracolumbar fascia Insertion: Linea alba, and by conjoined tendon to pubis Action: Compresses abdomen 40
The End 41
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