Origins and Insertions Lab 1

What is the superior attachment of the scalenus anterior?

transverse processes of C3-C6 vertebrae

What is the inferior attachment of the scalenus anterior?

1st rib

What is the nerve innervation of the scalenus anterior?

Cervical spinal nerves

What is the action of the scalenus anterior?

flex head

What is the superior attachment for the scalenus medius?

posterior tubercles of transverse processes of C5-C7 vertebrae

What is the inferior attachment of the scalenus medius?

superior surface of 1st rib, posterior to groove for subclavian artery

What is the nerve innervation of the scalenus medius?

anterior rami of cervical spinal nerves

What is the action of the scalenus medius?

flexes neck laterally, elevates 1st rib during forced inspiration

what is the superior atatchment of the scalenus posterior?

posterior tubercles of transverse processes of C5-C7 vertebrae

What is the inferior attachment of the scalenus posterior?

external border of 2nd rib

What is the nerve innervation of the scalenus posterior?

anterior rami of cervical spinal nerves C7 and C8

What is the action of the scalenus posterior?

flexes neck laterally, elevates 2nd rib during forced inspiration

What is the origin of the platysma?

Mandible, skin, and tissue of lower face

What is the insertion of the platysma?

pec major and deltoid

What is the nerve innervation of the platysma?

CN VII

What is the action of the platysma?

Draw down corners of the mouth, draw skin separately when teeth are clenched

What is the proximal attachment of the subclavius?

junction of the 1st rib and its costal cartilage

What is the distal attachment of the subclavius?

inferior surface of middle 3rd of clavicle

What is the nerve innervation of the subclavius?

nerve to subclavius (C5,C6)

What is the action of the subclavius?

anchors and depresses clavicle

What is the superior attachment of the SCM?

lateral surface of mastoid process of temporal bone and lateral half of superior nuchal line

What is the inferior attachment of the SCM?

sternal head: anterior surface of manubrium of sternum

clavicular head: superior surface of medial third of clavicle

What is the nerve innervation of the SCM?

spinal accessory nerve (CN XI) C3 and C4 nerves (pain and perception)

What is the action of the SCM?

unilateral: laterally flexes neck and rotates head

bilateral: elevates clavicle and manubrium and anterior ribs

What is the proximal attachment of the pectoralis major (clavicular portion)?

anterior surface of medial half of clavicle

What is the distal attachment of the pectoralis major (clavicular portion)?

lateral lip of intertubercular sulcus of humerus

What is the nerve innervation of the pectoralis major (clavicular portion)?

Lateral and medial pectoral nerves: clavicular head (C5 and C6)

What is the action of the pectoralis major (clavicular portion)

adducts and medially rotates humerus

draws scapula anteriorly and inferiorly

clavicular head flexes humerus

What is the proximal attachment of the pectoralis major (sternocostal portion)?

anterior surface of sternum

superior 6 costal cartilages

aponeurosis of external oblique muscle

What is the distal attachment of the pectoralis major (sternocostal portion)

Lateral lip of intertubercular sulcus of humerus

What is the nerve innervation of the pectoralis major (sternocostal portion)

C7, C8, T1

What is the action of the pectoralis major (sternocostal portion) ?

external humerus from flexed position

What is the proximal attachment of the pectoralis minor?

3rd-5th ribs near costal cartilage

What is the distal attachment for the pectoralis minor?

medial border and superior surface of coracoid process of scapula

What is the nerve innervation of the pectoralis minor?

medial pectoral nerve (C8 and T1)

What is the action of the pectoralis minor?

stabilizes scapula by drawing it inferiorly and anteriorly against thoracic wall

What is the superior attachment of the external intercostal muscles?

inferior border of ribs

What is the inferior attachment of the external intercostal muscles?

superior border below ribs

What is the nerve innervation of the external intercostal muscles?

Intercostal nerve

What is the action of the external intercostal muscles?

elevate ribs during forced inspiration

What is the superior attachment of the internal intercostal muscles?

inferior border of ribs

What is the inferior attachment of the internal intercostal muscles?

superior border of ribs

What is the nerve innervation of the internal intercostal muscles?

intercostal nerve

What is the action of the internal intercostal muscles?

Intercostal part: depresses ribs

Interchondral part: elevates ribs

What is the proximal attachment of the serratus anterior?

ribs 1-8

What is the distal attachment of the serratus anterior?

Medial border of scapula

What is the nerve innervation of the serratus anterior?

Long thoracic nerve (C5-C7)

What is the action of the serratus anterior ?

protracts and holds scapula against thoracic wall

rotates

What is the origin of the external oblique muscle?

external surfaces of 5-12th ribs

What is the insertion of the external oblique muscle?

Linea alba

pubic tubercle

anterior half of iliac crest

What is the nerve innervation of the external oblique muscle?

thoraco-abdominal nerves (T7-T11 spinal nerves) and subcostal nerve

What is the action of the external oblique muscle ?

compresses and supports abdominal viscera and flexes and rotates trunk

What is the origin of the internal oblique?

Thoracolumbar fascia

anterior 2/3 of iliac crest

CT deep to lateral 3rd of inguinal ligaments

What is the insertion of the internal oblique?

inferior borders of 10th and 12th ribs, linea alba, and pectin pubis via conjoint tendon

What is the nerve innervation of the internal oblique?

thoraco-abdominal nerves (anterior rami of T6-T12 spinal nerves) and first lumbar nerves

What is the action of the internal oblique?

compresses and supports abdominal viscera and flexes and rotates trunk

What is the origin of the transversus abdominis?

interbal surfaces of 7th-12th costal cartilages

thoracolumbar fascia

iliac crest

CT deep to lateral 3rd of inguinal ligaments

What is the insertion of the transversus abdominus?

Linea-alba with aponeurosis of internal oblique

pubic crest

pecten pubis via conjoint tendon

What is the nerve innervation of the transversus abdominis?

Thoraco-abdominal nerves (anterior rami of T6-T12 spinal nerves) and 1st lumbar nerve

What is the action of the transversus abdominis?

Compresses and supprots abdominal viscera

What is the origin of the rectus abdominis?

pubic symphysis and pubic crest

What is the insertion of the rectus abdominis?

Xiphoid process and 5th-7th costal cartilage

What is the nerve innervation of the rectus abdominis?

Thoraco-abdominal nerves (anterior rami of T6-T12 spinal nerves)

What is the action of the rectus abdominis?

Flexes trunk (lumbar vertebrae)

compresses abdominal viscera

stabilizes and controls pelvic tilt

What is the origin of the diaphragm?

Sternal Part: 2 slips attach to posterior xiphoid

Costal Part: slips attach to internal aspect of inferior 6 costal cartilages and adjoining ribs

What is the insertion of the diaphragm?

central tendon: top and center of the hood

What is the nerve innervation of the diaphragm?

phrenic nerve (C3,4,5)

What is the action of the diaphragm?

chief muscle of inspiration

pulls down during contraction