Ch 7 Musculature of the Back Flashcards
Bones involved in back muscle attachments
OVCHHSS
-occipital bone
-vertebrae (C,T,L)
-clavicle
-hip bone
-humerus
-scapula
-sacrum
Vertebral areas of muscular attachment
-the spinous process which projects posteriorly from 2 joined laminae
-the transverse processes which laterally project from joined area of pedicle and lamina
Scapular points of attachment
-ACROMION which is the ledge overlying the shoulder joint
-SCAPULAR SPINE which is a prominent ridge continuing laterally with the acromion(post. surface is the CREST) (SUPERIOR, INFERIOR, and at the SCAPULAR SPINE)
-MEDIAL BORDER which is parallel to vertebral column
Humerus points of attachment
-INTERTUBULAR GROOVE AKA SULCUS which is between greater tubercle and lesser tubercle
Superficial Muscles of the Back
-Trapezius
-Latissimus Dorsi
-Levator Scapulae
-Rhomboid Minor
-Rhomboid Major
Trapezius (origin)
-posterior skull/occipital bone
-spinous processes of ALL CV via ligamentum nuchae
-spinous processes of ALL TV
Trapezius (insertion)
LACS
-lateral 1/3 of clavicle
-acromion
-CREST OF SCAPULAR SPINE, SUPERIOR LIP
Trapezius (action)
-upward rotation of the SCAPULA where INFERIOR angle moves LATERALLY
-elevation of scapula AND LATERAL CLAVICLE
-depression of scapula AND LATERAL CLAVICLE
Trapezius (innervation)
-CN XI, accessory nerve
-ventral rami of C3-C4
Latissimus Dorsi (origin)
-lower 3-4 ribs
-iliac crest
-spinous processes of lower 6 TV
-spinous processes of ALL LV and SV via APONEUROSIS
Latissimus Dorsi (insertion)
-Intertubercular groove or sulcus of the humerus
Latissimus Dorsi (action)
MEADD!
-Medial rotation of arm at shoulder joint
-Extension of arm at shoulder joint
-ADDuction of arm at shoulder joint
Latissimus Dorsi (innervation)
-ThorACOdorsAL nerve
Levator Scapulae (origin)
-transverse processes of CV1-CV4
Levator Scapulae (insertion)
elevator UP-superior
-medial border of the scapula superior to scapular spine
Levator Scapulae (action)
-elevation of scapula
Levator Scapulae (innervation)
SHARES THIS WITH TRAPEZIUS
-Ventral Rami C3-4
Rhomboid Minor (origin)
-spinous processes of CV7-TV1
Rhomboid Minor (insertion)
Insertion:
-medial border of scapula AT the scapular spine
Rhomboid Minor (action)
SAME AS MAJOR
-ADDuction of scapula
Rhomboid Minor (innervation)
SAME AS MAJOR
-DorsAL scapulAR nerve
Rhomboid Major (origin)
-spinous processes of TV2-TV5
Rhomboid Major (insertion)
-medial border of scapula INFERIOR to the scapular spine
Rhomboid Major (action)
SAME AS MINOR
-ADDuction of scapula
Rhomboid Major (innervation)
SAME AS MINOR
-dorsal scapular nerve
Muscles of the Deep Back
-erector spinae
-splenius
-transversospinal group
-suboccipital muscles
Erector spinae AKA Sacrospinalis (define/components, best seen)
-largest muscle mass of back
-3 longitudinal muscles (spinalis, longissimus, iliocostalis)
-above 12th rib, moving from medial to lateral
Erector spinae (function/ innervation)
-postural muscle holding spine erect by EXTENDING vertebral column
-segmental from the dorsal rami
Spinalis (location)
most medial part of erector spinae, 1 cm WIDE found ALONG spinous process
Longissimus (location and fun fact)
intermediate part of erector spinae, muscle extending from sacrum all the way to the skull; longest column
Iliocostalis (location)
most lateral part of erector spinae, extends from ilium to ribs
Splenius (define/ components/ location)
-deep back muscle in the neck
-consists of splenius capitis and splenius cervicis; in total spans from ligamentum nuchae - CV1-TV6
Splenius (function/innervation)
when one side acts, the head and cervical column rotate toward the same side, when they act together head and cervical column EXTEND
-segmental from dorsal rami
Splenius Capitis (location)
superior part of splenius, extends from ligamentum nuchae and CV7-TV4 to the skull
Splenius Cervicis (courses from x-y)
inferior portion of splenius, courses from TV3-TV6 and upward to CV1-CV31
Transversospinal Group (components, origin/insertion)
includes: semispinalis, multifidus, and rotatores
Origin: all muscles in this group originate from transverse process
Insertion: all muscles insert into spinous process of vertebrae above it
Semispinalis (components/ courses how many V segments, unique fact)
consists of semispinalis capitis, cervicis and thoracis; courses 4-6 vertebral segments, deep muscle occupies upper half of vertebral column
Semispinalis Capitis / Biventer Cervisis (why its named other name, action)
has prominent intervening tendon;
A:EXTENDS head and rotates to SAME side
Semispinalis Cervicis ( superficial or deep to capitis, action?)
deep to semispinalis capitis,
A: rotate vertebrae towards the OPPOSITE side
Semispinalis Thoracis (where in regard to other semispinalis, action)
inferior to semispinalis capitis in thoracis section;
A:rotate vertebrae towards OPPOSITE side
Multifidus (courses, best seen, deep to, action)
course 2-4 vertebral segments; deep muscles best developed/seen in lumbar region deep to erector spinae;
A: rotate vertebral column towards OPPOSITE side
Rotatores (spans, best seen, where on bones, what makes it unique)
courses 1-2 vertebral segments; deep muscles best developed/seen in thoracic region deep to semispinalis thoracis; lie directly on LAMINAE between spines and transverse processes; the DEEPEST back muscles