Lecture 16: Skeletal Muscles II (Trunk) Flashcards
describe the origin, insertion, and innervation of Trapezius? is it ex or intrinsic
extrinsic (superficial)
origin: EOP& spinous processes of all cervical and thoracic vertebrae
insertion: upper fibres reach clavicle and acromion. lower fibres insert to spine of scapula
fxn: lower fibres depress scapula. middle fibres retract scapula.
nerve supply: CNXI
describe the origin, insertion, and innervation of Levator Scapulae?? is it extrinsic or intrinsic
Extrinsic (superifical)
origin: transverse processes of cervical vertebrae
insertion: superior angle scapula
fxn: elevate scapula
nerve supply: brachail plexus
describe the origin, insertion, and innervation of rhomboid minor and major? are they extrinsic or intrinsic?
extrinsic (superficial)
origin: spinous processes of upper thoracic vertebrae
insertion: medial border of scapula
fxn: elevation & retraction of scapula
innervated by: brachial plexus
what is the difference btw extrinsic and intrinsic muscles?
ex: origin and insertion in different regions
in: origin and insertion in same region
superficial and intermediate layers= extrinsic
deep layers = intrinsic
label:
1: trapezius
2:levator scapulae
3: rhomboid minor
4: rhomboid major
describe the origin, insertion, and innervation of latissimus dorsi?? is it extrinsic or intrinsic
origin: spinous processes of lower thoracic & all lumbar vertebrae & sacrum & ileum
insertion: intertubercular groove
fxn: prime mover for extension of shoulder.
can do medial rotation and adduction of shoulder
innervated: brachial plexus
extrinsic (sueprficial)
what muscle is this
lattissimus dorsi
what are the 3 groups of deep layer muscles in the trunk
- erector spinae
- transversospinalis
- segmentals
describe the origin, insertion, and innervation of erector spinae muscles?? is it extrinsic or intrinsic
list the 3 muscles in this group
3 muscles= spinalis (most medial), longissimus, iliocostalis (most lateral)
fxn: erect/extend spine and stabilize vertebrae
complicated origin/insertion. JUST KNOW they attach to vertebrae and ribs, can extend spine
innervate: posterior rami of spinal nerve
intrinsic (deep)
describe the origin, insertion, and innervation of transversospinalis?? is it extrinsic or intrinsic
list the 3 muscles in this group
muscles: semispinalis, rotatores (smallest, r) and multifidus
intrinsic (deep)
attachment/origin: run obliquely btw transverse and spinous processes
innvervated: dorsal rami of spinal nerves
fxn: rotatino of spine and stabilization of vertebrae
describe the origin, insertion, and innervation of Segmentals?? is it extrinsic or intrinsic
list the 2 muscles in this group
run btw segments of vertebrae. btw spinous OR transverse processes of adjacent vertebrae
- intertransversarii: btw 2 adj. transverse
processes, help with side flexion and stabilizes vertebrae - interspinales- run btw 2 spinous process. help with extension and stbailize
innvervated: dorsal rami
intrinsic (deep)
label 1-3. what muscle group are these
- spinalis
- longissimus
- iliocostalis
= erector spinae
what muscle group are these
1. semispinalis
2. rotatores
3. multifidus
- semispinalis
- rotatores
- multifidus
= transversospinalis
label 1 and 2. what muscle group are they from?
what is 3? what group?
- intertransversarii
- interspinales
= segmentals - rotatores (part of transversospinalis)
describe the origin, insertion, and innervation of pectoralis major?? is it extrinsic or intrinsic
origin: clavicle, sternum, upper 6 costal cartilaes
insertion: lateral tip of intertubercular groove (shoulder)
fxn: medial rotation, horizontal adduction (prime mover)
nerve supply: brachial plexus
extrinsic
what muscle is this
pectoralis major
describe the origin, insertion, and innervation of serratus anterior?? is it extrinsic or intrinsic
origin: first 8/9 ribs. fibres wrap around torso
insertion: medial border scapula
fxn: press scapula against thorax (stabilizes scapula) and prime mover for upward rotation of shoulder
nerve supply: brachial plexus
extrinsic
what muscle is this
serratus anterior
describe the intrinsic intercostal muscles?
3 layers: external, internal, innermost intercostal
run btw adjacent ribs
contract = bring ribs together
involved in forced inspiration
innervated by intercostal nerves (ventral rami of thoracic spinal nerves)
label
- external intercostal
- internal intercostal
- innermost intercostal
what are the origins of diaphragm
- xiphoid process
- lumbar vertebrae
- costal cartilage
fxn diaphragm
contraction brings down central tendon, during inhalation. compresses abdominal viscera (increases pressure)
nerve supply diaphragm
phrenic nerve
insertion diaphragm
central tendon
what are the 3 openings labelled in diaphragm
- inferior vena cava
- esophagus
- aorta
label
- central tendon (insertion )
- xiphoid process (origin)
- costal cartilage (origin)
- lumbar vertebrae (origin)
what muscles are in the anterolateral group?
- external oblique
- internal oblique
- transversus abdominus
- rectus abdominis
fxn/insertion/innervation External oblique
origin: lower ribs.
fibres continuous with aponeurosis tendon. lower border turns into ingeunal ligament. aponeurosis attaches muscle to insertion, which is linea alba tendon.
fxn: *** MOVES ORIGIN, not insertion. moves ribs/torso toward midline “contralateral rotation
nerve: lower 6 intercostal nerve
fxn/insertion/innervation internal oblique
origin: ilium
insertion: lower ribs and linea alba
fxn: moves linea alba and ribs toward origin (ilium) = ipsilateral rotation
nerve: lower 6 intercostal nerves
fxn/insertion/innervation transversus abdominus
origin: lower ribs and ilium, turns into aponeurosis
insertion: linea alba
fxn: compress abdo viscera, increase pressure
nerve: lower 6 intercostal nerves
fxn/insertion/innervation rectus abdominis
origin: pubic bone
insertion: xiphoid process and costal cartilage
fxn: flexion torso, priem mover
divided into tendinous intersections
nerve: lower 6 intercostal nerves
label
- linea alba
- tendinous intersection
- external oblique
- aponeurosis
- inguinal ligament
6.internal oblique - transversus abdominus
- rectus abdominis
label
A. Levator Ani
B. Perineal Muscles
what is this triangle called? what are the upper and lower divisions? what do the 4 blue dots represent
= perineum
top triangle= urogenital
bottom: anotriangle
top blue dot= pubic symphysis
bottom= coccyx??
sides= ischial tuberosity
fxn of Levator ani muscles
= part of pelvic diaphragm
lift anal canal and support weight of pubic viscera
innervated by sacral plexus
what are the 3 muscle groups of the pelvic region and their components?
- Pelvic Wall Muscles
- Pelvic Diaphragm: levitor ani and coccygeus
- perineal muscles
fxn of perineal muscles
reinforce diaphragm
innervated by pudendal nerve (sacral plexus)
make anus and urethra sphincters
what is the pelvic diaphragm defect?
L and R half cannot touch anteriorly bc of the three openings
therefore we have one more layer of muscles = perineal
