Spine (6A/6B) Flashcards
Spine
- cervical = 7 vertebrae (8 cervical spinal nerves)
- thoracic = 12 vertebrae
- lumbar = 5 vertabrae
- sacrum = 5 vertabrae (fused into 1 unit)
- coccyx = 1 unit
Splenii
- splenius capitus
- splenius cervicus
Attachments of splenii
- inferior (stationary) = spinous processes of spine
- superior = skull, transverse processes of spine
Innervation of splenii
Dorsal rami
Actions of splenii
- rotate the head and neck to the same side (unilaterally)
- laterally flex the head and neck to the same side (unilaterally)
- extend the head and neck (bilaterally)
Erector spinae group
Lateral to medial
- iliocostalis
- longissimus
- spinalis
Attachments of erector spinae group
- inferior (stationary) = lower T-spine and L-spine spinous processes and thoracolumbar fascia
- superior = C-spine and T-spine transverse processes, skull, and ribs
Innervation of erector spinae group
Dorsal rami
Actions of erector spinae group
- laterally flex vertebral column to the same side (unilaterally)
- extend the vertebral column (bilaterally)
Transversospinalis group
Longest to shortest (fiber length)
- semispinalis
- multifidi
- rotatores
- ex question = what plane does unilateral contraction of transversospinalis does? Transverse plan
- while erector group muscles are long and span the back, transversospinalis are short and only span a few vertebrae
Attachments of transversospinalis group
- inferior (stationary) = transverse processes of vertebrae
- superior = spinous processes of vertebrae and nuchal line (semispinalis)
Innervation of transversospinalis group
Dorsal rami
Actions of transversospinalis group
- rotate the vertebral column to the opposite side (unilaterally)
- extend the vertebral column and head (bilaterally)
Attachments of serratus posterior superior and inferior
- small and feather-like like their anterior counterpart
- proximal = spine
- distal = ribs
Innervation of serratus posterior superior and inferior
Dorsal rami
Actions of serratus posterior superior and inferior
- elevates ribs during respiration (superior)
- depress ribs during respiration (inferior)
Attachments of quadratics lumborum
- deep to erector spinae (and thoracodorsal fascia) in lumbar region
- inferior (stationary) = iliac crest of pelvis
- superior = lowest ribs and transverse processes of lumbar spine
Innervation of quadratics lumborum
Lumbar plexus (ventral rami)
Actions of quadratics lumborum
- laterally flex vertebral column to the same side (unilaterally)
- fix the last rib during forced inhalation and exhalation (bilaterally)
- assist to extend vertebral column (bilaterally)
Open-chain
Involve free movement of the distal body segment in space, allowing joints to move together or independently of others
Closed chain
Involves proximal joint(s) moving in relation to a fixed (non moving) distal segment
Resistance more than effort
Nothing happens, the body can’t move
Resistance equals effort
Isometric contraction
Effort more than resistance
Concentric or eccentric contraction
Resistance arm
Distance from the joint doing the work (action) to resistance
the longer the resistance arm, the more effort the muscle has to exert to overcome this force
Concentric contraction
Going against gravity
Eccentric contraction
Going with gravity
Attachments of sternocleidomastoid
- it says its attachment points = sternum, clavicle, mastoid process of temporal base of skull
- runs at an angle
- inferior (stationary) = sternum and clavicle
- superior = mastoid process of temporal bone
Innervation of sternocleidomastoid
Accessory nerve (CN VI) and C2-3
Actions of sternocleidomastoid
- laterally flex the head and neck to the same side (unilaterally)
- rotate the head and neck to the opposite side (unilaterally)
- flex the neck (bilaterally)
- assist to elevate the rib cage during inhalation (moving the inferior attachment, sternum, for respiration, inspiration)
Scalenes
- anterior
- middle
- posterior
- brachial plexus goes right through the anterior and middle scalenes
- if the muscles get tight, what happens? Squeezes the brachial plexus (leading to numbness and muscle weakness)
Attachments of scalenes
- inferior (stationary) = 1st and 2nd ribs
- superior = transverse processes of C-spine
Innervation of scalenes
Ventral rami
Actions of scalenes
- with ribs fixed, laterally flex the head and neck to the same side (unilaterally)
- rotate the head and neck to the opposite side (unilaterally)
- elevate ribs during inhalation (bilaterally with inferior attachment in movement)
- flex the head and neck (bilaterally)
Attachments of subclavius
- small little muscle that sits under the clavicle
- proximal = 1st rib
- distal = clavicle
Innervation of subclavius
Nerve to subclavius
Actions of subclavius
- lifts 1st rib in inhalation (important for respiration)
Linea alba
- connective tissue spanning from sternum to pubic symphysis
- an attachment point for abdominal muscles
Rectus abdominus
- encased in rectus sheath
- easy to move both attachments
- antagonists of erector muscles of back
Attachments of rectus abdominus
- inferior (stationary) = pubic symphysis
- superior = ribs
Innervation of rectus abdominus
Ventral rami
Actions of rectus abdominus
- flex the vertebral column (bilaterally)
Obliques
- internal and external obliques form abdominal wall
- internal deep to external
- important for compressing abdominal contents
- muscle fibers run in opposite directions
- internal and external are antagonists
- unilaterally muscle contraction on SAME side in rotation = ANTAGONISTS
- lateral flexion = AGONISTS
Attachments of obliques
- inferior (stationary) = iliac crest, linea alba
- superior = ribs
Innervation of obliques
Ventral rami
Actions of obliques
- laterally flex vertebral column to the same side (unilaterally)
- rotate vertebral column to the same side (unilaterally)
- flex the vertebral column (bilaterally)
- compress abdominal contents (bilaterally)
- external = bilaterally flex spine
- external = unilaterally rotate to opposite side (antagonists)
- internal = unilaterally rotate to same side (antagonists)
- laterally flex to the same side (unilaterally- agonists)
- when all contracts = stabilizes
Attachments of transverse abdominis
- deep to abdominal muscles
- wraps around at thoracolumbar fascia to rectus sheath and linea alba
Innervation of transverse abdominis
Ventral rami
Actions of transverse abdominis
- compress abdominal contents (stabilizer)
- stabilizes with lifting
Attachments of intercostals
- between ribs
Innervation of intercostals
Ventral rami
Actions of intercostals
- lifts and depresses ribs for respiration
Diaphragm
Forms the floor of thoracic cavity
Innervation of diaphragm
Phrenic nerve (C3-5)
Actions of diaphragm
- draw down the central tendon of the diaphragm
- increase the volume of thoracic cavity during inhalation (by contraction)
Inhalation
Ribs elevate
Expiration
Ribs depress
Inhalation muscles
- scalenes
- sternocleidomastoid
- serratus posterior superior
- subclavius
- pectoralis minor
Expiration muscles
- serratus posterior inferior
- quadratus lumborum
- rectus abdominus
Levator ani and coccygeus
- pelvic floor muscles
- continuous membrane of muscles that form the floor of pelvis (known as diaphragm)
- pelvic floor weakness occurs following birth (especially vagina birth)
- with all muscles, decrease in stretch and girth as we age
Innervation of levator ani and coccygeus
Sacral nerves
Actions of levator ani and coccygeus
- regulate urination and defection (actively)
- support reproductive organs (passively)
- stabilization
- preservation of control and ability to support pelvic organs against gravity both at rest and unexpected loads
