Section 3, Exam Content Flashcards
sacroiliac joint
- bumpy surface of ilium matches the bumpy auricular shaped side of the sacrum
- absorbs a lot of force from our lower limbs
- not a whole lot of movement here since the sacrum is a platform for the rest of the body
movements at the sacroiliac joint
nutation and counter-nutation
nutation
top part of sacrum tips forward
bottom part of sacrum tips backward
counter-nutation
top of sacrum moves backward and bottom of sacrum moves forward
ligaments of the sacroiliac joint
- anterior, posterior and interosseus ligaments
- sacrotuberous ligament
- sacrospinous ligament
anterior, posterior and interosseus ligaments of the sacroiliac joint
- anterior sits on inside surface of pelvis
- posterior sits outside of pelvis
- interosseus fills the surface between bones the make the joint more fibrous and stable
sacrotuberous ligament
runs from dorsal and lateral surfaces of sacrum and coccyx to the ischial tuberosity where it blends into tendons of the hamstrings
- a strong ligament that integrates with a strong muscle group (hamstrings)
- limits nutation of sacrum relative to the ilium
- is bigger and more superficial than sacrospinous ligament
sacrospinous ligament
comes from inferior lateral margins of sacrum and coccyx to the ischial spine
- limits nutation of sacrum relative to the ilium
pelvis actions and equivalent spine actions
- lateral tilt of pelvis causes contralateral side flexion of the spine to compensate
- anterior tilt of pelvis = extension of lumbar spine
- posterior tilt of pelvis = flexion of lumbar spine
- L and R tilt of pelvis causes spine to rotate in the opposite direction (to keep us facing forward as we move)
body of vertebra
weight bearing anterior portion
transverse process of vertebra
aka costal processes
- angle will change depending on the area of the spine we are looking at
articular process of vertebrae
superior and inferior articular processes make a joint between adjacent vertebrae
pedicel of vertebrae
foot that comes off of the body of the vertebrae that helps to create the foramen
lamina of vertebrae
the narrow portion between spinous processes and articular processes
shape of lumbar spine
lordsis
- a natural extension position of the spine
- somewhat the result of how the spine sits on the pelvis such that L3 is the most neutral lumbar vertebrae
ZA joints
where superior and inferior articular processes meet
- small synovial joints that block rotation and translation of vertebrae
- there is a L and R for each vertebral level
SAP and IAP face opposite directions so that they match up with one another
directionality of the superior articular process of a vertebrae
faces back and medially
directionality of the inferior articular process of a vertebrae
faces forward and laterally
spinal tripod
3 joints formed b/w 2 vertebrae that help to give the spine stability
- the body of the vertebrae make one joint
- the SAP and IAP form the other 2 joints (ZA joints)
components of the intervertebral disc
annulus fibrosis
nucleus pulposus
annulus fibrosis
collagen rings that form on the tough outer layer (a series of 20-30 rings that wrap around a core
- each layer’s fibres run in opposite directions, alternating (annulus fibrosis is responsible for managing rotational stress)
nucleus pulposus
a gel like core with fluid like properties
- responds by moving when we load the disc
- if we squish the intervertebral disc, the nucleus pulposus will bulge out in the direction of less stress
ligaments of the spinal column (6)
- anterior longitudinal ligament (ALL)
- posterior longitudinal ligament (PLL)
- interspinous ligament
- supraspinous ligament
- ligamentum flavum
- iliolumbar ligament
anterior longitudinal ligament
runs along anterior aspect of vertebral bodies and intervertebral discs
- tends to be broader than PLL by wrapping around the sides of vertebrae more
- connects vertebral bodies
- limits extension of the spine
posterior longitudinal ligament
runs along the posterior aspect of vertebral bodies and intervertebral discs within the spinal canal
- connects vertebral bodies
- limits flexion of the spine
interspinous ligament
runs between spinous processes of adjacent vertebrae
- limits flexion of the spine
supraspinous ligament
connects the tips of the spinous processes of adjacent vertebrae
- limits flexion of the spine
ligamentum flavum
runs in the spinal canal, connects laminae of adjacent vertebrae
- has more stretch to it
- limits flexion of the spine
iliolumbar ligament
runs from L5 transverse process to iliac crest (posterio-medial aspect)
- prevents anterior translation of L5 vertebrae relative to the sacrum/ilium (which is what gravity wants)
dorsal root of spinal nerve
is called afferent
- carries sensory info
ventral root of spinal nerve
is called efferent
- carries motor signals
dermatomes
area of skin innervated by the sensory axons within each spinal nerve
myotomes
collection of muscle fibres innervated by the motor axions within each spinal nerve
- the joint actions that we produce that are heavily influenced by a spinal level
meninges (layers)
3 levels protect the brain and SC:
- duramater: tough outer layer
- arachnoid mater: weblike middle layer
- pia mater: most delicate, closest to brain
cauda equina
at about level L1, the spinal cord tapers to a point and strands (spinal nerves) extend
intervertebral foramen
hole b/w 2 vetebrae (where pedicels are) that serve as an exit point for spinal nerves
naming spinal nerves
they are named the the level at which they exit the SC
- cervical spinal nerves are named for the vertebrae below them
- C1 nerve exits b/w skull and C1
- C8 sits above T1 and below C7
- spinal nerves below T1 are named for the vertebrae above them
sacrum (vertebrae and spinal nerves)
the sacrum is composed of a bunch of vertebrae fused together into one bone
- sacral spinal nerves exit through dorsal and ventral foramina (spinal nerves S1 to S5)
thoracic spine
has 12 vertebrae
- kyphosis: somewhat flexed position to balance extension of lumbar spine
- orientation of spinous processes change as we move along
ligaments associated with the ribs and vertebrae
- costotransverse ligaments
- radiate ligaments
costotransverse ligaments
3 ligaments that act like a big smear of ligaments which run from neck and costal tubercle of the rib to the TP of the matching vertebra
radiate ligament
attach around the circumference of the head of the rib to the body of the matching vertebra and the vertebra above it
sternal angle
junction where manubrium meets body of sternum
- helps us landmark our 2nd rib since it articulates with the sternum at the sternal angle
xiphoid process
the most inferior bony process sticking off of the bottom of the sternum
true ribs
ribs 1-7
- each have their own costal cartilage
- open in anterior/posterior direction when we breathe (less movement as a result of having short costal cartilages)
false ribs
ribs 8, 9, 10
- do not have their own individual costal cartilages, but share them instead so their costal cartilages are longer
- ribs face more laterally than anteriorly
- ribs move/open more laterally/medially where they hinge on the thoracic spine, opening up side to side dimensions
floating ribs
ribs 11 and 12
- have no costal cartilages attaching them to sternum
the difference b/w upper and lower thoracic vertebrae SP
- lower thoracic vertebrae look more like lumbar vertebrae with short, broad SPs
- upper thoracic vertebrae have longer, more narrow SPs that point downward, articulate with one another and limit extension
the difference b/w upper and lower thoracic vertebrae TP
- upper have TP pointing more anteriorly so is associated more with true ribs that move anteriorly/posteriorly
- lower. have TP that point to face more laterally and better articulates with false ribs, causing them to move more medial/laterally
thoracolumbar fascia (TCF)
3 layers: posterior, middle, anterior
- layers wrap around and compartmentalize muscles
- erector spinae are surrounded by posterior and middle layers
- quadratus lumborum is surrounded by anterior and middle layers
- TCF is the insertion for transverse abdominis and internal oblique muscles
- also connects upper and lower extremities (lat dorsi and glut max)
do abdominals connect directly to the spine?
no - they connect to the pelvis, rib cage and thoracolumbar fascia
linea alba
“white line” that runs through the centre of the anterior abdominal wall from xiphoid process to symphysis pubis
upper cervical spine
includes C1, C2 and occiput
- joints are designed to facilitate movement of the head relative to the neck
- there is A LOT more rotation here than the rest of the spine which allows us to turn our head 70-90 degrees
atlas
C1
axis
C2
AO joint
and joint actions
atlas meets with occiput (head)
- head rolls back and forth
- flexion of upper cervical spine = chin tuck where head rolls on axis
- extension would be the opposite
AA joint
and actions
atlantoaxial joint
- C1 rotates around C2 axis
lower cervical spine
includes C3-C7
- functions just like the rest of the spine
foramen transversarian
a hole in the TP of cervical vertebrae that the vertebral artery runs through to deliver blood to the circle of willis in the brain
TPs in the cervical spine
- TPs are longer
- TPs are bifid
superior nuchal line
spreads laterally from external occipital protuberance of skull
- note that inferior nuchal line is smaller and located just below the external occipital protuberance
nuchal ligament
runs from external occipital protuberance of skull to the spinous processes of all cervical vertebrae
- a broad ligament that limits flexion of the upper and lower cervical spine
features of the C2 (axis)
- dens
- shorter spinous process
- lots of ligaments holding the head onto the neck
ligaments associated with the C2 axis
- apical ligament
- alar ligaments
dens
upward projection on the C2 that has an articular surface on its anterior aspect that articulates with the C1 atlas
apical ligament
runs from apex (top) of dens to anterior margins the foramen magnum
alar ligaments
“wings”
a pair of ligaments that run from the lateral surfaces of the C2 dens to the margins of the foramen magnum, medial to the occipital condyles
features of the C1 atlas
- no body - dens sits where the body would be
- lateral masses
- no SP
- we have a posterior tubercle (larger) and an anterior tubercle (smaller)
lateral masses of C1 atlas
act like the body of the vertebrae but are much smaller
transverse ligament of C1 atlas
connects lateral masses of C1 to one another, crossing over the back of the C2 dens
- presses the dens against C1
3 membranes associated with vertebrae
- PAOM - posterior atlanto-occipital attaches to foramen magnum
- tectorial - in the middle, prevents dens from compressing SC
- AAOM - anterior atlanto-occipital limits atlanto-occipital joint translation
suboccipital muscles (4)
- obliquus capitis superior and inferior
cause side to side head tilt - rectus capitis major and minor
extend upper cervical spine
anterior upper cervical muscles
rectus capitis anterior - flexion of
rectus capitis lateralis - lateral flexion of
sterno-cleido-mastoid
attaches to clavicle, sternum and mastoid process
- lower portion flexes lower cervical spine
- upper portion flexes upper cervical spine
- whole muscle causes contralateral rotation of cervical spine
scalenes and brachial plexus
brachial plexus runs through the space between the middle and anterior scalenes
diaphragm
runs from xiphoid process to the inside surfaces of bottom 6 ribs and their costal cartilages
- connect to L1-L3 vertebrae via R and L crus
- 2 arcuate ligaments
- blends with deepest fibres of the transverse abdominis
arcuate ligaments and the diaphragm
- 1st arcuate ligament is over psoas
- 2nd arcuate ligament is over quadratus lumborum
central endon
surrounds the hole where the esophagus, aorta, and other major vessels pass through the diaphragm
