Bones, Joints, and Movements of the Thoracic Cage Flashcards
What is the distribution of vertebrae?
cervical: 7
thoracic: 12
lumbar: 5
sacral: 5 (fused - form sacrum)
coccygeal: 5 (forming coccyx)
define: sacralization
L5 fuses to sacrum so that theres 4 lumbar vertebra and 6 sacral
define: lumbarization
first segment of sacrum fails to fuse with sacral bodies and appears like a lumbar vertebrae
List some of the common features of the typical cervical vertebrae (C3-C6)
- small vertebral bodies but large compared to rest of vertebrae. saddle shaped at superior and inferior surfaces
- large and triangular vertebral foramen
- transverse foramina (contain vertebral vessels) in transverse process
- superior facets are superoposterior while inferior facets are infero-posterior
- short bifid dorsal spinous process
- most mobile portion of the spine
Describe C1
AKA atlas
Has only an anterior arch and posterior arch; no spinous process and a body
no disc between C1 and C2
superior articular facets receive the occipital condyles of the skull
atlantooccipital joint: flexion / extension
atlantoaxial joint: head rotation
Describe C2
AKA axis
dens/odontoid process projects from body
articulate in 3 places with C1 to form atlanto-axial joints (synovial) to permit head rotation (shake no)
medial atlantoaxial joint is held together by transverse ligament of atlas
Describe C7
largest cervical vertebrae. long, palpable, non-bifid spinous process
What ligament holds the dens to the facet of the atlas?
transverse ligament of the atlas
List some of the common features of the thoracic vertebrae
- demi facets on lateral aspect of vertebral body where the head of the ribs articulate
- costal facets on transverse process for the tubercle of the ribs
- long spinous process that slope inferiorly, overlapping the adjacent vertebral body below
- Long and strong transverse processes
- Vertebral foramen is relatively small compared to body
Nearly vertical articular facets allowing for less movement than in cervical spine.
Limited flexion and extension in thoracic spine due to spinous process and articular facet shape
List some of the common features of the lumbar vertebrae
large vertebral bodies
Articular facets are nearly vertical but oriented differently; directed (facing) primarily medially and laterally
. located on vertical articular process bilaterally
allows for flexion, extension, lateral flexion of spine
does not allow for a lot of rotation
Transverse and spinous process are short and blunt
describe the 2 major components of the intervertebral discs
annulus fibrosus: fibrocartilage ring
nucleus pulposus: gelatinous filling of disc
function of IV discs
absorb shock
support weight of rostral segments
sacrum
- function
- characteristics
function: stability and strength
contains sacral canal which permits passage of cauda equina
4 pairs of sacral foramina allowing passage of spinal nerves
sacral hiatus
- gap produced by lack of spinous process of S5
What is the emphasized importance of coccyx
anchor point for muscles such as gluteus maximus and coccygeus
Describe the 2 different types of breast implants
Subglandular: implant is inserted over the pectoralis minor and pectoralis major muscles in the chest (replicates natural anatomy)
Submuscular: implant is fully inserted under the pectoralis major muscle above the pectoralis minor muscle (more common now)
Fill in the blank:
the jugular notch is slightly ____ and ____ to the origin of the internal jugular veins
caudal
medial
Explain the position of esophagus in reference to the trachea
the esophagus is posterior to the trachea
What veins and arteries pass over the first rib causing their grooves?
subclavian artery and vein
What kind of joint is the 1st sternocostal joint
synarthrosis (immobile) and a synchondrosis (hyaline cartilage directly united with sternum)
What kind of joints are the 2nd - 7th sternocostal joints
synovial plane joints
What kind of joint is the sternoclavicular joint
synovial plane joint
What kind of joints are the manubriosternal joint and xiphisternal joint
symphyses (although they typically ossify in adulthood).
Define: intervertebral foramen
contains spinal nerves which exit and branch off the spinal cord off each spinal segment
Inferior vertebral notch and superior vertebral notch
Define: Zygapophysial joint
formed by inferior articular process of superior vertebra + superior articular process of inferior vertebra
Describe the difference between the atlanto-occipital joint and atlanto-axial joint
atlanto-occipital joint: occipital condyles of the skull and the superior articular facets of the C1; allow for flexion/extension (nodding yes)
atlanto-axial joint: formed by 3 articulations between atlas and axis that permit rotation (shake head no)
What are the 3 atlantoaxial joints?
2 lateral atlanto-axial joints
Median pivot joint: dens and anterior arch of the atlas (transverse ligament snugs dens into anterior arch of atlas)
What is a hangman’s fracture?
Den’s fracture
- abrupt hyperextension of the neck
What is the portion where the sacrum articulates with the iilium called?
auricular surface
xiphersternal joint
where the body of the sternum and the xiphoid process meet.
sternocostal joint vs costochondral joint vs costotransverse joint vs costovertebral joints
sternocostal: where the sternum meets the costal cartilage
costochondral: where the rib meets the costal cartilage
costotransverse joint refers to the articulation of the facet of the costal tubercle on the neck of the rib with the transverse processes of a corresponding vertebra. allows for rib cage expansion
costovertebral joint: collective term for costotransverse joint and joints of costal head. the joints that connect the ribs and the thoracic vertebrae.
joints of costal head: made up of head of rib, body of vertebra superior to rib, intervertebral disc, and body of vertebra same number as rib
What reinforces the costotransverse joints
Lateral costotransverse ligament. Limits gliding
Fill in the blank: the 7th rib articulates at its head with _____
At its tubercle, it articulates with ______
the body of T7 and T6
transverse process of T7
How do the shape of the costotransverse articulations in the rib change from rostral to caudal? What are the ramifications for movement?
middle costotransverse joints:
Articular surfaces on the tubercles of ribs 1-6 are cancave. These concave tubercles fit into the convex surface on the transverse processes of the same-numbered vertebrae.
allows for a pump handle movement of the ribs producing elevation and depression at the sternal end of the ribs in the sagittal plane.
lower costotransverse joint:
Articular surfaces of the tubercles of rib 7-10 are flat
Flat tubercles glide over the flat transverse processes of the same numbered vertebrae
Gliding movement produces elevation and depression of the lateral ribs in the transverse plane (bucket handle movement)
Lower ribs are the handle of the bucket tilting up and out.
The combination of rib movements increases the anterior posterior and transverse dimensions of the thoracic cage
What is flail chest?
Extreme case of rib fracture
Flail segment is an isolated segment of rib cage where 3 or more ribs break at both ends and the isolated section moves paradoxically.
During inspiration it gets sucked into the chest and during expiration it is pushed out
how many IV discs are there
23
define: herniated disc
structural failure of the annulus fibrosus leads to bulging (or extrusion) of the nucleus pulposus (ruptured or “slipped”)
Where is it most common for discs to be herniated?
L4-L5
L5-S1
Where do the sacral spinal cord segments arise from?
T12-L1
define: dermatome
portion of the skin innervated by a single spinal nerve.
define: myotome
portion of musculature innervated by a single spinal nerve
Spinal cord injury vs spinal nerve injury
Spinal cord injury affecting sensory and motor function at and below the level of injury
Spinal nerve injury affecting sensory and motor function within a specific dermatome and myotome
List the myotomes
C5 - elbow flexors
C6 - wrist extension
C7 - elbow extensors
C8 - finger flexors
T1 - finger abductors
L2 - hip flexors
L3 - knee extensors
L4 - ankle dorsiflexors
L5 - long toe extensors
S1 - ankle plantarflexors
Where do the spinal nerves exit from?
C1-C7 spinal nerves emerge from the vertebral canal above corresponding vertebra
All other ones, spinal nerves exit through the vertebral canal below the corresponding vertebra
vertebral canal is created by intervertebral foramen
What does a typical rib’s heads articulate with?
Example: T6
Rib 6 superior facet articulates with T5 and inferior facet articulates with T6
At Demi facets
