Bones, Joints, and Movements of the Thoracic Cage

Question 1

What is the distribution of vertebrae?

Answer 1

cervical: 7
thoracic: 12
lumbar: 5
sacral: 5 (fused - form sacrum)
coccygeal: 5 (forming coccyx)

Question 2

define: sacralization

Answer 2

L5 fuses to sacrum so that theres 4 lumbar vertebra and 6 sacral

Question 3

define: lumbarization

Answer 3

first segment of sacrum fails to fuse with sacral bodies and appears like a lumbar vertebrae

Question 4

List some of the common features of the typical cervical vertebrae (C3-C6)

Answer 4

• 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

Question 5

Describe C1

Answer 5

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

Question 6

Describe C2

Answer 6

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

Question 7

Describe C7

Answer 7

largest cervical vertebrae. long, palpable, non-bifid spinous process

Question 8

What ligament holds the dens to the facet of the atlas?

Answer 8

transverse ligament of the atlas

Question 9

List some of the common features of the thoracic vertebrae

Answer 9

• 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

Question 10

List some of the common features of the lumbar vertebrae

Answer 10

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

Question 11

describe the 2 major components of the intervertebral discs

Answer 11

annulus fibrosus: fibrocartilage ring

nucleus pulposus: gelatinous filling of disc

Question 12

function of IV discs

Answer 12

absorb shock

support weight of rostral segments

Question 13

sacrum
- function
- characteristics

Answer 13

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

Question 14

What is the emphasized importance of coccyx

Answer 14

anchor point for muscles such as gluteus maximus and coccygeus

Question 15

Describe the 2 different types of breast implants

Answer 15

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)

Question 16

Fill in the blank:
the jugular notch is slightly ____ and ____ to the origin of the internal jugular veins

Answer 16

caudal

medial

Question 17

Explain the position of esophagus in reference to the trachea

Answer 17

the esophagus is posterior to the trachea

Question 18

What veins and arteries pass over the first rib causing their grooves?

Answer 18

subclavian artery and vein

Question 19

What kind of joint is the 1st sternocostal joint

Answer 19

synarthrosis (immobile) and a synchondrosis (hyaline cartilage directly united with sternum)

Question 20

What kind of joints are the 2nd - 7th sternocostal joints

Answer 20

synovial plane joints

Question 21

What kind of joint is the sternoclavicular joint

Answer 21

synovial plane joint

Question 22

What kind of joints are the manubriosternal joint and xiphisternal joint

Answer 22

symphyses (although they typically ossify in adulthood).

Question 23

Define: intervertebral foramen

Answer 23

contains spinal nerves which exit and branch off the spinal cord off each spinal segment
Inferior vertebral notch and superior vertebral notch

Question 24

Define: Zygapophysial joint

Answer 24

formed by inferior articular process of superior vertebra + superior articular process of inferior vertebra

Question 25

Describe the difference between the atlanto-occipital joint and atlanto-axial joint

Answer 25

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)

Question 26

What are the 3 atlantoaxial joints?

Answer 26

2 lateral atlanto-axial joints Median pivot joint: dens and anterior arch of the atlas (transverse ligament snugs dens into anterior arch of atlas)

Question 27

What is a hangman's fracture?

Answer 27

Den's fracture - abrupt hyperextension of the neck

Question 28

What is the portion where the sacrum articulates with the iilium called?

Answer 28

auricular surface

Question 29

xiphersternal joint

Answer 29

where the body of the sternum and the xiphoid process meet.

Question 30

sternocostal joint vs costochondral joint vs costotransverse joint vs costovertebral joints

Answer 30

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

Question 31

What reinforces the costotransverse joints

Answer 31

Lateral costotransverse ligament. Limits gliding

Question 32

Fill in the blank: the 7th rib articulates at its head with _____ At its tubercle, it articulates with ______

Answer 32

the body of T7 and T6 transverse process of T7

Question 33

How do the shape of the costotransverse articulations in the rib change from rostral to caudal? What are the ramifications for movement?

Answer 33

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

Question 34

What is flail chest?

Answer 34

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

Question 35

how many IV discs are there

Answer 35

23

Question 36

define: herniated disc

Answer 36

structural failure of the annulus fibrosus leads to bulging (or extrusion) of the nucleus pulposus (ruptured or “slipped”)

Question 37

Where is it most common for discs to be herniated?

Answer 37

L4-L5 L5-S1

Question 38

Where do the sacral spinal cord segments arise from?

Answer 38

T12-L1

Question 39

define: dermatome

Answer 39

portion of the skin innervated by a single spinal nerve.

Question 40

define: myotome

Answer 40

portion of musculature innervated by a single spinal nerve

Question 41

Spinal cord injury vs spinal nerve injury

Answer 41

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

Question 42

List the myotomes

Answer 42

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

Question 43

Where do the spinal nerves exit from?

Answer 43

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

Question 44

What does a typical rib’s heads articulate with?

Answer 44

Example: T6 Rib 6 superior facet articulates with T5 and inferior facet articulates with T6 At Demi facets