Thoracic spine
Costal facet vs demi-facet
*Costal facet* = a whole flat/nearly flat surface *Demi-facet* = hals of a facet. Therefore 2 required (inferior from above T vertebrae, and superior from below vertebrae) Demi facets on ribs 2-9 (inferiorly on rib1) Facets on ribs 1, 10, 11, 12 *note: there's also an articulating surface on the transverse process of the vertebrae- for the tubercle of the rib. only on T1-10).
Where are demi facets and facets (go through each rib)
*RIB 1*: 1x full facet, 1x Inferior demi-facet *RIBBS 2-9* 2x demi facets (1x superior, 1x inferior) Full facets on *BODIES* of T1, T10, T11, T12 (*rule of 1's*) T1-T10 Transverse costal facets *NO* transverse costal facets on T11/T12
Exceptions to costal facets
*RULE OF 1s!* Vertebrae T1, T10, T11, and T12 have *complete costal facets* on the bodies for ribs* 1 and 10-12*, which articulate on the vertebral bodies instead of between vertebrae. Vertebrae T11 and T12 have no transverse costal facets. Similarly, ribs 11 and 12 articulate with the bodies of T11 and T12, but since the ribs do not have tubercles they also cannot attach to the non-existent transverse costal facets of T11 and T12. These ribs also lack a cartilaginous connection to the sternum and higher costal cartilages, and are only embedded in the lumbar muscle, therefore, T11 and T12 are known as the floating ribs.
Which ribs articulate on ONE vertebral body (1 vertebrae) and NOT between ribs (2 vertebrae)
*T1, T10, T11, and T12* have *complete costal facets* on the bodies for ribs* 1 and 10-12* (which articulate on the vertebral bodies instead of between vertebrae.)
Actions of each thoracic nerve root
*T1-T6* Intercostals and trunk above the waist *T7-L1* Abdominal muscles Think '6 pack' - below T6= abdominals. Above = intercostals + trunk.
*CLINCIAL APPLICATION* 2. Why does thoracic kyphosis increase in old age?
*osteoporosis *- a condition whereby *bone mass is lost* (mostly in older people). This leaves the spine less able to support the weight of the body, thus resulting in characteristic kyphosis.
What movements are available in the thoracic spine?
*restricted by the rib cage*. *saggital flexion *saggital extension *lateral rotation *Restricted range of motion for lateral flexion and extension - due to *RIBS* Flexion/extension/lateral flexion is *restricted by the rib cage*. T2-T3 to T11-T12 have the lowest range of motion in the spinal section highest range of motion in T1-T2, of all three planes *however, motion in all planes if allowed by angles of the joints in the thoracic spine; rotation, flexion extension and lateral flexion. *
Clinical importance of thoracic vertebrae (common pathologies)
-Herniated discs -Scoliosis
How do the thoracic vertebrae articulate with the rest of the thoracic cage?
-somewhat concave *costal facets* for the attachment of the ribs -On vertebral body -On transverse process (ribs 1-10) -Superior costal facet -Inferior costal facet -Transverse costal facets (w tubercle of rib) Ribs are generally inserted between two vertebrae Each vertebra therefore has a pair of superior articular facets that face posteriorly and a pair of inferior articulating facets that face anteriorly (except for T12). This means that *the rib will articulate with the inferior costal facet of the upper vertebrae and the superior costal facet of the lower vertebrae*
Unique points of thoracic vertebrae anatomy
1. *costal facets* for the joints with the ribs :in the form of: -Superior and inferior demifacets -Full facets on vertebral body 2. Transverse articulation surfaces To articulate with tubercle of ribs. Present on ribs 1-10. 2. *Spinous processes are more pointed* than other vertebrae and *angle sharply downward* 3. The *body is smaller than in lumbar, but larger than in the cervical* vertebrae 4. Body is heart shaped 5. *Body increases in size* as descending towards lumbar vertebrae
Unique joints of thoracic spine
1. costovertebral joint - head of rib -facet/superior demifacet + inferior demifacet -intervertebral disk 2. costotransverse joint -articulating surface of *transverse process* - tubercle of rib (only ribs 1-10)
How many thoracic nerve roots are there? Where are they located in relation to the vertebrae?
12 nerve roots Project below the vertebrae 1-12 From the intervertebral foramen
How many thoracic vertebrae are there?
12! Breakfast at 7 (7 C vertebrae) Lunch at 12 (12 T vertebrae) Dinner at 5 (5 Lumbar/Sacral)
All atomically characteristics of thoracic vertebrae (common and unique) HUGE
1: Body: increase in size as descending to the lumbar vertebrae 2. Spinous process: dorsal bony prominence 3. Costal facets/ demifacets /articulations. surfaces for head of the rib/ tubercles of ribs. 4. Transverse process: bony process that arises from the vertebral arch, for 1-10, these attach to the rib tubercle. 6. Lamina: bony imbrication that covers the subjacent vertebrae and *connect with pedicles to protect the spinal cord* 7. Intervertebral foramen: paired foramina (one left, one right) intended for the exiting nerve roots 8. Vertebral foramen: large opening posterior to the body that forms spinal canal through which the spinal cord passes Distinguishing features: 1) Presence of facets for the joints with the ribs/tubercles - combo of full facets, superior/inferior demifacets, transverse articulation surface 2)Spinous processes are more pointed than other vertebrae and angle sharply downward 3)The body is smaller than in lumbar, but larger than in the cervical vertebrae 4) Body is heart shaped
How many costal facets per typical T vertebrae?
6 4x demi facets (2x side) 2x transverse articulating facets (with tubercle of rib)
Anterior thoracic muscles: Abdominal muscles
Abdominal muscles a. rectus abdominis b. external and internal abdominal oblique muscles c. transversus abdominis.
Ligaments for T spine (all)
Anterior and posterior longitudinal ligaments Ligamentum flavum: (Connects the laminae of adjacent vertebrae). *Inter*spinous ligament: (spinous processes ) *Supra*spinous ligament: Unique ligaments to costovertebral joints: 1.Radiate ligament of head of rib - 2. Costotransverse ligament - Connects the neck of the rib and the transverse process. 3.Lateral costotransverse ligament - Extends from the transverse process to the tubercle of the rib. 4. Superior costotransverse ligament - From the upper border of the neck of the rib to the transverse process of the vertebra *ABOVE IT*
Describe the formation of a typical thoracic nerve
Each thoracic nerve root exits the spinal canal through an *intervertebral foramen* After branching from the spinal cord and travelling through the foramen, a thoracic nerve root *branches into two different nerve bundles* that feed into the rami -ventral ramus and - dorsal ramus.!
Posterior muscles
Erector Spinae Quadratus lumborum Multifidus Rotatores
Superior costotransverse ligament
FROM RIB TO TRANSVERSE PROCESS ON VERTEBRAE ABOVE from neck of rib to transverse process of adjacent *superior *
1. gross movements of the thoracic spine 2. osteokinematics of each joint (spin, roll, glide, direction)
Facet joint is slightly convex in both the transverse and sagittal planes This orientation permits multidirectional movement *PHYSIOPEDIA SAYS NO FLEXION/EXTENSION BUT?*FLEXION: -Z joint: inferior facet of vertebrae above, *glides anteriorly* on facet below - superior glide of tubercle of rib on transverse process - spin with anterior roll at costovertebral joint EXTENSION: -Posterior rotation -Zygapophyseal Joint: Inferior facets of the superior vertebra glides inferoposteriorly on facet beneath *costotransverse joint*: -Posterior rotation of the rib results in an *inferior glide* of the tubercle of the rib at the costotransverse joint LATERAL FLEXION: - THEORY: Bending to the right creates a relative superior glide of the tubercle of the right rib and a relative inferior glide of the left rib. The effect of this motion is to *rotate the vertebal body contralaterally* -Zygapophyseal joint The left inferior articular facet of the superior vertebra *glides superomedially* and the right inferolaterally *Costotransverse joint* Left tubercle glides inferior Right tubercle glides superior THORATIC ROTATION: Zygapophyseal : Ipsi - inferior glide Contra - superior glide Costotransverse: Ipsi - inferior glide Contra - superior glide Costovertebral Ipsi - posterior roll Contra - anterior roll
What muscles cause each movement of the thoracic spine?
Main ones: Spinal erectors Rhomboids Middle trapezius. *Anterior* Abdominal muscles: - rectus abdominis -external and internal abdominal oblique muscles -transversus abdominis. *Posterior* Erector Spinae Quadratus lumborum Multifidus Rotatores
Intervertebral foramen
Opening formed by the inferior and superior notches on the pedicles of adjacent vertebrae. Allows passage of spinal nerves and vessels.
O I A for each muscle
Other quizlet
T12
Similar to T11, but can be distinguished by its inferior articular surfaces, (convex and directed lateralward), *similar lumbar vertebrae*. This vertebrae most closely resembles a lumbar vertebra also by its *transverse process* that is *subdivided into 3 elevations*—the superior, inferior, and lateral tubercles. The thoracic spinal nerve 12 passes through underneath T12.
2 muscles directly integrating with thoracic vertebrae
Spinalis Longissimus (erector spinae muscles)
T1-T12- facets.
T1-10 have transverse articulating surfaces with the tubercles of the ribs T1: 1 full facet, 1 inferior demifacet T2-9: inferior and superior demifacet T10: one full facet facets are located across both the vertebral body *and* the pedicle. T11-12: one full facet - located on pedicles
What are the limiting factors for each movement?
The rib cage Joints (facet joint orientation) Ligaments
anatomical adaption to function T vertebrae !!!!!
The zygapophyseal joints are tight enough to protect vital organs but loose enough to allow for respiratory movements as well as to allow the thoracic segment to have the *greatest freedom of rotation of the entire spine.* The zygapophyseal joints, as well as the relatively thin intervertebral discs, cause the thoracic region to have the *least flexion/extension ability of the spine*. limits flexion Prevents downward flexion on heart and lungs The increase in vertebral body size as the spinal column descends is directly related to the increased weight-bearing requirement;
*CLINICAL APPLICATION* 1. Explain why rotation has the largest range of movement in the thoracic spine
The zygapophyseal joints are tight enough to protect vital organs but loose enough to allow for respiratory movements as well as to allow the thoracic segment to have the greatest freedom of rotation of the entire spine.
What effect does the direction of the facets of the zygoapophyseal (facet) joints and the intervertebral disc, have on these movements?
Thoracic Region = 60 degrees; frontal plane; lateral flexion and rotation; no flexion/extension The facet joints between adjacent thoracic vertebrae are angled at 60° to the transverse plane and 20° to the frontal plane, with the superior facets facing posterior and a little up and laterally and the inferior facets facing anteriorly, down, and medially
Joints of the thoracic spine
Typical to whole spine: 1.Facet/ zygopophysial (synovial) 2.Disk (symphysis) Unique to T spine: Each *costovertebral joint* - head of the rib articulating with: 1.Superior costal facet 2.Inferior costal facet 3.Intervertebral disc separating the two vertebrae *ONLY SLIGHT GLIDING MOVEMENTS* *costotransverse* -Transverse processes of a thoracic vertebra -Tubercle of the adjacent rib.
Ventral and dorsal ramus of the thorax
Ventral ramus - Eleven of them are situated between the ribs, and are therefore termed *intercostal*; the twelfth lies below the last rib. Each nerve is connected with the adjoining ganglion of the sympathetic trunk by a grey and a white ramus communicans. Dorsal ramus go into the back muscles and also provides sensation to the skin.
Lamina of vertebrae
bone segments form most of the arch, connecting the transverse and spinous processes.
Pedicles of vertebrae
cylindrical segments of bone that connect the arch to the body,
Lateral costotransverse ligament
fibrous band that crosses transversely! (see diagram) O: from the posterior surface of the tip of a transverse process of a vertebra to I: the non-articular part of the tubercle of the corresponding rib
Radiate ligament of head of rib
from head of rib to sides of vertebral bodies associated with it Fans outwards from the head of the rib to the bodies of the two vertebrae and intervertebral disc.
Costotransverse ligament
from neck of rib to transverse process of vertebra
Costal facets
gliding joints where ribs meet thoracic vertebrae 3 types: -superior, inferior *demi-facets* -full facets -transverse costal *facets* (articulations between transverse process and tubercle of rib)
Curve of the thoracic spine
kyphotic hyperkyphosis = hunch back ! Height of body is slightly higher posteriorly than anteriorly - kyphosis
floating ribs
last two pairs of ribs; do not attach to sternum Ribs 11/12 do not have tubercles so cannot attach to transverse costal facets of T11/12 But T11 and T12 have *complete costal facets* on their bodies
Unique ligaments for T spine
ligaments unique for costovertebral joints: 1.Radiate ligament of head of rib - Fans outwards from the head of the rib to the bodies of the two vertebrae and intervertebral disc. 2. Costotransverse ligament - Connects the neck of the rib and the transverse process. 3. Lateral costotransverse ligament - Extends from the transverse process to the tubercle of the rib. 4.Superior costotransverse ligament - Passes from the upper border of the neck of the rib to the transverse process of the vertebra superior to it.
systems the thorax is involved in
musculoskeletal, respiratory cardiac digestive urogynecological
Demonstrate the movements occurring in the thoracic spine
no flexion/ extension due to facet joints ?