lecture 3 Flashcards
Spine and Bony Thorax
what is the axial skeleton comprised of?
the skull, vertebral column, bony thorax, hyoid bone
what is the appendicular skeleton comprised of?
pectoral girdle, upper limb, pelvic girdle, and lower limb
what is the spinal column?
composed of stacked vertebrae divided into five regions with normal curvatures and the possibility of pathogenic curvatures
since the spinal cord is divided up into 5 regions, what are they and describe them?
cervical, thoracic, lumbar, sacral, coccygeal
what is the cervical comprised of?
composed of 7 vertebrae
what is the thoracic comprised of?
composed of 12 vertebrae
what is the lumbar comprised of?
composed of 5 vertebrae
what is the sacral comprised of?
5 vertebrae fused together into a bone called the sacrum
what is the coccygeal comprised of?
4 vertebrae fused into 1 or 2 bones called the coccyx
what is something to consider when considering the vertebrae in each region?
there can be variation in vertebrae number in each region
with respect to normal curvatures, what is the curvature of the fetus?
single anteriorly concave curve
how does the curvature of the fetus change as he develops?
cervical and lumbar regions develop convex anterior curves as child begins holding head erect and sitting up and so thoracic and sacral/coccygeal regions maintain concave anterior curves called primary curves, keep in mind that cervical and lumbar region curves are convex anteriorly and are called secondary curves
what causes pathogenic curves?name examples?
it can be due to congenital, disease or postural in origin; scoliosis, hyper kyphosis, hyper lordosis
what is scoliosis?
lateral curvature, most often in thoracic region
what is hyper kyphosis?
exaggerated thoracic curvature (hunchback)
what is hyper lordosis?
exaggerated lumbar curvature (swayback) usually due to carrying extra abdominal weight
what are the components of the typical vertebrae?
body, vertebral arch, spinous process, transverse process, superior and inferior articulating processes, intervertebral disc
what is the vertebral body?
disc shaped anterior portion of the vertebrae and is the weight bearing portion of the vertebrae
what is the vertebral arch?
it extends posteriorly from the body and protects the spinal cord
what are the components of the vertebral arch?
pedicles and laminae
what is the pedicle?
short processes that form lateral portions of vertebral arch
what is the laminae?
flat processes that form posterior portions of vertebral arch
what are the other prominent features of the vertebral arch?
vertebral foramen, vertebral canal/spinal canal, vertebral notches
what are the vertebral foramen?
opening bounded by body and vertebral arch
what are the vertebral canal/spinal cord?
vertebral foramen of all vertebrae stacked together
what are the vertebral notches? what is a significant feature of this part of the vertebrae?
superiorly and inferiorly on each vertebra;) with adjacent vertebra they form an intervertebral foramen which allows passage of a spinal nerve
what are some clinical correlations associated with the vertebral arch?
spinal stenosis and laminectomy
what is spinal stenosis?
abnormal narrowing of vertebral foramen
what is a laminectomy?
removal of one or more of the spinal processes and their supporting lamina or pedicle
what is the spinous process?
projects dorsally from junction of laminae and is the site for muscle attachment
what is the transverse process?
extend laterally from junction of pedicle and lamina site for muscle attachment
what are the superior and inferior articulating processes?
articulate with adjacent vertebrae to limit movement
what is the intervertebral disc?
cartilage located between the bodies of adjacent vertebrae
what is the structure of the intervertebral disc?
annulus fibrosis and the nucleus pulpous
what is the length of the intervertebral disc?
1/4 of length of the nonfused vertebral column
what is a herniated disc?
compresses the spinal cord or spinal nerve
what are the movements between adjacent vertebrae?
flexion, extension, lateral flexion, lateral extension and rotation
what are the unique features of the cervical vertebrae?
each transverse process contains a transverse foramen and transmits vertebral arteries and veins to/from the brain; bifid spinous process; uncinate process
whats the uncinate process? which vertebrate have the uncinate processes?
hook-shaped process on lateral superior surface of bodies that provides more structural support in stacking of vertebrae; C3-T1
what is the C1 also known as?
the atlas
describe the prominent features of the atlas?
1) lacks spinous process and body, has anterior and posterior arches
2) large lateral masses
3) superior articulating facets
4) no intervertebral disc between C1 and C2
what do articulating facets do?
articulate with occipital condyles of the skull to form atlanto-occipital joint
so if we already know what articulating facets are, what do they do?
no rotation at this joint
there are intervertebral discs between C1 and C2, T/F?
false, there are none
what is C2 also known as?
axis
name some features of the axis?
it has the dens/odontoid process also known as the hangman’s bone
what is the dens or odontoid process?
projects superiorly through anterior portion of vertebral foramen of C1 providing a pivot point for rotation
why is the dens also called the hangman’s bone?
trauma can sheer dens, driving it into the medulla oblongata causing instantaneous death
what is significant about the C7?
it is the veterbra prominence, which is a large non bifid spinous process that can be easily palpated at the base of the neck
what are the characteristic features of the thoracic region?
1) bodies considerably larger than cervical vertebrae
2) longer, thicker transverse processes compared to cervical vertebrae
3) vertebrocostal joints - thoracic vertebrae articulate with ribs
since we know vertebrocostal joints can be found in the thoracic region, what are they comprised of?
1) facets and demifacets on the body that articulate with heads of ribs
2) facets on transverse processes and these articulate with tubercles of ribs
T/F, there are facets on the transverse processes of T11 and T12?
F
describe the spinous processes on the thoracic regions?
long, pointing slightly inferior
describe the lumbar region?
largest bodies due to weight bearing function and all processes are short and thick and serve as attachment sites for large back muscles
describe the sacral region?
1) five vertebrae begin to fuse by age 18 and completed by 30
2) anterior/posterior surface
3) articulations present
what is the anterior surface of the sacral region comprised of?
anterior sacral foramina and the sacral promontory
what is the sacral foramina?
formed from the fused spinous processes
what is the sacral promontory?
point used for measurements of the pelvis
what is the posterior surface of the sacral region comprised of?
median sacral crest, lateral sacral crest, posterior sacral foramina, sacral hiatus, sacral cornua
what is the median sacral crest?
formed from fused spinous processes
what is the lateral sacral crest?
formed by fusion of transverse processes
what is the posterior sacral foramina?
continuous with anterior sacral foramina which allow passage of spinal nerves and blood vessels
where is the sacral hiatus?
laminae of S5 (and sometimes S4 as well) fail to merge at midline which leave opening to vertebral foramen which than can be used for caudal anesthesia
where is the sacral cornua?
located bilateral to sacral hiatus which form from inferior articular processes of S5
with respect to the sacral region, we know articulations are present? what are they?
sacroiliac joint, lumbosacral joint
where is the sacroiliac joint?
between iliac and articular surface of the sacrum
where is the lumbosacral joint?
1) base of sacrum with inferior surface of the body of L5
2) superior articular processes of sacrum with inferior articular processes of L5
how is the coccyx formed?
from the fusion of 4 and sometimes 5 coccygeal vertebrae and these fuse between 20-30 years of age
why is the coccygeal cornua of the coccyx important?
form from pedicles and superior articular processes of Co1»_space; attached via ligaments to sacral cornua
what is the bony thorax comprised of?
sternum and ribs
what is the sternum comprised of?
manubrium, body and xiphoid process
what is the maubrium comprised of?
suprasternal/jugular notch, clavicular notches, sternocostal joints, sternal angle/angle of louis
what does the body of the thorax articulate with?
it articulates with costal cartilages of ribs 2-10
what does the xiphoid process provide attachment for?
abdominal muscles
til how old does the cartilage of the xiphoid process last?
40 years old
what can happen when you perform CPR on the xiphoid?
it can be broken and driven into internal organs if CPR is done incorrectly
how can we classify the ribs?
vertebrosternal or true ribs (1-7), the false ribs or vertebrochondral ribs (8-10), floating or vertebral ribs (11-12)
where do the vertebrosternal or true ribs connect (1-7)?
they connect to the sternum directly via costal cartilage and increase in length with increasing number
where do the false ribs or vertebrochondral ribs attach (8-10)?
they attach to the sternum via costal cartilage of the 7th rib
what is significant about the FLOATING ribs (11 and 12)?
anterior ends do not connect to the sternum
how do we classify the ribs based on anatomical structures?
typical and atypical ribs
which ribs are the typical ribs?
3-9 and these ribs consist of a head, neck, tubercle, costal angle, costal groove, and body
what is the head of the of typical ribs?
it contains superior and inferior facets that articulate with demifacets on the thoracic vertebrae
what comprises the tubercle of the typical ribs?
non-articular and articular part
what is the non-articular part of the tubercle in the typical rib?articular?
the non-articular part provides attachment of ligaments to vertebrae; the articular part articulates with facet of transverse process of the thoracic vertebra
what is a costal angle with respect to the typical rib, define it?
weakest part of the rib
what is the costal groove with respect to the typical ribs?
it protects blood vessels and the small nerve
what are the atypical ribs?
1,2,10,11,12
why is the first rib considered atypical?
shortest, broadest, and most sharply curved rib
describe the first rib?
deep to clavicle, lacks costal cartilage, and superior surface which the superior surface serves as attachments for the anterior and middle scalene and has grooves for subclavian artery and vein
how do the movement of the ribs work during inspiration?
you have the elevation of ribs via muscle contraction that increases the volume of the thorax creating negative pressure that brings air into the lungs
in which dimension dose the air increase in the lung cavity?
the anterior and posterior dimension and not so much in the transverse dimension, the sternum moves anteriorly and also inferiorly and at the manubriosternal joint in children
where can we find thoracic apertures?
in the thorax, divided into the superior and inferior thoracic aperture
how is the superior thoracic aperture bounded?
its bounded by T1, first ribs and cartilages, and the superior rim of the manubrium
what is a clinical correlation tied to superior thoracic aperture?
thoracic inlet syndrome
what is thoracic inlet syndrome?
neuromuscular disorder associated with compression of nerves, blood vessels and lymphatic vessels of the thoracic inlet
how is the inferior thoracic aperture bounded?
by T12, 11th and 12th ribs, costal cartilages of ribs 7-10 and xiphoid process
what can affect the thoracic wall?
changes due to age, congenital anomalies, traumatic injuries, surgical procedures
because we know that age can affect the thoracic wall, please explain how?
the costal cartilages become calcified with advanced age like becoming more radiopaque and less resilient; keep in mind too, that the xiphoid process ossifies in early 40
how does congenital anomaly form with respect to the thoracic cavity?
the sternum develops from fusion of bilateral sternal bars, aka improper fusion
what are the different types of sternal congenital anomalies?
complete sternal cleft, partial sternal cleft, and the sternal foramen
what is complete sternal cleft?
this allows the heart to protrude through thoracic wall (ectopic cordis)
what is the partial sternal cleft?
it produces U- or V-shaped clefts in the sternal body; repaired during infancy or childhood
what is the sternal foramen?
a small circular opening due to improper fusion
what are the other types of congenital anomalies?
pectus excavutum, pectus carinatum, bifid rib, and the supernumerary ribs
what is the pectus excavatum?
sunken chest due to abnormal growth of multiple ribs and sternum
what is the pectus carinatum?
a pigeon chest due to overgrowth of costal cartilage
what is bifid rib?
sternal portion of the rib cleaved into two portions usually asymptomatic
what is the supernumerary ribs?
it can be cervical or lumbar that can interfere with neuro or vascular structures and can be mistaken for a landmark
because traumatic injury can also affect the thorax, rib fractures can result. What typically causes this, where and name a few examples?
most commonly due to direct blows; can be broken anywhere, just note that just anterior to the costal cartilage is the weakest point; you can have displaced fractures, non-displaced fractures
which of the ribs in a traumatic injury are less likely to be injured?
the 1st and 2nd ribs because they are protected by the clavicle and also the vertebral ribs not connected anteriorly and so they have more mobility
which ribs are commonly fractured?
ribs 7 and 10
what is unique about children’s cartilage?
they are more pliable and less likely to fracture
can a flail chest be considered traumatic injury to the thorax?
yes! this happens when you have multiple rib fractures allowing segment of the thoracic wall to move freely, paradoxical movement most likely evident, painful and ventilation impaired
what can you do to immobilize a flail segment?
hooks and wires
what is dislocated in a rib dislocation?
dislocation of sternocostal or interchondral joints with painful lump over site
what happens in a rib separation?
dislocation of costal chondrial junction usually through tough fibrous covering and separated ribs that move to overlap superior ribs
what are the surgical procedures we can use to fix medical problems concerning the thorax?
sternal biopsy, thoracotomy, median sternotomy
what is a sternal biopsy?
when you take a subcutaneous position of spongy bone for bone marrow biopsy especially done for marrow transplants, biopsy for metastatic cancer or blood disorders
what is a thoracotomy?
a surgical entrance through thoracic wall into the pleural cavity
what are the different types of thoracotomy?
anterior thoracotomy (entrance through costal cartilages) and posterior thoracotomy (allows for posterolateral access through the 5th -7th intercostal spaces),
what is the median sternotomy?
the splitting and retracting of sternum in medial plane used to gain access to the mediastinum
