Vertebral Column & Thoracic Wall Flashcards
Components of vertebral column
Cervical (7), thoracic (12), lumbar (5), sacrum (about 5 fused), coccyx (3-4 fused)
Curvatures of spine and direction they curve in
2 primary (concave) and 2 secondary (convex)
Is first curvature primary or secondary?
secondary
lamina
separates traverse from spinous process
How do vertebrae create motion?
joints between articular processes
Cervical zygapophysial joint
sloped from anterior to posterior
Motions from cervical vertebrae
rotation, flexion, and extension
Thoracic zygapophysial joint direction and motion
vertical for rotation, flexion, and extension
lumbar zygapophysial joint
processes of vertebrae below are wrapping around processes of vertebrae above
What is the lumbar zygapophysial joint important for?
Stability
Cervical vertebrae
Triangular shaped vertebral canal with small, short vertebral body w delicate arches, Foramen transversarium
Bifurcated spinous process
Foramen transversarium
Provides place for vertebral artery to move down only cervical vertebrae
Atlas
C1
Axis
C2
Axis shape and function
50% of rotation in neck from specialized vertebral body (dens) shaped like a tooth, hardly any traverse processes
thoracic vertebrae
Round vertebral foramen, heart-shaped vertebral body, extra articulations for rib and vertebrae (costovertebral joints), spinous processes long, flat, & angled inferiorly
lumbar vertebrae
small triangular foramen and large kidney-shaped body, stocky posteriorly projecting spinous processes, mammillary & accessory process
Zygapophysial joint
Flat synovial plane joint that connects
sup & inf facets of adjacent vertebrae, allows gliding spinal motion, but articular process orientation aid or limit movement
intervertebral discs/joints
Solid joint symphyses that connects adjacent vertebrae and shock absorption
parts of intervertebral discs
annulus fibrosus and nucleus pulposus
Annulus fibrosus structure and functon
Ring of fibrocartilage inserts on rim of vertebral bodies, Limit rotation between adjacent vertebrae
nucleus pulposus structure and functon
Gelatinous center, absorbs compression forces, semi-fluid ball bearing; avascular
spinal ligaments and location
anterior and posterior longitudinal ligaments, ligamentum flavum, supraspinous ligament, interspinous ligament, and ligamentum nuchae
anterior vertebral ligament and function
courses along ant. vertebral bodies from skull base to sacrum, prevents hyperextension of vertebral column
Posterior vertebral ligament
courses along post. vertebral bodies from C2 to sacrum, prevents hyperflexion of the vertebral column, smaller than anterior longitudinal ligament
Supraspinous ligament and function
connects adjacent vertebral spines, resists flexion in head
ligamentum nuchae and function
thickened extension of supraspinous and interspinous ligaments in cervical region, resists flexion in head
interspinous ligament and function
between adjacent spinous processes and blends with suprapsinous ligament and ligamentum flava, limits flexion
vertebral column functions
. Maintains erect posture and aids in locomotion
. Supports head, trunk, limbs
. Protects the spinal cord and spinal nerve roots
typical structure of vertebrae
body, vertebral arch, 7 processes, sup/inf vertebral notches, intervertebral foramina
body of vertebrae
also called centrum, weight bearing portion, covered by hyaline c.
vertebral arch
also called neural arch, 2 pedicles & 2 laminae surrounding vertebral foramen
muscle attachment sites in typical vertebrae
2 transverse process projecting laterally and 1 spinal process projects post/inferiorly
articular process in typical vertebrae
sup & inf articular processes (zygapophyses) w facets for processes adjacent vertebrae articulate w one another at zygapophysial joints
what determines direction and movement of zygapophysial joints?
orientation of articular processes
sup & inf vertebral notches in typical vertebrae
indentations formed between projection of vertebral body & articular processes sup & inf to pedicles
intervertebral foramina in typical vertebrae
lateral openings that form between sup & inf vertebral notches of adjacent vertebrae
what do intervertebral foramina house?
spinal nerve roots or dorsal root ganglia & vessels
cervical vertebrae body
Superior surface of body: concave from side-to-side w uncus
Inferior surface of body is convex from side-to-side.
uncus
superiorly projecting lateral margins on vertebral body of cervical vertebrae
where do facets face on thoracic vertebrae
sup articular facets face posteriorly, inf facets face anteriorly
costal hemifacets
small articular surfaces on lar. side of T2-9 (2 at each joint w rib head)
costal facets
large articular surfaces on lat. side of T1 and T10-12 (1 facet per joint)
mammillary process
located on sup. articular process on lumbar vertebrae, attachment for multifidus
accessory process
located between mammillary and transverse processes on lumber vertebrae, attachment for longissimus
sacral vertebrae
base, apex directed inf. to articulate w L5, apex directed inf. to articulate w coccyx, 4 pairs of dorsal & ventral foramina, median sacral crest, auricular surface
sacral promontory
ventral projection of sacral base
what do dorsal and ventral sacral foramina do?
transmit dorsal & ventral rami of sacral spinal nerves
median sacral crest and how is it formed?
dorsal midline crest formed from fused spinous processes of S1-S3/4
sacral canal and where does it end
vertebral canal through sacrum ends at sacral hiatus
what is sacral hiatus site for?
injecting extradural anesthesia
auricular surface
on sacru,, ear-shaped lat. surface contributes to sacroiliac joint
coccygeal vertebrae formation
result of fusion of 4 rudimentary tail vertebrae
how much length of spinal column is from discs?
1/4 of total length
Is there a disc between C1 and C2?
NO
caniovertebral joints
formed between skull and C1 & C2
ligamenta flava
paired ligaments joining laminae of adjacent vertebrae on post. wall of vertebral canal
ligamenta flava function
contributes to post. boundary of intervertebral foramina, elastic fibers aid in recoil from ant. flexion and maintaining upright posture
where are cervical z-joints located and how large are discs?
horizontal plane & intervertebral discs are large relative to bodies
where are thoracic z-joint, how large are discs and why?
coronal plane to allow rotation, discs thin compared to bodies
why are flexion and extension limited in thoracic spine?
attachments to rib cage
where are lumbar z-joints located and how large are discs and why?
sagittal plane for flexion, extension, &lat. flexion, discs large to limit rotation
parts of thoracic skeleton
thoracic vertebrae, ribs and costal cartilages, and sternum
thoracic skeleton function
rigid yet flexible cage that protects thoracic & abdominal viscera, supports weight of upper limbs, provides muscle attachments, & aids in respiration
typical rib components
head, neck, tubercle, & body
rib head
two facets that articulate w same-numbered & sup. adjacent vertebral bodies at the joint of the head of the rib
rib neck
joins head and body
rib tubercle location and function
junction of neck & body and has an articular part to articulate w transverse process of same-numbered vertebrae at costotransverse joint.
rib body characteristics
thin, flattened portion, most curved at angle of the rib, costal groove along inferior margin
costal groove function
transmits the intercostal nerve and vessels, on inferior inner side of rib body
where does rib body attach to costal cartilage?
costochondral junction.
atypical ribs
1, 10-12
rib 1 characteristics
short and flattened w the most curvature, superior surface has grooves for the subclavian vessels, articulates w T1 only
ribs 10-12 characteristics
articulate w only the same-numbered vertebral body or pedicle
do ribs 11-12 have neck and tubercle?
NO
true ribs
Ribs 1-7 attach directly to sternum via costal cartilages
false ribs
Ribs 8-10 attach indirectly to sternum via costal cartilage of the next sup. rib
floating ribs
Ribs 11-12: short w rudimentary cartilages w no attachment to sternum, terminate in abdominal wall musculature
sternum components
manubrium, body of the sternum, and xiphoid process
sternal angle
junction of the manubrium & sternum (manubriosternal joint); palpable surface landmark located between the 2nd pairs of costal cartilages at T4/T5
costal notches
sites of articulation w costal cartilages, located along lat margins of sternal body
costovertebral joints
synovial plane joints, joint of head of rib forms btw rib head & hemifacets on bodies of same-numbered and sup. thoracic vertebrae
costotransverse joint
forms between the rib tubercle and transverse costal facet of transverse process of same-numbered vertebra (T1-T10 levels)
sternocostal joints
formed between medial ends of the costal cartilages 1-7 and sternum
which sternocostal joint is synchdrosis?
1st
which sternocostal joints are synovial plane joints?
2-7
costochondral joints characteristics
synchondrosis joints formed between each rib and its corresponding costal cartilage; no movements
interchondral joints
synovial plane joints formed between costal cartilages of ribs 6-10
manubriosternal joint
symphysis formed between the manubrium and sternal body
xiphisternal joint
synchondrosis between xiphoid process and sternal body
thoracic cage spaces
sup. thoracic aperture, inf. thoracic aperture, intercostal spaces
sup. thoracic aperture
sup. boundary of thoracic cavity formed by T1 vertebra, first ribs and manubrium.
sup. thoracic aperture function
transmits major vessels and other soft tissue structures btw thoracic cavity, neck & upper limb.
inf. thoracic aperture
Formed by T12 vertebra, ribs 11-2 and their cartilages, the costal margin (costal cartilages 6-10), & xiphoid process
inf. thoracic aperture function
attachments for the muscular thoracoabdominal diaphragm
thoracoabdominal diaphragm function
separates the thoracic and abdominopelvic cavities
intercostal spaces
Spaces between adjacent ribs/cartilages that extend from vertebral column posteriorly to sternum ant.
how are intercostal spaces numbered?
sequentially sup. to inf. beginning w first intercostal space between ribs 1 and 2
subcostal space
inf. to rib 12
what do intercostal spaces contain?
intercostal muscles, nerves, and vessels
intercostal muscles
external intercostal, internal intercostal, innermost intercostal,
where do intercostal muscles attach?
attach along inf. border of sup. rib and sup. border of the next lower rib
what are intercostal muscles supplied by?
intercostal nn. and ant. and post. intercostal aa.
external intercostal mm.
most superficial of the intercostal group; muscle fibers are replaced anteriorly by membrane
external intercostal mm fiber orientation
inferiorly and anteriorly (\\ ///) (hands in pockets).
external intercostal mm. action
elevates ribs
internal intercostal mm. location
Just deep to the external intercostals, muscle replaced posteriorly by a membrane.
internal intercostal mm. fiber orientation
oriented inferiorly and posteriorly (/// \).
internal intercostal mm. action
depresses ribs
innermost intercostal mm. location
deepest layer; present only in the most lateral parts of the intercostal spaces
innermost intercostal mm. fiber orientation
oriented inferiorly and posteriorly (/// \).
innermost intercostal mm. action
depresses ribs
subcostal m. OIA
O: Internal surface of inferiormost ribs, near their angles
I: fibers course inferior and posterior to insert on sup. borders of 2nd or 3rd rib below
A: Depresses ribs
Transversus thoracis muscle OIA
O: post. surface of inf. sternum and xiphoid process
I: fibers course sup. & lateral to insert on internal surface of costal cartilages 2-6, spans 2-3 intercostal spaces per muscle
A: Depresses ribs
intercostal nerves
ventral rami of T1-11 spinal nerves
subcostal nerve
T12 ventral ramus
intercostal nerve pathway
nerves enter same-numbered intercostal space & go laterally btw parietal pleura & membranous part of internal intercostal mm.
At costal angle, nerve enters costal groove and goes ant. btw internal and innermost intercostal mm.
branches of intercostal nerve
lateral and ant. cutaneous n., branches to intercostal, subcostal, transversus thoracis, & serratus post. mm
lat. cutaneous n. location
at midaxillary line, it leaves intercostal space & divides into the ant. & post. branches
ant. cutaneous n. location
exits the intercostal space just lateral to the sternum
what nerves enter and supply abdominal wall from thoracic wall?
nn. 7-11 and the subcostal n. after giving rise to lat. branches
intercostal arteries come from what branches?
anastomosing branches from thoracic aorta & internal thoracic artery
post. intercostal aa. location
enter intercostal spaces lateral to the vertebral column.
lateral cutaneous a.
branches course with the lateral cutaneous nerves.
what do post. intercostal aa. 1-2 arise from?
costocervical branch of the subclavian artery.
what do post. intercostal aa. 3-11 branch from?
directly from the thoracic aorta
what is internal thoracic a. a branch from?
subclavian a.
internal thoracic a. location
descends lat. to sternum btw transversus thoracis mm. and ant. thoracic wall
anterior intercostal aa.
arise directly from internal thoracic a., goes posteriorly to anastomose w the corresponding post. intercostal a.
anterior perforating branches
emerge lat. to sternum & contribute to vasculature of chest & breast
where does the internal thoracic a. divide and into what arteries?
6th costal cartilage into sup. epigastric (to abdominal wall) and musculophrenic a.
intercostal veins
Anterior and posterior intercostal veins
Anterior and posterior intercostal veins pathway
course immediately sup. to corresponding artery & nerve in intercostal spaces
order of artery, vein and nerve in bundles
VAN, superior to inferior
where does the venous blood from thoracic wall drain to?
sup. vena cava via internal thoracic vein & azygos venous system
thoracic wall function
Coordinated movements btw thoracic wall & thoracoabdominal diaphragm increase intrathoracic dimensions (volume) which reduces pressure in lungs & allows lungs to inflate
what does contraction of thoracoabdominal diaphragm do?
causes it to descend/flatten which increases vertical dimensions of thoracic cavity.
what does rib elevation do?
(bucket-handle action) increases the transverse dimensions of the thoracic cavity.
what does sternum elevation do?
Sternum elevation (pump-handle action) increases the anterior-posterior dimensions
how does quiet inspiration occur?
primarily by contraction and descent of thoracoabdominal diaphragm
External intercostal mm. assist w rib elevation & stiffen intercostal spaces
how does quiet expiration occur?
passive recoil of lung tissues and thoracic wall as the diaphragm relaxes and ascends.
how does active inspiration occur?
assisted by accessory muscles of respiration that forcefully elevate the sternum and ribs
muscles involve in active inspiration
levatores costarum, serratus, pectoral muscles, sternocleidomastoid & scalene muscles in neck.
how does active expiration occur?
assisted by abdominal wall muscles whose contractions increase intra-abdominal & intra-thoracic pressure & depress the lower ribs (belly breathing).
Why are primary curvatures in spine considered primary?
You have had them since you were a fetus, curve due to uneven size of vertebrae, secondary has the same size vertebrae ant. And post.
Atlas shape and function
. Hold head weight, no spinous processes only tubercle, small transverse process, no vertebral body
What angle are cervical spine facets oriented?
45 degrees from horizontal plane to allow for all movements
How are facets oriented in thoracic spine?
. Oriented in coronal plane to allow rotation but limits lateral flexion
Where are facets oriented in lumbar spine?
. Medically and laterally nearly in Sagittarius plane
. Limited rotation, but has flexion and extension and lateral flexion
External intercostal membrane
Replaces external intercostal mm. Anteriorly to sternum
Internal intercostal membrane
Replaces internal intercostal mm. Posteriorly towards vertebral column
