Osteology, Anthology, and Myology of Thorax Flashcards
thorax
- region b/w neck and abdomen
- superior portion of the trunk
superior thoracic aperture
- “thoracic inlet”
- communication b/w neck and thorax
- contents: trachea, esophagus, plus nerves and vessels that supply and drain head, neck, upper extremities
- boundaries: T1 vertebral segment, paired 1st ribs and superior manubrium
inferior thoracic aperture
- “thoracic outlet”
- irregular communication b/w thorax and abdomen
- contents: esophagus, inferior vena cava, aorta
- boundaries: T12 vertebral segment, 11th/12th ribs, 7th-10th costal cartilages, xiphisternal joint
thoracic cavity
-surrounded by osteocartilaginous thoracic cage
-3 division:
1 and 2. pulmonary cavities–contain lungs and pleurae
3. mediastinum–contain heart, great thoracic vessels, trachea, thoracic esophagus, thymus
3 parts of sternum
- manubrium
- body of sternum
- xiphoid process
manubrium
- superior portion of sternum
- suprasternal notch (superior border of manubrium)
- sternal angle (junction of manubrium and body)
- clavicular notch–articulates with sternal end of clavicle
- costal notches (1st and half of 2nd)
body of sternum
- middle portion, longer, narrower, and thinner than manubrium
- xiphoid/sternal joint (junction of body and xiphoid process)
- costal notches (half of 2nd, 3rd-6th, and half of 7th)
- transverse ridges (anterior surface, b/w costal notches)
xiphoid process
- inferior portion of sternum
- costal notch (half of 7th)
costal notches
where costal cartilages insert, not ribs
3 types of ribs
- true (vertebrocostal) ribs (1st-7th)–attaches directly from vertebral segments to sternum via there own costal cartilage
- false (vertebrochondral) ribs (8th-10th)–attaches from vertebral segments to join costal cartilage immediately superior to segment
- floating (vertebral) ribs (11th and 12th)–do not attach to sternum at all
head of typical ribs
- articulates with thoracic vertebrae
- superior articular facet–articulates with inferior costal demifacet on thoracic vertebral body one numeric segment inferiorly)
- inferior articular facet–articulates with superior costal demifact on thoracic vertebral body of sam numeric segment
- crest of head (separates 2 articular facets)
neck of typical ribs
stretch of bone b/w head and tubercle
tubercle of typical ribs
possesses an articular part with an articular facet and a nonarticular part that is attachment point for lateral costotransverse L.
-articular facet–articulates with transverse costal facets on thoracic vertebrae
body (shaft) of typical ribs
- costal groove–houses intercostal nerve and vessels
- costal angle–anterolateral turning point of rib
which ribs are typical?
3-9
first rib
- atypical
- broad, flat, wide
- head–possesses only a single facet
- scalene tubercle–insertion point for anterior scalene M
- groove for subclavian A–superior aspect, posterior to groove for subclavian V
- groove for subclavian V–superior aspect, anterior to groove for subclavian A
second rib
- atypical
- longer than first rib
- tuberosity of serratus anterior M–serratus anterior M
tenth rib
- atypical
- head–possesses only a single facet
eleventh rib and twelfth rib
- atypical
- short, does not attach to sternum
- head–possesses only a single facet
- tubercle (not present)
- neck (not present)
rib fractures
- most commonly occurs in middle ribs
- occurs at weakest spot anterior to costal angle
- can damage internal organs and produce severe pain with respiration, coughing, laughing, and sneezing
supernumerary ribs
- extra ribs in cervical/lumbar region
- cervical ribs usually produce no symptoms, bit can produce neural or circulatory problems based on proximity to brachial plexus and subclavian A
- lumbar ribs usually no symptoms, however, can result in confusion when reading radiographs and other diagnostics
thoracic vertebrae
- 12
1. vertebral body–articulates with 12 ribs- superior costal facet
- inferior costal facet
- vertebral foramen–transmits spinal cord
- vertebral arch
- pedicle–b/w transverse process and vertebral body
- lamina–b/w transverse process and spinous process
- spinous processes
- transverse processes
- transverse costal facet–on the transverse process
- superior articular process (articulates with inferior articular process of vertebral segment above)
- articular facet
- inferior articular process (articulates with superior articular process of vertebral segment below)
- articular facet
costal cartilages
- connect anterior portion of ribs to sternum
- 1st-7th individually connect ribs to sternum
- 8th-10th articulate its costal cartilage superior to them before articulating with sternum
manubriosternal joint
- on sternum
- b/w manubrium and body of sternum
- symphysis
xiphosternal joint
- on sternum
- b/w body of sternum and xiphoid process
- synchondrosis
- inferior limit of thorax
sternocostal joint
- junction of costal cartilages with sternum
- rib 1 (synchondrosis)
- rib 2-7 (synovial planar)
- anterior radiate sternocostal L.
- posterior radiate sternocostal L.
costovertebral joint
- synovial planar
- where head of rib meets up with 2 vertebrae
- radiate L.-head of rib to vertebral body
- intraarticular L.-head of rib to intervertebral disc
- articular capsule-strongest anteriorly as radiate L, from crest of head to intervertebral disc
articulations of the head of ribs
- articulates with inferior costal facet of vertebra from one level up
- articulates with superior costal facet of vertebra of same number
- meet with transverse processor same number of rib
**head of 6th rib is b/w T5 and T6 and contacts facet of T6
costotransverse joint
- b/w tubercle and transverse process
- synovial planar
- lateral costotransverse L.: from transverse process one level onto rib of same number to tubercle of rib
- superior costotransverse L.: from transverse process one level down to rib neck
2 forms of movement at costovertebral joint
- both fcn to increase thoracic volume–SO decreases thoracic pressure producing inspiration
- bucket handle movement–lateral part of rib moves like a bucket handle which increases transverse diameter of thorax
- pump handle movement–front of rib and sternum move like pump handle, inc anterior to posterior diameter of thorax
costochondral joint
- articulation b/w ribs and costal cartilages
- synchondrosis
dislocation of rib
costal cartilage comes away from sternum at sternocostal joint
separation of rib
separation at the costochondral joint
interchondral joint
- b/w 6th/7th, 7th/8th, 8th/9th costal cartilages
- planar synovial
- b/w 9th/10th costal cartilages
- fibrous joint
- interchondral L.–strengthen the interchondral joint
thoracic vertebral joints
- intervertebral joint: symphysis
- zygopophyseal joint: planar synovial
anterior longitudinal L.
travels on anterior surface of the vertebral bodies
posterior longitudinal L.
travels on posterior surface of the vertebral bodies, inside vertebral canal
ligamentum flavum
pale yellow fibers which travel on ventral surfaces of vertebral laminae, inside vertebral canal
interspinous L.
travels b/w adjacent spinous processes
intertransverse L.
exist fibrous cords in thoracic region
supraspinous L.
travels on the dorsal surface of the spinous processes
intervertebral discs
- annulus fibrosis (tough outer fibrous region)
- nucleus pulposus (soft gelatinous inner portion)
external intercostal M.
- 11 pairs
- inferiorly the M is continuous with external abdominal oblique M.
- origin: inferior border of ribs (posteriorly)
- insertion: superior border of ribs below (anteriorly)
- action: elevate ribs
- N: intercostal N
external intercostal membrane
- replaces external intercostal M. anteriorly
- overlies internal intercostal M
internal intercostal M
- 11 pairs
- inferiorly it is continuous with internal abdominal oblique M
- origin: inferior border of ribs (anteriorly)
- insertion: superior border of ribs below (posteriorly)
- action: depress ribs (interchondral part elevates ribs)
- N: intercostal N
internal intercostal membrane
- replaces internal intercostal M posteriorly
- visible in posterior mediastinum lateral to vertebral column
innermost intercostal M
- 11 pair
- deepest fibers of internal intercostal M–separated from internal intercostal Ms by intercostal N and vessels
- origin: inferior border of ribs
- insertion: superior border of rib below
- action: undetermined, probably same as internal intercostal M
- N: intercostal N
thoracentisis
- insertion of hypodermic needle through intercostal musculature b/w ribs to obtain a fluid sample or drain small amounts of blood or fluid from pleural cavity
- needle is inserted b/w ribs inferior to intercostal neuromuscular bundle but superior to collateral branches
insertion of chest tube
- insertion of a tub to remove large amounts of air, fluid, blood, or pus from pleural cavity
- tube is typically inserted in 5th or 6th intercostal space
thoroscopy
-insetion of thoroscope into pleural cavity through small incisions for visualizing and biopsying the space inside the pleural cavity
transverse thoracic M
- origin: posterior surface of lower part of sternal body and xiphoid process
- insertion: internal surface of 2nd-6th costal cartilages
- action: depress ribs
- nerve: intercostal N
subcostal M
- over the innermost intercostal M on the internal surface of the posterior thoracic wall, near the angles of the ribs
- origin: inferior border of rib
- insertion: superior border of rib (1-2 rib segments)
- action: probably act as the internal intercostal M
- N: intercostal N