thoracic wall Flashcards
Thoracic wall function and formed by
- thoracic cage is formed by
- 12 thoracic vertebrae posteriorly
- 12 pairs of ribs and their costal cartilages
- sternum anteriorly - protects contents of thoracic cavity and mechanical function of breathing
Superior thoracic aperture (thoracic inlet) description
what passes the inlet?
- access for thoracic cavity to communicate with the neck
- bounded by body of T1
- 1st ribs and costal cartilage
- superior border of manubrium - pass inlet:
- trachea
- esophagus
- common carotid arteries
- jugular veins
- subclavian aa & vv
- vagus & phrenic nerves
- thoracic duct
Inferior thoracic aperture (thoracic outlet)
- access from thoracic cavity to communicate with abdomen
- closed by thoracic diaphragm
- slopes downward and backward
- bounded by T12, 12th rib, costal margins, xiphisternal joint
three parts of sternum
- manubrium-jugular (suprasternal) notch, clavicular notch, manubriosternal joint
- body- costal notches, xiphisternal joint
- xiphoid process
General vertebrae characteristics
- body support weight
- superior/inferior articular facets for articulation with other vertebrae; restrict movement
- transverse process and spinous process for muscle attachments
Thoracic vertebrae (5)
- costal facets on bodies articulate with head of ribs
- costal facets on transverse process articulate with tubercles of ribs
- long, inferiorly-directed spinous processes
- superior articular facets face posteriorly
- inferior articular facets face anteriorly
- true ribs
- false ribs
- floating ribs
- typical ribs
- atypical ribs
- 1-7th vertebrocostal ribs-costal cartilage attaches directly to sternum
- 8-10 vertebrochondral ribs-costal cartilage attaches to costal cartilage of rib 7
- 11 & 12 no attachment to sternum
- 3-9
- 1 & 2, 10-12, 11-12
a. )1st-broad and most curved and shortest- grooves for subclavian vessels
- scalene tubercle
- 1 articular facet
b) 2nd- 2 facets - tubercles for posterior scalene
- serratus anterior
c) 10-12 - only one facet on head
d) 11-12 - short and no neck or tubercles
Three articulations per rib
- inferior costal facet of superior vertebrae (rib 3 with inferior costal facet of T2
- superior costal facet of same number vertebra (rib 3 with superior costal facet of T3)
- costal facet on transverse process of same vertebrae (rib 3 with T3)
Breast: superficial and deep contents
- Superficial
- areola
- niple - deep
- superficial fascia
- mammary lobes
- lactiferous ducts
- lactiferous sinus
- suspensory ligament (Cooper’s)
lactation (3)
- ducts enlarge to form lactiferous sinus which serves as reservoir for milk during lactation
- remaining mass is adipose tissue and suspensory ligaments
- common site of cancer and benign tumors in women
Muscles of thoracic wall
-3 layers intercostal muscles
- external intercostal muscle (superficial); do not extend to the sternum anteriorly
- internal intercostal muscle (middle); does not extend to vertebrae posteriorly
- innermost intercostal muscle (deepest); only present laterally
all innervated by intercostal nerves
Posterior thoracic wall vessels and structures 4
- posterior intercostal vein/artery + intercostal nerve in each intercostal space (VAN)
- posterior intercostal arteries are direct branches of descending aorta
- posterior intercostal veins drain into hemiazygous (Left) nad azygous vein (right)
- vessels and nerve lie between internal and innermost intercostal muscles
Blood supply to thoracic wall anastomosis between posterior and anterior intercostal aa.
-vessels
- descending thoracic aorta
- posterior intercostal a.
- internal thoracic artery (from subclavian artery
- anterior intercostal artery
Nerves of thoracic wall
intercostal nerve are the anterior rami T1-T11
Innervation of muscles nad skin
- dermatone
- myotome
spinal nerves have:
motor-innervate certain muscles
sensory fibers innervate skin
-dermatome-skin area innervated by sensory fibers of single nerve root
-myotome-group of muscles primarily innervated by motor fibers of single nerve root