Thoracic Wall Flashcards
Function of ribcage
protect vital organs; needs movement to breathe
Level of suprasternal notch
vertebral level T2-T3
Sternal angle (of Louis)
Vertebral level T4-T5
Manubriosternal joint
costal cartilage of 2nd rib
Xiphoid process
Vertebral level of T9-T10
ossifies at about 40 years of age
Sternum
flat bone, levels T5-T9
Root of spine of scapula
vertebral level T4, palpate at spine of T3
Inferior angle of scapula
vertebral level T8, overlies Rib 7 and points to rib 8
Midclavicular line
1/2 way through clavicle
Anterior axillary line
vertical line dropped at lateral border of pectoralis major
Mid-axillary line
vertical line through middle of axillary fossa, down middle of armpit to illiac crest
Posterior axillary line
vertical line dropped at lateral border of latissimus dorsi
Scapular line
vertical line through inferior angle of scapula
Midsternal line
vertical line cuts body in half down sternum
Thoracic Inlet (Superior thoracic aperture) consists of
Body of T1, 1st pair of ribs and cartilages, and superior end of manubrium (suprasternal notch)
Thoracic Outlet syndrome
things get pinched between first rib and clavicle (arteries, nerves, veins)
Thoracic Outlet (inferior thoracic aperture) consists of
Xiphisternal joint, 12th ribs and costochondral junction, closed by thoracic diaphragm
Sternal region of thoracic cavity (median anterior wall) consists of
Sternum (manubrium, body, xiphoid process), Clavicular and chondral attachments to sternum
Costovertebral joint
connects head of rib and vertebral body at and above its level
Costotransverse
Tubercle of rib and transverse process of vertebra - at same level
True Ribs
connected to vertebrae and sternum; 1st to 7th pair
False ribs
Don’t directly attach to sternum; 8th to 12th pair
Floating ribs - 11th & 12th
Rib head
attaches to vertebral body
2 facets - demifacets articulate with vertebral body at level and one above
Rib Tubercle
part of rib that articulates with transverse processes at transverse costal facet
Rib Shaft
angle - point of greatest curvature
forms lateral thoracic wall
Rib costal groove
houses intercostal neurovascular bundle
VAN - vein on top, artery, nerve on bottom
Costochondral joint
rib to cartilage - no movement
Sternocostal joint
1st rib is primary cartilaginous joint, rest are synovial plane-type joints
Sternoclavicular joint
between sternum and clavicle; synovial, saddle-type joint
Manubriosternal joint
immovable - between sternal body and manubrium
secondary cartilagenous joint
Xiphisternal joint
primary cartilagenous joint - immovable
between xiphoid process and body of sternum
Male breast is located
in 4th intercostal space
Female breast is located in
superficial fascia, is a modified sweat gland
1/3 sits on serratus anterior and 2/3 sits on pectoralis major
vertically from 2nd to 6th ribs, transversely from lateral border of sternum to mid-axillary line
Lactiferous ducts
open onto the nipple
Pectoralis Major
O: lateral border of sternum upper 6 costal cartilages, clavicle
I: lateral lip of interubercular sulcus of humerus
N: medial and lateral pectoral nerves (on deep surface)
A: flex, adduct, and rotate arm medially
B: pectoral branch of thoraco-acromial artery
Pectoralis Minor
Deep to P. major O: outer surface of ribs 3-5 I: Coracoid process of scapula N: Medial pectoral nerve B: Pectoral branch of thoraco-acromial trunk A: lowers lateral angle of scapula
Serratus Anterior
O: lateral surface of upper 8-9 ribs
I: costal surface of medial border of scapula
N: Long thoracic nerve
B: Lateral thoracic artery (on superficial surface of muscle)
A: protracts scapula, holds it against thoracic wall
Retromammary Space
between lactiferous glands and deep fascia, allows movement of breast
Suspensory (Cooper’s) ligament
attaches gland to dermis of skin, well developed superiorly
If breast tumor grows here, will pull suspensory ligament in and dimples skin
Vasculature to breast
Internal thoracic a., lateral thoracic a., and pectoral branches of thoracoacromial trunk
Levator Costarum
Transverse processes C7-T11 to costal tubercle and costal angle
12 pairs of fan shaped muscles
Intercostal muscles
between ribs, innervated by local intercostal nerves (ventral primary ramus of spinal nerve)
11 intercostal spaces
External intercostal muscle
Elevates ribs
Fibers run anteroinferiorly from upper to lower rib
starts at costal tubercle, runs to costochondral junction
Extends to sternum as external (anterior) intercostal membrane
Internal intercostal muscle
starts anteriorly
Costal (bony ribs) portion depresses
Chondral (costal cartilage) portion elevates
Fibers run posteroinferiorly from upper to lower rib
Muscle starts at lateral border of sternum, runs to costal angle
Extends to vertebrae as internal (posterior) intercostal membrane
Innermost intercostal muscle
elevates ribs
located in third muscular layer of intercostal space
found internally on poserolateral thoracic walls
Subcostal muscle
located internally on posterior thoracic wall
crosses more than one intercostal space
elevates ribs
located in third muscular layer of intercostal space posteriorly
Transversus thoracics
Depresses ribs
Lower sternum to internal surface of 2nd to 6th costal cartilage
Located in third muscular layer of intercostal space anteriorly
Parietal pleura
lines internal thoracic cavity external to the pulminary pleura, covers diaphragm
attaches to thoracic muscles via endothoracic fascia
Neurovascular bundle
housed in the costal groove between the second and third muscular layers
Intercostal nerves
in costal groove Thoracic nerves (T1-T11) Thoracoabdominal nerves (T7-T11)
Intercostal arteries
anastomoses within intercostal space
Anterior internal thoracic artery
terminates at 6th IC space
Branches into Musculophrenic and Superior epigastric arteries
Musculophrenic artery
branch of internal thoracic artery
supplies 7th - 9th IC space
Superior epigastric artery
branch of internal thoracic artery
No anterior intercostals in
10th and 11th intercostal spaces
Posterior intercostal artery
supplies 3rd to 11th IC spaces
Superior intercostal artery
branch of costocervical trunk, assists in supplying 1st and 2nd spaces - posterior
Thoracic aorta
supplies all 11 IC spaces
posterior
Subcostal nerve, artery, and vein
located under 12th rib
T12 nerve
