Thoracic Wall Flashcards
Suprasternal (Jugular Notch)
T2-T3 at level of intervertebral disc
Sternal Angle (Angle of Louis)
T4-T5. Manubriosternal joint. Costal cartilage of 2nd rib. Slop below jugular notch. Tob ribs is covered by clavicle; sternal angle slopes up to 2nd rib
Xiphoid process
T9-T10. Starts off cartilaginous, ossifies @ approximately 40 years of age. Sits approximately in front of heart. CPR @ approximately xiphoid process
Root of spine of scapula
On medial border of spine @ T4/spine of T3
Inferior angle of scapula
Points to T8, lies over T7
Midclavicular Line
Verticle line extending from midpoint of clavicle
Anterior axillary line
Verticle line dropped at lateral border of pectoralise major
Mid-axillary line
Vertical line dropped through middle of axillary fossa
Posterior axillary line
Vertical line dropped at lateral border of Latissimus Dorsi
Scapular line
Vertical line dropped from inferior angle of scapula
Midsternal line
Vertical line dropped from middle of sternum
Thoracic Inlet
Body of T1, 1st pair of ribs and cartilages, and superior end of manubrium. AKA Superior thoracic aperture. COUNTERINTUITIVE NOTE: Thoracic outlet syndrome deals with a problem (impingement of nerves and vessels) with the thoracic INLET, not the thoracic outlet.
Thoraic Outlet
Round opening whose edges are the lowest ribs. Closed by the diaphragm. Bounded by ribs 11-12, T12, xiphoid process. COUNTERINTUITIVE NOTE: Thoracic outlet syndrome deals with a problem (impingement of nerves and vessels) with the thoracic INLET, not the thoracic outlet.
Sternal Region
Median anterior wall. Sternum (manubrium, body, xiphoid process) & clavicular/chondral attachments to sternum make up the sternal region
Costovertebral Joint
Point of articulation between head of rib and the vertebral body at and above its level. EX: Rib 4 articulates with SUPERIOR COSTAL FACET of T4 and INFERIOR COSTAL FACET of T3.
Costotransverse joint
Point of articulation between rib and transverse process of vertebra at SAME level alone.
True ribs
Rib pairs 1-7. True because they attach to spine and sternum
False ribs
Rib pairs 8-12. “False” because they attach to spine, but not sternum. 8-10 anchor to the costal cartilages of the rib above them. 11-12 have no anchor in the front.
Floating ribs
Rib pairs 11 and 12. Floating because they lack any anchor at all in the front.
Head of rib
End closest to the vertebra with which it articulates
Tubercle of rib
Eminence of rib on its back surface at the junction between neck and body of the rib.
Shaft of rib
Rib consists of head, neck, and shaft. The angle of the rib is the point on the shaft of greatest curvature
Costal Groove
groove between the ridge of the internal surface of the rib and the inferior border. Houses intercostal neurovascular bundle (nerves and bloodvessels)
Costochondral joint
Joint between bone and cartilage at manubrium. No movement. Cartilage –> sternum
Sternocostal joint (1st Rib)
1st rib is a primary cartilaginous joint (point of attachment to axial skeleton).
Sternocostal Joint
synovial plane type joints
Manubrium
Runs T2-T5
Body of sternum
T5-T9
Joints of sternum
Sternoclavicular, manubriosternal, and xiphisternal
Sternoclavicular Joint
Synovial, saddle-type joint
Manubriosternal Joint
Secondary cartilagenous joint
Xiphisternal Joint
Primary cartilagenous Joint
Breast
Located in the superficial fascia. Modified sweat gland. Males: 4th intercostal, females: 2nd-6th ribs.
Areola
Darkened area around nipple so baby can locate it for feeding.
Nipple
Location where lactiferous ducts empty
Lactiferous ducts
Milk is secreted into ducts and flows into ampulas (sinuses). Milk is pulled from sinus to nipple, resulting in more milk being pulled to the sinus.
Anatomical location of breast
Male: 4th intercostal. Female 2-6th ribs vertically. Medial 2/3rds over pectoralis major, lateral 1/3rd over seratus anterior.
Pectoralis major
Proximal attachment: Clavicle, sternum, upper 6 costal cartilages. Distal attachment: Lateral lip of intertubercular groove [also an attachment for Lat. Dorsi]. Innervated by medial and lateral pectoral nerves on deep surface. Blood supply by pectoral branches of thoracoacromial trunk
Pectoralis minor
Proximal attachment: ribs 3-5. Distal attachment: coracoid process of scapula. Innervated by medial pectoral nerve. Blood supply: pectoral branches of thoracoacromial trunk.
Serratus anterior
Proximal attachment: upper 8-9 ribs. Distal attachment: medial order of scapula. Innervated by long thoracic nerve. Blood supply: lateral thoracic artery on superficial surface
Retromammary space
Allows breasts to move. Between glands and deep fascia.
Suspensory ligaments
Cooper’s ligaments. Attach gland to dermis of skin. Well developed superiorly. Tumor growing in this region can pull on ligaments leading to dimpling of the skin as the skin is pulled in
Vasculature of the breast
Internal thoracic artery, lateral thoracic artery, and pectoral branches of thoracoacromial trunk
Internal thoracic artery
Medial aspect of breast, lateral to sternum. AKA internal mammary artery (IMA)
Lateral thoracic artery
Found at lateral angle of thoracic cavity
Pectoral branches of thoracoacromial trunk
Go to pecs, supply glands
Lymphatic drainage of breasts
75% via axillary nodes in axilla’s apex, 25% through clavicular and parasternal nodes. Parasternal nodes responsible for potential of breast cancer to spread from one breast to another.
Serratus posterior superior
Elevate 2-5 ribs, aiding respiration
Serratus posterior inferior
Depress lower ribs, aiding expiration
Levator costarum
Attach transverse processes C7-T11 to costal tubercle and costal angle. 12 pairs of fan shaped muscles. Aid in respiration
Intercostal muscles
Innervated by local intercostal nerves (ventral primary rami of spinal nerve)
External intercostal muscle
ELEVATION. Fibers run anteroinferiorly from upper rib to lower rib. Muscle starts at the costal tubercle and runs to chostochondral junction. Extends to sternum as an external intercostal membrane (aka anterior intercostal membrane)
External (anterior) intercostal membrane
Membrane that replaces the external intercostal muscles anteriorly from costochondral junctions to the sternum.
Internal intercostal muscle
Costal (bony rib) portion depresses. Chondral (costal cartilage) portion elevates. Fibers run posteroinferiorly from upper rib to lower rib. Muscles start at lateral border of sternum and run to the costal angle. Extend to the vertebrae as internal (posterior) intercostal membrane at the angles of the ribs.
Innermost intercostal muscle
Deepest layer. Elevate. Located in third muscular layer of intercostal space. Found internally on posterolateral thoracic wall.
Subcostal muscle
Located internally on posterior thoracic wall. Muscles cross more than one intercostal space. Elevate. Located in third muscular layer of intercostal space posteriorly
Transversus thoracis
Depress ribs. Lower sternum to internal surface of 2-6th costal cartilage. Located in third muscular layer of intercostal space anteriorly.
Thoracic diaphragm.
Sternal, costochondral, and lumbar attachments. Responsible for 80% of quiet breathing.
Endothoracic Fascia
Serves to attach muscles of intercostal space to parietal pleura
Parietal Pleura
Fused to innermost surface of chest wall via endothoracic fascia
Neurovascular bundle
Housed in costal groove between 2nd and 3rd muscular layers. Contains intercostal nerves, intercostal arteries, intercostal veins, and subcostal nerve
Intercostal Nerves
Spinal nerves. Thoracic nerves T11-T11. Thoracoabdominal nerves T7-11
Intercostal arteries
Anastomose within the intercostal space. Anterior and posterior
Intercostal arteries on anterior side
Internal thoracic artery. Terminates in 6th intercostal space. 1st Branch of subclavian
Musculophrenic artery
Branch of internal thoracic artery. Supplies 7-9th intercostal spaces
Superior epigastric artery
Branch of internal thoracic artery. Supplies anterior part of abdominal wall and some of diaphragm.
Posterior intercostal arteries
Superior intercostal and thoracic aorta
Superior intercostal artery
Branch of costocervical trunk. Assists in supplying 1st and 2nd spaces
Thoracic aorta
Suplies all 11 IC spaces. First 2 IC spaces reinforce blood supply of superior intercostal artery from costocervical trunk and superior thoracic artery from 1st part of axillary artery
Intercostal veins
Azygos system of veins (drains everything in region) and internal thoracic vein (drains thoracic cavity)
Subcostal Nerve, artery and vein
Located under 12th rib. T12 nerve.
