Lecture 14: Thoracic osteology and wall Flashcards
Components of thoracic cage
12 thoracic vertebrae
12 pairs of ribs and costal cartilages
Sternum
Intercostal muscles
Lateral mammary rami
From lateral cutaneous branches of intercostal arteries to lateral part of gland
Nipple, areola, lactiferous lobules drain into
Subareolar lymph node
Fatty tela subcutanea
Adipose tissue deep to fibrous layer
Medial mammary rami
From 2nd-4th anterior perforating arteries to deep medial part of gland
Bicuspid heart sound
Fifth intercostal space about 10cm to left of sternal midline
Rib tubercle articulates with
Transverse process of same number vertebra
Bifurcation of the trachea
Between sternal angle and T4/5 vertebral level
Sternal angle
Marks rib 2
Lies at level of T4-5 intervertebral disc
Contents of intercostal space include
Intercostal vein
Intercostal arteries (anterior and posterior)
Intercostal nerves
Vertebra prominens
First spinous process to be palpaged (C7)
Vertebrosternal ribs
1-7
Rib head
Two articular facets for articulation with costal demifacets on adjacent thoracic vertebrae
Inferior boundary thoracic cage
Twelfth thoracic vertebra
Twelfth pair of ribs/costal cartilages
Xiphisternal joint
Larger of the two openings
Pulmonary valve heart sound
Can be heard at the second intercostal space along left side of sternum
Internal intercostals
Begin at lateral edge of sternum and extend toward vertebral column
Deep fascia extends to vertebrae as internal intercostal membrane
Fiber direction is inferiorly and posteriorly
Innervation of upper thorax
T1-5
Costal cartilage slope
Takes upward slope
Innervation of clavicular and scapular region of upper thorax
C3-4
Angle of louis
Area at which the manubrium articulates with the body of the sternum
Sternal end level compared to vertebral end
Sternal end is at a lower level than the vertebral end
Anterior perforating arteries to breast
From internal thoracic artery to medial part of gland
Manubriosternal joint type
Symphysis
Vertebrochondral ribs
8-10
Innervation of xiphoid process region
T6
Fibrous tela subcutanea
Connective tissue layer surround the entire gland
Lateral mammary artery
From lateral thoracic artery to inferior part of gland
Venous drainage from breast
Mainly to axillary vein via lateral thoracic veins and medial mammary veins
Some drainage to internal thoracic vein via anterior intercostal veins
Especially important due to role in metastasis of cancer
Contents of intercostal space protected by
Groove on inferior border of each rib
Subareolar plexus drains into
Lateral lymphatic trunk
Medial lymphatic trunk
Posterior intercostal arteries arise from and give off
PIA 1&2 arise from costocervical trunk
3-12 are segmental branches from descending aorta
Posterior arteries give off lateral cutaneous branch
Tricuspid valve
Projected to the fifth intercostal space on right side
Rib tubercle
Articulates with transverse process of vertebra with same number
Suspensory ligament of cooper
Bundles of collagen fibers in dermis and hypodermis
Innervation of lower thorax and lateral/anterior abdominal wall
T7-12
Perilobular and interlobular lymphatic vessels drain into
Subareolar plexus
Mammary glands are
Modified sweat glands
Rib head articulates with
Demifacets of its own number vertebra and the vertebra above, as well as intervertebral disc between
75% of lymph from breast drains into
Axillary lymph nodes
Intercostal nerves description 1st, 2nd, 12th, branches
IC Nerves have lateral and cutaneous branches
Most of the first intercostal nerve joins the brachial plexus and has no anterior cutaneous branches
Lateral cutaneous branch of the 2nd intercostal nerve supplies the floor of the axilla
Lateral cutaneous branch of the subcostal (12th IC) nerve supplies the skin over the gluteal region
Transversus thoracis
Four or five slips that originate from the inferior sternum and extend superolaterally to internal surface of upper ribs
Vertebral ribs
11-12
Medial/lateral lymphatic trunks drain into ___ which drain into
Pectoral group of axillary lymph nodes into subclavian lymphatic channels
Innermost intercostals
Incomplete layers with fibers arranged in a more horizontal pattern
Infrasternal angle
Important in CPR
Depression between is the infrasternal fossa
Xiphisternal joint within fossa is at level of the body of T9
Aortic valve heart sound
Can be heard at the second intercostal space on the right side of sternum
Anterior axillary line formed by
Lower border of pectoralis major
First rib shallow groove for subclavian vein is ______ to tubercle
Anterior to tubercle
Posterior axillary line formed by
Tendon of latissimus dorsi
First rib shallow groove for subclavian artery is _______ to tubercle
Posterior to tubercle
External intercostals
Extend from vertebrae posteriorly to junction of ribs and intercostal cartilages
Deep fascia continues to sternum and forms external intercostal membrane
Fiber direction is inferiorly and anteriorly
First rib scalene tubercle
For insertion of scalenus anterior muscle
Scapular line
Vertical line running through inferior angle of scapula
Apex heart beat
Fifth intercostal space along midclavicular line about 8.5cm from adult midline
Intercostal nerves derived from, how many
Ventral ramus of a spinal nerve
12 pairs
Remaining lymph of breast drains into
Parasternal and abdominal lymph nodes
Costal margin superior and inferior marks
Superior marked by 7th cartilage
Inferior marked by 10th cartilage
Most prominent spinous process
T1
Anterior intercostal arteries arise from and give off
Branch of the internal thoracic arteries
Give off anterior cutaneous branches
Rib shaft- costal groove contains what, listed superior to inferior
Intercostal vein- most superior
Intercostal artery
Intercostal nerve- most inferior
Shaft angles downward
Innervation of breast tissue
Lateral mammary nerve
Anterior branches of lateral cutaneous branches of intercostal nerves
Lateral branches of anterior cutaneous branches of intercostal nerve
Supraclavicular nerves
Mammary gland rests on, innervated by, retromammary space is,
Pectoral fascia above pec major
IC nerves 4-6
Potential space between breast and pec fascia
Breast extends from
2nd-3rd rib superiorly to 6-7th costal cartilage inferiorly
From lateral border of sternum to beyond the anterior axillary fold
Xiphoid process marks
Level of dermatome 6
Superior boundary thoracic cage
First thoracic vertebra
First pair of ribs and costal cartilages
Manubrium