Thoracic Wall And Breasts Flashcards
Thorax
Area between neck and abdomen
*rib cage and what is inside
Chest
Thorax + pectoral girdle
Thoracic cavity compartments
- Central mediastinum
- Right pleural cavity
- Left pleural cavity
Boundaries of thorax
1. Superior thoracic aperture A. Manubrium B. Rib 1 and costal cartilage C. T1 vertebra 2. Inferior thoracic aperture A. Xiphoid process B. costal margin C. Rib 12 D. T12 vertebra E. Diaphragm - fills space
T4-T5 landmarks
- Sternal angle on transverse plane
- Ascending aorta ends and arch begins
- More posterior aortic arch ends and thoracic (descending) aorta begins
- Trachea bifurcates
Root of neck
Junction area between thorax and neck 1. Viscera A. Trachea B. Esophagus 2. Nerves A. Sympathetic trunks B. Vagus C. Phrenic D. Roots/trunks of brachial plexus 3. Veins A. Subclavian - upper limbs B. Venous angle - where veins and lymphatic meet C. Anterior jugular vein D. Jugular venous arch - connects anterior jugular veins 4. Arteries A. Subclavian and branches *Part 1 (medial) 1. Vertebral 2. Internal thoracic - posterior side of anterior wall 3. Thyrocervical A. Suprascapular B. Transverse cervical C. Inferior thyroid (ascending cervical) *Part 2 (posterior) 1. Costocervical trunk A. Superior (supreme) intercostal B. Deep cervical *Part 3 (lateral) 1. Dorsal scapular
Thoracic outlet syndrome
Disorders that occur when vessels or nerves between clavicle and rib 1 are compressed *symptoms depend on structure compressed 1. Neurogenic A. Most common B.compression of brachial plexus 2. Vascular A. Veins/arteries compressed
Layers of thoracic wall
- Skin
- Superficial fascia
- Pectoral fascia
- Skeletal elements, musculature, neurovascular bundle
- Endothoracic fascia - internal
- Pleura
Thoracic cage
- Thoracic vertebrae and IVD
A. T1, T10-T12: one full facet
B. T2-T8: typical (one full and 2 demifacets on each side)
C. T9 - one full facet and one Demi facet - Ribs - 12 pairs
A. True ribs (1-7): attaches sternum
B. False ribs (8-10): rib above shares costal cartilage
C. Floating ribs (11-12): no anterior articulation - Sternum
Coastal cartilage and joints
Typical ribs structure
Ribs 3-9
- Two demifacets
- Head
- Neck
- Tubercle w/ facet
- Angle
- Strong costal groove
- Shaft
- Sterna end (pitted)
Atypical ribs
A. Rib 1: shorter, single facet on head, scalene tuberacle, subclavian artery groove
B. Rib 2: shorter, tuberosity for serratus anterior
C. Ribs 11 and 12: rudimentary
Sternum
- Manubrium: clavicular notch, jugular notch, 1st costal notch, sternal angle
- Corpus sterni (body): costal notches
- Xiphoid process
Costovertebral joints
1. Costotransverse joints: A. Associated ligaments 1. Costotransverse 2. Lateral costotransverse 3. Superior costotransverse 2. Joints of head ribs A. Associated ligaments 1. Intra-articulate: internal between rib and vertebral bodies 2. Radiate: external 3. Sternocostal A. R1 and manubrium B. R2 and sternal angle C. R3-7 and body 4. Interchondral 5. Costochondral 6. Manubriosternal 7. Xiphisternal 8. Intervertebral 9. Stenoclavicular
Intercostal muscles
- External intercostal
- Internal intercostal
- Innermost intercostal
External intercostal muscles
- Fxn: elevates ribs (inspiration)
- Prox and distal: infero -anterior from rib tubercle to costochondral joint
- Innervation: 1-11th ant. Rami thoracic sp. n. (Intercostal n)
- Supply: intercostal a.
Internal intercostal muscles
- Fxn:
A. Interosseous part: depresses ribs (expiration)
B. Interchondral part: elevate costal cartilage (inspiration) - Prox and distal: supero-anterior from costal angle to sternum
- Innervation: intercostal n (1-11)
- Supply: intercostal a.
Innermost intercostal muscles
- Fxn: depresses ribs (expiration)
- Prox and distal: supero-anterior along lateral surface of thoracic wall
- Innervation: intercostal n. (1-11)
- Supply: intercostal a.
Subcostal muscles
- Fxn: depresses ribs (expiration)
- Prox and distal: from lower margin rib to inner surface of ribs 2-3 (fibers blend w/ innermost intercostal muscle)
- Innervation: 12th thoracic sp. n
- Supply: subcostal a.
Transversus thoracis
- Fxn: weakly depresses ribs (expiration)
- Prox: inner surface of sternum
- Distal: inner surface of ribs 2-6
- Innervation: 2-6th thoracic sp. n.
- Supply: intercostal a.
Neve branching in thoracic wall
From ventral rami of T1-T12 spinal n.
- Lateral cutaneous
- Anterior cutaneous
- Collateral
- Muscular
- Rami communicans
Thoracic wall cutaneous dermatomes
- T4 = nipple
2. T10 = umbilicus
Thoracic wall arterial supply
- Posterior intercostal a.: mostly arise from thoracic aorta
A. Upper 2 arise from superior intercostal a. - Anterior intercostal a.:
A. From internal thoracic a. -> supply spaces 1-6
B. From musculophrenic a. -> supply spaces 7-9 - Occlusion thoracic aorta -> effect lower 9 intercostal muscles
Thoracic wall venous drainage
- Anterior intercostal veins -> internal thoracic veins -> brachiocephalic veins
- Posterior intercostal veins -> azygos system
A. Lower left side (7-11) -> hemiazygos
B. Upper left side (1-6) -> accessory hemiazygos
C. Hemiazygos and accessory hemiazygos -> azygos
Herpes zoster
Shingles
1. Distributed along dermatome associated w/ infected ganglion
Intercostal nerve block
Local anesthetic injected in intercostal space
1. Usually not complete loss of sensation because of nerve overlap
Diaphragm
- Fxn: primary muscle of inspiration
- Attachments: costal margin, xiphoid process, L1-L3 vertebrae
- Innervation:
A. Phrenic nerve (C3, C4, C5): motor to all and sensory to most
B. Intercostal and subcostal (T6-T12): sensory to periphery of diaphragm
Thorax changes in breathing
- Elevation and depression of diaphragm -> vertical dimension change
- Pump handle -> anterioposterior dimension (ribs 1-6)
- Bucket handle -> lateral dimension (ribs 10-11)
Passive inspiration
Bucket and pump handles raised
1. Contract:
A. Diaphragm
B. External intercostals
Passive expiration
Bucket and pump handles lowered
1. Relax:
A. Diaphragm
B. External intercostals
Forced inspiration
Contract:
- Diaphragm
- External intercostals
- Sternocleidomastoid
- Trapezius (superior)
- Pectoralis minor
- Scalenes
Forces expiration
1. Relax: A. Diaphragm B. External intercostals 2. Contract: A. Abdominal muscles
Breast
- External: nipple and areola (and glands)
- Internal: Axillary tail (tail of Spence) = adipose and mammary tissue
- Retromammary space: between breast and pectoral fascia
- Lactiferous ducts
- Lobules of mammary gland
- Lactiferous sinus
- Suspensory (Cooper’s) ligaments
- Lymphatic drainage
A. Axillary lymph nodes (75% drains here)- Pectoral (initial drainage)
- Subscapular
- Humeral
Anterior median (midsternal) line (AML)
Intersection of median plane w/ anterior thoracic wall
Midclavicular line (MCL)
Passes thru midpoint of clavical
1. Parallel to AML
Anterior Axillary line (AAL)
Vertical along anterior Axillary fold formed by inferolateral border of pectoralis major
1. Spans from thoracic cage -> humerus
Midaxillary line (MAL)
Runs from apex of axillary fossa
1. Parallel to AAL
Posterior axillary line (PAL)
Vertical along posterior fold formed by latissmiss Doris and teres major
Posterior median (midvertebral) line (PML)
Vertical along tips of spinous processes
Scapular lines (SLs)
Intersect inferior angles of scapula
1. Parallel to PML
Superior thoracic aperture
Structures passing thru:
- Trachea
- Esophagus
- Lung apices
- Brachiocephalic veins
- Brachiocephalic trunk
- Left common carotid a.
- Left subclavian a.
- Vagus n.
- Phrenic n.
- Recurrent laryngeal nerves
- Sympathetic trunk
- Lymphatics
Breast vasculature
- Subclavian a. And v.
- Axillary a. And v.
- Internal thoracic a. And v.
A. Perforating branches - Lateral thoracic a. And v.
A. Medial mammary branches
B. Lateral mammary branches
C. Mammary branches
Breast innervation
Derive from anterior and lateral cutaneous branches of 4-6th intercostal n. 1. Supraclavicular n. 2. Intercostal n. A. Lateral mammary branches B. Medial mammary branches
Pectus carinatum
Pigeon chest
- Chest juts out due to unusual growth of sternum, ribs, and cartilage
- Usually no symptoms, sometimes SOB
- Tx: braces
Pectus excavatum
Funnel chest
- Sunken sternum
- If severe, may interfere w/ heart and lung fxn
- Can be surgically corrected
Flail chest
Can be caused by multiple rib fractures
1. Changes lung movement in breathing
Breast cancer
- Carcinomas
A. Often adenocarcinomas
B. Form epithelial cells of lactiferous ducts - If enter lymphatics -> lymphodema ->
A. Peau d’orange sign (edema of skin)
B. Nipple deviation/retraction - If invade glandular tissue and fibrosis -> dimpling
Polymastia
Accessory breast
Polythelia
Accessory nipple
Amastia
No breast dev.
Gynocomastia
Breast hypertrophy in males after puberty
- Age
- Drug-related
- Hormone imbalance
- Change in sex hormone metabolism in liver
- Should be explored further