Thorax Anatomy

1. Parietal Pleura

   Annotations:

   • Aspects: --> Cervical --> Costal --> Mediastinal --> Diaphragmatic
   1. = lines the chest wall, secretes pleural fluid to reduce friction
2. = potential space between parietal and visceral layers
   1. Pneumothorax causes it to become real space - air enters and lung collapses due to breakage of surface tension
   2. Lungs grow INTO pleural sac during development (budding week 4, splitting into 2 week 6)
3. Visceral Pleura
   1. = firmly attached to the lungs, continuous with mediastinal pleura
4. Pleural Recesses

   Annotations:

   • Parts of pleural cavity NOT filled during QUIET inspiration
   1. Costo-diaphragmatic
   2. Costo-mediastinal

Annotations:

• Surfaces: --> Costal --> Vertebral --> Diaphragmatic --> Cardiac

1. Hilum (Root)
   1. Bronchi (posterior)

      Annotations:

      • Cartilagenous 
   2. Pulmonary arteries (superior)
   3. Pulmonary veins (inferior)
   4. Bronchial lymph nodes?

      Annotations:

      • may appear black due to pollution
   5. Pulmonary ligament (inferior to hilum)

      Annotations:

      • Just a fold of pleural membrane - attaches lung to mediastinum
2. Fissures
   1. Oblique (on both)
   2. Horizontal (RIGHT only)
3. Cardiac notch (LEFT)

   Annotations:

   • where heart sits
4. Lingula (LEFT)

   Annotations:

   • Angle between diagphragmatic surface and cardiac notch
5. Impressions
   1. LEFT
      1. Aortic arch
      2. LEFT common carotid (vertically)
      3. LEFT subclavian artery
   2. RIGHT
      1. SVC
      2. Azygous arch
6. Tracheobronchial lymph nodes
   1. Tracheal

      Annotations:

      • either side of trachea
   2. Bronchial

      Annotations:

      • around bifurcation
   3. Bronchiopulmonary

      Annotations:

      • hilum of lungs
   4. Pulmonary

      Annotations:

      • within lungs

1. Standing up
   1. Aortic arch = thoracic plane (T4/5)
   2. Trachea bifurcation BELOW plane
   3. Diaphragm central tendon = mid-xiphoid process (T9/10)
2. Lying down
   1. Aortic arch ABOVE thoracic plane
   2. Trachea bifurcation = plane
   3. Diaphragm central tendon = xiphisternal junction (T9)

1. Fibrous sac
2. Sinuses
   1. Transverse pericardial

      Annotations:

      • separates aorta and pulmonary trunk
   2. Oblique pericardial

      Annotations:

      • posterior; behind left atrium
3. Pericarditis

   Annotations:

   • Inflammation of the pericardium
   1. Can causes capillaries to become leaky = pericardial effusion
      1. Fibrous sac cannot expand so limits expansion of heart = lowered CO
   2. Chest pain
4. Heart
   1. RIGHT atrium
      1. Inputs = SVC, IVC, coronary sinus
      2. Smooth part

         Annotations:

         • Crista terminalis
      3. Fibrous muscle

         Annotations:

         • Musculi pectinati
      4. Fossa ovalis

         Annotations:

         • Should be closed - foramen ovale in embryo
      5. Tricuspud valve
         1. 3 cusps

            Annotations:

            • Anterior, posterior, septal
         2. Connected to chordae tendinae
   2. RIGHT ventricle
      2. Papillary muscles

         Annotations:

         • innervated by Purkinje fibres
      3. Irreg. muscle fibres

         Annotations:

         • = Trabeculae carnae
      4. Moderator band

         Annotations:

         • nerve tissue connecting anterior papillary muscle to septum
      5. Infundibulum

         Annotations:

         • Smooth wall leading to pulmonary valve
         1. Pulmonary valve

            Annotations:

            • 3 semilunar cusps
            1. Pulmonary trunk
               1. LUNGS
   3. LEFT atrium
      1. Input: pulmonary veins
      2. Auricle has musculi pectinati, but smooth inside
      3. Fossa ovalis depression
      4. Mitral valve
   4. LEFT ventricle
      1. Mitral valve

         Annotations:

         • Bicuspid - anterior and posterior
      2. Irreg. muscle fibres

         Annotations:

         • trabeculae carnae
      3. Chordae tendinae + paillary muscles
      4. Aortic valve

         Annotations:

         • Semilunar
         1. Aorta
            1. BODY
   5. Coronary vessels
      1. RIGHT coronary artery

         Annotations:

         • in atrio-ventricular groove
         1. RIGHT marginal
            1. Small Cardiac Vein
         2. Posterior Inter-ventricular

            Annotations:

            • (Right posterior descending)
            1. Middle cardiac vein
      2. LEFT coronary artery
         1. Circumflex
         2. LAD
            1. Great Cardiac Vein

1. Arises from the cisterna chyli

   Annotations:

   • root of the mesentery of the small intestine
2. Drains lymph fluid
   1. Abdomen
   2. Pelvis
   3. LEFT thorax
   4. Head and neck
   5. Upper and lower limbs
3. Empties into vein at junction of IJV and left subclavian

1. C shaped

   Annotations:

   • Because oesophagus is behind it
2. Rings of cartilage

   Annotations:

   • hold trachea open
3. Bifurcates at T4/5

   Annotations:

   • (transverse thoracic plane)
   1. "Carina"

      Annotations:

      • mucus membrane here responsible for cough reflex
4. Lined with pseudostratified ciliated columnar epithelium

   Annotations:

   • glands to secrete mucus

1. Pierces diaphragm at T10

   Annotations:

   • through muscular part to help prevent reflux
2. 3 constrictions
   1. Upper/ Pharyngeal

      Annotations:

      • level of cricoid cartilage
   2. Middle/ aortic

      Annotations:

      • at bifurcation of trachea
   3. Inferior/ diaphragmatic

      Annotations:

      • at piercing of diaphragm (lower oesophageal sphincter)
   4. = Likely place for obstructions
3. Oesophageal plexus
   1. Vagus fibres
   2. From sympathetic trunk
4. Thick, stratified epithelium

   Annotations:

   • to resist damage/abrasion as food travels down throat
5. Muscular, flat

   Annotations:

   • except when food is passing down it

1. Body
2. Lamina

   Annotations:

   • between transverse and spinous processes
3. Pedicles

   Annotations:

   • between body and transverse processes
4. Articulations
   1. Superior/ Inferior articular facets

      Annotations:

      • articulate with inferiort/superior articular facets of vertebra above/below
   2. Transverse costal facets

      Annotations:

      • articulate with tubercles of ribs
   3. Superior/inferior demifacets

      Annotations:

      • on vertebral body - articulate with head of rib at that level and one below

1. Rib 1, manubrium, T1

1. Xiphoid process, inf. margin of costal cartilages, ribs 11+12, T12

1. Typical (2-10)
   1. Head
   2. Neck
   3. Tubercle
   4. Angle

      Annotations:

      • most likely to break (not in infants)
   5. Body
   6. Costal groove

      Annotations:

      • protects neurovascular bundle
2. Rib 1
   1. Head
   2. Neck
   3. Tubercle
   4. Angle
   5. Body
3. Ribs 11+12
   1. Head
   2. Angle
   3. Body
4. Infants - horizontal
5. Age - cartilage ossifies

   Annotations:

   • becomes harder to move ribcage to breathe

1. Manubrium
   1. Jugular notch
   2. Articular sites for clavicle and rib 1

      Annotations:

      • primary cartilagenous joints = no movement
   3. Superior demifacet for rib 2
2. Body
   1. Inferior demifacet for rib 2
   2. Articular facets for ribs 3 - 6
   3. Superior demifacet for rib 7
3. Xiphoid process
   1. Inferior demifacet for rib 7

1. Fat lobules
2. Suspensory ligaments
3. Secretory lobules

   Annotations:

   • produce milk
4. Lactiferous ducts
5. Lactiferous sinuses
6. Simple mammary gland

   Annotations:

   • All lobules supplying one duct
7. Complex mammary gland

   Annotations:

   • All glands serving one nipple
8. Nipple
9. Blood supply
   1. Medial + Lateral mammary artieries

      Annotations:

      • from internal thoracic
   2. Drains to axillary vein
10. Innervated by anterior + lateral cutaneous branches of intercostal nerves 4 - 6
11. Lymph drains to axillary nodes

    Annotations:

    • Anterior Posterior Infraclavicular Central Apical Lateral
    1. Some to parasternal or other breast

1. Posterior intercostals

   Annotations:

   • 11 pairs: Upper 2 from costocervical trunk of subclavian Lower 9 from thoracic aorta
2. Anterior intercostals

   Annotations:

   • 9 pairs: Upper 6 from internal thoracic artery  Lower 3 from musculophrenic artery
3. Internal thoracic artery
   1. Musculophrenic
   2. Superior epigastric

1. Intercostal nerves

   Annotations:

   • in costal grooves of ribs
2. Long thoracic

   Annotations:

   • supplies serratus anterior
3. Medial + Lateral Pectoral

   Annotations:

   • Medial = both Pec major and minor Lateral = ONLY Pec major

1. Pectoralis Major

   Annotations:

   • Origins: medial half of clavicle, sternum, costal cartilages 1-7 Insertions: Proximal part of humerus Innervation: Medial and Lateral Pectoral nerves
2. Pectoralis Minor

   Annotations:

   • Origins: Surface of ribs 3-5 Insertions: Coracoid process Innervation: Medial pectoral nerves
3. Diaphragm
   1. Phrenic nerve (C3,4,5)

      Annotations:

      • Central tendon developed at C2, then picked up myotomes from C3,4,5 during development
   2. Attachments
      1. Sternum
      2. Ribs
      3. Lumbar vertebrae

         Annotations:

         • L and R crurae
      4. Lateral arcuate ligaments

         Annotations:

         • over quadratus lumborum muscle
      5. Medial arcuate ligaments

         Annotations:

         • Over psoas major
      6. Median arcuate ligaments

         Annotations:

         • over aorta
   3. Hiatuses
      1. Vena Cava

         Annotations:

         • T8
      2. Oesophagus

         Annotations:

         • T10
      3. Aorta

         Annotations:

         • T12
4. Serratus anterior

   Annotations:

   • Origins: Anterior surface of ribs 1-8/9 Insertion: Anterior surface of medial border of scapula Innervation: Long thoracic nerve (C5-C7)
5. Latissimus dorsi

   Annotations:

   • Origins: spinous processes of T6-L5+sacrum, iliac crest, ribs 10-12 Insertions: intertubercular sulcus of humerus Innervation: C6-C8
6. Intercostals
   1. External

      Annotations:

      • \\// used in inspiration
   2. Internal

      Annotations:

      • //\\ in forced expiration
      1. Neurovascular bundle between
   3. Innermost

      Annotations:

      • //\\ in forced expiration
      1. Neurovascular bundle between