- flat bone consisting of manubrium, body and xiphoid

- articulates with ribs 3-7

- angle of louis: level of bifurcation of trachea into right and left main stem bronchi

- true/vertebrosternal: 1-7

- false/vertebrochondral: 8-10 with 11 and 12 being vertebral

Muscles of Ventilation

1. Inspiration at rest

2. Accessory Muscles

3. Muscles of Expiration

-cause reduction in intrathoracic pressure

1. diaphragm/internal intercostals

2. SCM (increase AP diameter), scalenes (elevate), upper trap (elevate), pecs, serratus, rhomboids (raise ribs), lats , serratus posterior superior, thoracic erector spinae (trunk into extension)

- external intercostals raise the ribs because go forward and down

-internal intercostals go down and back

3. abs and internal intercostals

- parenchyma: substance of the lung, porous/spongy

- cone shaped

- hilus: where principal bronchus, pulmonary artery, pulmonary vein, bronchial arteries/veins (pulmonary nerve plexus and lymph vessels)

Tracheobronchial Tree- conducting airways

trachea

main stem/lobar bronchi

segmental/subsegmental bronchi

terminal respiratory (acinar) units= alveoli

respiratory bronchioles

alveolar ducts

alveoli

Parasympathetic- vagus

Sympathetic- thoracic sympathetic ganglia

- functional unit of the lungs

- squamous pneumocytes (Type I): flat and thin and cover ~93 %

- granular pneumocytes (Type II): 7% of walls and produce surfactant, thick and cuboidal

- lies between right and left pleura of lungs

- contains all thoracic visera except the lungs

- can have a mediastinal shift which occurs the opposite direction of the affected lung in tension pneumothorax or pneumonectomy

1. pericardium: outer layer with parietal and viseral layers

2. myocardium: muscles

3. endocardium: lines heart chambers

AV: R tricuspid, L mitral

Semilunar: R pulmonic, L atrial

Conduction:

- SA node: 60-100 bpm

- AV node: 40-60 (delay here to allow ventricles to fill)

- bundle of His or purkinje fibers: 20-40

Innervation:

Parasympathetic- Vagus

Sympathetic- epi and norepi

Aorta -> aortic sinuses, corontary arteries, brachiocephalic trunk, L common carotid, L subclavian

Right Coronary: arises from right anterolateral surface of the aorta and descends into coronary sinus

Left Coronary: (main stem occlusion is widowmaker) originates from left anterolateral aspect of aorta and splits into anterior interventricular (aka left anterior descending) and circumflex (most common site for occlusion)