Thoracic Anatomy

Anatomy of the Thorax

Overview

trunk

thorax

abdomen and pelvis

perineum

back

boundaries

thoracic inlet

wall ¹

ribs

sternum

intercostal spaces

thoracic outlet

diaphragm

R & L hemidiaphragms

costal portion

mediastinal portion

aponeurotic central tendon

hiatuses

caval hiatus: through R hemidiaphragm at T8 level

esophageal hiatus: through L hemidiaphragm at T10 level

hiatal hernia

aortic hiatus: through L hemidiaphragm at T12 level near midline

Internal anatomy

cavities

pleural cavities

pleura

parietal

visceral

lungs

pericardial cavity

pericardium

parietal

fibrous layer

serous layer

“visceral”—epicardium

heart

the mediastinum

level of the sternal angle (angle of Louis)

divisions

superior

middle

posterior

Respiratory system anatomy

nasal cavities

nares

vestibule

conchae, recesses, and meati

olfactory organ

sinuses

lining mucous membrane

nasopharynx

larynx ²

cartilages

thyroid

cricoid

arytenoid

epiglottic

vocal folds

glottis

trachea

tracheal ring cartilages

carina

bronchi

primary (mainstem)

secondary (lobar)

tertiary (segmental)

lungs ³

borders and surfaces

hilus

apex

lobes

fissures

oblique

horizontal

microscopic anatomy ⁴

bronchioles

alveoli

type I pneumocytes

type II pneumocytes

surfactant

alveolar macrophages

respiratory membrane

Go to beginning

Questions for thought
1.		How is it possible to change the pitch of our voice from high to low?
2.		The contraction of the diaphragm and the external intercostal muscles begins inspiration. Explain exactly what happens, in terms of volume and pressure changes in the lungs, when these muscles contract.
3.		How is alveolar gas exchange affected by emphysema and pneumonia?
4.		Describe how the invasion of the lung bud into the pleural cavity results in the formation of visceral and parietal layers.

Go to beginning

Links

Referenced sites
- ¹ Images of the thorax, from the Gross Anatomy Project of the University of Arkansas for Medical Sciences
- ² Diseases of the larynx from the Texas Voice Center
  Clinical pictures from Stanford Hospital
- ³ Lung & mediastinal anatomy from e-Anatomy
- ⁴ Respiratory system histology, from The University of Western Australia, Department of Anatomy and Human Biology
  For a slightly different perspective, check out this overview of avian repiratory system histology
  or Bergman, Afifi, & Heidger
Other sites
- An Interactive Atlas of Thoracic Viscera by David M Conley and Cornelius Rosse, University of Washington
- Chest X-Ray has several nice interactive pages; topics include cross-sectional anatomy, mediastinal anatomy, lungs, and an introduction to cardiothoracic imaging
- [ Site no longer exists ]
  The index page for images of radiologic anatomy of the thorax
- Thoracic imaging landmarks, from the Atlas of Echocardiography, Yale University