Anatomy of the Thorax

Overview

trunk

thorax

abdomen and pelvis

perineum

back

boundaries

thoracic inlet

wall 1

ribs

sternum

muscles

external intercostal m

internal intercostal m

innermost muscles

transversus thoracis m (ant)

innnermost intercostal m (lat)

subcostalis m (post)

blood vessels

intercostal v → azygos system

intercostal a ← descending aorta

intercostal n ← ventral ramus of spinal n

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”´┐Żepicardium

heart

the mediastinum

level of the sternal angle (angle of Louis)

divisions

superior

anterior

middle

posterior

Respiratory system anatomy

images

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

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.


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