Respiratory system
Respiratory system
The airway from larynx to alveolus, the lungs, and the pleura.
73 structures
Thorax
39Accessory muscles of respiration
Muscles recruited according to breathing demand
MuscleAlveolus
Microscopic air space at the gas-exchange surface
OrganAortic hiatus
Posterior route beneath the median arcuate ligament
SpaceBronchioles
Small airways without supporting cartilage
OrganBronchopulmonary segment
Bronchovascular subdivision of a lung lobe
OrganBronchopulmonary segments of the left lung
Left-lung territories with common segment combinations
OrganBronchopulmonary segments of the right lung
Ten standard named right-lung territories
OrganCarina
Internal ridge between the main bronchial openings
OrganCaval opening
Passage for the vena cava within tendon
SpaceCentral tendon of the diaphragm
Mobile fibrous center of the breathing diaphragm
LigamentCostodiaphragmatic recess
Pleural extension below the resting lung edge
SpaceCostomediastinal recess
Anterior pleural interval beside the mediastinum
SpaceCostovertebral joints
Rib-to-spine joints that permit breathing movement
JointEsophageal hiatus
Muscular opening around the lower esophagus
SpaceHorizontal fissure
Usual boundary between right superior and middle lobes
SpaceInnermost intercostals
Intercostal fibers deep to the main nerve and vessels
MuscleIntercostal space
Muscle and neurovascular layers between ribs
SpaceLeft inferior lobe
Left lobe behind the heart and above the diaphragm
OrganLeft lung
Two-lobed lung sharing the chest with the heart
OrganLeft main bronchus
Main airway beneath the aortic arch
OrganLeft superior lobe
Upper left lobe including the lingula
OrganLingula
Two-segment projection of the left superior lobe
OrganLobar (secondary) bronchi
Airways assigned to individual lung lobes
OrganOblique fissure
Sloping pleural boundary beside the inferior lobe
SpaceParietal pleura
Pleural lining attached to the thoracic boundary
OrganPleural cavity
Fluid-lined interval around each lung
SpacePulmonary plexus
Nerve connections around the lung roots
NerveRight inferior lobe
Posterior and basal right lung lobe
OrganRight lung
Three-lobed lung beside the right mediastinum
OrganRight main bronchus
Short main airway entering the right lung
OrganRight middle lobe
Anterior right lobe between two fissures
OrganRight superior lobe
Upper right lobe containing the lung apex
OrganRoot of the lung
Structures connecting a lung to the mediastinum
SpaceSegmental (tertiary) bronchi
Airways defining bronchopulmonary segments
OrganSubcostal muscles
Variable deep slips that bridge several ribs
MuscleSuprapleural membrane
Fascial reinforcement over the cervical pleura
LigamentTrachea
Cartilage-supported airway between larynx and bronchi
OrganTransversus thoracis
Deep muscle slips behind the sternum
MuscleVisceral pleura
Thin pleural covering attached to the lung
OrganAbdomen
1Head & neck
33Arytenoid cartilage
Movable attachments at the back of the vocal folds
CartilageArytenoid muscles (transverse and oblique)
Muscles linking the two arytenoid cartilages
MuscleCorniculate and cuneiform cartilages
Elastic supports along the laryngeal entrance
CartilageCricoarytenoid joint
A moving joint beneath each arytenoid
JointCricoid cartilage
The complete cartilage ring below the vocal folds
CartilageCricothyroid
Changes vocal-fold length from outside the laryngeal cavity
MuscleCricothyroid joint
Allows the thyroid and cricoid cartilages to change angle
JointCricothyroid ligament
Elastic support beneath the vocal ligaments
LigamentEpiglottis
Elastic cartilage contributing to airway protection
CartilageEthmoidal air cells
Small sinuses between the nasal cavity and orbit
SpaceFrontal sinus
Variable air spaces above the medial orbits
SpaceKiesselbach's plexus
A common bleeding site in the anterior nasal septum
VesselLaryngopharynx
The pharyngeal passage beside and behind the larynx
OrganLarynx
A movable airway valve that produces the voice
OrganLateral cricoarytenoid
Draws the vocal processes toward the midline
MuscleMaxillary sinus
A large sinus between the orbit and upper teeth
SpaceNasal cavity
Paired chambers for breathing and smell
SpaceNasal conchae
Bony shelves covered by vascular nasal mucosa
BoneNasopharynx
Pharyngeal airway behind the nose
OrganOropharynx
The pharyngeal passage behind the oral cavity
OrganOsteomeatal complex
Linked drainage pathways around the middle meatus
SpacePiriform recess
A swallowing channel on either side of the larynx
SpacePosterior cricoarytenoid
The muscle that opens each vocal fold
MuscleQuadrangular membrane
Fibroelastic support above the vocal folds
LigamentRecurrent laryngeal nerve
Vagal motor and sensory supply returning to the larynx
NerveRima glottidis
The changing opening between the true vocal folds
SpaceSphenoid sinus
A variable sinus close to the central skull base
SpaceSuperior laryngeal nerve
Two vagal branches with different laryngeal roles
NerveThyroarytenoid
Adjusts vocal-fold length, closure and stiffness
MuscleThyroid cartilage
The largest supporting cartilage of the larynx
CartilageVestibular folds
Upper laryngeal folds with protective and vocal roles
OrganVocal folds
Layered tissue that vibrates and closes the glottis
OrganVocalis
Specialized medial muscle within the vocal fold
Muscle