respiratory system anatomy · 2008-06-26 · 7/5/02 mr. davenport 2 functions of the respiratory...

7/5/02 Mr. Davenport 1

Respiratory SystemAnatomy

Copyright 1999, Stephen G. Davenport, No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form without prior written permission.


Functions of the Respiratory System

• Provides surface area for gas exchange• Moving air to and from exchange surfaces• Protection of surfaces from dehydration• Production of sounds (vocal apparatus)• Providing olfactory sensations


Chest x-ray


Nose and Nasal Cavity• Nose

Functions include– Provides an airway– Moistens and warm air– Filters– Resonation for sound– Houses olfactory receptors– Primary passageway of skin covered

bone and cartilage– External nares (nostrils)


Nasal Cavity– External nares (nostrils) airway entrance

• Vestibule is inlet superior to nostrils – Nasal septum divides right and left portions– Conchae (pl, kong´-ke; sing., concha, kong´ kah) are three

bony projects into cavity– Meatuses (pl, me-a´-tus-es; sing. meatus, me-a´-tus) are airway

grooves formed by the conchae– Internal nares (nar´-ez) are posterior openings from

nasal cavity into nasal pharynx (throat)


Nasal Cavity Mucosa– Lined with pseudostratified ciliated columnar

epithelium– Numerous goblet cells, with mucous and serous

glands in underlying connective tissue


Pharynx (FAR-inks)

• Pharynx is commonly called throat• Nasopharynx (internal nares to soft palate)

– Auditory tubes (pharyngotympanic or eustachian)

– Pharyngeal tonsil (adenoid)• Oropharynx (soft palate to hyoid bone)

– Uvula• Laryngopharynx (hyoid bone to cricoid

cartilage and esophagus)


Larynx (LAR-inks)

• Commonly called the voice box– Thyroid cartilage– Cricoid cartilage– Epiglottis– Vocal folds (cords)– Ventricular folds– Glottis


Trachea (TRĀ-kē-uh)

• Trachea extends from larynx to primary bronchi

• Three layers: – mucosa: pseudostratified ciliated

columnar epithelium– submucosa: seromucous glands in

connective tissue– adventitia: hyaline cartilage “C” rings and

dense connective tissue


TRACHEA Cilia Goblet cell

Mucosa

Submucosa

Adventitia

Seromucous glands

Pseudostratified ciliated columnarepithelium

Hyaline cartilage


TRACHEA 8

Photograph 2

• 1 Mucosa• 2 Submucosa• 3 Adventitia• 4 Ciliated pseudo-

stratified columnar epithelium

• 5 Goblet cells• 6 Seromucous glands• 7 Hyaline cartilage• 8 Cilia


Primary Bronchi (BRONG-kī)

• Primary bronchi are the two branches from trachea– Right and left primary

bronchi– Right is larger in diameter

and steeper angle


Lungs• Left lung -

– two lobes (superior, inferior)

– cardiac notch• Right lung -

– three lobes (superior, middle, inferior)

• Apex of each lung is just inferior to each clavicle• Base of each lung rests upon the diaphragm• Costal surface rest near the ribs (anterior, lateral,

and posterior)• Root is where vascular and bronchial attachments

enter the lung (the indentation called the hilus).


Pleural Coverings

• Plumonary pleura is the serous membrane of the lung– Parietal pleura is the region associated with the

thoracic wall surrounding each lung– Visceral pleura is the region associated with the

surface of each lung– Each lung has a potential space, the pleural

cavity, which contains serous fluid.


Bronchial treeThe Conducting Zone

• Consists of primary bronchi and their branches– primary bronchi– secondary (lobar) bronchi– tertiary (segmental) bronchi– terminal bronchioles


Bronchial tree

• Decrease in size results in– decreased amounts of cartilage– increased amounts of smooth muscle

• Bronchioles vary airway resistance• Bronchodilation - sympathetic• Bronchoconstriction – parasympathetic

– Also chemical mediators such as histamine


Respiratory Zone• Respiratory bronchioles have alveoli (air

sacs) associated with their wall• Alveolar ducts originate from respiratory

bronchioles and lead into groups of air sacs called alveolar sacs


Alveoli

• Located individually (respiratory bronchioles) and grouped into alveolar sacs

• Sites of gas exchange• Surrounded by capillaries

and elastic tissue


Alveolus

• Alveolar epithelium is simple squamous• Alveolar macrophages roam epithelium• Septal cells produce surfactant (sur-FAC-tant)

which reduces surface tension


Respiratory Membrane

Red blood cell

Endothelium

Alveolar epithelium(simple squamous)

Fused basementmembranes

• Site of gas exchange

• Consists of– endothelium– basement

membranes– alveolar

epithelium (simple squamous)


Respiratory Membrane

• Driving force for gas exchange is diffusion• Two reasons diffusion proceeds rapidly:

• Distance across membrane is small• Oxygen and carbon dioxide are lipid soluble

respiratory system anatomy · 2008-06-26 · 7/5/02 mr. davenport 2 functions of the respiratory...

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