Principles of Anatomy and Physiology

Thirteenth Edition

Chapter 23The Respiratory System

Copyright © 2012 by John Wiley & Sons, Inc.

Gerard J. Tortora • Bryan H. Derrickson

Nose

Nasal cavity

Larynx

Trachea

Pharynx

Right primarybronchus

Lungs

(a) Anterior view showing organs of respiration

TracheaRight common carotid artery

Thyroid gland

Subclavian artery

Phrenic nerveLeft common carotid arteryArch of aorta

Rib (cut)

Left lung

Heart in pericardial sac

Diaphragm

TracheaRight subclavian arteryBrachiocephalic arterySuperior vena cava

Right lung

Liver

(b) Anterior view of lungs and heart after removal of anterolateral thoracic wall and pleura

Lateral nasal cartilages

Frontal bone

Nasal bones

Maxilla

Dense fibrousconnective andadipose tissue

Septal cartilage

Alar cartilage

Bony framework:

Cartilaginous framework:

(a) Anterolateral view of external portion of nose showing cartilaginous and bony framework

Sphenoid bone

Frontal sinus

(b) Parasagittal section of left side of head and neck showing location of respiratory structures

Frontal bone

Olfactory epithelium

SuperiorMiddleInferior

Nasal vestibuleExternal narisMaxillaOral cavity

Palatine boneSoft palateLingual tonsilMandibleHyoid bone

Ventricular fold (false vocal cord)Vocal fold (true vocal cord)LarynxThyroid cartilageCricoid cartilageThyroid gland

Sphenoidal sinusInternal narisPharyngeal tonsil

NASOPHARYNX

Opening of auditory tube

UvulaPalatine tonsilFauces

OROPHARYNX

Epiglottis

LARYNGOPHARYNX

Esophagus

Trachea

Inferior

Middle

Superior

Nasalconchae

Nasal meatuses

Regions of the pharynx

Nasopharynx

Oropharynx

Laryngopharynx

Parasagittalplane

Tongue

Periorbital fat

EyeballEthmoidal cell

Superior nasal concha

Middle nasal concha

Inferior nasal concha

Maxillary sinus

Perpendicularplate of ethmoid

Vomer

Hard palate

Frontal plane

View

(c) Frontal section showing conchae

Nasal septum:

1

3

2 4

Anterior view

1. Root: Superior attachment of the nose to the frontal bone2. Apex: Tip of nose3. Bridge: Bony framework of nose formed by nasal bones4. External naris: Nostril; external opening into nasal cavity

Hyoid boneEpiglottis

Thyrohyoid membraneEpiglottis:

LeafStem

Corniculate cartilage

Thyroid cartilage(Adam’s apple)

Arytenoid cartilage

Cricothyroid ligament

Cricoid cartilage

Cricotracheal ligament

Thyroid glandParathyroid glands (4)

Tracheal cartilage

Thyroid glandLarynx

(a) Anterior view (b) Posterior view

Hyoid bone

(c) Sagittal section

Thyrohyoid membrane

Fat body

Ventricular fold(false vocal cord)

Thyroid cartilage

Vocal fold(true vocal cord)

Cricothyroid ligament

Cricotracheal ligament

Thyrohyoid membrane

Epiglottis

Cuneiform cartilage

Corniculate cartilage

Arytenoid cartilage

Laryngeal sinus

Cricoid cartilage

Tracheal cartilage

Sagittalplane

Thyrohyoid muscle

Epiglottic cartilage

Vestibular foldVocal foldVocalis muscleInferior pharyngealconstrictor muscle

Sternothyroid muscle

Lateral cricoarytenoidmuscle

Cricothyroid muscle

Cricothyroid ligaments

Trachea

Thyroid gland

Parathyroid gland

Hyoid boneThyrohyoid membrane

Rima vestibuliLaryngeal sinus

Thyroid cartilage

Rima glottidis

Cricoid cartilage

Cricotracheal ligament

First tracheal cartilage

Vestibule of larynx

Cavityof larynxCavity

of larynx

Cavityof larynxCavity

of larynx

(d) Frontal section

Thyroid cartilage

Superior view of cartilages and muscles

Cricoid cartilage

Vocal fold

Arytenoid cartilage

Posteriorcricoarytenoid muscle

TongueEpiglottis

Rima glottidis

Ventricular folds(false vocal cords)Cuneiform cartilage

Glottis:Vocal folds(true vocal cords)

Corniculate cartilageView through a laryngoscope

(a) Movement of vocal folds apart (abduction)

(b) Movement of vocal folds together (adduction)

Lateralcricoarytenoidmuscle

Epiglottis

(c) Superior view

Vocal folds(true vocal cords)

Rima glottidis

Cuneiform cartilage

Corniculate cartilageVentricular folds(false vocal cords)

Larynx

View

Cartilage of trachea

Right lateral lobeof thyroid gland

Fibromuscularmembrane oftrachea (containstrachealis muscle)

Esophagus

Left lateral lobe of thyroid gland

ANTERIOR

POSTERIORSuperior view of transverse section of thyroid gland, trachea, and esophagus

Esophagus Trachea

Transverseplane

Larynx

Anterior view

Trachea

Left lung

Location of carina

Left secondary bronchus

Left tertiary bronchus

Left primary bronchus

Left bronchiole

Left terminal bronchiole

Diaphragm

Right lung

Visceral pleura

Parietal pleura

Pleural cavity

Right primarybronchus

Right secondarybronchus

Right tertiarybronchus

Right bronchiole

Right terminalbronchiole

Cardiac notch

BRANCHING OFBRONCHIAL TREE

Trachea

Primary bronchi

Secondary bronchi

Tertiary bronchi

Bronchioles

Terminal bronchioles

POSTERIOR

Sternum

Visceral pleura

Superior vena cava

Left lung

Ascending aorta

Pulmonary arteries

Pulmonary vein

Esophagus

Thoracic aorta

Body of T4Spinal cord

Parietal pleura

Right lung

Pleural cavity

MEDIALLATERAL

Inferior view of transverse section through thoracic cavityshowing pleural cavity and pleural membranes

Transverseplane

View

(a) Anterior view of lungs and pleurae in thorax

First rib

Apex of lung

Left lung

Base of lung

Pleural cavity

Pleura

(b) Lateral view of right lung

Apex

View (b)

Superior lobe

ANTERIOR

Horizontalfissure

Cardiac notch

Middle lobe

Base

Oblique fissure

Inferior lobe

POSTERIOR

(c) Lateral view of left lung

Oblique fissure

Inferior lobe

POSTERIOR

View (c)

(d) Medial view of right lung

Apex

View (e)

Superior lobe

POSTERIORHilum and itscontents (root)

Cardiac notchMiddle lobe

Base

Oblique fissure

Horizontalfissure

ANTERIOR

(e) Medial view of left lung

Oblique fissure

Inferior lobe

View (d)

ANTERIOR

(a) Diagram of portion of lobule of lung

Terminal bronchiole

Pulmonaryvenule

Elasticconnectivetissue

Pulmonarycapillary

Visceralpleura Alveoli

Pulmonary arteriole

Lymphatic vessel

Respiratory bronchiole

Alveoli

Alveolar ducts

Alveolar sac

MICROSCOPIC AIRWAYS

Terminal bronchioles

Respiratory bronchioles

Alveolar ducts

Alveolar sacs

Alveoli

Terminal bronchiole

Blood vessel

Respiratory bronchiole

Alveolar ducts

Alveoli

Alveolar sacs

Visceral pleura

LM about 30x

(b) Lung lobule

Red blood cell

(a) Section through alveolus showing cellular components

Capillary endothelium

Capillary basementmembraneEpithelial basementmembrane

Type I alveolar cellInterstitial space

Type I alveolarcell

Respiratorymembrane

Type II alveolar(septal) cell

Alveolarmacrophage (dust cell)

Red blood cellin pulmonary capillary

Alveolus

Elastic fiber

Reticular fiber

Monocyte

Alveolar fluid with surfactant

(b) Details of respiratory membrane

Alveolus

Diffusionof CO2

Diffusionof O2

Alveolar macrophage(dust cell)

Alveolus

(c) Details of several alveoliLM 1000x

Alveolus

Type II alveolar(septal) cell

Type I alveolar (squamouspulmonary epithelial) cell

Pressuregauge

Piston

Volume = 1 literPressure = 1 atm

Volume = 1/2 literPressure = 2 atm

Internal oblique

Transversus abdominis

Rectus abdominis

External oblique

Internal intercostals

Sternocleidomastoid

Scalenes

External intercostals

Diaphragm

MUSCLES OF INHALATION MUSCLES OF EXHALATION

(a) Muscles of inhalation and their actions (left);muscles of exhalation and their actions (right)

Exhalation

Inhalation

(b) Changes in size of thoracic cavityduring inhalation and exhalation

Diaphragm:

Exhalation

Inhalation

Sternum:

(c) During inhalation, the ribs move upwardand outward like the handle on a bucket

Alveolar pressure =758 mmHg

2. During inhalation (diaphragm contracting)

Intrapleural pressure =754 mmHg

1. At rest (diaphragm relaxed)

3. During exhalation (diaphragm relaxing)

Atmospheric pressure = 760 mmHg Atmospheric pressure = 760 mmHg

Alveolar pressure =760 mmHg

Intrapleural pressure =756 mmHg

Alveolar pressure =762 mmHg

Intrapleural pressure =756 mmHg

Atmospheric pressure = 760 mmHg

During normal quiet inhalation, the diaphragm and external intercostals contract. During labored inhalation, sternocleidomastoid, scalenes, and pectoralis minor also contract.

Alveolar pressureincreases to 762 mmHg

Atmospheric pressureis about 760 mmHgat sea level

Alveolar pressuredecreases to 758 mmHg

During normal quiet exhalation, diaphragm and external intercostals relax. During forceful exhalation, abdominal and internal intercostal muscles contract.

Thoracic cavitydecreases in sizeand lungs recoil

Thoraciccavity increases

in size and volume oflungs expands

(a) Inhalation (b) Exhalation

LUNG CAPACITIESLUNG VOLUMES

6000 mL

5000 mL

4000 mL

3000 mL

2000 mL

1000 mL

INSPIRATORYRESERVEVOLUME3100 mL

(1900 mL)

TIDALVOLUME 500 mL

EXPIRATORYRESERVEVOLUME1200 mL(700 mL)

RESIDUALVOLUME1200 mL

(1100 mL)

INSPIRATORYCAPACITY

3600 mL(2400 mL)

VITALCAPACITY

4800 mL(3100 mL)

TOTALLUNG

CAPACITY6000 mL

(4200 mL)

FUNCTIONALRESIDUALCAPACITY

2400 mL(1800 mL)

Start ofrecord

End ofrecord

Exhalation

Inhalation

CO2 exhaledO2 inhaled

Atmospheric air:PO2 = 159 mmHgPCO2 = 0.3 mmHg

Alveolar air:PO2 = 105 mmHgPCO2 = 40 mmHg

Oxygenated blood:PO2 = 100 mmHgPCO2 = 40 mmHg

Deoxygenated blood:PO2 = 40 mmHgPCO2 = 45 mmHg

Systemic tissue cells:PO2 = 40 mmHgPCO2 = 45 mmHg

Pulmonary capillariesPulmonary capillaries

(a) External respiration:pulmonary gas

exchange

(b) Internal respiration:systemic gas

exchange

Systemic capillariesSystemic capillaries

To lungs

To right atrium

To left atrium

To tissue cells

AlveoliCO2CO2 O2

O2

CO2 O2

Transport of CO2

7% dissolved in plasma23% as Hb-CO2

70% as HCO3–

Transport of CO2

1.5% dissolved in plasma98.5% as Hb-O2Alveoli

(a) External respiration:pulmonary gas

exchange

(b) Internal respiration:systemic gas

exchange

7% 23%70%

1.5% 98.5%

1.5%70%

7%23%

CO2

(dissolved)

CO2

(dissolved)

HCO3–HCO3– O2

(dissolved)

O2

(dissolved)

O2

(dissolved)

O2

(dissolved)HCO3–HCO3–

Hb

Hb

To lungs

To right atrium

To left atrium

To tissue cells

Systemiccapillaries

Systemictissue cells

Plasma

Red blood cell

Pulmonary capillaries

CO2CO2 O2

O2

CO2CO2 O2

O2

Hb + O2Hb + O2

Hb–O2Hb–O2

CO2 + HbCO2 + Hb

Hb–CO2Hb–CO2

HbHb

Hb–CO2Hb–CO2 Hb–O2

Hb–O2

O2O2

P (mmHg)O2

Oxygenated bloodin systemic arteries

Deoxygenated bloodin systemic veins(average at rest)

Deoxygenated blood(contracting skeletal muscle)

Perc

ent s

atur

atio

n of

hem

oglo

bin

P (mmHg)O2

Perc

ent s

atur

atio

n of

hem

oglo

bin

High blood pH(7.6)

Normal blood pH(7.4)

Low blood pH(7.2)

(a) Effect of pH on affinity of hemoglobin for oxygen

Low bloodP CO2

(b) Effect of P on affinity of hemoglobin for oxygenCO2

P (mmHg)O2

Perc

ent s

atur

atio

n of

hem

oglo

bin

Normal blood

High blood CO2

P

CO2P

Low temperature(20°C, 68°F)

P (mmHg)O2

Perc

ent s

atur

atio

n of

hem

oglo

bin

Normal bloodtemperature(37°C, 98.6°F)

High temperature(43°C, 110°F)

P (mmHg)O2

Perc

ent s

atur

atio

n of

hem

oglo

bin

Maternal

Fetal

(a) Exchange of O2 and CO2 in pulmonary capillaries (external respiration)

Exhaled

Inhaled

Alveolus

Interstitialfluid

Pulmonarycapillary wall

Plasma

Red blood cell

Reversechloride

shift

CO2 CO2 CO2CO2 + H2O

CO2 + Hb Hb–CO2

O2 O2 O2 O2 + Hb–H Hb–O2+ H+

HCO3–

HCO3– + H+H2CO3

Cl – Cl –

Carbonic anhydrase

(b) Exchange of O2 and CO2 in systemic capillaries (internal respiration)

Tissue cell

Interstitialfluid

Systemiccapillary wall

Plasma

Red blood cell

Chlorideshift

CO2 CO2 CO2CO2 + H2O

CO2 + Hb Hb–CO2 + O2

O2 O2 O2 O2 + Hb–H Hb–O2

HCO3–

HCO3– + H+H2CO3

Cl – Cl –

Carbonic anhydrase

Midbrain

Pons

Medullaoblongata

Spinalcord

Pneumotaxic area

Apneustic area

Inspiratory area

Expiratory area

Medullary rhythmicity area:

Sagittalplane

RESPIRATORYCENTER:

Sagittal section of brain stem

INSPIRATORY AREA

Diaphragm and external intercostals relax, followed

by elastic recoil of lungs

ACTIVE INACTIVE

Diaphragm and externalintercostals contract

Normal quiet inhalation Normal quiet exhalation Forceful inhalation Forceful exhalation

Internal intercostaland abdominal

muscles contract

Diaphragm,sternocleidomastoid,and scalene muscles

contract

INSPIRATORY AREAACTIVE

EXPIRATORY AREA

Activates

3 seconds2 seconds

(a) During normal quiet breathing (b) During forceful breathing

Medulla oblongata

Sensory axons in glossopharyngeal nerve(cranial nerve IX)

Carotid body

Carotid sinus

Sensory axons in vagus nerve(cranial nerve X)

Arch of aorta

Aortic bodies

Common carotidartery

External carotidartery

Internal carotidartery

Heart

Peripheralchemo-receptorsin aorticandcarotidbodies

CentralChemo-receptorsin medulla

Muscles ofinhalation andexhalationcontract moreforcefully andmore frequently(hyperventilation)

Decrease in arterial blood PCO2, increase in pH, and increase in PO2

Return to homeostasis when response brings arterial blood PCO2 , pH, and PO2 back to normal

Effectors

Control center

Receptors

Increasing

Nerveimpulses

Input

Nerveimpulses

Output

Arterial blood PCO2 (or decreasing pH or PO2)

Some stimulus disruptshomeostasis by

Inspiratory area inmedulla oblongata

PharynxPharynx

Respiratorydiverticulum

Tracheal bud

Esophagus

Trachea

Bronchialbuds

Esophagus

Fourth week

Trachea

Fifth week

Right primarybronchus

Rightsecondarybronchi

Left primarybronchus

Left secondarybronchi

Righttertiarybronchi

Sixth week

Lefttertiarybronchi

Trachea

Eighth week

Left superiorlobe

Right superiorlobe

Right middlelobe

Right inferiorlobe

Leftinferiorlobe Developing

pleura