CHAPTER 24Respiratory System

RESPIRATION INCLUDES

� __________________

� Air moves in and out of lungs

� Continuous replacement of gases in alveoli (air sacs)

� __________________

� Gas exchange between blood and air at alveoli

2

� Gas exchange between blood and air at alveoli

� Transport of respiratory gases

� Between the lungs and the cells of the body

� Performed by the cardiovascular system

� __________________

� Gas exchange in capillaries between blood and tissue cells

Nasal cavity

Nasopharynx

Frontal sinus

Hyoid boneUPPER

RESPIRATORY

SYSTEM

LOWER

RESPIRATORY

SYSTEM

Nasal conchae

Nose

Larynx

Trachea

Bronchus

Sphenoidal sinus

Internal nares

FIGURE 24.1 STRUCTURES OF THE RESPIRATORY SYSTEM

Clavicle

Ribs

LEFT

LUNGRIGHT

LUNG

Bronchioles

Diaphragm

FUNCTIONS OF THE RESPIRATORY SYSTEM

1. Provides area for gas exchange between air and

blood

2. ____________________________________________

3. ____________________________________________

4. Produces sound involved in verbal 4. Produces sound involved in verbal

communication

5. Assists in regulation of blood volume, blood

pressure, and body fluid pH

RESPIRATORY EPITHELIUM

� ____________________________cells

� Except for the pharynx, smaller bronchi, and alveoli

� Function:

� ____________________________cells� ____________________________cells

� Found in the pharynx

� Function:

� _____________________________cells

� Found in the nasal cavity and lower respiratory tract

� Function:

Frontal sinusNasal conchae

Nasal vestibule

External nares

Nasal cavitySuperior

Middle

InferiorInternal nares

Entrance to auditory tube

Pharyngeal tonsil

Pharynx

Nasopharynx

Oropharynx

FIGURE 24.4A RESPIRATORY STRUCTURES IN THE HEAD AND NECK© 2015 Pearson

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A sagittal section of the head and neck

Epiglottis

Thyroid gland

Soft palate

Trachea

Thyroid cartilage

Laryngopharynx

Glottis

Vocal fold

a

Uvula

Vestibular fold

Inferior nasalconcha

Spinal cord Hyoid bone

Laryngopharynx

Tongue

Hard palate

Soft palate

Nasopharynx

Oropharynx

Epiglottis

Dens

of

axis

(C2)

C3

C4

C5

FIGURE 24.5 RESPIRATORY STRUCTURES IN THE HEAD AND NECK© 2015 Pearson Education, Inc.

Thyroid cartilage

Vestibular fold

Esophagus

Trachea

Tracheal cartilages

Pleural cavity

Vocal foldC6

C7

T1

T2

T3

RESPIRATORY SYSTEM: AIR FLOW

1. Air enters ____________________

2. Passes by the ______________________

3. Enters ___________________

4. Enters and flows in and around ______________

Air enters _____________________5. Air enters _____________________

6. Air enters nasopharynx area _____________

laryngopharynx

7. ___________

8. Bronchus

9. Bronchioles

NASAL CAVITY CONSISTS OF:

� Nasal bones

� Nasal septum

� Cartilage

� External nares

Alar Cartilage� Alar Cartilage

� Dorsum and apex of the nose

� Nasal conchae

Major alarcartilage

Apex

Dorsumof nose

Lateral nasalcartilage

Minor alar

FIGURE 24.3 RESPIRATORY STRUCTURES

IN THE HEAD AND NECK, © 2015 Pearson

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Minor alarcartilage

Externalnares

LOWER RESPIRATORY SYSTEM: THE LARYNX

� Cylinder with cartilaginous walls stabilized by

ligaments and skeletal muscle

� Begins at level and vertebra C3 or C4 and ends

at C7.

� Unpaired Cartilage� Unpaired Cartilage

� Thyroid cartilage

� Cricoid cartilage

� Epiglottis

� Paired Cartilage

� Arytenoid cartilage

� Corniculate cartilage

� Cuneiform cartilage

Epiglottis

Lesser cornu

Hyoid bone

Thyrohyoid ligament(extrinsic)

LaryngealprominenceThyroid

cartilageLarynx

FIGURE 24.6A ANATOMY OF THE LARYNX© 2015 Pearson

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cartilage

Cricoid cartilage

Larynx

Cricothyroid ligament(intrinsic)

Cricotracheal ligament(extrinsic)

Trachea

Tracheal cartilages

Epiglottis

Thyroidcartilage

Vocalligament

Vestibularligament

Arytenoid cartilage

FIGURE 24.6B ANATOMY OF THE LARYNX© 2015 Pearson

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Cricoidcartilage

Arytenoid cartilage

Tracheal cartilages

FIGURE 24.7A THE VOCAL CORDS

Glottis (open)

Vocal fold

Vestibular fold

Corniculate cartilage

POSTERIOR

Cuneiform cartilage

Aryepiglotticfold

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Epiglottis

Root of tongue

ANTERIOR

Glottis in theopen position.

a

SOUND PRODUCTION

� Air passing through vocal cords

� Amplification of sound occurs in sinus cavities

� Production of definite sounds depends on movement

of the lips, tongue, and cheeks

Pitch depends on the diameter, length, and tension � Pitch depends on the diameter, length, and tension

in vocal cords

� Children have slender, short vocal folds = high-pitched

sound

� At puberty, vocal cords of males become thicker and

longer = deeper voice than females

Glottis (open)

Vocal fold

Vestibular fold

Corniculate cartilage

POSTERIOR

Cuneiform cartilage

Aryepiglottic

fold

Corniculate cartilage

Glottis (closed)

Vocal fold

FIGURE 24.7AB THE VOCAL CORDS© 2015 Pearson

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Epiglottis

Root of tongue Epiglottis

Vestibular fold

ANTERIOR

Glottis in theopen position.

Glottis in theclosed position.

a b

Hard palate

Soft palate

Bolus

Larynx

Tongue forcescompacted bolusinto oropharynx

Laryngeal movementfolds epiglottis;pharyngeal musclespush bolus intoesophagus

Soft palate

Tongue

Bolus

Epiglottis

Trachea

1

2

FIGURE 24.8 MOVEMENTS OF THE LARYNX DURING SWALLOWING

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Bolusesophagus

Epiglottis

Epiglottis

Bolus

Trachea

Bolus movesalong esophagus;larynx returnsto normal position

3

Tongue

Nasal cavity

Esophagus

Nasopharynx

Frontal sinus

Hyoid boneUPPER

RESPIRATORY

SYSTEM

LOWER

RESPIRATORY

SYSTEM

Nasal conchae

Nose

Larynx

Trachea

Bronchus

Sphenoidal sinus

Internal nares

FIGURE 24.1 STRUCTURES OF THE RESPIRATORY SYSTEM© 2015 Pearson

Education, Inc.

Clavicle

Ribs

LEFT

LUNGRIGHT

LUNG

Bronchioles

Diaphragm

TRACHEA

� Size: 11 cm by 2.5 cm diameter

� Bifurcates at the carina into right and left

bronchi at T5

� Contains 15-20 tracheal cartilages

� Each cartilage is a C-shaped ring� Each cartilage is a C-shaped ring

� Tracheal cartilages are connected by annular

ligaments

Trachealismuscle

Lumen of

Esophagus

FIGURE 24.9B ANATOMY OF THE TRACHEA

AND PRIMARY BRONCHI© 2015 Pearson

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Respiratoryepithelium

Thyroidgland

Trachealcartilage

Lumen oftrachea

LM × 3The trachea

Larynx

FIGURE 24.9A ANATOMY OF THE TRACHEA AND PRIMARY BRONCHI© 2015 Pearson

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Primarybronchi

Lung tissue

RIGHT LUNG

Secondarybronchi

Root ofright lung

LEFT LUNG

Root ofleft lung

FIGURE 24.11

BRONCHI AND

BRONCHIOLES

Cartilage ring

Root of lung

Secondary (or inferior

lobar) bronchus

BRONCHIOLE

Primary bronchusLEFT LUNG

Tertiary (or

segmental)

bronchi

Secondary

(or superior

lobar)

bronchus

Cartilage plates

Visceral pleura

Respiratory

epithelium

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Smooth muscle

Lobule Respiratory

bronchioles

Terminal

bronchiole

Bronchioles

epithelium

Bronchopulmonarysegments ofsuperior lobe

Broncho-pulmonary

segments ofsuperior lobe

Broncho-

LEFTRIGHT

FIGURE 24.12A THE BRONCHIAL TREE AND DIVISIONS OF THE LUNGS© 2015 Pearson

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Broncho-pulmonarysegments ofinferior lobe

Broncho-pulmonary

segments ofmiddle lobe

Broncho-pulmonary

segments ofinferior lobe

Gross anatomy of the lungs showingthe bronchial tree and its divisions.

a

PRIMARY BRONCHI

� Each primary bronchus enters lung at the point

of ________________

� The _______ is also the point of entrance and exit of

the pulmonary blood vessels

� The combination of the bronchus, artery, and � The combination of the bronchus, artery, and

vein is called the root

LUNGS AND PLEURA

Around each lung is a

flattened sac of serous

membrane called pleura

Parietal pleura – outer layer

Visceral pleura – directly on

lung

Pleural cavity – slit-like potential space filled with pleural fluid

� Lungs can slide but separation from pleura is resisted (like film between 2 plates of glass)

� Lungs cling to thoracic wall and are forced to expand and recoil as volume of thoracic cavity changes during breathing

lung

CXR(chest x-ray)

26

FIGURE 24.10A SUPERFICIAL ANATOMY OF

THE LUNGS

Trachea

Aortic arch

Superior lobe

Fibrous layer

of pericardium

Left lungRight lung

Superior vena cava

Superior lobe

Horizontal fissure

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of pericardium

Oblique fissure

Inferior lobe

Cut edge of

diaphragmLiver,

left lobeLiver,

right lobe

Middle lobe

Oblique fissure

Inferior lobe

Falciform ligament

Anterior view of the opened chestshowing the relative positions ofthe left and right lungs and heart

a

FIGURE 24.10B SUPERFICIAL ANATOMY OF

THE LUNGS

Diagrammatic views ofthe lateral surfaces ofthe isolated right andleft lungs

Apex

Horizontalfissure

Superiorlobe

Middle

Lateral Surfaces

Apex

Superior lobe

b

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Middlelobe

Inferiorlobe

Obliquefissure

Base

Inferiorlobe

Cardiacnotch

Obliquefissure

Base

RIGHT LUNG LEFT LUNG

FIGURE 24.10C SUPERFICIAL ANATOMY OF

THE LUNGS

Medial Surfaces

Diagrammatic views ofthe medial surfaces ofthe isolated right andleft lungs

Apex

Pulmonary arteries

Superior

lobe

Pulmonary

veins Pulmonary

veins

c

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Hilum

Inferior

lobe

Cardiac

impression

Horizontal

fissure

Oblique

fissure

RIGHT LUNG

Base

LEFT LUNG

veins

Oblique

fissure

STRUCTURE OF THE LUNGS

� The apex points superiorly and the base

inferiorly

� The _______ lung has ________ lobes

� Superior, middle, and inferior lobes

� Consists of a horizontal fissure and an oblique fissure� Consists of a horizontal fissure and an oblique fissure

� The ________ lung has ______ lobes

� Superior and inferior lobes

� Contains the oblique fissure

� Left lung has a cardiac notch

Apicoposterior

Anterior

Superior lingular

Inferior lingular

Bronchopulmonarysegments ofsuperior lobe

Anterior

Apical

Posterior

Anterior

Broncho-pulmonary

segments ofsuperior lobe

LateralBroncho-

LEFTRIGHT

FIGURE 24.12A THE BRONCHIAL TREE AND DIVISIONS OF THE LUNGS

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Anteriorbasal

Lateralbasal

Medialbasal

Posteriorbasal

Superior

Broncho-pulmonarysegments ofinferior lobe

Lateral

MedialBroncho-

pulmonarysegments ofmiddle lobe

Anteriorbasal

Lateralbasal

Posteriorbasal

Medialbasal

Superior

Broncho-pulmonary

segments ofinferior lobe

Gross anatomy of the lungs showingthe bronchial tree and its divisions.

a

FIGURE 24.12B THE BRONCHIAL TREE AND

DIVISIONS OF THE LUNGS

Apical

Posterior

Anterior

Medial

Lateral

Superior

Bronchopulmonarysegments of

superior lobe

Bronchopulmonarysegments ofmiddle lobe

Apicoposterior

Anterior

Superior lingular

Inferior lingular

Bronchopulmonarysegments ofsuperior lobe

Superior

Medial basal

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Lateralbasal

Medialbasal

Bronchopulmonarysegments ofinferior lobe

Right lung, costal surface

Posteriorbasal

Anteriorbasal

Left lung, costal surface

Isolated left and right lungs have been colored to showthe distribution of the bronchopulmonary segments.

Posterior basal

Anterior basal

Lateral basal

Bronchopulmonarysegments ofinferior lobe

b

FIGURE 24.11

BRONCHI AND

BRONCHIOLES

Cartilage ring

Root of lung

Secondary (or inferior

lobar) bronchus

BRONCHIOLE

Primary bronchusLEFT LUNG

Tertiary (or

segmental)

bronchi

Secondary

(or superior

lobar)

bronchus

Cartilage plates

Visceral pleura

Respiratory

epithelium

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Smooth muscle

Lobule Respiratory

bronchioles

Terminal

bronchiole

Bronchioles

epithelium

Trachea

Tertiarybronchi

Smallerbronchi

Secondarybronchus

Leftprimary

bronchus

Visceralpleura

Branch ofpulmonaryartery

Bronchial artery (red),vein (blue), and

nerve (yellow)

Respiratorybronchiole

Elastic fibers

CapillarybedsBranch of

pulmonaryLymphaticvessel

Smooth musclearound terminalbronchiole

Arteriole

Terminalbronchiole

Bronchiole

Respiratoryepithelium

Bronchioles

FIGURE 24.13A BRONCHI AND BRONCHIOLES© 2015 Pearson

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Bronchopulmonarysegment

Alveoli in apulmonary

lobule

pulmonaryvein

Alveolar sac

Pleural cavity

Alveoli

vesselAlveolarduct

The structure of one portion of a single pulmonary lobule

Interlobularseptum

Visceral pleura

Parietal pleura

Bronchioles

Terminal bronchiole

Respiratory bronchiole

a

FIGURE 24.14A ALVEOLAR ORGANIZATION

Respiratory bronchiole

Smooth muscle

Alveolar duct

Alveolus

Elastic fibers

Smooth muscle

Capillaries

Basic structure of a lobule, cut to reveal thearrangement between the alveolar ducts and alveoli.A network of capillaries surrounds each alveolus.These capillaries are surrounded by elastic fibers.

Alveolarsac

a

FIGURE 24.14B ALVEOLAR ORGANIZATION

Alveolar

Alveoli

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Alveolar

sac

Alveolar

duct

SEM of lung tissue showing the appearanceand organization of the alveoli.

Lung tissue LM × 125

b

AVEOLAR DUCTS AND ALVEOLI

� Each lung has approx 150 million alveoli

� Network of capillaries surround each alveolus

� Capillaries drop off carbon dioxide and pick up

oxygen

� Elastic tissue surrounds each alveolus� Elastic tissue surrounds each alveolus

� Maintains the shape and position of each alveolus

during inhalation and exhalation

CELLS ASSOCIATED WITH ALVEOLI

� The cells associated with alveoli

�The lining consists of a single layer of

_______________

�These are called ___________________

________________are scattered among the �________________are scattered among the

type I pneumocytes

�_____________________secrete surfactant

�Surfactant prevents alveolar collapse

�_________________wander around

phagocytizing particulate matter

GAS EXCHANGE AT THE ALVEOLI

�Pulmonary arteries transport

carbon dioxide to the alveolar

capillaries

�Carbon dioxide leaves the capillaries Carbon dioxide leaves the capillaries

and enters the alveolar sacs

�Oxygen leaves the alveolar sacs and

enters the capillaries

�Oxygen enters the pulmonary veins

and returns to the heart to be pumped

to all parts of the body

FIGURE 24.14D

ALVEOLAR

ORGANIZATION

Red blood cell

Capillary lumen

EndotheliumNucleus of

endothelial cell

0.5 µm

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Alveolarepithelium

Fused basallaminae

Alveolar air space

The respiratory membrane.

Surfactant

d

THE PLEURAL CAVITIES AND PLEURAL

MEMBRANES

� The pleural cavity between the visceral and

parietal membranes consists of:

� Pleural fluid

� Reduces friction when the lungs move upon inhalation and

exhalation

� Pleurisy

� A condition in which the membranes produce too

much pleural fluid or the membranes adhere to the

thoracic wall thereby resulting in pain upon

inhalation and exhalation

FIGURE 24.15 ANATOMICAL RELATIONSHIPS

IN THE THORACIC CAVITY

Left lung,

superior lobe

Oblique fissure

Body of sternum

Pericardial

cavity

Right lung,

middle lobe

Right pleural

cavity

Rib

Visceral pleura

Ventricles

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Aorta Bronchi

Right lung,

inferior lobe

Atria

Posterior

mediastinum

Spinal cord

Left pleural cavity

Visceral pleura

Esophagus

Left lung,

inferior lobe

Parietal pleura

RESPIRATORY MUSCLES AND PULMONARY

VENTILATION

� Respiratory Muscles

� The muscles involved in pulmonary ventilation

(breathing) are:

� Diaphragm

� External intercostals

� Internal intercostals

RESPIRATORY MUSCLES AND PULMONARY

VENTILATION

� Diaphragm

� Contracts (lowers) to cause inhalation

� Relaxes (raises) to cause exhalation

� External intercostals

� Elevate the ribs to aid in inhalation� Elevate the ribs to aid in inhalation

� Internal intercostals

� Depress the ribs to aid in exhalation

Accessory

Respiratory Muscles

(Inhalation)

Scalene muscles

Pectoralis minor

muscle

Primary

Respiratory Muscles

(Inhalation)

Accessory

Respiratory Muscles

(Exhalation)

The Respiratory Muscles1

Sternocleidomastoid

muscleExternal intercostal

muscles

FIGURE 24.16 RESPIRATORY MUSCLES AND PULMONARY

VENTILATION (1 OF 4) © 2015 Pearson

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muscle

Internal intercostal

muscles

Primary

Respiratory Muscles

(Inhalation)

Rectus abdominis

Internal oblique muscle

(Exhalation)

Serratus anterior

muscle

Diaphragm

External oblique

muscle

Transversus thoracis

muscle

FIGURE 24.16RESPIRATORY MUSCLES

AND PULMONARY

VENTILATION (2 OF 4) Ribs andsternumelevate

The Mechanics of Breathing2

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Diaphragmcontracts

RESPIRATORY MUSCLES AND PULMONARY

VENTILATION

� Respiratory Movements

� Respiratory movements can be classified two ways:

eupnea or hyperpnea

� ________: quiet breathing

� May involve diaphragmatic (deep) breathing or costal

breathing (shallow breathing) or both

� During pregnancy, due to the uterus pushing upward on the

diaphragm , women typically use costal breathing

� ________________: forced breathing

� Generally requires the use of accessory breathing muscles

RESPIRATORY CHANGES AT BIRTH

� Prior to Birth

� Pulmonary arterial resistance is high

� Pulmonary vessels are collapsed

� Rib cage is compressed

� Lungs and passageways contain no air but do contain � Lungs and passageways contain no air but do contain

small amounts of fluid

� At Birth

� Air enters and forces the fluid out

� Closure of:

� Foramen ovale and ductus arteriosus

AGING AND THE RESPIRATORY SYSTEM

� The respiratory system becomes less efficient as

we age

� Noteworthy changes include:

� Elastic tissue begins to deteriorate

� Lungs cannot expand or constrict as much as they used to� Lungs cannot expand or constrict as much as they used to

� Movements of the ribs are restricted due to arthritis

� Some degree of emphysema, which hinders

breathing

� With age, roughly 1 square foot of respiratory

membrane is lost each year after age 30

� There are many diseases of the respiratory system, including asthma, cystic fibrosis, COPD (chronic obstructive pulmonary disease – with chronic bronchitis and/or emphysema) and epiglottitis

example:

normal emphysema

50

YOU MIGHT WANT TO THINK TWICE ABOUT

SMOKING….

51How does the histology of the respiratory track change when one smokes?