Fundamentals of Anatomy & Physiology

Environmental Exchange

The Respiratory System

What are the primary functions of

the respiratory system?

Oxygen

• Is obtained from the air by diffusion across delicate _______ surfaces of lungs

• Is carried to cells by the cardiovascular system which also returns _____ _____ to the lungs

5 Functions of the Respiratory System

1. Provides extensive gas exchange _____ ____ between air and circulating blood

2. Moves air to and from exchange surfaces of lungs

5 Functions of the Respiratory System

3. ______ respiratory surfaces from outside environment

4. ______ sounds-speaking, singing5. Participates in ________ sense

Components of the Respiratory System

Figure 23–1

Organization of the Respiratory System

• The respiratory system is divided into the _______ respiratory system, above the larynx, and the _______ respiratory system, from the larynx down

The Respiratory Tract

• Consists of a ________ portion:– from nasal cavity to terminal

bronchioles• Consists of a ___________ portion:

– the respiratory bronchioles and alveoli - Are air-filled pockets within the lungs• where all gas exchange takes place

The Respiratory Epithelium

• For gases to exchange efficiently:– alveoli walls must be very thin (< 1 µm)

– surface area must be very great (about __ times the surface area of the body)

The Respiratory Mucosa

• Consists of:– an ________ layer– an _______ layer

• Lines conducting portion of respiratory system

Figure 23–2

Alveolar sac

Alveoli

The Lamina Propria• Underlies areolar tissue• In the upper respiratory system, trachea,

and bronchi:– contains _______ glands that secrete onto

epithelial surface

• In the conducting portion of lower respiratory system:– contains _____ muscle cells that encircle

lumen of bronchioles

The Respiratory Epithelium

Figure 23–2

How are delicate respiratory exchange

surfaces protected from pathogens, debris, and

other hazards?

The Respiratory Defense System

• Consists of a series of _____ mechanisms

• Removes particles and _________

Components of the Respiratory Defense System

(1 of 2)• _______ cells and mucous glands:

– produce mucus that bathes exposed surfaces

• Cilia:– _______ debris _______ in mucus

toward the pharynx (mucus escalator)

Components of the Respiratory Defense System

(2 of 2)• _________ in nasal cavity removes

large particles• Alveolar _________ engulf small

particles that reach lungs

What are the organs of the upper respiratory

system and their functions?

The Upper Respiratory System

Figure 23–3

The Nose

• Air enters the respiratory system:– through nostrils or ______ nares– into nasal _________

• Nasal hairs:– are in nasal vestibule – are the first particle filtration system

The Nasal Cavity

• The nasal ________:– divides nasal cavity into left and right

• Mucous secretions from paranasal sinus and tears:– clean and moisten the nasal cavity

• Superior portion of nasal cavity is the _________ region:– provides sense of smell

Air Flow• From

vestibule to internal nares:– through

superior, middle, and inferior meatuses

Meatuses• Constricted

passageways that produce air turbulence:– _____ and

_______ incoming air

– ______ particles

The Palates• Hard palate:

– forms ______ of nasal cavity

– separates nasal and oral cavities

• Soft palate:– extends _______

to hard palate– divides superior

nasopharynx from lower pharynx

The Nasal Mucosa

• Warm and humidify inhaled air for arrival at lower respiratory organs

• Breathing through mouth bypasses this important step

The Pharynx• A chamber

shared by digestive and respiratory systems

• Extends from internal nares to entrances to larynx and esophagus

Divisions of the Pharynx

• ____pharynx• ____pharynx• ______pharynx

The Nasopharynx

• ______ portion of the pharynx

• Contains pharyngeal tonsils and openings to left and right auditory tubes

The Oropharynx

• ______ portion of the pharynx

• Communicates with oral ______

The Laryngopharynx• _______ portion

of the pharynx• Extends from

hyoid bone to entrance to larynx and esophagus

What is the structure of the larynx and its

role in normal breathing and production of sound?

Anatomy of the Larynx

Figure 23–4

Cartilages of the Larynx

• 3 large, unpaired cartilages form the larynx:– the ______

cartilage – the ______

cartilage– the _______

The Thyroid Cartilage

• Also called the Adam’s apple

• Is a _______ cartilage• Forms anterior and

lateral walls of larynx

• Ligaments attach to _____ bone, epiglottis, and laryngeal cartilages

The Cricoid Cartilage

• Is a ______ cartilage

• Form posterior portion of larynx

• Ligaments attach to first tracheal cartilage

• Articulates with arytenoid cartilages

The Epiglottis

• Composed of _______ cartilage

• Ligaments attach to ______ cartilage and hyoid bone

Cartilage Functions

• Prevents entry of food and liquids into respiratory tract – During __________:– the larynx is elevated– the epiglottis folds back over glottis

• Thyroid and cricoid cartilages support and protect:– the _______ – the entrance to trachea

The Glottis

Figure 23–5

Sound Production• Air passing through glottis:

– _______ vocal folds– produces sound waves

Sound Variation

• Sound is varied by:– tension on vocal folds– voluntary muscles (position arytenoid

cartilage relative to thyroid cartilage)

What is the structure of airways outside the

lungs?

Anatomy of the Trachea

Figure 23–6

The Trachea • Also called

the _________• Extends from

the cricoid cartilage to the internal ridge– where it

branches into right and left pulmonary _________

The Tracheal Cartilages

• ___–20 tracheal cartilages:– strengthen and protect airway– discontinuous where trachea contacts

esophagus• Ends of each tracheal cartilage are

connected by:– an elastic ligament and __________

muscle

The Primary Bronchi• Right and left primary bronchi:

– separated by an internal ridge (the ______)

The Right Primary Bronchus

• Is ______ in diameter than the left• Descends at a _________ angle

The Lungs• Left and right

lungs:– are in left and

right _______ cavities

• The base:– inferior portion

of each lung rests on superior surface of ________

The Right Lung

• Has _ lobes: – superior,

middle, and ______

– separated by horizontal and oblique fissures

The Left Lung• Has _ lobes:

– superior and inferior

– are separated by an oblique fissure

Relationship between Lungs and Heart

Figure 23–8

Lung Shape

• Right lung:– is wider – is displaced upward by _____

• Left lung:– is _______ – is displaced leftward by the heart

forming the cardiac notch

The Bronchial Tree• Is formed by the primary bronchi and

their branches

Extrapulmonary Bronchi• The left and right bronchi branches _____

the lungs

Intrapulmonary Bronchi• Branches within the lungs

A Primary Bronchus• Branches to form secondary bronchi

(lobar bronchi)• 1 secondary bronchus goes to each lobe

Bronchi and Lobules

Figure 23–9

Secondary Bronchi

• Branch to form ______ bronchi, also called the segmental bronchi

• Each segmental bronchus:– supplies air to a

single bronchopulmonary segment

Bronchial Structure

• The walls of primary, secondary, and tertiary bronchi:– contain

progressively less ________ and ____ smooth muscle

– increasing muscular effects on airway constriction and resistance

Bronchitis

• _____________ of bronchial walls:– causes constriction and breathing

difficulty

Figure 23–10

The Bronchioles

Bronchiole Structure• Bronchioles:

– have no ___________– are dominated by smooth muscle

Autonomic Control• Regulates smooth muscle:

– controls diameter of bronchioles– controls airflow and resistance in lungs

Asthma

• Excessive stimulation and bronchoconstriction

• Stimulation severely restricts airflow

The Bronchioles• Each tertiary bronchus branches into multiple bronchioles

• Bronchioles branch into terminal bronchioles: – 1 tertiary

bronchus forms about 6500 terminal bronchioles

Figure 23–11

Alveolar Organization

Alveolar Organization• Respiratory

bronchioles are connected to alveoli along alveolar ducts

• Alveolar ducts end at alveolar sacs: – common

chambers connected to many individual alveoli

An Alveolus• Has an

extensive network of capillaries

• Is surrounded by ______ fibers

Alveolar Epithelium

• Consists of simple squamous epithelium

• Consists of thin, delicate Type I cells

• Patrolled by alveolar __________, also called dust cells

• Contains septal cells (Type II cells) that produce __________

Surfactant • Is an _____

secretion• Contains

phospholipids and proteins

• Coats alveolar surfaces and _______ surface tension

• Helps diffusion of O2

Inflammation of Lobules

• Also called pneumonia:– causes fluid to leak into alveoli– compromises function of respiratory

membrane

Figure 23–8

Pleural Cavities and Pleural Membranes

Respiration• Refers to 2 integrated processes:

– external respiration– internal respiration

External Respiration• Includes all processes involved in

exchanging O2 and CO2 with the environment Internal Respiration

• Also called cellular respiration• Involves the uptake of O2 and production

of CO2 within individual cells

3 Processes of External Respiration

1. Pulmonary ventilation (breathing)2. Gas diffusion:

– across membranes and capillaries

3. Transport of O2 and CO2:– between alveolar capillaries– between capillary beds in other

tissues

Gas Pressure and Volume As volume decreases, pressure

increases

Figure 23–13

Figure 23–14

Mechanisms of Pulmonary Ventilation

Respiration

• Causes volume changes that create changes in pressure

• Volume of thoracic cavity changes:– with expansion or contraction of

diaphragm or rib cage

Figure 23–16a, b

The Respiratory Muscles

The Respiratory Muscles

Figure 23–16c, d

3 Muscle Groups of Inhalation Diaphragm is the main one.

Abdominal muscle system used in exhaling

Respiratory Performance and Age

Figure 23–28

3 Effects of Aging on the Respiratory System

1. Elastic tissues deteriorate:– reducing lung compliance– lowering vital capacity

2. Arthritic changes:– restrict chest movements– limit respiratory minute volume

3. Emphysema:– affects individuals over age 50– depending on exposure to

respiratory irritants (e.g., cigarette smoke)