CHAPTER 19 THE RESPIRATORY SYSTEM
I. Respiration = the exchange of ______________________________ between
atmosphere & _____________________________.
A. Ventilation = actual act of breathing = the exchange of air between atmosphere
& lungs.
1._______________________________________________ respiration
a.Gas exchanges b/n air spaces in lungs & blood in pulmonary capillaries.
2.________________________________________________ respiration
a.Gas exchanges between blood in systemic _______________________ & tissue
_________________________________________________.
3._________________________________________________ respiration
a.Occurs in mitochondria of cells in metabolic rxns that use oxygen & give off carbon dioxide.
II. Anatomy of Respiratory System Organs/Structures:nose, nasal cavities, pharynx,
larynx, trachea, bronchi, lungs with alveoli (air sacs)Fig. 19.1, 19.2, 19.3, 19.8, 19.9, 19.12, 19.14
A. Two parts:
1.Outside thorax = upper respiratory tract
2.Inside thorax = lower respiratory tract
a.Gas exchange occurs in ___________________________________
b.Rest of the organs are only PASSAGEWAYS
1.)Purify & warm the air.
B.Organs
1.Nose
a.The only visible part
b.Made of 2 nostrils ( __________________) with internal hairs
1.)Trap dust; made of cartilage.
2.Nasal cavities
a.Two spaces behind the nose
b.Separated by septum
1.)Perpendicular plate of _________________________________
2.)& _____________________________ bone into rt. & left nostrils
c.Separated from mouth by ___________________________________.
d. If any of these terms are unfamiliar, get the skulls & review these parts.
3.Nasal conchae
a.Curl out from lateral walls in nasal cavity
b.Divide cavity into: superior, middle, & inferior meatuses. Fig. 19.2
c.Function
1.)Support mucous membrane lining nasal cavity
2.)Helps increase _______________________________.
4. Mucous membrane cavity
a.Contains pseudostratified ciliated columnar epithelium
1.)____________________________________ cells & many vessels.
b.____________________________ air from heat radiating
c.____________________________ air by evap. of water from mucous
d. trap dust
e. cilia pushes dust toward pharynx � stomach acid destroys bacti
f. Summary: function is to filter, moisten & warm air.
5. Sinuses
a. Air filled spaces in maxillary, frontal, ethmoid & sphenoid bones
1.) Open into nasal cavity
2.) Lined with mucous membrane � continuous w nasal cavity
a.) If openings blocked == PAIN
b. FUNCTION
1.) Reduce weight of skull
2.) Resonant chamber �affects quality of voice
3.) Produce mucous
6. Pharynx == throat = 3 parts
a. Nasopharynx � area behind nose; contains opening for Eustachian tube
b. Oropharynx � area behind mouth
c. Laryngopharynx � area behng larynx
d. Function of pharynx
7. Larynx
a. Voice box
1.) Made of 9 cartilages connected by muscle & ligaments
2.) Enlargement in airway at superior end of trachea below pharynx.
b. Function
1.) Passage for air moving in & out of trachea
2.) Prevents foreign products from getting into trachea
3.) Houses vocal cords
8.Cartilages of larynx
a.Thyroid
1.) One structure made of hyaline cartilage
2.) Largest & most superior
3.) Epiglottis attaches to the thyroid cartilage
4.) Thyroid gland covers lower portion
5). Male sex hormone makes it larger in men.
b. Cricoid cartilage
1.) One structure
2.) Most inferior cartilage; forms base; others rest on it;
3.) Small ant. region, large post. Region
4.) Attaches to first ring of trachea
c. Epiglottic cartilage
1.) Large flap of elastic cartilage covering glottis
2.)Stem attaches to thyroid cartilage.
d. Arytenoids: two pyramid shaped cartilages; visible from posterior;
_____________________________________________
e. Corniculates: two cone shaped cartilages beside arytenoids
f. Cuneiform:
1.) Two small cylindrical cartilages
2.) In mucous membrane between epiglottis & arytenoids.
9. 2 pairs of horizontal folds in mucous membrane extend from lateral walls
of larynx.
a. Upper folds � vestibular folds =________________________________
1.) Don't make sounds, but close to seal off larynx
b. Lower folds � TRUE VOCAL CORDS = ligaments = ______________
1.) Responsible for _______________________________________
2.) Sound waves created by forcing air between the folds
a.) Folds vibrate from side to side == sound waves
3.) ELASTIC FIBERS + AIR == VIBRATIONS = SOUND WAVES
c. Steps involved in making sound
1.) Skeletal muscles of larynx called _______________________,
a.). Attach internally to the arytenoid cartilages & to vocal folds.
2.) Elastic fibers (ligaments) are stretched between pieces of cartilage
3.) Muscles contract
a.) Pull the strings of the elastic ligaments tightly
b.)Vocal folds are stretched out into the air passage
c.) Glottis is narrowed.
d.) Folds vibrate
e.) Sound waves travel through column of air in pharynx, nose, mouth
4.) Changing shape of pharynx forms _________________________
5.) Using mouth, tongue, lips, muscles of the face to form _________
d. Loudness depends on the FORCE of air passing over cords
e. Sinuses serve as resonating chambers that affect quality of voice
f. Males � thicker & longer cords so they vibrate more slowly
g. Increase tension on cords: _________________
1.) Nervous, afraid, angry � voice becomes tight, high pitched
2.) Decrease tension: _____________
h. Normal breathing � vocal cords relaxed
i. Swallowing � muscles of larynx close the glottis
j. Cancer of larynx � almost exclusively in smokers = hoarse; pain in swallowing; pain to ear
k. Laryngitis � cords swollen, enflamed, can't vibrate freely
10. Trachea = windpipeFigure 19.8
a.______________________________________ = anterior to esophagus
b. lined with ciliated mucous membrane w goblet cells
c. __________________ cartilages; open side on dorsal surface
d. Function of C shape
1.) Prevents trachea from collapsing
2.) Allows esophagus to expand
11. Bronchial Tree
a. Branches leading from trachea to ___________________ AIR SPACE
b. Right & left primary bronchi branch from trachea
1.)Level of the ________________________ vertebra (sternal angle)
c._____________________________ - point at which trachea bifurcates;
1.) Last tracheal cartilage
2.) Forms an internal ridge
3.) Contains sensitive mucous membranes assoc. w the cough reflex.
4.) Widening of this area indicates cancer of lymph nodes around it.
d. Right Primary bronchus
1.) More __________________________ than the left
2.) More objects get into this region.
e. Bronchi-general characteristics
1.)Contain C shaped rings of cartilage
2.)Lined w pseudo-stratified ciliated epithelium
3.)Divide into secondary (lobar) bronchi
a.)One/lobe; rt. lung � 3, left lung � 2
4.)Tertiary bronchi (segmental)
f. Bronchioles � have _______________ rings or plates that enter lobules
g. Terminal bronchioles
1.) Air sacs bud off their sides
2.) Rings of cartilage replaced by plates
3.) Finally disappear deep in the bronchial tree.
h. As cartilage ____, smooth muscle _____
j. Pseudostratified ciliated columnar epithelial tissue changes to simple cuboidal deep in the bronchioles.
k. Alveolar ducts have only a _____________________________
l. Alveolar sacs
1.)Thin walled ______________________________ of the alveolar ducts
m. Alveoli
1.)Thin walled, microscopic air sacs
2.) Open on the side communicating with an alveolar sac.
3.) Alveoli contain one layer of ______________________________________________.
n. Function of alveolus � exchange of _____________ & ___________.
12. Lungs
a. Soft, spongy, cone shaped, separated by heart & mediastinum
b. Enclosed by diaphragm & thoracic cage
c. Suspended by bronchi & vessels.Fig. 19.12
d. Hilum � indentation on medial surface
e. Visceral pleura - __________________ membrane around lung
1.) Attached, folded back at hilum to become the _____________
f. Parietal pleura � lines the thoracic cavity
1.) Only a potential space exists between visceral & parietal pleura
a.) Contains thin film of fluid
b.) Reduces friction & helps hold membranes together.
g. Lobes � rt. superior, middle, inferior lobe; left superior & inferior lobe.
h. Fissures � 2 oblique; one horizontal
i. Lobes are divided by connective tissue into lobules containing terminal bronchioles, alveolar ducts, sacs, alveoli
j. Apex � narrow superior part
k. Base
l. Costal surface � looks like ribs;
m. Hilum � a vertical slit
n. Mediastinal surface
o. Cardiac notch � on left lung
III.Why do we breathe?
A._______________________ in pressure between atmosphere & lung
B. Pressure outside body on thoracic cavity == __________________
C. Pressure inside alveoli (at rest) == ______________
D. During normal inspiration
1. Diaphragm & external intercostals contract
2.Thoracic cavity increases in size, lungs expand
3. Intrapulmonic pressure decreases to _________
a. Parietal and visceral pleura are pulled out
b. Volume of lungs increases
c. Intrapulmonic � pressure drops from 760 mm Hg & air rushes in
d. Intrapulmonic pressure = atmospheric pressure.
E.During normal expiration
1.Nomal exhalation is passive since no muscle contractions are involved
2.Diaphragm & external intercostals muscles relax
3.Thoracic cavity decreases in size & lungs recoil
4.Intrapulmonic pressure increases to 763 mm Hg
5.Expiration
F. Why is intrapleural pressure normally subatmospheric?
1. Is this vital to breathing? Why or why not?
2. What would happen if the individual received a puncture would to the chest
wall, but the lungs were not punctured?
IV. Control of Breathing Figures 19.28 &19.29
A. Respiratory center � collection of scattered neurons in brain stem
1.Two special areas in ________________________________________
2. Motor impulses on cranial & spinal nerves stimulate breathing muscles
3. Medullary rhythmicity area
a. 2 groups of neurons in medulla adjust _________________________
b. Dorsal respiratory group � basic breathing
1. Bursts of impulses of 2 seconds
2. Increase in strength
3. Stop for 3 seconds
4. Burst for 2 seconds
5. Stop for 3 seconds
6. Bursts go to _______________________________ muscles
c.Ventral respiratory group activates for forceful inspiration & expiration
V. Two Regulators of Breathing
A. Pneumotaxic center
1. In upper pons ( _____________________________________________)
a. Inhibitory impulses to medullary inspiratory center & apneustic center
1.) PREVENTS OVERINFLATION
2. Apneustic center � in lower pons
a. Sends ____________________________
1.) Extends time span of inspiration == causes gasping
VI. What are the factors that affect the rate & depth of breathing?
A._____________________________________________
1. Dorsal & ventral groups in medulla oblongata
a.Pneumotaxic center in upper pons regulates
1.) Limits time span of inspiration
b. Apneustic center in lower pons
1.) Extends time span of inspiration
B. _________________________________________________
1. Chemosensitive area within respiratory center
2. In ventral portion of medulla oblongata near origin of vagus nerve
3. Sensitive to changes in blood concentration of CO2 and H+
a.) Increase in CO2 or H+ == signal to chemosensitive areas =
b.) Causes breathing rate to increase. Why?
c.) CO2 + H+ à
H2CO3 à
HCO3- + H+ (influences chemosens. area)
4. Breathing rate & tidal volume increase, thus CO2 & H+ return to normal
5. Figure 19.30
6. _________________________________________________________
sensed by chemoreceptors in carotid and aortic bodies
a.) Impulses sent to respiratory center = breathing rate & tidal vol increase
b.) Result: alveolar ventilation increases: requires a very low level of O2
c.) Refer to box in book
C. Carbon dioxide and hydrogen ions
1. Affect ______________________________ of aorta & carotid, but this is not considered an important stimulus
D.Inflation Reflex (_________________________________________________)
1.Stretch receptors in visceral pleura, bronchioles & alveoli are stimulated
2.Impulse travels on vagus nerve (10th cranial) to pneumotaxic area
3. Shortens the duration of impulse and prevents over inflation
E. Emotional upset or strong sensory stimulation
1. Gasp, rapid rate of breathing
F. Hyperventilation
1. Causes a _______ in blood CO2 à
increase in pH (respiratory alkalosis)
2. Result: localized vasoconstriction of cerebral arterioles == _______ in
blood & oxygen to brain == FAINTING; harmful when swimming
3. Page 784 (box) *******
4. Page 785 (graph) ********
a. Increase in CO2, acidity & temperature
1.) Increase in amount of O2 released by oxyhemoglobin *********
G. Temperature
1. Increase in temperature (fever, exercise) = _________ in respiratory rate
2. Decrease in temperature = _______________ in respiratory rte
3. Plunge in cold water = ___________________
H. Stretching of the anal sphincter = increases respiratory rate: can be used to
stimulate respiration in person who has stopped breathing.
I. Irritation of airways � mechanical/chemical irritation of pharynx/larynx
VII. Chloride Shift � the exchange of 2 neg. charged ions that maintains ionic balance between RBC and plasma ************************
A. How is oxygen carried in the blood?
B.How is carbon dioxide carried in the blood?
C.Why do the gases exchange?
D.Refer to chloride shift handout and to book.
E.This concept is vital to a thorough understanding of how O2 and CO2 are carried and released. **************
F. Example: site of lungs near the alveolus
G. Example:site of the tissue cells
H. How is CO2 transported?
1. In plasma in dissolved state == _______%
2. As carbaminohemoglobin = _______%
3. Most as part of _______________
4. __________ + ________ à
________ - slow in plasma, fast
5. __________ + ________ à
_________ + _________ in systemic caps
6. ________ + deoxyhemoglobin à
HgH+
7. HCO3- à
diffuses out of RBC, enters blood; thus 70% of CO2 is carried as HCO3-
IX. Oxyhemoglobin dissociation Figure 19.36,19.38, 19.39, 19.40
A. Chemical bonds between oxygen & hemoglobin molecules are unstable
1. As partial pressure of oxygen decreases, oxygen is released from oxyhemoglobin
2. When concentration of carbon dioxide, acidity, & temperature increase, the amount of oxygen that is released from oxyhemoglobin increases.
3. How do these facts relate to exercise, exposure to cold temperature, lethargy
B. Pay very close attention to figures 19.35-19.40. Be prepared to answer questions
concerning these graphs.
X.Terms
A. What is eupnea?
B. What is shallow breathing? Diaphragmatic breathing?
C. Table 19.4 and Figure 19.26
D. Table 19.5
E. Atelectasis
F. Bradypnea (brad-e-ne-ah)
G. Dyspnea (disp-ne-ah)
H. Eupnea (up-ne-ah)
I. Hypoxia (hi-pox se-ah)
J. Pneumothorax
K.Tachypnea(tak ip-ne ah)
Helpful Activities to do after you finish reading this chapter
1. Crossword puzzle on Respiratory vocabulary
2. Check out the following web site: