Chapter 22: Respiratory System Flashcards
What are the four processes involved with respiration?
pulmonary ventilation, external respiration, transports of o2 and co2 via blood stream, internal respiration
Pulmonary Ventilation
breathing; exchange of o2 and co2 between atmosphere and lungs
External Respiration
exchange of o2 and co2 between lungs and blood
Internal Respiration
exchange of o2 and co2 between blood and tissues
Upper Respiratory System
warms, moistens, and cleanses inhaled air; includes nose, paranasal sinuses and pharynx
External Nose
overlying skin with many sebaceous glands; supported by nasal cartlages (plates of hyaline cartilage)
Nasal Cavity
extends from nares (nostrils) to posterior nasal aperture; ethmoid and sphenoid bone form roof; hard and soft palate form floor; lateral walls exhibt nasal conchae (create turbulance and increase surface area); divided meidally by nasal septum ; serves as resonance chamber of speech
What are the two types of mucosa that lines the nasal cavity?
olfactory mucosa and respiratory mucosa
Olfactory Mucosa
contains olfactory receptors
Respiratory Mucosa
consists of pseudostratified ciliated columnar epithelium with goblet cells and seromucous nasal glands
Paranasal Sinuses
mucosa lined, air filled cavities located in frontal, ethmoid and maxilla; mucus drains into nasal cavity
Rhinitis
inflammation of respiratory mucosa
Sinusitis
inflammation of paranasal sinuses
Pharynx
muscular tube connecting nasal and oral cavities to larynx and esophagus; subdivided into 3 regions- nasopharynx, oropharynx and laryngopharynx
Nasopharynx
air passageway; lined with pseudostratified ciliated columnar epithelium; contains pharyngeal tonsil (adenoids), opening to pharynogotympanic tubes (equlizes middle ear and atmospheric pressrue) and tubal tonsils
Oropharynx
passageway for BOTH food and air; lined with stratified squamous epithelium; contains palatine tonisls and lingual tonsils
Laryngopharynx
passageway for both air and food; lined with stratified squamous epithelium; joins with larynx and esophagus
Upper Respiratory Passage
nose to nasal cavity to nasopharynx to oropharyns to larynogopharynx
Lower Respiratroy Passage
larynx to trachea to main brochi to local branch to segmental branch to bronchiol to terminal bronchiole
Lower Respiratory System
includes larynx, trachea, bronchi and lungs
Larynx
voive box; extends from larynogopahrynx to trachea; air passageway supported by 9 cartilages; houses vestibular folds (false vocal cords) and vocal folds (true vocal cords); superior larynx lined wiht straififed squamous epithelium; inner lined with pesudostrafied columnar epithelium
Laryngitis
inflammation of vocal folds and vestibular fold; from yelling/ talking
Trachea
windpipe; from larynx to main bronchi; wall consists of four layers: mucosa (pseudostratified ciliated columnary); submucosa (CT containing sermucous galnds); C Shaped hyaline cartilgage; adventitia (CT Covering)
Conduction of Bronchial Tree
main bronchi to lobar bronchi to segmental bronchi to bronchioles to terminal bronchioles
Structural Changes in Wall of Conducting Tubes (Main Brochi to Terminal Bronchioles)
cartilage rings gradually replaced by plates; absent in bronchioles; mucosa thins; pseudostratified ciliated columnar epithelium transitions to simply columnar the to simple cuboidal; as tube diameter decreases smooth muscle increases
Respiratory Zone Structures
respirartory bronchioles to alveolar ducts to alverolar sacs to alveoli (main sites of gas exchange); alveoli are closely associated with capillaries
What are the types of cells in the alveoli?
Type I alveolar cells; type II alveolar cells; alveolar macrophages
Type I Alveolar Cells
simple squamous epithelium
Type II Alveolar Cells
cuboidal epithelial cells; secrete surfactant and antimicrobial proteins; surfactant reduces surface tension in alveioli
Alveolar Macrophages
consume bacteria and debris
Lungs
occupy entire thoracic cavity except mediastinum; consists largely of air spaces and elastic connective tissue; contains 3 lobes; left lung only has 2 lobes because of heart; left lung also has a cardiac notch where the heart sits
Pulmonary Circulation
pulmonary arteries convey low o2 blood to lungs to be oxygenated; pulmonary veins convey high o2 blood to left ventricle
Bronchial Circulation
bronchial arteries convey high o2 blood to all lung tissues except alveoli
Dual Innervation
sympathetic NS dilates bronchioles; parasympathetic NS constricts bronchioles
Parietal Pleura
lines each pleural cavity
Visceral Pleura
adheres tightly to surface of each lung
Pleural Cavity
contains pleural fluid
Pleurisy
inflammation of the pleural membrane
Pressure Relationships
pressure changes within thoracic cavity are relative to atmospheric pressure
Atmospheric Pressure
Patm; pressure exerted by gases around the body; at sea level Patm = 760 mmHg = 1atm;
0 Respiratory Pressure
means you are equal to 760 mmHg
Positive REspiratory pressure
means its value is greater than 760 mmHg; below sea level
Negative Respiratory Prssure
means its value is less than 760 mmHg; above sea level
Intrapulmonary Pressure
Ppul; pressure in the alveoli; ALWAYS equalizes with atomospheric pressure (Patm)
Intrapleural Pressure
Pip; pressure within pleural cavity; always les than Ppul (~4 mmHg less); MUST be negative for the lungs to remain inflated
Atelectasis
lung collapses (partial or full) due to a plugged bronchiole
Pneumothorax
lung collapse (full) due to air entering pleural cavity; some causes include knife stab or ruptured visceral pleura
Breathing occurs…
inspiration and expiration; in response to changes in volume and pressureB
Boyles Law
at constant pressure, the pressure (P) of a gas varies INVERSLY with its volume (V); if V increase P decrease; if V decreases P increases
During ventilation…
a change in volume causes a change in pressure resulting in gases moving to equalize pressure
Inspiration (quiet/nonforced)
active process; inspiratory muscles contract (diaphragm and external intercostal muscles); thoracic V increases; lungs are stretch and intrapulmonary V increases; intrapulmonary P drops; air from outside flows down pressure gradient into lungs
Deep/Forced Inspiration
contraction of steroclediodomastoid and pectoralis minor further increases thoracic volume
Expiration (quiet/nonforced)
passive process; inspiratory muscles relax; thoracic volume decreases; lungs recoil passively and intrapulmonary volume decreases; intrapulmonary P rises; air flows out of lungs down pressure gradients
Deep/Forced Expiration
contraction of external oblique, transversus abdominus and internal intercostals further decrease thoracic volume
Airway Resistance
greatest in medium sized bronchi
Alveolar Surface Tension
reduced by surfactant production
Lung Compliance
distensibility of lungs or chest wall; high compliance- both expand easily; low compliance- one or both resist expansion
ADD RESPIRATORY VOLUMES AND CAPACITIES
Anatomical Dead Space
portion of inspired air that does no take part in gas exchange (extends from to terminal bronchioles
Respiratory Capacity Values
are used to distinguish between obstructive and restrictive pulmonary disease
Obstructive Pulmonary Disorders
emphysema, chronic bronchitis, asthma, lung cancer; involve increased air way resistance; TLC, FRC and RV are elevated because lungs hyperinflate
Restricted Pulmonary Disorder
TB, asbestos exposure, chest compression; VC, TLC, FRC, and RV are rediced because lung expansion is limited
Daltons Law of Partial Pressures
total pressure exerted by a mixture of gases is the sume of th epressures exterted by each gas in the mixture
Henrys Law
when a gas is in contact with a liquid, the gas will desolve in the liquid in proportion to its partial pressure; CO2 very soluble, O2 1/20 as soluble as CO2, and N2 is insoluble;
Temperature of LIquid
solubility is inversley proportional to temperature
External Respiration is influenced by…
partial pressure gradients and solubility; thickness and surface area of respiratory membrane; ventilation perfusion coupling
Ventilation Perfusion Coupling
matching alveolar ventilation with pulmonary blood perfusion; controlled by local conditions in the lungs; Partial pressure (P) o2 controls perfusion by changing diameter of local arterioles ; Pco2 controls ventilation by chanign diameter of bronchioles
O2 Transport
1.5% dissolved in plasma; 98.5% bound to heme portion of hemoglobin; each hemoglonin molecule transports 4 O2 molecules ; amount of o2 released to tissues depends on need (the lower PO2 of a tissue = needier it is)
In tissue capillaries at rest…
Po2 = 40 mmhg; Hb is 75% saturated thus Hb releases 25% o2 to the tissues
In tissue capillaries during strenous excersise…
Po2 = 20 mmhg; Hb 35% saturated thus Hb releases 65% o2 to the tissues
Hemoglobins release of o2 to tissues is enhanced by….
increased temp (hb less saturated); increased Pco2; increased H (lower blood pH); increase BPG (waste product of glycolysis)
Shifting curve to the right…
bohr effect; indicates that more o2 is being delivered to the tissues
CO2 Transport
7-10% dissolved in plasma; 20% as carbaminohemoglobin (bound to globin portion of hemoglobin) ; 70% as bicarbonate ions in the plasma
Elevated and lowered Co2…
elevated lowers blood pH (more acidic); low co2 raises blood pH (more basic)
Hypoxia
inadequate o2 delivery to tissues; cyanosis and respiratory distress are characteristic signs
Anemic Hypoxia
too few RBC or too little hemoglobin
Ischemic Hypoxia
impaired or blocked blood circulation
Histotoxic Hypoxia
cells unable to used o2; such as cyanide poisoning
Carbon Monoxide Poisoning
CO binds to hemoglobin more readily than O2; patients do not exhibit cyanosis but instead exhibit bright red skin
Medullary Centers
ventral respiratory group (VRG)–contains rhythm generators that control normal rate and depth of breathing (eupnea); dorsal respiratory group (DRG)–modified VRG rhythms based on input from chemoreceptors and stretch receptors
Pontine Centers
smooth transitions from inspiration to expiration and vice versa
Factors Influencing Rate and Depth of Breathing
higher brain centers; emotions; stretch receptors in lungs (inflation reflex); irritant receptors in lungs; chemical factors in arterial blood and brain tissue (decreased o2, increased co2, and increased h)
What is the most important stimulus for breathing?
co2 levels NOT o2 levels
Hyper/hypocapnia
hyper- increased co2 levels, hypo- decreased co2 levels
Hyperventilation leads to…
hypocapnia; dangerous to free divers because you blow out too muchco2 and by the time low o2 is detected you are passed out and drowning
Arterial Po2 must drop below 60 mmhg before…
o2 becomes the major stimulus for respiration; carotid bodies are main o2 sensors
Chronic Obstructive Pulmonary Disease
COPD; irreversible decrease i ability to force air out of lings; usually caused by smoking; ex) emphysema, chronic bronchitis; treated with inhalers- bronchiodilates and corticosteroids
Emphysema
pink puffer; destruction of alveolar wall
Chronic Bronchitis
blue bloater; inhaled irritants lead to chronic excessive mucous production
Asthma
reversible decrease in ability to force air out of lungs caused by an immune response that constricts respiratory passages; treated with inhaled corticosteroids
Tuberculosis
infectious dieases caused by the bacterium myobacterium tuberculosis; treated with antibiotics
Lung Cancer
most cases (90%) caused by smoking; 5yr survival rate is 16%
Sleep Apnea
temporary cessation of breathing during sleep; may be obstrucive or central (caused by reduced drive from respiratory center)
Aspiration
inhaling or drawing something into the lungs or respiratory passageways; typically gets lodged in right bronchioles
Epistaxis
nosebleed
Cystic Fibrosis
most common lethal genetic disease in teh US; production of excessively think mucus
Pneumonia
inflammation of lungs; fluid accumulates in lungs
Pulmonary Embolism
embolus (blood clot) obstructs pulmonary artery
Sudden Infant Death Syndrome (SIDS)
parts of brain not fully developed and they will stop breathing in their sleep
