127 terms

The Respiratory System

What three regions is the Pharynx divded into?
Nasopharynx, Oropharynx, Laryngopharynx.
Where is the Pharynx located?
From the base of the skull to the level of the sixth cervical vertebra.
What is the location of the Nasopharynx?
Lies posterior to the nasal cavity.
What is the function of the Nasopharynx?
Strictly an air passageway. Closes during swallowing to prevent food from entering the nasal cavity.
What accessory organ is in the Nasopharynx?
The Pharyngeal tonsils (adenoids) that lie high on the posterior wall.
What are the tubes that open into the lateral walls of the Nasopharynx?
The Pharyngotympanic auditory tubes.
What is the location of the Oropharynx?
Extends inferiorly from the level of the soft palate to the epiglottis.
What is the function of the Oropharynx?
Serves as a common passageway for food and air.
What accessory organs are in the Oropharynx?
The Palatine tonsils that lie in the lateral walls of the fauces (latin for throat), and the Lingual tonsils that covers the base of the tongue.
What is the location of the Laryngpharynx?
Lies posterior to the upright epiglottis.
What is the function of the Laryngopharynx?
Serves as a common passageway for food and air.
What is the location of hte Larynx?
Attaches to the hyoid bond, continuous with the trachea posteriorly.
What are the function of the Larynx?
To provide a patent airway, to route air and food into the proper chanels, to function in voice production.
What is the Epiglottis?
Elastic cartilage that covers the laryngeal inlet during swallowing.
What is the function of the Vocal Folds (True Vocal Cords)?
Folds vibrate to produce sound as air rushes up from the lungs.
What is the function of the False Vocal Cords (Vestibular Fold)?
Have no function in sound production.
What is the opening between the vocal folds?
The glottis.
What is Speech?
Intermittent release of expired air while opening and closing the glottis.
What is Pitch?
Determined by the length and tension of the vocal cords.
What is Loudness?
Depends upon the force at which the air rushes across the vocal cords.
What chambers amplify and enhance sound quality?
Pharynx, oral, nasal and sinus cavities.
How is sound shaped into launguage?
By action of the pharynx, tongue, soft palate, and lips.
What is the primary bronchi?
What does each bronchus enter?
The hilum of one lung.
Which bronchus is wider, shorter and more vertical?
Right main bronchus.
What do each main bronchus branch into?
Lobar (secondary) bronchi.
What does each lobar bronchus branch into?
Segmental (tertiary) bronchi.
What is the diameter of a bronchiole?
Less than 1 mm.
What is the diameter of terminal bronchioles?
Less than 0, are the smallest.
What accounts for most of the lungs volume and are the mains ite for gas exchange?
300 million Alveoli.
What is the function of Alveoli?
Provide tremendous surface area for gas exchange.
What two circulations are the lungs perfused by?
Pulmonary and bronchial.
What are Pulmonary Arteries?
Supply systemic venous blood to be oxygenated.
What are Pulmonary Veins?
Carry oxygenated blood from the respiratory zones to the heart.
What are Bronchial Arteries?
Provide system blood to the lung tissue.
What do bronchial veins anastomose with?
Pulmonary veins.
What are the two phases pulmonary ventilation consists of?
Inspiration and Expiration.
What is Inspiration?
Gases flow into the lungs.
What is Expiration?
Gases exit the lungs.
What is Atmospheric Pressure?
Patm. Pressure exerted by the air surrounding the body.
What is the Atmospheric Pressure at Sea Level?
760 mm Hg.
What is Respiratory Pressure?
Relative to Patm.
What is Negative Respiratory Pressure?
Less than Patm.
What is Postive Respiratory Pressure?
Greater than Patm.
What is Zero Respiratory Pressure?
Equal to Patm.
What is Intrapulmonary (Intra-Alveolar) Pressure?
Ppul. Pressure in the alveoli, fluctuates with breathing.
What is Intrapulmonary Pressure always eventually equalized with?
What is Intrapleural Pressure?
Pip. Pressure in the pleural cavity. Fluctuates with breathing.
What is Intraplueral Pressure always?
Negative pressure - always less than intrapulmonary and atmospheric pressure (<Patm and <Ppul).
What is Lung Collapse?
Caused by equalization of the intrapleural pressure with the intrapulmonary pressure.
What is Transpulmonary Pressure?
Difference between the intrapulmonary and intrapleural pressures (Ppul - Pip). Keeps the airways open.
What is Atelectasis?
Lung collapse due to plugged bronchioles that resulted in colapse of alveoli, or would that admits air into pleural cavity (pneumothorax).
What is Pulmonary Ventilation?
Mechanical processes that depend on volume changes in the thoracic cavity.
What happens in volume changes in pulmonary ventilation?
Pressure changes.
What happens if pressure changes in pulmonary ventilation?
Gases flow to equalize pressure.
What is Boyles Law?
The relationship between the pressure and volume of a gas. P varies inversely with V. P1V1 = P2V2.
What is the process of Inspiration?
An active processes. Inspiratory muscles contract. Thoracic volume increases. Lungs are stretched and intrapulmonary volume increases. Intrapulmonary pressure drops. Air flows into the lungs, down its pressure gradiant until Ppul = Patm.
What are the Inspiratory muscles?
Diaphragm, external intercostals.
What does Intrapulmonary pressure drop too during Inspiration?
- 1 mm Hg.
What is the process of Expiration?
A passive processes. Inspiratory muscles relax. Thoracic cavity volume decreases. Elastic lungs recoil and intrapulmonary volume decreases. Ppul rises. Air flows out of the lungs down its pressure gradiant until Ppul = 0.
What does Ppul rise to during expiration?
+1 mm HG.
What is forced expiration?
An active process that uses abdominal and internal intercostal muscles.
What is Surface Tension?
The attraction of liquid molecules to one another at a liquid-gas interface.
What is the liquid coasting of the alveolar surface always acting to reduce?
The alveoli to the small possible size.
What is Surfactant?
A detergent like complex, reduces surface tension and helps keep the alveoli from collapsing.
What does Insufficient quanity of Surfactant in premature infants result in?
Infant Respiratory Distress Syndrome (IRDS).
What is a Spirometer?
Instrument used to measure respiratory volumes and capacities.
What can a Spirometer distrinquish between?
Obstructive pulmonary disease - increased airway resistances (e.g., chronic bronchitis), and Restrictive disorders - reduction in total lung capacity due to structual or functional lung changes (e.g., fibrosis or TB).
What may increases in TLC, FRC and RV occur as a result of?
Obstructive diseases.
What may reduction of VC, TLC, FRC, and RV result from?
Restrictive diseases.
What is the Alveolar Ventilation Rate?
AVR - measures the flow of fresh gases into and out of the alveoli during a particular time.
What does slow deep breathing do?
Increases AVR.
What does rapid, shalow breathing do?
Decreases AVR.
What is Daltons Law of Partial Pressures?
Total pressure exerted by a mixture of gases is the sum of the pressures exerted independently by each gas in the mixter.
What is the partial pressure of each gas directional proportional too?
Its percentage in the mixture.
What is Henry's Law?
What a mixture of gases is in contact with a liquid each gas will disolve in the liquid in proportion to its partial pressure.
What does the amount of gas that will dissolve in a liquid also depend on?
Its solubility.
What is most soluble?
Carbon dioxide.
What is 1/20th as soluble as C02?
What is practicall insoluble?
What is ventilation?
Amount of gas reaching the alveoli.
What is perfusion?
Blood flow reaching the alveoli.
What needs to be matched (coupled) for efficient gas exchange?
Ventilation and perfusion.
How is molecular oxygen carried in the blood?
Bound to hemoglobin (HB) within red blood cells and is dissolved in plasma.
What does is Hb molecule bind too?
Four oxygen atoms.
What does each red blood cell have?
~270 million hemoglobin molecules.
What is hemoglobin-oxygen combination called?
Oxyhemoglobin (HBO2).
What is Saturated Hemoglobin?
When all four hemes of the molecule are bound to oxygen.
What is Partially Saturated Hemoglobin?
When one to three hemes are bound to oxygen.
What is the rate of loading and unloading of 02 regulated by?
P02, Temperature, Blood Ph, and Pco2.
How does Po2 effect the rate of loading and unloading of 02?
Increase unloading, as concentration of 02 decreases.
How does temperature effect the rate of loading and unloading of 02?
Increases unloading as temperature increases.
How does Blood pH effect the rate of loading and unloading of 02?
Increases unloading as H+ increases (pH drops).
How does Pco2 effect the rate of loading and unloading of 02?
Increases unloading as concentration of CO2 increases.
What is Hypoxia?
Inadequate O2 delivery to tissues.
What is Nitric Oxide (NO) in Hemoglobin-Nitric Oxide partnership?
A vasodilator that plays a role in blood pressure regulation.
What is Hemoglobin in Hemoglobin-Nitric Oxide partnership?
A vasconstrictor and a nitric oxide scavenger (heme destroys NO).
What happens when oxygen binds to a hemoglobin in the Hemoglobin-nitric oxide partnership?
Nitric oxide binds to a cysteine amino acid on hemoglobin, bound nitric oxide is protected from degratation by hemoglobin's iron.
What happens as deoxygenated hemoglobin picks up carbon dioxide?
Binds nitric oxide and carries these gases to the lungs for unloading.
What are the three forms that carbon dioxide is transported in the blood?
Disolved in plasma - 7 to 10%. Chemically bound to hemoglobin - 20% is carried in RBC's as carbaminohemoglobin. Bicarbonate ion in plasma - 70% is transported as bicarbonate (HCO3-).
What is the Haldane Effect?
The lower the PO2 and hemoglobin saturation with O2, the more CO2 can be carried in the blood.
What happens at the tissues as more carbon dioxide enters the blood?
More O2 dissociates from hemoglobin (Bohr effect). More Co2 combines with hemoglobine and more bicarbonate ions are formed.
What is the Dorsal Respiratory Group?
DRG - Near the root of cranial nerve IX. Integrates input from peripheral stretch and chemoreceptors.
What is the Ventral Respiratory Group?
VRG - Rhythm generating and integrative center. Sets Eupnea. Inspiratory neurons excite the inspiratory muscles via the phrenic and intercostal nerves. Expiratory neurons inhibit the inspiratory neurons.
What is Eupnea?
eu = good, pne = breath, 12 - 15 breaths/minute.
What is the Pontine Respiratory center?
Influence and modify activity of the VRG, smooth out transition between inspiration and expiration and vice versa.
What is the Hering-Breur Reflex?
Stretch receptors in the pleurae and airs are stimulated by lung inflation. Inhibitory signals to the medullary respiratory centers end inhalation and allow expiration to occur. Acts more as a protective response.
What happens if PCO2 levels rise?
Hypercapnia CO2 levels decline - results in increased depth and rate of breathing.
What is Hyperventilation?
Increased depth and rate of breathing that exceeds the body's need to remove CO2. May cause cerebral vasoconstriction and cerebral ischemia.
What is Apnea?
Period of breathing cessation that occurs when PCO2 is abnormally low.
What is Hyperpnea?
Increase in ventilation (10 to 20 fold) in response to metabolic needs.
What are the three nerual factors that cause an increase in ventilation as exercise begins?
Psychological stimuli, simultaneous cortical motor activation of skeletal muscles and respiratory centers. Excitatory impulses reaching respiratory centers from proprioceptors in moving muscles, tendons and joints.
What happens as Exercise ends?
Ventilation declines suddenly as the three neural factors shut off.
What is Acidosis reflect?
Carbon doxide retention, accumulation of lactic acid, excess fatty acids in patients with diabeletes mellitus.
What is Acute Mountain Sickness?
AMS - quick travel to altitutes above 8000 feet may produce symptoms.
What are teh Symptoms of AMS?
Headaches, shortness of breath, nausea, and dizziness. Severe cases lethal cerebral and pulmonary edema.
What is Acclimatization?
Respiratory and hematopoietic adjustments to altitude include increased ventilation and decline in blood 02.
How long does it take to denefit from high altitude training for increased performance?
3 - 4 weeks.
What is COPD?
Chronic Obstructive Pulmonary Disease. Irreversible decrease in the ability to force air out of the lungs.
What are the common features of COPD?
History of smoking in 80% of patients, Dyspnea, Coughing and frequent pulmonary infections, most victims develop respiratory failure accompanied by respiratory acidosis.
What is Asthma?
Active inflammation of the airways preceds bronchospasms, airway inflammation is an immune response. 1 in 10 people suffer.
What is TB?
Tuberculosis - infections disease caused by the bacterium Mycobacterium tuberculosis. Fever, night sweats, weight loss a racking cough and spitting up blood. Treated by 12 months course of antibiotics.
What is Lung Cancer?
Leading cause of cancer deaths in North America. Metastasizes rapidly and widely; most victims die within 1 year of diagnosis. 90 % of all cases are the result of smoking.
What are the 3 most common types of Lung Cancer?
Squamous Cell Carcinoma (20 - 40% of cases) in bronchial epithelium. Adenocarcinoma (~40% of cases) originates in peripheral lung areas. Small cell carcinoma (~20% of cases) contains lymphocyte-like cells that originate in the primary brochi and subsequently metastasize.
By what week can a prematurely born baby breathe on its own?
28th week.
What is the respiratory rate of newborns?
Highest - 40 - 80 respirations per minute.
What is the respiratory rate of adults?
Slower - 12 - 15 per minute.