Ch. 22 Respiratory System

ciliated mucous lining in the nose

Alveolar macrophages Alveolar macrophages wander freely, ingesting and destroying invading microorganisms or foreign matter. Proteins produced by these type II cells have an element of innate immunity. They do not ingest or transport microorganisms.

simple squamous epithelium Squamous epithelia are thin and easily passed by respiratory gases. The membrane is also kept thin by organizing the squamous cells in a single layer.

Type II alveolar cells Type II alveolar cells secrete a detergent-like surfactant that lessens the surface tension on the alveolar walls, preventing them from sticking to each other. Infants with IRDS can be treated until their cells produce adequate surfactant.

force with which air rushes across the vocal folds

True

intrapulmonary pressure Intrapulmonary pressure rises when the thorax volume is reduced (during exhalation) and drops when the thorax volume rises (during inhalation). When there is no change in thorax volume, intrapulmonary pressure equalizes with the atmospheric pressure.

intrapleural pressure Intrapleural pressure is created as the lungs attempt to shrink away from the thoracic wall. This negative pressure, as well as the adherence due to moisture, is what keeps the lungs from collapsing.

761 millimeters of mercury The intrapleural pressure is always about 4 millimeters of mercury less than the intrapulmonary pressure, and the intrapulmonary pressure is equal to the atmospheric pressure if the subject is at rest. Intrapleural pressure is always about 4 millimeters of mercury less than intrapulmonary pressure, but this does not represent that actual pressure in the pleural cavity.

an active process; a passive process During quiet breathing, inspiration requires muscle actions, while expiration is caused by elastic recoil.

True When the external intercostal muscles are activated, the rib cage is elevated, increasing thoracic volume. This increases ventilation.

due to insufficient exocytosis in the type II alveolar cells Type II alveolar cells make surfactant. Without surfactant, the surface tension created by the water vapor within the alveoli would cause them to collapse.

the intrapleural pressure would not decrease normally during inhalation As the size of the thoracic cavity increases, so does its volume. This causes intrapleural pressure to go below atmospheric pressure so that air (gases) can move into the lungs during inspiration. If the thoracic cavity cannot change its size (volume), then air movement will not occur.

greater than the pressure in the atmosphere

Boyle's law

pulmonary ventilation

partial pressure of oxygen in the air Partial pressures affect the diffusion and dissolving of gasses into and out of the blood.

0.5 to 1 micrometer thick

a drop in blood pH The pH in blood tends to drop when plasma reacts with carbon dioxide, a common condition in tissue. This pH drop causes weakening of the Hb-O2 bond, a phenomenon called the Bohr effect. Carbon dioxide loss from the blood, as occurs in proximity to alveoli, tends to cause more oxygen to enter the blood.

as bicorbonate ions in the plasma Carbon dioxide reacts with water inside RBCs to form carbonic acid, which dissociates into bicarbonate and hydrogen ions. About 70% of carbon dioxide travels in the plasma as bicarbonate.

Chloride rushes into RBCs to counterbalance the outflow of bicarbonate. The outflow of negative bicarbonate ions from RBCs is balanced by the inflow of chloride ions. Chloride does not bind to hemoglobin in the chloride shift

anemic hypoxia

dissolved in plasma Most CO2 is transported by combining with hemoglobin or dissolved in the plasma as bicarbonate. A very small percentage is dissolved into the plasma. Bicarbonate makes up about 70% of total CO2 in blood, its greatest fraction.

hyposecretion of erythropoietin Hypoxia occurs when a tissue or organ has an insufficient supply of oxygen. Erythropoietin is a hormone that stimulates the maturation of red blood cells in the bone marrow

only about 1.5% of the oxygen carried in the blood

too little oxygen in the atmosphere

as bicarbonate ions in plasma after first entering the red blood cells

attached to the heme part of hemoglobin

hyperbaric oxygen chamber to increase PO2 and clear CO from the body

false

inadequate O2 delivery to tissues

impaired/blocked circulation (anaerobic)

cells unable to use O2 as in metabolic poisons (mushrooms)

abnormal ventilation; pulmonary disease (COPD)

especially from fire; 200x greater affinity for Hb than oxygen *you never know you're not getting enough oxygen

-7 to 10 % dissolved in plasma -20% bound to globin of hemoglobin -70% transported as bicarbonate ions (HCO3-) in plasma

HCO3- quickly diffuses from RBCs into plasma Outrush of HCO3- from RBCs balanced as Cl- moves into RBCs from plasma

-HCO3- moves into RBCs (while Cl- move out): binds with H+ to from H2CO3 (forms carbonic acid) -H2CO3 split by carbonic anhydrase into CO2 and water -CO2 diffuses into alveoli

increased depth and rate of breathing that exceeds body's need to remove C02

~40% of cases, originates in peripheral lung areas- bronchial glands, alveolar cells; most common type

20-40% of cases, in bronchial epithelium; can spread and metastasize quickly

~20% of cases; contains lymphocyte-like cells that originate in primary bronchi and subsequently metastasize (known as the silent killer because it grows quickly and does not obstruct the bronchi)

-most common lethal genetic disease -abnormal, viscous mucus clogs passageways causes bacterial infections -life expectancy up to early 20s

Respiratory system (breathing) movement of air into and out of lungs

Respiratory system O2 and CO2 exchange between lungs and blood

Circulatory system O2 and CO2 in blood

Circulatory system O2 and CO2 exchange between systemic blood vessels and tissues

muscles of the pharynx, tongue, soft palate and lips

to get oxygen into cells

Vocal folds

-glottis closes to prevent exhalation -abdominal muscles contracts -intra abdominal pressure rises -helps to empty rectum or stabilize trunk during heavy lifting

Begins as terminal bronchioles -> respiratory bronchioles -> alveolar ducts -> alveolar sacs

-single layer of squamous epithelium called TYPE I ALVEOLAR CELLS -scattered cuboidal called TYPE II ALVEOLAR (they secrete surfactant and antimicrobial proteins)

alveolar macrophages

Alveolar pores

Inspiration

Expiration