Ch. 22: Respiratory System part 2 Flashcards
Pulmonary ventilation (breathing) consist of two phases:
Inspiration( breathing in)
Expiration (breathing out)
List the 3 Pressures
Atmospheric pressure 760 mmhg Intrapulmonary pressure (alveoli, equalizes with atm Intrapleural pressure( pleural cavity, always negative)
Intrapleural cavity is always negative due to
lungs natural tendency to recoil
surface tension of alveolar fluid
Atelectasis ( lung collapse) occurs due to
Plugged bronchioles - collapse of alveoli
Wound that admits air into pleural cavity (pneumothorax)
Lack of surfactant
__________, Pressure is inversely proportional to Volume, P increase, V decrease
Boyle’s law
Inhalation: effects on diaphragm and intercoastal muscles and pressure
Pressure: decreases Volume: increases
Diaphragm: contracts Intercoastal muscles: contracts
During inhalation the pressure in the lungs are ____ than the atmospheric pressure
lower
The 3 physical factors influencing breathing are
Lung compliance, air resistance and alveolar surface tension
_______ is the major nonelastic source of resistance to gas flow
Friction
The relationship between flow (F), pressure (P), and resistance (R) is:
F= P/R
Change of pressure and Resistance
Gas flow inversely with resistance
Factors that decrease air resistance are:
Epinephrine and Antihistamines dilates bronchioles and reduces air resistance
Function of surfactant:
Reduces surface tension of alveolar fluid and discourages alveolar collapse
Define lung compliance
measure of the change in lung volume that occurs with a change in transpulmonary pressure.
Lung compliance is diminished by:
Nonelastic scar tissue (fibrosis)
Reduced production of surfactant
Decreased flexibility of the thoracic cage
___________, pulmonary gas exchange, capillary – alveoli
External respiration
three factors that influence external respiration
thickness and surface area of the respiratory membrane
partial pressure gradients and gas solubilities
ventilation( amount of gas reaching the alveoli) and perfusion ( blood flow in pulmonary)
_________, normal breathing
tidal volume
_______, maximum air you can inhale
inspiratory reserve volume
__________, forcefully exhale out
expiratory reserve volume
____________, air remaining in the lungs
Residual volume
_________, inspired air fills the conducting respiratory passageways and never contributes to gas exchange in the alveoli
DEAD SPACE
___________ involves capillary gas exchange in body tissues
Internal respiration
Oxygen transport is carried in two ways
Bound to hemoglobin (98.5%)
Dissolved in Plasma (1.5%)
Each hemoglobin molecules can bind to _ oxygen molecules
4
When 1-3 oxygen molecules are bound to a hemoglobin molecule, they refer as
partial saturated
When 4 oxygen molecules bound to hemoglobin molecule, they refer as
fully saturated
The rate at which Hb reversibly binds or releases O2 is regulated by
P02 and Pco2
temperature
blood pH
Increases in temperature, H+, Pco2, and BPG lead to
Enhance O2 unloading
Inadequate O2 delivery to tissues
Hypoxia
Abnormal or too little Hb Blocked circulation Metabolic poisons Pulmonary disease Carbon monoxide
Anemic
Ischemic (stagnant)
Histotoxic
Hypoxemic
Carbon dioxide transport 3 ways:
Dissolved in plasma: 7-10%
Chemically bound to hemoglobin: 20%
As bicarbonate ions in plasma: 70%
___________, an enzyme that reversibly catalyzes the conversion of carbon dioxide and water to carbonic acid
carbonic anhydrase
__________ and _____ are the main controllers of the regulation of breathing
medulla oblongata, and pons
___________, sensors responding to the changing levels of co2, o2 and h+ in arterial blood
chemoreceptors
______ is the most potent and most closely controlled, as well as the most powerful respiratory stimulant
CO2
An adaptive response to high altitudes
Acclimatization
___________, distinguished by destruction of alveolar walls, and permanent enlargement of the alveoli
emphysema
________, inhaled irritants lead to chronic production of excessive mucus, obstruct airways, impaling breathing and gas exchange
Chronis bronchitis
__________ , infectious disease caused by the bacterium Myobacterium tuberculosis
Tuberculosis
