Chapter 22 Flashcards
Pulmonary Ventilation
(breathing) movement of air into and out of lungs
External respiration
O2 and CO2 exchange between lungs and blood
Internal Respiration
O2 and CO2 exchange between systemic blood vessels and tissues
Major organs of the respiratory system
- Nose, nasal cavity, and paranasal sinuses.
- pharynx
- larynx
- trachea
- bronchi and their branches
- lungs and alveoli
respiratory zone
site of gas exchange
microscopic structures-respiratory bronchioles, alveolar ducts and alveoli
conducting zone
conduits to gas exchange sites
function of the nose
provides and airway for respiration filters, moistens and warm entering air produces mucus serves a resonating chamber for speech Houses olfactory receptors
function of Paranasal sinuses
lighten skull
secrete mucus
help to warm and moisten air
functions of Pharynx
connects nasal cavity and mouth to larynx and esophagus
passageway for food and air
composed of skeletal muscle
Function of Larynx
provides patent airway
Routes air and food into proper channels
houses vocal folds
Trachea
air passageway
Cleans, warms and moistens incoming air
Conducting Zone Structures
lobes of lungs, trachea, primary and secondary bronchus
Respiratory zone
Respiratory bronchioles, alveolar ducts and alveolar sacs
The alveolar sacs contain clusters of alveoli (site of gas exchange)
Alveolar macrophages
keep alveolar surfaces sterile
Pulmonary arteries
deliver systemic venous blood to lungs for oxygenation
Pulmonary veins
carry oxygenated blood from respiratory zones to heart
Bronchial Arteries
provide oxygenated blood to lung tissue
Inspiration
gases flow into lungs
Expiration
gases exit lungs
Atmospheric pressure (P atm)
Pressure exerted by air surrounding body
760 mm Gh at sea level = 1 atmosphere
Intrapulmonary Pressure (P pul)
Pressure in alveoli
fluctuates with breathing but always eventually equalizes with Patm
Alveolar surface tension
Attracts liquid molecules to one another at gas-liquid interface
Resists any force that tends to increase surface area of liquid
Tidal Volume
Quiet breathing volume (~500ml)
Inspiratory reserve volume (IRV)
Volume forcibly inspired past normal TV inspiration
Expiratory reserve volume (ERV)
Volume forcibly expelled after normal TV expiration
Residual Volume (RV)
Volume present after ERV that keeps lungs from collasping
Spirometer
instrument for measuring respiratory volumes and capacities
External respiration
diffusion of gases in lungs
Internal respiration
Diffusion of gases at body tissues
Dalton’s Law
Total pressure extered by mixture of gases= sum of pressures exerted by each gas.
Partial Pressure- Pressure exerted by each gas in mixture.
Henry’s Law
Gas will dissolve in liquid in proportion to its partial pressure.
Amount of each gas that will dissolve depends on;
-Solubility-CO2 20 times more soluble in water than O2; little N2 dissolves in water
-As temperature rises, solubility decreases
Perfusion
Blood flow reaching alveoli
Ventilation
Amount of gas reaching alveoli
how is Oxygen transported in blood
Molecular oxygen is carried in the blood;
- 5% of it is dissolved in the plasma
- 5% is loosely bound to each Fe (Iron) of hemoglobin (Hb) in RBC’s
How is Carbon dioxide transported in the blood?
it is transported in the blood in three forms:
7-10% dissolved in plasma
20% bound to gloving of hemoglobin
70% transported as bicarbonate ions in plasma
Hyperventilation
increased depth and rate of breathing that exceeds body’s need to remove CO2. Decreased blood CO2 levels (hypocapnia)
Apnea
Breathing cessation from abnormally low Pco2
Acclimatization
respiratory and hematopoietic adjustments to long-term move to high altitude.
Chemoreceptors become more responsive to Partial co2 when partial o2 declines
Always lower than normal Hb saturation levels. (less oxygen available)
Decline in blood oxygen stimulates kidney to accelerate production of EPO.
RBC numbers increase slowly to provide long term compensation
major functions of the respiratory system
supplys the body with O2 for cellular respiration.
Dispose of CO2, which is a waste product of cellular respiration
