Traffic - Week 13 Flashcards
pulmonary ventilation (simple)
breathing
external respiration
gas exchange between the blood and alveoli (air sacs)
gas transport (car)
blood transports gases to tissues (CV system)
internal respiration
gas exchange between the blood and tissues (CV/tissues)
cellular respiration
use of O2 to produce ATP (cells)
functions of respiratory
obtain O2, eliminate CO2
nonrespiratory functions (traffic police - door)
- route for water and heat loss
- enhance venous return
- acid-base balance (CO2)
- vocalization
- defense against inhaled
invaders - sense of smell
- alters blood composition
airways - smallest bronchioles (smooth)
have no cartilage; smooth muscle regulates air flow (broncho constriction and broncho dilation)
alveoli (air sacs) (alvin-doorway)
- thin walled and surrounded by capillaries
a. large surface area for gas exchange
b. type I cells - simple squamous epithelium c. type II cells - secrete surfactant
d. macrophages fight invaders
pleural sacs (lubricate - thor)
- each lung is separate
2. intrapleural fluid lubricates surfaces and helps lungs stick to thoracic wall
in ventilation air flows down a…
pressure gradient
atmospheric pressure (measurement)
atmospheric pressure (760 mmHg at sea level)
lungs will always expand to fill the thoracic cavity (cats couch)
intrapleural fluid (sticky)
b. transmural pressure gradient (difference in pressure in areas)
(1) intra-alveolar pressure always equilibrates with atmospheric pressure
(2) greater pressure outward than inward
inspiration (ops)
a. inspiratory muscles contract (diaphragm and external intercostals)
b. volume of thoracic cavity and lungs increases
c. intra-alveolar pressure decreases
d. air flows in
expiration (ops sleeping - piano)
a. inspiratory muscles relax (quiet breathing)
b. volume of thoracic cavity and lungs decreases c. intra-alveolar pressure increases
d. air flows out
forced expiration (body builder - fridge)
expiratory muscles contract (abdominal wall muscles and internal intercostals)
airway resistance adjusted to…
meet the body’s needs
matching airflow to blood flow (ventilation-perfusion coupling) (berkeley bowl)
local controls act on bronchiolar and arteriolar smooth muscle
simultaneous adjustments mean air and blood not wasted ex. - if blood flow > airflow (more__in blood)
brocho___
vaso___
if blood flow > airflow, increased CO2 and decreased O2 in alveoli, so broncho dilation and vasoconstriction
healthy lungs (recoil)
recoil after stretching and are compliant (easy to inflate)
2 main factors - lung elasticity
a. elastin fibers in lung connective tissue
b. alveolar surface tension
in healthy lungs breathing requires little energy (percentages)
a. 3% of total energy at rest
b. 5% during exercise
c. up to 30% at rest with obstructive lung
disease
gases diffuse down partial pressure gradients (slide)
pressure exerted by a particular gas in a mixture of gases or dissolved in a body fluid)
alveolar PO2 is lower than..
we naturally have more CO2 bc its produced in body.
atmospheric PO2.
and alveolar PCO2 is higher than atmospheric PCO2
a. water vapor in lungs dilutes gases
b. newly inspired air mixes with old air (15% new air with inspiration)
CO2 requires a smaller gradient for (sol)
efficient transfer because it is more soluble (usually about equal amounts of O2/CO2 exchanged)
at lungs PO2 is always higher in..
CO2 is higher in the..
alveoli, O2 is moving to the blood.
b. PCO2 always higher in blood (bc you made it), CO2 moves from blood into alveoli
at tissues, PO2 always higher in..
the blood, O2 is moving to the tissues.
b. PCO2 always higher in tissues (bc you made it), so CO2 moves into the blood
during exercise…(alvin, caps trenchcoat - bookshelf)
a. more pulmonary capillaries open, increasing surface area for exchanges
b. greater stretching of alveolar membranes increases surface area and thins membrane (decreased distance for diffusion)
disease thickens (EFP)
EFP
membrane and increases distance for diffusion (pulmonary edema, pulmonary fibrosis, pneumonia
O2 (% dissolved) (both)
- 1.5% dissolved in blood
- 98.5% on hemoglobin (Hb)
Hb + O2 ↔ HbO2 (reduced Hb) (oxyhemoglobin)