Respiratory System Flashcards
At a cellular level the exchange of oxygen and carbon dioxide occurs
By simple diffusion across the plasma membrane
Ventilation
Simple movement of air into and out of the lungs
Respiration
Actual exchange of gases (between the lungs and blood or the blood and other tissues)
Conduction zone
Participate ONLY in ventilation
Respiratory zone
Participate ONLY in gas exchange/respiration
Tasks of the respiratory system (40
pH regulation
Thermoregulation
Respiration/ventilation
Protection from disease and particles
Respiratory alkalosis
Hyperventilation (too much breathing) causes pH of the blood to increase because CO2 converted into carbonic acid is expelled
Respiratory acidosis
Hypoventilation (too little breathing) causes acidification of the blood because the carbonic acid from CO2 is not expelled
Thermoregulation by. the respiratory system
Breathing can result in heat loss via evaporative water loss
Mucociliary escalator and alveolar macrophages
Protect us from harmful inhaled particles
Inhaled air follows this pathway:
nose, nasal cavity, pharynx, larynx, trachea, bronchi, terminal bronchioles, respiratory bronchioles, alveolar ducts, alveoli
Pharynx
Throat
Larynx 3 functions
Below pharynx
Cartilage portion keeps airway open
Epiglottis seals the trachea during swallowing to prevent entry of food into respiratory system
Vocal cords prod. sound
Trachea
Remains open to permit air flow rings of cartilage prevent its collapse
Primary bronchi
Two trachea branches each going to one lung
Bronchioles
Very small bronchi made of smooth muscle allowing regulation of airflow into the system
Too thick of walls to allow respiration, only ventilation occurs
Terminal bronchioles
Final branches of conduction zone
Alveolus (alveoli plural)
Structures in which gas diffuses walls are only one cell thick
Alveolar duct
Duct leading to the alveoli from the respiratory bronchiole
Respiratory bronchiole
Smooth muscle tube similar to the terminal bronchioles except it has alveoli on the walls allowing gas exchange
Entire respiratory track is lined with
Epithelial cells
Epithelial cells in the respiratory track from the nose to the bronchioles are columnar meaning
Too thick to exchange in gas exchange, only provide a conduit for air
Goblet cells
Specialized columnar epithelial cells that secrete mucus
Mucociliary escalator
Upper respiratory track epithelial cells have cilia to sweep the mucus toward the pharynx where it is coughed out as mucus
Simple squamous epithelial cells
Single layer of cells that allows respiration
Principle lining of the alveoli walls
Alveolar macrophages
Prevent the alveoli gas exchange centers from getting covered in layer of mucus by engulfing foreign particles
Surfactant
Coats the alveoli to reduce surface tension and prevent collapse when exposed to water
Pulmonary ventilation
Exchange of air into and out of the lungs to replace gases in the alveoli with those in the atmosphere
Inspiration and expiration
Inspiration: drawing air into lungs (active process driven by diaphragm contraction)
Expiration: air out of lungs (passive, elastic recoil of the lungs)
Each lung is surrounded by two membranes
parietal pleura and visceral pleura
Pariteal pleura
Lines inside of the cheat cavity
Visceral pleura
Lines surface of lungs
Pleural space
Between the two pleura (membranes around the lungs)
Pressure in the pleural space
Negative
2 membranes are drawn tightly together like a vacuum and fluid keeps the surface tension
Keeps the surface of lungs drawn up against chest wall
Intercostal muscles
Between the ribs also contract during inspiration, pulling the ribs upward and further expanding the chest cavity
Forced expiration
Active process
During exertion, contraction of the abdominal muscles helps the expiration process by pressing upward on the diaphragm, further shrinking the size of the lungs and forcing more air out
During inspiration, the pressure of air in the alveoli and pleural space:
- Diaphragm contacts and flattens (moves down)
- Volume of chest cavity expands
- Pleural space decreases, more negative
- Lungs expand outward
- Pressure in the alveoli becomes negative
- Air enters lungs and alveoli
Spirometry
Measurement of volume of air entering or exiting the lungs at various stages of ventilation
Spirometer
Device used to measure spirometry (vol of air entering/exiting lungs)
Tidal volume
Normal light breathing and is equal to 10 percent of the total lung capacity
Expiratory reserve volume
Volume of air that can be expired after a passive resting expiration
Inspiratory reserve volume
Volume of air that can be inspired after a relaxed inspiration
Functional residual capacity
Volume of air left in the lungs after resting expiration
Inspiratory capacity
Max volume of air which can be inhaled after a resting inspiration
Residual volume
Amount of air remaining in the lungs after strongest possible exhalation
Vital capacity
Max amount of air that can be forced out of the lungs after taking the deepest possible breath
Total lung capacity
Vital capacity plus the residual volume
(Amount of air remaining in the lungs after strongest possible exhalation) + (Max amount of air that can be forced out of the lungs after taking the deepest possible breath) = TLC
Pulmonary/alveolar capillaries
Branching of the pulmonary veins supplying deoxygenated blood to the lungs leads to these
Pulmonary edema
When pressure in left atrium is increased past a certain point, not only do the veins dilate but the pressure in the capillaries increases and fluid is drawn out of the capillaries and into the lungs
Normal the lymphatic system prevents pulmonary edema by
Carrying interstitial fluid out of the lungs
Primary structure of the lungs allowing it to expose large amounts of blood to large amounts of air
Large surface area
Henry’s Law
Amount of gas that will dissolve into a liquid is dependent on the partial pressure and solubility in the liquid
[O2]= (Partial pressure) x (solubility)
Inc pressure, inc amount of gas dissolved in a liquid
Gases become _____ solute in liquid when temperature increases
Less
Driving force for evangelical of gases in the lungs
Difference in partial pressure between the alveolar air and the blood
For diffusion of a gas into the bloodstream what must occur: (3)
- Pass alveolar epithelial
- Through interstitial liquid
- Across capillary endothelium
Respiratory membrane includes (3)
- Pass alveolar epithelial
- Through interstitial liquid
- Across capillary endothelium
Respiratory control center is located
In the medulla of the brainstem
Chemical stimuli affecting RR
Decreased pH due to increased CO2 presence
Peripheral chemoreceptors:
Located ___ and measure ___
In aorta and carotid arteries Measure P(CO2), P(O2), and pH
Central Chemoreceptors:
Located ___ and measure ___
Medulla
Measure pH and P(CO2) of the CSF
Mechanical stimuli affecting RR
Physical stretching of lungs (stimulates inhibitory signals involved in respiration) and irritants
Bronchoconstriction
Contraction of the smooth muscle that prevents irritants from entering passageways
Irritant receptors
Trigger coughing and/or bronchoconstriction when an irritating chemical is detected
