respiratory system key questions Flashcards
What are the anatomical and functional divisions of the respiratory system?
-upper respiratory system: nose to pharynx
-lower respiratory system: larynx down to alveoli
-conduction zone (air moving in)
-respiratory zone (gas exchange)
What are the major functions of the respiratory system?
-move air in and out of the lungs
-sense of smell
-sound production (voice box)
-gas exchange at blood-air barrier
-acid-base balance of blood is maintained (carbonic anhydrase)
-mucous lining the epithelia in the respiratory tract, traps foreign particles
what are the components of respiratory system and their main functions
-nasal cavity: nose hair-filters matter
irregular bones, turbulent air, makes stays longer, warms up, humidity
-pharynx: acts as passageway for air, digestive function
-larynx: voice box, decides what goes into windpipe, trachea, esophagus
-trachea: offers mechanical support, smooth muscle trachealis
-bronchus
-bronchioles
-lungs: gas exchange
Describe the path a oxygen molecule follows from the atmospheric air to the alveolar sac
-nasal cavity
- pharynx
-larynx
-trachea
-bronchus
-bronchioles
-lungs (alveolar sac)
How does gas exchange happen across the blood-air barrier
Diffusion
What are the differences between the left and right lung
-number of lobes (right has 3 left has 2)
-number of fishers (right has 2left has 1)
-shape (right is wider/shorter to accommodate liver) left is thinner/taller to accommodate heart
What are the factors influencing inspiration and expiration
Boyles law
-pressure exerted by gas in contained space depends on volume of space (box and balls)
Two types of muscles leading to inspiration
-intercostal muscles (between the ribs)
-diaphragm
Muscle contraction leads to inspiration
What are the factors influencing lung compliance
(ease at which it expands)
-negative intrapleural pressure
-elastic recoil of the thoracic wall
What is the composition of air (proportions of nitrogen, oxygen, carbon dioxide, and water vapor) in the atmosphere?
-nitrogen 79%
-oxygen 21%
-water vapor 0.5%
-carbon dioxide 0.04%
Does the alveolar sac have the same composition of air?
No
-residual air remaining in alveoli
-due to gas exchange
What is daltons law
total pressure of a gas mixture is the sum of the partial pressures of its components
how can you use daltons law to calculate partial pressure of oxygen
take total air pressure and multiply by fraction of total
what is ficks law and what factors does it say impairs diffusion
-explains factors that influence the diffusion of gas
-surface area of alveoli
-partial pressure differences
-greater solubility and smaller molecular weight
-thickness of barrier where diffusion takes place
what is more soluble
oxygen or carbon dioxide
carbon dioxide
what is henrys law
why is it important in the alveolus
-a gas dissolving in a liquid is going to depend on the partial pressure of that gas in the air above the liquid
-in alveolar the partial pressures match to arterial blood
what are the differences between Hb and myoglobin O2 saturation curves
-the structures are different
-number of subunits
myoglobin single subunit
hemoglobin has multiple subunits
what is meant by the cooperative binding of O2 to hemoglobin
as more oxygen is available more hb will bind
what are the factors which increase or decrease Hb binding O2
-structure of hemoglobin creating higher affinity
How do changes in tempature, CO2, BPG, pH cause a left or ight shift in the O2 dissociation curve?
CRUCIALLLLLL??/?????
-high temp/CO2 levels, low pH (exercising) will lead to a rightward shift
-BPG when binds to hemoglobin will cause rightward shift
What is carbonic anhydrase?
Where is it found in the blood?
Why is it important?
-catalyzes carbon dioxide and water combining to form carbonic acid which dissociates hydrogen ions and bicarbonate
-found in red blood cells
-maintains blood pH
How is CO2 transported from tissues to lungs?
-dissolved in blood plasma
-bind directly to hemoglobin
-converted to bicarbonate by carbonic anhydrase
How is O2 transported from the lungs to the tissues
-mainly by binding to hemoglobin
-small portion dissolved in blood plasma
what is the difference between the chloride shift and reverse chloride shift
-chloride shift, chloride enters red blood cell
-reverse chloride shift is chloride leaving the red blood cell
why is the Bohr effect important for respiratory function
takes place in tissues down below in bowels of body
-why hemoglobin is giving up its oxygen
why is the haldane effect important for respiratory function
takes place higher up in lungs
-why hemoglobin is having oxygen bind to it, low concentration of carbon dioxide
how are the various gas laws related to the functioning of the respiratory system
-Boyles: inspiration
-daltons: how much oxygen is available depending on the partial pressure
-Ficks: why oxygen is going to diffuse across the blood-air barrier
-henrys: how much of oxygen will dissolve in blood plasma
(same order in which oxygen is flowing through)
how does the brain control the rate of respiration?
chemoreceptors in CNS that monitor pH spinal fluid
while peripheral chemoreceptors monitor oxygen and CO2 levels in blood vessels
-send signals to the brain stem
-intercostal muscles activated by intercostal nerves
-diaphragm controlled by phrenic nerve
