Respiratory System Part 1 Flashcards
During inhale, diaphragm contracts and pulls _______ and increases ___________.
Down
Length
During inhale, chest muscles pull __________ and increase ____________.
Out
Width
What does nasal cavity mucus contain that kills bacteria?
Lysozymes
4 air-filled spaces behind nasal cavity that moisturize and warm air, as well as amplify voice
Para-nasal sinuses
Name 4 paranasal sinuses
Frontal
Ethmoid
Maxillary
Sphenoid
Airways that goes from paranasal sinuses to throat
Pharynx
Part of pharynx close to nasal cavity
Nasopharynx
Part of pharynx close to throat
Oro pharynx
Tissues that create a valve at back of throat to prevent food from going up nasal sinus
Soft palate and uvula
Structure also known as “voice box”
Larynx
Flap on larynx that acts as a lid to prevent food from entering airway
Epiglottis
Opening in larynx between vocal cords
Glottis
Also known as “wind pipe”
Trachea
What does trachea split into
R/L main stem bronchi
Point where R and L main stem bronchi split
Carina
How many lobes in right lung
3
How many lobes in left lung
2
Which main stem bronchus is wider and more vertical
Right
What airways have cartilage rings for support to stay open?
Trachea and main stem bronchi
Trachea and 1st few branches of bronchi have smooth muscle that contain ?
Autonomic nerves (symp/para)
2 autonomic receptors in smooth muscle of trachea and 1st few branches of bronchi
Beta-2 adrenergic
Muscarinic
Stimulated by sympathetic nerves to increase diameter of airways
Beta 2 adrenergic receptors
Stimulated by parasympathetic nerve to decrease diameter of airways
Muscarinic
Cells in lining of airways are mostly
Ciliated columnar
Cells in lining of airways that produce mucus
Goblet cells
Name for when particles trapped in mucus are moved by cilia to be expelled
Muco ciliary escalator
Smaller branches of bronchi
Bronchioles
Air goes through these for 15-20 generations
Conducting bronchioles
Conducting bronchioles receive oxygenated blood from
Bronchial arteries
3 types of cells that make up of conducting bronchiole lining
Ciliated columnar
Goblet
Club cells
What do Club Cells secrete to protect bronchial epithelium?
GAGs
What cell can transform into ciliated columnar cells to regenerate and replace damaged ones?
Club cells
What is last branch of bronchioles before reaching air sacs
Terminal bronchioles
Bronchioles with out pouches along them
Respiratory bronchioles
Unique out-pouches along respiratory bronchioles are called
Alveoli
How many alveoli in the lungs
500 million
Why are alveoli considered a duct and not a respiratory bronchiole
Because they are the final destination of inhaled air.
Thin, epithelial cells that line the alveoli
Pneumocytes
Most common pneumocyte in alveoli where gas exchange occurs
Type 1
Pneumocyte that secretes surfactant to decrease surface tension from water vapor and keep alveoli from collapsing
Type 2
True/false: type 2 pneumocyte can morph into type 1 to regenerate damaged cells
True
Immune cell in alveoli that consumes debris and pathogens
Alveolar macrophages
How does polarity of surfactant in alveoli prevent water vapor from sticking together
Breaks H+ bonds in H20
What joins alveoli and pulmonary capillaries
Basement membrane
What is the basement membrane that joins alveoli and pulmonary capillaries also known as
Blood-Gas Barrier
2 types of respiration
Internal (cellular)
External
What are the main 2 inputs for Internal Respiration
Food + O2
What is another term for internal respiration
Cellular Metabolism
In what part of cell does aerobic metabolism take place
Mitochondria
O2 is used as an electron receptor at the end of metabolic process called what?
Oxidative phosphorylation
What is produced by cellular respiration
ATP, heat and CO2
How much captured energy is stored as ATP in cellular respiration
25%
How much energy is released as heat to maintain core temperature in cell respiration
75%
Byproduct of internal respiration
CO2
2 purposes of external respiration
1) deliver O2 to tissue
2) remove CO2
Main purpose of external respiration is to aid what?
Cell respiration
Air that enters thoracic cavity only goes to what structures?
Lungs
Where does thoracic cavity run from/to
Clavicles to diaphragm
Fluid between visceral and parietal membranes
Intrapleural fluid
Thoracic pressure is higher or lower than atmosphere and abdominal cavity?
Lower
What maintains lower pressure in thoracic cavity?
Air-tight seal in pleural cavity
What is intrapleural fliud mostly made of?
H2O
What covers alveoli sacs?
Pulmonary capillaries
Where does gas exchange happen?
Pulmonary capillaries
What cells are in the pulmonary capillaries
Endothelial
RBCs
Gas exchange happens via what process
Passive diffusion
What causes passive diffusion
Partial pressure gradient
What is the measure of concentration of gas?
Partial pressure
What is the atmospheric pressure at sea level
760 mmHg
How much of air is Nitrogen
79%
How much of air is Oxygen
21%
What is partial pressure of N if atmosphere is 760?
600 mmHg
760 x 0.79
What is partial pressure of O2 if atmosphere is 760?
160 mmHg
760 x 21%
What is partial pressure of CO2 in air
0.03 mmHg
In lungs, why does partial pressure of O2 and N2 go down?
Humidity (H2O) in lungs
Why is Po2 in alveoli lower than Po2 in lungs?
Because only 15% is fresh air; higher CO2
What is Po2 of deoxygenated blood in pulmonary artery?
40 mmHg
What is partial pressure gradient between alveoli and pulmonary capillaries?
60
100 in alveoli - 40 in deoxygenated blood
What happens when Po2 of capillary blood and alveolar space become equal?
Diffusion stops
What is Pco2 in deoxygenated blood?
46 mmHg
What is Pco2 in alveoli
40 mmHg
What is partial pressure gradient for CO2 between alveoli and capillaries
6 mmHg
What does CO2 do in the body?
Contributes to pH balance
What is Po2 of fully oxygenated blood
100 mmHg
What is surface area/barrier thickness x partial pressure?
Diffusion barrier
How big is the surface area of the lungs
75 m2
If lungs were just hollow sacs without alveoli, what would surface area be?
0.01m
True/false: lungs are highly adapted to maximize gas diffusion
True
What is thickness of diffusion barrier between alveoli air and blood
0.5 microns
What 3 things can alter diffusion of gas
Reduced alveoli function
Thickness of barrier (scar)
Change in pressure (atmosphere, narrow airways)
How much of O2 is chemically bound in blood?
98%
How much O2 is physically dissolved in plasma?
1.5%
4 subunits of hemoglobin
Heme groups
What in heme group can bind to 1 molecule of O2?
Iron
If one hemoglobin molecule is carrying four O2 molecules, it’s considered to be
Fully Saturated
Hemoglobin molecule is made up of
Beta and Alpha chains
What is main factor that determines binding of O2 to hemoglobin (Hb)?
Partial pressure of O2
What is O2 + Hb called ?
Oxyhemoglobin
Po2 of blood determines what
Hemoglobin saturation
When blood has high saturation of O2 after leaving lungs, what does hemoglobin do to O2
Holds on tight
When Po2 in capillaries decreases, what does hemoglobin do with O2?
Let’s go easily to give O2 to tissue
What does % of Hb reflect?
Metabolic activity
3 factors that influence %Hb
1) CO2
2) acidity
3) local temperature
High CO2, low pH (acidic) and high temperature indicates what?
Increase in metabolism
What happens on dissociation curve with increase metabolism?
Right shift
What does a right shift of curve indicate
Lower saturation of hemoglobin
When there is a lower saturation of hemoglobin, how does that affect tissue?
Means O2 was delivered to it
Is Hb saturation higher or lower with left shift on diss curve?
Higher
True/False: When there is higher saturation (left shift), tissue doesn’t need O2
True
4 Steps of external respiration
Ventilation
Exchange
Transport
Extraction
% of CO2 that physically dissolved in blood
10%
Why does CO2 dissolve better in blood?
Because it’s more polar
% of CO2 bound to globin (not heme group) in blood
30%
What happens when CO2 binds to globin?
Decreases hemoglobin’s affinity for O2 and it lets go of O2
What effect helps lungs release CO2
Haldane Effect
What helps metabolizing tissue release O2 (right shift)
Bohr’s effect
How much of blood CO2 is carried by bicarbonate (HCO3)?
60%
HCO3 leaves RBC via what?
An exchanger
What comes into the RBC as HCO3 leaves?
Chloride
What type of transporter is the HCO3/chloride exchanger?
Secondary active transporter
