3B Flashcards
How is the respiratory system divided?
-structurally with lower and upper or functionally with conducting and respiratory zone
What is included in the upper respiratory tract?
nose, nasal cavity, pharynx
- pharynx and above
What is included in the lower respiratory tract?
larynx, trachea, bronchi, alveoli, alveolar ducts
- larynx and below
What does the conducting zone do?
transport air in and out of the lungs and to respiratory zone
What is included in the conducting zone?
nose to terminal bronchioles
What does the respiratory zone do?
helps with gas exchange
What is included in the respiratory zone?
respiratory bronchioles to alveoli
- over 500 million alveoli
What are the steps in respiration?
-pulmonary ventilation
-alveolar gas exchange
- gas transport
- systemic gas exchange
What is pulmonary ventilation
-first step in respiration
-movement of gases between atmosphere and alveoli
What is gas transport?
- third step in respiration
- transport of gases between lungs and systemic cells
What is alveolar gas exchange?
- second step in respiration
- external respiration
-exchange of gases between alveoli and blood
What does the nose do?
first conducting structure for inhaled air
flared part of nostrils (nares)
What does the nasal cavity include?
nasal septum, nasal vestibule, olfactory region, respiratory region
What is the nasal cavity
- internal space from nostrils to choanae (paired openings that lead to pharynx)
What are choanae?
paired openings that lead to pharynx
What does the nasal cavity do?
-conditions the air (warms, humidifies, cleanses)
- traps foreign materials and moves toward the pharynx
What does the nasal septum do and what are the parts?
- divides the nasal cavity into right and left sides
- has superior, middle, inferior nasal conchae
What does the nasal vestibule of the nasal cavity do?
- lined by skin particle trapping hairs
What does the olfactory region of the nasal cavity do?
contains olfactory epithelium
What does the respiratory region of the nasal cavity do?
-has extensive vascular network (i.e. nosebleeds)
- nasolacrimal ducts drain lacrimal secretions from eye surfaces to nasal cavity
What are the parts of the pharynx?
nasopharynx
oropharynx
laryngopharynx
What does the nasopharynx include
-soft palate
- pharyngeal tonsils
- connects to the middle ear via auditory (eustachian) tube
What does the nasopharynx do?
- only an air passage (no food allowed)
- soft palate elevates as we swallow preventing food from going the wrong way
What does the oropharynx include?
palatine and lingual tonsils
What does the oropharynx do?
passageway for air and food
What does the laryngopharynx do?
passageway for food and air
What is the larynx
voice box
What does the larynx include?
laryngeal inlet
epiglottis
vocal chords
vocal folds
vestibular ligaments
vocal ligaments
What does the laryngeal inlet do?
-also called the laryngeal aperture connecting the pharynx and larynx
- allows passageway of air while preventing ingested material from entering the respiratory tract (larynx and trachea)
What does the epiglottis do?
covers superior opening during swallowing
What does the larynx do?
- allows for passageway of air while preventing ingested material from entering the respiratory tract ( larynx and trachea)
- produces sound for speech
How is sound produced?
-extrinsic muscles stabilize the larynx and help it move during swallowing
-intrinsic muscles contraction occurs in voice production and swallowing resulting in the change in dimension of rima glottides (narrows with adduction, widens with abduction)
- vocal ligaments/ cords vibrate during expiration producing sound
What do the vocal folds contain?
vocal ligaments
vestibular ligaments
How do vocal ligaments work?
-covered with mucosa to form vocal folds (true vocal cords)
-vibrate during expiration producing sound
- contains glottis and rima glottidis
What is the glottis made of?
Rimma glottides and vocal folds= glottis
What is the rima glottidis
opening between ligaments
How do the vestibular ligaments work?
-covered with mucosa to form vestibular folds (false vocal cords)
- play no role in sound production
-protects vocal cords
- contains Rimma vestibuli
What is the rimma vestibuli?
opening betweem vestibular folds?
What dimension changes happen during sound production in the rimma glottidis?
- abduction= widening
-adduction= narrowing
What does voice range depend on?
- length and thickness of vocal cords
- males have longer and thicker folds which result in deeper voices
What does pitch depend on?
-determined by tension on focal chords
-increased tension= folds vibrate more= higher pitch
What does loudness depend on?
-the force of air passing across vocal cords, how much air is pushing
- more air= louder sound
What is the trachea?
windpipe
How is the trachea supported?
- supported by cartilage that connects the larynx to the main bronchi of each lung
- c-shaped rings of tracheal cartilage ensures the trachea remains open providing structural support?
What is the trachea made of?
c-shared cartilage rings
more cartilage
carina
trachealis muscle
What is the trachealis muscle?
- posterior of the trachea that runs along the length of the open end of “c”-cartilages allowing for the accommodation of food being swallowed
-has a little bit of give - contracts during coughing
What is the carina?
- inferior end of the trachea (where is splits or bifurcates)
-contains sensory receptors which initiate the cough reflex when irritated
What is the bronchial tree structure?
- begins with main bronchi (r+L) that enter each lung
-lobar bronchi enter each lobe and branch into smaller-diameter bronchi - then goes to bronchiole that lacks cartilage and have proportionally thicker layer of smooth muscle responsible for bronchoconstriction and dilation
What are the bronchioles responsible for?
bronchoconstriction and diation
How many lobes does the right lung have?
3
How many lobes does the left lung have
2
What is the difference between bronchi and bronchioles?
bronchi have cartilage, bronchioles do not
What are terminal bronchioles?
last structure in conducting zone
What marks the beginning of the respiratory zone?
respiratory bronchioles
What is bronchoconstriction?
muscle contraction that decreases air flow
What is bronchodilation?
muscle relaxation that increases air flow
What is an alveolar sac?
- a cluster of alveoli connected through alveolar pores
- like a bunch of grapes where the grapes are the alveoli and fused together with pores in between
What is the alveolar sac structure?
- alveoli are clustered together with pores in between
- alveoli are surrounded by the pulmonary capillary beds and elastin
-elastin allows the alveoli to stretch and open with volume decreases
What are the parts of the lung?
- the root of each lung is the hilum region, then contains a main bronchus, pulmonary artery, and pulmonary vein
- pleura
- visceral pleura
parietal pleura
What are the parts of the right lung?
-consists of three lobes divided by 2 fissures
- horizontal fissure separates the upper lobe from the middle lobe
- oblique fissure separates the middle lobe from the inferior lobe
What are the parts of the left lung?
- smaller because of heart
- single oblique fissure separates superior and inferior lobes
- cardiac impression on medial surface and cardiac notch on the anterior surface
-lingula: projection from superior lobe that is homologous to right lungs middle lobe
What are the parts of the left lung?
- smaller because of heart
- single oblique fissure separates superior and inferior lobes
- cardiac impression on medial surface and cardiac notch on the anterior surface
-lingula: projection from superior lobe that is homologous to right lungs middle lobe
What is the pleura?
serous membrane lining lung surface and thoracic wall
What is the visceral pleura?
- adheres to lung surface and thoracic wall
What is the pleural membrane?
- a membrane that surrounds. encloses each lung
What is the parietal pleura?
lines the internal thoracic walls, lateral surface of the mediastinum, superior surface of the diaphragm
What is the pleural cavity
- the space in between the visceral and parietal serous membranes
- filled with serous fluid secreted by membranes and continually drained by lymphatics
What is intrapleural pressure?
pressure in pleural cavities
-fluctuates with breathing
-always sub-atmospheric
What is intrapulmonary pressure?
- pressure in alveoli/ lung
- fluctuates with breathing
creates a vacuum so lungs stay inflated
What is the relationship between pulmonary and intrapleural pressure?
- Ppul > Pip
What is transpulmonary pressure equal to?
Ptp= Ppul-Pip
Ptp= 760-765= 4mmhg
normal Ptp >0 mm, keeps lungs inflated
What happens if Ptp< 0?
pneumothorax, the lungs collapse as a result of their inherent elastic recoil when gradient is lost
What is pulmonary ventilation?
-process of moving air in and out of lungs allowing for the movement of bases between the atmosphere and alveoli
- measures as the amount of air moved between the alveoli and the atmosphere in one minute
What is the pulmonary ventilation formula?
tidal volume x respiration rate
What is tidal volume?
amount of air per breath
What is respiration?
Number of breaths per breath
What determines the direction of airflow?
pressure gradient
high to low pressure
How does atmospheric pressure change with atmosphere?
-the higher you go the less pressure there is
-sea level =760
What is inspiration pressure?
pressure in lungs is less than atmosphere
What is expiration pressure?
pressure in lungs is greater than atmosphere
How does the thoracic cavity change volume?
-changes volume due to contraction/relaxation of respiratory muscles
- during quiet breathing diaphragm movement accounts for 2/3 of volume change; external intercostal movement accounts for 1/3
How are pulmonary volume and thoracic volume correlated?
-positively (increase in one = increase in the other)
What is boyle’s law?
increase in volume = decrease in pressure
What happens to respiratory muscles during expiration?
- respiratory muscles relax, decrease in volume = increase in pressure
- decreases in thoracic cavity volume result in a decrease in lung volume
- Patm< Ppul
-sternum in, diaphragm in and up
What happens to respiratory muscles during inspiration?
sternum out, diaphragm down and out
What are the steps in pulmonary ventilation?
- intrapulmonary pressure= atmosphere pressure (inspiration- increasing volume, contracting, decreasing pressure)
- intrapulmonary pressure is less than atmospheric pressure, air flows in, pleural cavity volume goes up, intrapleural pressure goes down, the alveolar volume goes up, intrapulmonary pressure goes down
- intrapulmonary pressure= atm pressure
- intrapulmonary pressure is greater than atmospheric pressure, air goes out pleural cavity volume goes down, intrapleural pressure goes up, the alveolar volume goes down, intrapulmonary pressure decreases.
What happens when intrapulmonary pressure is less than atmospheric pressure?
-air flows in,
-pleural cavity volume goes up,
-intrapleural pressure goes down,
-the alveolar volume goes up,
-intrapulmonary pressure goes down
What happens when intrapulmonary pressure is = to atm pressure?
inspiration- increasing volume, contracting, decreasing pressure
What happens when intrapulmonary pressure is greater than atm?
-air goes out pleural cavity volume goes down
- intrapleural pressure goes up,
- the alveolar volume goes down,
-intrapulmonary pressure decreases.
How is venilation regulated?
-by respiratory centers in the pons and medulla oblongata and peripheral chemoreceptors in the aorta and common carotid arteries
What do respiratory centers do when regulating ventilation?
- monitor the CSF
control the rate and depth of breathing by coordinating the respiratory skeletal muscles (diaphragm) through nerves - detects H+ levels which indicates Co2 levels due to the lack of protein buffers in the CSF
What do peripheral chemoreceptors due when regulating ventilation?
- detects CO2 levels
-detects only large changes in O2 levels
-PO2 levels normally influence breathing rate by causing peripheral chemoreceptors to be more sensitive to blood PCO2 in response to the dropping of O2 levels
What is atmoshpheric pressure made of
O2
CO2
N
water vapor
What is partial pressure?
the pressure that would be exerted by one of the gas mixtures if it occupied the same volume on its own
What is the Partial pressure of O2?
21%
159mmhg
pulls O2 out
What’s the partial pressure of CO2?
.4% 3mmhg, puts O2 in
What effects solubility?
partial pressure gradient and solubility coefficent
What is a partial pressure gradient?
-when the partial pressure for a gas is higher in one region of the respiratory system than in another
-goes high pressure to low pressure
-O2>CO2
What is a solubility coefficient?
- volume of gas that dissolves in a specified volume of liquid at a given temp and pressure
- CO2 > O2
What is an alveolar sac made from?
multiple alveoli connected by alveolar pores
What do alveolar type two cells do?
secrete protein-rich, oily, pulmonary surfactant that coats the inside of the alveolus that opposes collapse during expiration by holding surface tension
What is the respiratory membrane?
-thin, physical barrier separating air and blood (liquid environment) in which respiratory gases cross
- made of alveolar epithelium (type 1) fused basement membrane, capillary endothelium
- thin so it helps with diffusion
What is more soluble C or O2
C has a solubility coefficient that makes it over 20x more soluble than O2
Which way do O2 and CO2 move at the tissues?
- CO2 goes into the blood
-O2 goes into tissues
What is the concentration of gasses at the tissues when resting?
40mmmhg O2 and 45mmhg CO2
What is the concentration of the gasses in the blood before it gives the tissues O2?
95mmhg O2 and 40 mmhg CO2
What is the concentration of the gasses in the blood after it gives the tissues O2
40mmhg 02 + 45 mmhg CO2
What is the concentration of gasses in blood right before it gives the lungs CO2?
40mmhg + 45mmhg CO2
What is the concentration of the gasses in blood right after it gets O2 from the lungs
90 mmhg O2 and 40mmhg CO2
What is the gas concentration in the lungs?
104mmhs O2 40mmhf CO2
How does activity effect gas levels?
increase in activity= decrease O2 and increase CO2
What is Oxygen loading
- blood plasma has O2 which binds to the heme part of hemoglobin
What is hemoglobulin?
-red pigment in erythrocyts that transport O2 and CO2
-other substances that can bind are H+, 2,3-BPG
What is the hemoglobulin structure?
- Heme, iron ion center
- O2 binds reversibly to the iron ion so each hemoglobin can bind 4 O2 molecules (four things can bind)
- Co2 reversible binds to the globulin protein part
-changes shape ased on what gas binds which helps push foward release
What is Oxygen unloading?
- O2 is released from hemoglobin into plasma and tissues
What is CO2 loading?
- occurs in RBC as blood moves through the systemic capillaries and CO2 goes from tissues to plasma
- CO2 and H2O bind to corm carbonic acid (H2CO3) in RBC
-H2CO3 splits into H+ and HCO2 (bicarbonate ion) - H+ attaches to and is buffered by hemoglobin
- HCO3 moves out and CL moves in creating the CL shift
0 building the equation
What is bicarbonate?
a buffer
What is CO2 unloading?
- splitting the equation
- occurs in lungs as blood moves thorugh pulmonary capillaries and CO2 goes from blood to the alveoli
-CL goes out as HCO3 goes in
H+ unbinds from hemoglobin and goes on to blood cell
H+ binds with HCO2 and forms carbonic acid (H2CO3) again
H2CO3 splits into H2O and CO3
CO2 diffuses out of blood and into an alveolus
What are the concentrations of gasses in blood?
CO2 is dissolved in Plasma 7%
CO2 is attached to hemoglobin 23%
HCO is dissolved in plasma 70%
What is a saturation curve?
-amount of O2 bound to a hemoglobulin
- expressed as %O2 saturation
What is the saturation curved determined by?
Coopertive binding effect of O2 loading
PO2= most important
What is the cooperative binding effect of O2 loading?
binding of each O2 molecule makes a conformational change making it easier for O2 to bind so the headrest to bind is first
What causes a shift right in the saturation curve?
Increase in temp, CO2, 2-3-BPG
What does a shift right in the saturation curve mean
- a decreased O2 affinity for hemoglobulin
- reduces saturation
- releases O2
What causes a shift left in the saturation curve?
decrease in temp, CO2, 2-3BPG, H+
What are the different PO2 levels?
20 when active
40 when at resting
104 in lunges
How does %saturation change as PO2 gets larger?
at smaller PO2 larger saturation changes occur, at a higher PO2 only small saturation changes ocur
What is resting O2 saturation?
75% so we have some O2 we can give when needed
When does O2 loading occur?
when partial pressure is at its highest and there is a 100% O2 saturation ( 4/4 O2 molecules per hemoglobin
When does O2 unloading occur?
-when O2 saturation is 75%
-3/4 O2 molecules per Hemoglobin
-this means we drop of about 25% of O2 at tissues
- the remaining 75%= O2 reserve
What happens to O2 reserve during exercise?
- if tissues have increased metabolic demand PO2 drops lower to about 20 and saturation drops lower to about 50% meaning reserve is at 50%
