ch 22 the respiratory system part 1 Flashcards
pulmo or pneumo
lungs
functions of respiratory system
gas exchange, tissues in body supplied w O2, CO2 disposed.
4 processes involved with gas exchange
pulmonary ventilation, external respiration (gas exchange in lungs), transport of respiratory gas to and from tissues, and internal respiration (gas exchange occurring in tissues)
which 2 functions of respiratory system are not actually in the system
transportation of gases to and from tissues and internal respiration
two zones of the respiratory system
conducting- respiratory passages from nose to respiratory bronchioles, air transport
respiratory- actual gas exchange, found in bronchioles and alveoli and ducts
upper conducting zone consist of
nasal cavity, pharynx, oropharynx
nasal cavity
better to breathe here, air is warmed and humidified as air passes, has mucous membranes and respiratory mucous.
how would breathing change without nasal cavity
cold and dry air and slow respiration rate, too slow. temp affects respiratory rate
mucous membranes of respiratory have respiratory mucosa, and 2 cells r present here
goblet- mucous producing cells
seromocous nasal glands- mucous traps particles and debris, serous secretes watery fluid with lysozyme (a digestive enzyme destroys pathogen)
pharynx consists of
nasopharynx, oropharynx, laryngopharynx
nasopharynx
has pharyngeal tonsils and tubal tonsils (MALT organs) and closes using soft palate and uvula
oropharynx
meets oral cavity as isthmus of the fauces, has palatine tonsils and lingual tonsils.
laryngopharynx
where respiratory and digestive passages split
lower conducting zone
divides laryngopharynx from respiratory passages
consists of epiglottis, larynx (voice box), glottis, trachea, trachealis, bronchi
function of epiglottis
sits at top of lower conducting zone, each like we swallow it is pushed over opening and prevents anything from entering besides air
larynx
composed of cartilage, thyroid and cricoid. these keep the larynx open. if it was closed, each breath would be gasping a lot
vocal cords and glottis
vocal cords r in larynx to make sound, and glottis is open passage surrounded by vocal cords. the ligaments must vibrate for sound.
tense vocal cords/greater force with air
higher pitch/louder
trachea
windpipe, elaatic fibers and cartilage rings. elastic fibers make flexibility and trachea can relax or stretch.
what is importance of cartilage rings
stiffness helps trachea not collapse on itself
trachealis
smooth muslce tissue of trachea
what happens to diameter of trachea when the trachealis contracts? what happens to air?
diameter changes, NS affects it. sympathetic, fight/flight so trachea relaxes and diameter increases/dilates. parasympathetic rest/digest trachea contracts and becomes narrower. nerves hate the contraction, will make u cough so it gets large
bronchi
allows air to reach respiratory zone. bronchis branch 20-25 times forming bronchioles. these get smaller, even to terminal bronchioles.
lungs and its hilum
where gas exchange occurs, has a hilum (where bronchi and any blood or nerve supply enter or leave the lung)
why do lungs need to be elastic in nature
elastic connective tissue allows lungs to change size constantly, increase in size as we inhale and returns to original shape without deformity. we don’t want stretched out lungd
blood supply to lungs
pulmonary circulation - pulmonary artery brings O2 poor blood to lungs, artery branches like bronchi does. (external respiration)
pulmonary capillary network- immediately surrounded alveoli, pulmonary veins bring blood away
bronchial circulation
bronchial arteries supply lung tissue with O2 rich systemic blood.
innervation of lungs
nerve fibers enter lungs at pulmonary plexus. have sympathetic and para fibers
parasympathetic and sympathetic fibers in the lungs
para- air tubes constrict and narrow
symp- causes air tubes to dilate
how does parasympathetic and sympathetic fibers in the lungs influence breathing rate
para- resting resp rate (12 breath per min)
symp- seeds up respiratory rate
pleurae
thin, double layered serous membranes
parietal pleura
covers thoracic wall and upper portion of diaphragm
viceral plerua
covers external lung features, like cling wrap
pleural fluid
fills cavity between visceral and parietal layers.
each lung has its own pleura, what are the benefits of the chambers made from this
as organs shift with breathing, pleural layers slide over one another. also prevents infection from one organ to anther. sort of a lung immune system
respiratory bronchioles
branch from terminal bronchioles of the conducting zone.
order of lungs stuff
resp brinchioles, alveolar sacs, alveoli, alveolar pores
alveolar sacs are made up of
alveoli, which are simple squamous
gas exchange occurs in the
alveoli, covered in capillary beds
how are individual alveoli connected
alveolar pores. air enters and is able to push air away and farther out, helping gas exchange
3 types of alveolar cells
type I, type II, alveolar macrophages
type I alveolar cell
squamous epithelium cells, creates walls of alveoli where gas exchange happens
type II alveolar cells
cuboidal cells scattered among type I cells, less of them so not rly used for gas exchange. more of an immune function
surfactant and why its important
produced by Type II alveolar cells, needed for slippery small amt to coat alveoli. helps prevent alveoli collapse and prevents sticking…also antimicrobial proteins create innate immunity
alveolar macrophage
mobile cells, consumes debris and pathogens so active phagocyte.
2 processes involved in Respiratpry physiology
pulmonary ventilation and gas exchange
pulmonary ventilation
flow of air in and out of lungs, always high to low.
gas exchange
exchange of respirsoptry gases across alveoli. from air space in lungs rod blood or from blood to air space.
3 gas laws influencing respiratory system
Boyles, daltons, henrys
boyles law and ventilation
volume of gas is inversely proportional to pressure exerted by gas onto walls of container. volume change means pressure change.
volume increases pressure increases. volume decreases pressure decreases.
inhalation n exhalation changes our lung volume…
pressure of lungs is
relative to atmospheric pressure
at sea level, Patm is
760 mmHg
intrapulmonary pressure Ppul
pressure in alveoli changes as u inhale or exhale. always equalizes eventually with Patm
inspiration/what muscles do what to help breathe
active process that needs muscles. diaphragm flattens during contraction, so thoracic cavity is larger. intercostal muscles pull ribs up and out, and thoracic cavity becomes larger here too.
why is the change in size of thoracic cavity important for respiration
thoracic must be larger for more air to come. enlargened thoracic cavity, pulls lungs outward, so volume increases
what happens to intrapulmonary pressure when lungs increase in size
volume up, pressure down
air flows into lungs along pressure gradient, why?
Ppul = Patm, air flows into lungs until this point, where it stops
expiration
due to lung elasticity, respiratory muscles relax and return to rest length, elastic fibers get smaller, pulls lungs inward and thoracic less.
what happens to volume of lungs during expiratio
pressure increase and volume decrease. air flows out along pressure gradient, ends when Ppul=Patm
