exam 1 respiratory Flashcards
What is the respiratory system made of?
conducting zone structures & respiratory zone structures
What are conducting zone structures?
includes the nose, pharynx, trachea, left & right primary bronchi, secondary bronchi, tertiary bronchi, & terminal bronchioles; they warm, moisten, & filter incoming air & carry it into the lungs
What are respiratory zone structures?
includes the lungs & respiratory bronchioles; the site of gas exchange (moves oxygen from air into blood & at the same time, moves carbon dioxide from blood into “air”)
What are conducting zones covered by?
2 tissue types: stratified epithelium & respiratory epithelium
What is stratified epithelium?
many layers of cells packed closely together; tough/good for protection
What is respiratory epithelium?
very delicate; one layer of pseudostratified epithelium that is made of column-shaped cells with cilia that project from their apical surface
What are goblet cells?
can be found scattered throughout respiratory epithelium; produces mucous
What is the anterior boundary of the nose?
the nose holes which are called anterior nares
What is the posterior boundary of the nose?
2 holes known as posterior nares that connect to the pharynx
What is the superior boundary of the nose?
cribriform plate of ethmoid; tiny holes called olfactory foramina which allow nerve endings of CNI to extend into the nasal cavity
What is the inferior boundary of the nose?
palatine processes & palatine bones
What is the lateral boundary of the nose?
contains 3 spongy bone shelves called nasal conchae that are covered in respiratory epithelium
What are characteristics of nasal conchae?
they are paired (3 on left, 3 on right); air swirls between them in grooves called nasal meatuses
What is the nasal septum?
divides the nose into left & right; made of hyaline cartilage which is supported by the vomer bone & the perpendicular plate of the ethmoid bone
What is the nasal fossa?
the left & right sides of the nasal cavity; small holes drain sinus cavities into the nasal fossa
What is the nasal vestibule?
the area posterior to the external anterior nares; it is lined with stratified epithelium for protection & contains nose hairs
What are vibrissae?
nose hairs; they trap large particles so they don’t enter the rest of the respiratory system
What is the pharynx?
throat; muscular tube that begins at the posterior nares & ends at the split of the trachea & esophagus; divided into nasopharynx, oropharynx, & laryngopharynx
What is the nasopharynx?
posterior to the nose; funnel-shaped; lined in respiratory epithelium; has opening of auditory tube that connects to middle ear
What is the pharyngeal tonsil?
embedded in posterior wall of nasopharynx; lump of lymphatic tissue that filters debris & pathogens from air
What is the oropharynx?
posterior to the mouth cavity; has respiratory & digestive function; lined with stratified epithelium that has mucous & no keratin
What is the uvula?
where the oropharynx begins; cone-shaped projection from the roof of the mouth which is an area called the soft palate; it raises as we swallow to seal off the nasopharynx
What are palatine tonsils?
a pair contained in the oropharynx; they catch pathogens & debris to remove them/filter them out
Where does the oropharynx end?
the level of the hyoid bone
What is the laryngopharynx?
most inferior part of the throat; holds the larynx (voice box)
What are the functions of the larynx?
produce sound, keep airway patent, & route food/liquid properly
What is the larynx made of?
9 pieces of hyaline cartilage joined by elastic connective tissue (ligaments)
What is the thyroid cartilage?
largest; provides anterior attachment of vocal cords; has testosterone receptors which are responsible for voice change at puberty
What is the laryngeal prominence?
anterior-most point of the thyroid cartilage
What is the cricoid cartilage?
ring-shaped; inferior to thyroid cartilage; functions in maintaining a patent airway
What is the thyrohyoid ligament?
connects the thyroid cartilage of the larynx to the hyoid bone
What is the cricothyroid ligament?
connects the thyroid cartilage of the larynx to the cricoid cartilage of the larynx
What is the epiglottis?
embedded in a mucous membrane fold; elevates as we swallow to seal the airway & prevent us from choking
What are the arytenoids?
a pair of small triangular cartilages on posterior side of larynx; provide posterior attachment of vocal cords
What are the corniculates & cuneiforms?
very small pairs of cartilage that move, changing the tension on the vocal cords to create different sounds
What is the trachea?
windpipe; 4.5 inch long flexible airway made of C-shaped hyaline cartilage rings
What is the trachealis?
a smooth muscle that encloses the posterior side of the trachea; the esophagus is located posterior to this muscle
What is the carina?
a triangular ring where the trachea splits into left & right primary bronchi; contains many touch receptors that cause violent coughing when stimulated
What is the cilia escalator?
the trachea is lined with respiratory epithelium & this term represents the cilia movement from bottom-up
What is the difference between the left & right primary bronchi?
the right is steeper than the left which can cause particles to be aspirated (sucked into lungs) resulting in pneumonia
What is the cricotracheal ligament?
connects the cricoid cartilage of the larynx to the trachea
What do the left & right primary bronchi divide into?
secondary bronchi; there are 2 on the left & 3 on the right (1 designated for each lobe of both lungs)
What do the secondary bronchi divide into?
tertiary bronchi
What do the tertiary bronchi divide into?
terminal bronchioles; these end the conducting zone structures
What changes as each branch of bronchi occurs?
we find less organized structure & more smooth muscle which is controlled by the ANS
What happens to the bronchial tubes during sympathetic & parasympathetic stimulation?
sympathetic stimulation relaxes/dilates these tubes & parasympathetic stimulation returns them to their normal diameter
What are the lungs?
made of 1000s of balloon-like structures called alveoli; each lung is surrounded by a folded sheet of serous membrane called pleura
What are the respiratory bronchioles?
tiny tubes that branch from the terminal bronchioles of the conducting zone; each one connects to an alveolus
What 3 cell types make up the alveolar membrane?
type I, type II, & wandering macrophages
What are type I cells?
most abundant; made of simple squamous epithelium (1 layer of thin, flat cells)
What is the function of type I cells?
diffusion of gases (O2 & CO2) across the alveolar membrane & into/out of surrounding blood vessels called alveolar capillaries
What are type II cells?
they secrete surfactant which reduces surface tension along the inner part of the alveolar membrane so that the air space can easily be filled
What are wandering macrophages?
cells that develop from white blood cells & move around the interior of the alveolus, engulfing & destroying potentially harmful particles
What is oxygenated blood?
O2 rich & bright red in color
What is deoxygenated blood?
O2 poor, CO2 rich & dark red/maroon in color
What are the pleural surfaces?
parietal pleura & visceral pleura
What is the parietal pleura?
lines the thoracic cavity
What is the visceral pleura?
adheres to the lungs/alveoli
What is between the parietal & visceral pleura?
hydrogen bonds connecting the 2 & clear, watery serous fluid for lubrication
What occurs when we breathe in?
the ribs & diaphragm move, causing the thoracic cavity to get larger; the hydrogen bonds between the pleura are then pulled, increasing the size of the lungs & allowing air to rush in
What happens when the hydrogen bonds between parietal & visceral pleura are broken?
the lung will collapse: pneumothorax
What are the 2 phases of respiratory physiology?
external & internal respiration
What is external respiration?
all events that move O2 in the air that we breathe into “target” tissues; includes pulmonary ventilation, gas exchange, & gas transport
What is internal respiration?
all chemical reactions that use O2 & generate CO2; these occur inside cells/tissues
What is pulmonary ventilation?
act of breathing; part of external respiration; involves inspiration & expiration
What is inspiration?
to breathe in; increases size of thoracic cavity by contracting intercostal muscles & flattening the diaphragm causing air to rush in
What is expiration?
to breathe out; decreases size of thoracic cavity by contracting intercostal muscles & relaxing the diaphragm causing air to exit
What does pulmonary ventilation require?
a patent airway, adequate neural control of respiratory muscles, & compliant alveoli
What is the phrenic nerve?
provides most of the neural control of respiratory muscles; made of ventral roots from C3, C4, & C5 vertebrae
What does it mean for alveoli to be “compliant”?
they must be stretchy, flexible, & thin; alveoli lose flexibility in lung disease such as black lung, covid-19, etc.
What is gas exchange?
part of external respiration; moves O2 from the alveolar air space into alveolar capillaries & at the same time, moves CO2 from alveolar capillaries into the alveolar air space
How does gas exchange occur?
through diffusion (with the concentration gradient)
What happens to PO2 as we increase in elevation?
environmental PO2 decreases; this makes moving O2 into the blood more difficult & diffusion does not occur as easily; can result in altitude sickness
What is the PO2 of our blood at rest?
40 mmHg; as long as environmental PO2 is greater than our blood PO2, diffusion moves O2 into our alveolar capillaries & we have oxygenated blood
What happens to PO2 as we exercise?
PO2 in blood decreases which makes diffusion of O2 into the blood happen more easily/readily
What affects the transfer of O2 from the alveolar air space into the alveolar capillaries?
concentration of O2 in air vs blood, the alveolar membrane’s thickness, & lots of surface area to ensure blood is adequately oxygenated
What is gas transport?
part of external respiration; involves moving O2 from alveolar capillaries to our body tissues/cells; at the same time, CO2 moves from body tissues/cells to alveolar capillaries
How does gas transport occur for oxygen?
O2 combines with hemoglobin in red blood cells; the iron part of hemoglobin chelates to O2 & releases it at body tissues/cells
What happens after O2 is released at body tissues/cells?
it diffuses inside; this is controlled by the concentration of O2 inside tissues/cells vs the concentration of O2 inside the blood
Which tissues/cells receive the most oxygen?
active tissues/cells because they are using more oxygen to produce ATP
What affects the delivery of O2 to tissues/cells?
concentration gradient of O2, pH of blood & tissues/cells, temperature of tissues/cells, & presence of fetal hemoglobin
How does pH affect the delivery of O2 to tissues/cells?
as tissues/cells are active, they produce lots of CO2 which decreases the pH; this low pH acts to stimulate respiratory centers in the brain & draw O2 into the tissues/cells
Is O2 delivery increased when tissues are warm or cold?
warm
What type of hemoglobin has the greatest attraction for O2?
fetal hemoglobin
How is CO easily carried from the alveolar capillaries to the body tissues/cells?
CO has a greater attraction for hemoglobin than O2 does
What are the 3 ways CO2 travels from body tissues/cells?
dissolves into blood’s liquid part (plasma), combines to hemoglobin making deoxygenated blood, & most of it forms carbonic acid in the blood which lowers the pH
When does respiratory acidosis occur?
if the brain’s respiratory centers don’t respond to a decrease in pH; too much CO2
What is carbonate?
a blood buffer; CO2 is also converted into this; it combines with hydrogen ions causing an increase in blood pH
What is normal blood pH?
7.35-7.45
When does respiratory alkalosis occur?
when blood pH is too high & there is not enough CO2 in blood; this is a result of hyperventilation making us breathe out more CO2 than we produce
What are characteristics of internal respiration?
it is essentially metabolism; these biochemical reactions can occur in cytoplasm or organelles
