22) Respiratory System Flashcards
1-29 quiz, 30-86 lecture notes
passageway for air and food
pharynx
serves as resonate chamber and reduces weight of skull
sinus (paranasal sinus)
most inferior portion of the larynx
carotid cartilage
opening between vocal cords
glottis
increases surface area of nasal mucosa membrane
nasal concha
fold of mucous membrane containing elastic fibers responsible for sound
vocal cord (true)
partially covers opening of larynx during swallowing
epiglottis
microscopic air sac for gas exchange
alveolus
potential space between visceral and parietal pleurae
pleural cavity
consists of large lobes
lungs
amount of air that can be inhaled or exhaled under resting conditions
tidal volume
amount of air that can be forcefully exhaled after a normal tidal volume expiration
expiratory reserve volume
maximum amount of air that can be expired after a maximum inspiratory effort
vital capacity
amount of air remaining in the lungs after a forceful expiration
residual volume
volume of air remaining in the lungs after a normal tidal volume expiration
functional residual capacity
maximum amount of air contained in lungs after a maximum inspiratory effort
total lung capacity
maximum amount of air that can be inspired after a normal tidal volume expiration
inspiratory capacity
amount of air that can be forcefully inhaled after a normal tidal volume inspiration
inspiratory reserve volume
force of water molecules strongly attracted to each other
surface tension
the pressure inside the lungs
intrapulmonary pressure
the pressure in between the visceral and parietal pleural membranes
intrapleural pressure
increased concentration of this gas increases oxyhemoglobin dissociation
carbon dioxide
the total pressure of a gas mixture is the sum of all the partial pressure of the individual gases
dalton’s law
a detergent-like molecule released by Type II alveolar cells
surfactant
oxygen is primarily transported in this manner
bound to hemoglobin
pressure and volume are inversely related
boyle’s law
a gas will dissolve in a liquid in proportion to its concentration gradient to the degree of its solubility
henry’s law
carbon dioxide is transported mostly in this manner
bicarbonate ion
the ability of the lungs to stretch
lung compliance
respiration
process of exchanging gases between the atmosphere and body cells
respiratory system
passages that filter incoming air and transport it into the body, via airway to the lungs and microscopic air sacs where gas exchange occurs.
why we breath
*gas exchange
*O2 to accomplish ATP production
*CO2 generated as metabolic waste
upper respiratory tract
*nose: nostrils, nasal cavity, nasal septum, nasal conchae, mucous membrane, sinuses,
*pharynx; nasopharynx, oropharynx, laryngopharynx, glottis, epiglottis
Nose
*air enters nose thru nostrils, internal hair prevents large particles from entering nasal cavity, divided by nasal septum.
*nasal conchae curls from lateral walls of the nasal cavity which helps surface area, rich in blood vessels that warm the air.
*supports the mucous membrane-pseudostratified epithelium rich in cilia and mucous secreting goblet-cells.
sinuses
*air filled spaces in the frontal, sphenoid, ethmoid, and maxillary bones of the skull
*continuous with nasal cavity and lined with mucous membrane
*help reduce weight of the skull and serve as resonate chambers that affect quality of the voice
Pharynx
*passageway for food to the esophagus and air into and out of the trachea
*subdivisions: Nasopharynx, Oropharynx, Laryngopharynx
lower respiratory tract
larynx, trachea, vocal cords, bronchus, left and right bronchi, secondary lobar bronchi, tertiary segmental bronchi, intralobular bronchioles, terminal bronchioles, alveolar ducts, alveolar sacs
larynx
*superior enlargement of the trachea
*houses muscular folds- false vocal cords and elastic tissue- vocal cords
vocal cords
*elastic cartilage responsible for vocal sounds
*air forced between cords, cords vibrate from side to side causing sound waves
*form into different sounds when changing shape of the pharynx and oral cavity, tongue, and lips.
hyaline cartilage of larynx
*hold mucous lined larynx open during breathing
*thyroid cartilage-largest cartilage
*cricoid cartilage- below thyroid cartilage
*epiglottis cartilage- part of flap-like epiglottis
trachea
*cartilage-ringed windpipe, extends down to 5th vertebrae
*divides into right and left bronchi
bronchial tree
*from the trachea to deep within the lungs
*held open by the cartilage called carina
*R & L primary bronchi> secondary lobar bronchi> tertiary segmental bronchi> intralobular bronchioles> terminal bronchioles> alveolar ducts> alveolar sacs
lungs
*soft, spongy organs in the thoracic cavity
*right lung: 3lobes, left lung: 2lobes
visceral pleura
*membrane attached to the surface of the lung and folds back to form parietal pleura that attaches to the wall cavity
breathing mechanism
two actions: Inspiration (inhalation)
expiration (exhalation)
atmospheric pressure
*weight of air pressure down on a surface or surrounding body
*760mmHg at sea level = 1 atmosphere
*negative resp. pressure: < 1 atmosphere -4mmHg = 756mmHg
*positive resp. pressure: > 1 atmosphere 3mmHg = 763mmHg
*zero resp. pressure: 1 atmosphere
intrapulmonary pressure
*“intra-alveolar” pressure
*pressure in alveoli
*fluctuates wit breathing, usually equalizes with atm. pressure
intrapleural pressure
*pressure in pleural cavity
*usually always -4mmHg, less than alveolar pressure
*fluctuates with breathing, always negative pressure
transpulmonary pressure
*intrapulmonary pressure - intrapleural pressure
*pressure that keeps lung space open
*> transpulm. pressure, the large the lungs will be
lungs will collapse if (pressure)
*intrapleural pressure = intrapulmonary pressure
*intrapulmonary pressure = atmospheric pressure
*negative intrapleural pressure must be maintained to keep lungs inflated
inspiration
movement of air into the lungs
boyle’s law
*relationship between pressure and volume of gas
*Pressure varies inversely with volume
*gases will always fill container they are in
*if amount of gas is same & container size is reduced-pressure will increase
*if amount of gas is same & container size is increased, pressure will reduce
during inspiration 3 things happen
1) rib muscles contract pulling ribs up and out
2) diaphragm contracts making it straighten and lower-enlarging thoracic cavity, decreasing atmospheric pressure
3) abdominal muscles relax-allowing compression of abdominal content.
surface tension
*attraction of water molecules to one another
*makes it difficult for alveoli to inflate
pulmonary surfactant
mixture of lipoprotein secreted into the alveoli, helps them to stay open.
expiration
movement of air out of the lungs
during expiration 4 things happen
1) external intercostal muscles relax-ribs move down
2) diaphragm relaxes-rising to original position
3) abdominal muscles contract-pushes abdominal organs against diaphragm
4) elastic fibers in lungs shrink- helps force air out
respiratory cycle
one inspiration and one expiration
tidal volume
*volume of air that enters or leaves during a respiratory cycle
*approximately 500mL (~1 pint) of air is exchanged
inspiratory reserve volume
- volume of air that enters the lungs during forced inspiration
*about 3000mL
expiratory resever volume
*volume of air that leaves the lungs during forced expiration
*about 1100mL
*some air always remains in the lungs
residual volume
*volume of air that remains in the lungs after expiration
*about 1200mL
vital capacity
*maximum amount of air exhaled after taking the deepest possible breath
*vital capacity = tidal vol. + insp. reserve vol. + exp. reserve vol.
total lung capacity
*total lung capacity = vital capacity + residual volume
*about 5800mL
minute ventilation
*volume of new atmospheric air moved into the respiratory passage each minute
*minute ventilation = tidal volume * respiratory rate
*much of the air remains in the physiologic dead space
alveolar ventilation rate
*the volume of air that reaches the alveoli
*alveolar vent. rate = tidal vol. - dead space * respiratory rate
*impacts the concentration of oxygen and carbon dioxide in the alveoli
non-respiratory movements
*air movements other than breathing that clear air passages or express emotion
*coughing, sneezing, laughing, crying, hiccup, yawn, speech
respiratory control center
*nerves from lungs, diaphragm, and external intercostals lead to a respiratory control center in the brainstem
*medulla oblongata and pons
resp. center of medulla oblongata
*ventral resp. group-controls basic rhythm of breathing
*dorsal resp. group-controls rate and depth of breathing
resp. center of the pons
contributes to rate of breathing by limiting inspiration
partial pressure of gas
*amount of pressure each gas contributes to the total pressure
*method of referring to the relative amounts of gases in a mixture instead of using concentrations
factors that affect breathing
*partial pressure of O2
*partial pressure of CO2
*degree of stretching of the lungs
*emotional state & level of physical activity
*Mechanoreceptors & Chemoreceptors
central chemoreceptors
*located in the medulla oblongata, respond to changes in blood pH
*CO2 crosses blood-brain barrier>combines w/H2O from CSF>forms carbonic acid>releases hydrogen ions>ventilation increases
peripheral chemoreceptors
*located in carotid and aortic bodies in walls of carotid sinus and aortic arch
*when blood oxygen decreases>receptors stimulate respiratory center>increases breathing rate & tidal volume
*does not play major role until partial pressure of O2 is <50%of normal
mechanoreceptors
*stretching of lung tissue triggers inflation reflex
*reduces during inspiratory movements
*prevents overinflation of the lungs during forceful breathing
exchange of gasses
*pulmonary arteries carry deoxygenated blood to lungs
*arteries>arterioles>capillaries>respiratory membrane< alveoli<bronchioli<bronchioles<bronchi<bronchus
*air in alveoli-high in O2, blood in capillaries-high in CO2
*O2 diffuses from air into blood capillaries
*CO2 diffuses from blood into alveolar air
alveoli
*site of gas exchanged between the air and blood
*alveolar pores permit air to pass from one alveoli to another=alternative air pathways
*alveolar macrophages help clean alveoli
alveolar cell types
*most are simple squamous epithelium (Type I cells)
*some cells secrete pulmonary surfactant (Type II cells)
respiratory membrane
*alveolar wall-simple squamous epithelium
*blood capillary wall-simple squamous epithelium
*basement membranes-thin layer that lies between alveolus and capillaries
factors that influence diffusion
*amount of surface area
*distance gas molecules must travel
*gas solubility
*partial pressure gradient
gas transport
*O2- 98% of O2 bound to HGB in RBC, 2% dissolved in plasma
*CO2-metabolic byproduct of cellular respiration, 7-10%-dissolved in plasma, 20% bound to HGB in RBC, 70%- transported as bicarbonate ions HCO3-
** CO2 + H2O <> H2CO3 <> H+ + HCO3- **
oxyhemoglobin
*O2 is loosely bound to iron in the heme unit of each of the 4 polypeptide chains in hemoglobin.
*1 hemoglobin can bind to 4 oxygen molecules
carbonic anhydrase
*enzyme that helps form carbonic acid when CO2 combines with H2O
chloride shift
*as negatively charged bicarbonate ions diffuse out of RBC, chloride ions from plasma diffuse into the RBC
*maintains the electrical charge in the RBC
carbonic acid
*H2CO3-
*carbon dioxide combined with water
*CO2 + H2O = H2CO3-
