compare's subject to normal range; identify diseases
compliance
measure of the ease with which the lungs & thorax expand
levels of compliance
expressed in LITERS (volume of air) per centimeter of water (pressure)
what is normal compliance?
0.13L/cm H2O- for every 1 cm H2O change in alveolar pressure, the volume changes by 0.13L
the greater the compliance
the easier it is for a change in pressure to cause EXPANSION of lungs & thorax
Example of greater compliance
emphysema destroys elastic lung tissue; therefore, lungs expand (nothing to bring them back like an overstretched rubber band) and higher than-normal compliance
lower-than normal compliance (example)
pulmonary fibrosis - (non-elastic fibers in lung) so that lungs cannot expand
list of conditions that DECREASE compliance
pulmonary fibrosis - respiratory distress syndrome and pulmonary edema (both collapse alveoli) airway obstructions such as ashtma, bronchitis and lung cancer & deformities of thoracic wall such as scoliosis & khyphosis (wall cannot expand)
pulmonary volumes are measured by
spirometry - process of measruing volumes of air that move in & out of respiratory system
tidal volume (TV)
air inspired or expired with each breath
inspiratory reserve volume (IRV)
amount of air forcefully inspired (after quiet inspiration)
expiratory reserve volume (ERV)
volume of air forcefully expired (after a normal expiration)
Residual volume (RV)
volume of air remaining in the lungs after forceful expiration
Vital capacity (VC)
greatest extreme in air volume between inspiration & expiration
pulmonary capacities
sum of two or more pulmonary volumes
Inspiratory capacity
Tidal Volume TV plus Inspiratory reserve volume (IRV) - amount of air that a person can inspire maximally (after normal breath)
Functional residual cpacity
Expiratory reserve volume plus resideula volume, which is amount of air remaining in the lungs at the end of normal respiration
Vital capacity
IRV plus TV plu ERV
Total lung capacity
TLC - normal 6000-7500 mL
FEV - forced expiratory vital capacity
subject inspires maximally & then exhales maximally into a spirometer - as quickly as possible
FEV one
amount of air expired during the first second of the FEV test
minute volume
amount of air moved into & out of respiratory system each minute
minute volume is calculated
respiratory rate times TV tidal volume - normal about 12-18 breaths per minute
Average minute volume calculation
TV usually equals 500 mL times 12 breaths per minute or about 6 L/min
does minute ventialtion measure the amount of air available for gas exchange?
no, because some parts of lungs don't actually exchange gas - only the alveoli & alvolar ducts & respiratory bronchioles
in a mixture of gas, the "partial pressure" of each gas is added to make 100%; add nitrogen, oxygen, carbon dioxide to get total pressure
what adds to partial pressure?
water vapor pressure
what effect does water vapor pressure have on lungers?
affect pressure of total gases & absorption in body--remember that air is humidified in nasal conchae-
partial pressure are affected by
1. humidified air 2. oxygen diffusing from alveoli into blood along with carbon dioxide diffusing from pulmonary capillaries into alveoli and then - air within alveoli is only partially replaced with atmospheric air during respiration
Henry's law (effecting lungs)
concentration of dissolved gas = partial pressure of each gas times the solubility coefficient
Henry's law in liquids
gases move from areas of higher to areas of lower partial pressure
solubility coefficient
physical characteristic of each gas-whcih cannot be altered
henry's law - decompression sickness "the bends"
increased depth means increased pressure; nitrogen bubles come out of blood if pressure changes too quickly
hyperbaric oxygenation
increase pressure to force more oxygen into the blood
how is diffusion of bases, ventilatio & pulmonary blood flow affected
respiratory membrane thickness, change in surface area, or diffusion coefficient of gas
respiratory membran thickness
increased in diseases tuberculosis, pneumonia, advanced silicosis - also plumonary edema casuded by failure of left side of heart causes increase in thicckness of respiratory membrane
surface area of lungs
normally 70m2-however, emphysema (destroys alveolar walls) lung cancer or tuberculosis decrease surface area
diffusion coeficient of gas
"diffusion coefficient" of oxygen is rate "one" and of carbon dioxide is "20" therefore carbon dioxide diffuses through respiratory membran 20 times more readily than oxgen does
when respiratory membrane becomes damaged
capacity to move oxygen into blood is impaired- causes oxygen deprivation
relationship between ventilation & pulmonary capillary blood flow
2 ways to disrupt-ventilation exceeds blood (in heart attack) or ventilation not great enough to oxygenat blood (asthma)
anatomic shunt
normal for some deoxygenated blood to mix with oxygenated blood in lungs
physologic shunt
blood from anatomic shunt & any blood NOT oxygenated in pulmonary capillaries (for instance if there is a blocked bronciole)
gravity affects regional blood flow
pressure at lung base is greater; therefore more blood flows at base
regional blood flow increases
with exercise - more blood at apex & greater gas exchange
smoking
decreases lung capacity-smokers have less gas exchange
carbonic anhydrase
buffering system in blood - carbon dioxide & water are changed w/enzyme into carbonic acid
bohr effect
as pH of blood declines, oxygen is released for use in tissues;
during exercise, your temperature goes up
this also decreases tendency of oxygen to bind to hemoglobin; therefore it is released where needed
effects of 2,3-bisphosphglercerate BPG
BPG binds to hemoglobin & increases its ability to release oxygen
fetal hemoglobin
fetus is able to absorb more oxygen from mother - 50% greater in fetal hemoglobin
double Bohr effect
in fetal hemoglobin, this means that baby gets maximum oxygen
medullary respiratory center
consists of dorsal respiratory group & ventral respiratory group
dorsal respiratory group
stimulate the inspiration
ventral respiratory
stimulate experiration
pontine (pneumotaxic)
pons is involved in switching between expiration & inspiration
modification of ventilation - 7 factors
1. change in ways you breathe 2. emotions 3. chemoreceptors 4. exercise 5 pain 6. sneeze-cough reflex 7. increase in body temperature
herring-breuer reflex
in infants, prevents overinflation of lungs & regulates basic breathing - 2. in adults, important when tidal volume is high during exercise.
where does the lining of the respiratory tract change?
In oropharynx - where food also must pass--the epithelium is stratified squamous epithelium (like oral cavity)
what is lining of nasal cavity and superior portion of pharynx?
pseudo stratified ciliated columnar epihtelium
what is lining of lower respiratory system?
pseudo stratified ciliated columnar epithelium
what is lining in smaller bronchioles?
cuboidal epithelium with scattered cilia
what is lining of alveoli?
very delicate simple squamous epithelium
lamina propria
underlying layer of tissue of a mucous membrane
hard palate is made up of what bones
maxillary and palatine bones
soft palate marks the end of the
nasopharynx
what bones form bridge of nose?
nasal bones plus extensions of the frontal (forms small attachment) and maxillary bones
nasal septum
the anterior is cartilage and the posterior is the vomer bone and the perpendicular plate of the ethmoid bone
external nares
external opening of the nose
internal nares
choanae - openings into the pharynx
what two special bones constitute the bony part of the nasal septum?
vomer bone and the perpendicular plate of the ethmoid bone
paranasal sinuses (4)
named for bones they are located in; frontal, maxiallary, sphenoidal & ethmoid
what is ethmoid sinus also called?
the ethmoid labyrinth (near eyes)
what supports the nsal concahe?
part of ethmoid bone
where is crista galli? what is on either side of crista galli?
olfactory fossa
what forms the floor of the olfactory fossa?
the cribiform plate of the ethmoid bone
conjunctivitis
inflammation of thin membrane covering eye -also called "pink eye"
sinusitis
inflammation of mucou membrane of any sinus, especially paranasal sinuses
rhinitis
inflammation of the nasal mucous membrane
two major bones that make up hard palate
maxillary and palatine bones
function of soft palate & uvula
prevents swallowed material from entering the nasal cavity & nasopharynx
palatine process of maxillary bone
anterior portion of hard palate
palatine bones
posterior portion
nasal conchae are connected to
ethmoid bone -
nasal chonchae consist of
"turbinates" and "meatus" tunnels
purpose of turbinates
clean air, warm air, & humidifying incoming air
tonsils in nasopharynx and oropharynx
swallowing
opening & closing of glottis involves rotational movement of arytenoid cartilages that move vocal folds; epiglottis is bent over glottis; bolus glides over it
eustachian tube opening
in nasopharynx-below pharyngeal tonsil
cartilaginous rings -how many in trachea? what is distinctive feature?
15-20 C-shaped rings - with cartilage onANTERIOR wall-posterior wall has NO CARTILAGE
what is in the space on the trachea where there is no cartilage?
trachealis muscle - causes coughing reflex?
what is posterior to the trachea?
the esophagus - trachea can move to allow large bolus to pass
tissue lining trachea
dense regular connective tissue with pseudo stratified ciliated epithelium
remember - what is TISSUE
dense regular connective tissue
Re-absorptionand filtration of proximal & distal tubule