Midterm II stuff - Hes III Flashcards
What does the upper resp tract go from and to? Lower?
from nasal cavity. to the larynx
from trachea to alveoli
Describe the pathway of air
Nares - nasal cavity - nasopharynx - osopharynx - laryngopharynx - larynx - trachea - prim bronchii - secindary bronchi - multipel rbanches of bronchi - bronchioles - terminal bronchioles - respiratory bronchioles - alveolar ducts - alveolar sacs
what are the three structures of the respiratory zone
respiritory bronchioles, alveolar ducts, alveolar sacs
What is the end of the conducting zone?
Terminal bronchioles
what epithelium is found in the nasal/oral areas and then what in the throat?
respiratory mucosa w mucous cells then stratified squamous then - respiratory mucosa - cuboidal - simple squamous
What does the nasal cavity do?
hair and mucosa filter air and rap particcles -
What are the three parts of the throat/pharynx? in order
nasopharynx -
osopharynx
laryngopharynx
function of nasopharynx, osopharynx and laryngopharynx
naso - warm, humidify, filter air
oso - passafe for both air and food
laryngo - also passage for air and food
ant opens into larynx post opens into esophagus
What does larynx contain and do? what happens during swallowing?
contains vocal chords
Passage for keeping food and lquids out of resp tract
During swallowing larynx lifted by surrounding muscles and glottis (opening to larynx) is closed by the epiglottis
What does epiglottis do?
Close the glottis - preventing food from entering respiratory tract (trachea)
what covers anterior and lat surface of trachea? what does posterior opening allow?
hyaline cartillage, post pening allows esophagus to expand during swallowing
what is the lumen of trachea lines with and what does tracheabranch into?
lumen of trachea lined w mucosa (pseudosgart ciliated columan ep cells and goblet cells)
Trachea branches into the right and left primary bronchi
what 2 things happen as bronchi become smaller?
Cartillage rings become more incomplete , more space betw each ring
smooth muscle lining- small bronchi can change dimater to control airflow into bronchioles and alveoli
what are the smallest airways?
bronchioles
What is the structure of bronchioles? Inner lining =__ outer layer = ___and there is NO ___
Also lined w ____
What occurs here?
innner lining = simple cubodial outer = smooth muscle NO hyaline cartillage
also lined w elastic fibres
Bronchoconstiction and bronchodilation
what are the two things off of respiratory bronchioles
some alveoli bud directly off and some resp bronchioles branch in two or more alveolar ducts
what do alveolar ducts end in and what are alveoli lined w
alveolar ducts end in alveolar sac and alveoli are lined with elastic fibres
what are the three types of alveolar cells?
Type I, Type II and alveolar macrophages
what are the most common cells in alveoli? what is their function
Type I - gases diffuse across -why it is simple squamous
what is the rold of type Ii alveolar cells? what type of cells are they
They make surfactant - small cubiodal
what do alveolar macrophages do?
Theya re immune cells that eatt and digest debris that gets into alveolus
What would happen if water was the only molecule present on the inner lining of alveoli? How does surfactant prevent this?
force created by tension would cause alveoli to collapse - suraactant interrupts H bonds in order to reduce surface tension
How many lobes in each lung? what is each lung seperated by?
Left - 2
Right - 3
They are seperated by heart and mediastinum
Inferior base on disphragm
found in pleural cavity
What are the 2 serous membranes that encase each lung? What do they secrete?
Parietal pleura - outer - fused to rib cage and diaphragm
Turns over itself into..
Visceral pleura - inner layer - lung surface and divide into fissures to form lobes
Pleural membranes secrete fluid into pleural cavity - lubrication for lungs during ventilation
what is ventilation?
the movement of air down its pressure grad
What is Boyles Law?
Pressure and Volume are inversely related:
P α 1/V
what does the process of pulm ventialtion involve and what does this create?
The process of pulmonary ventilation onvolves volume changes in the thoracic cavity and lung leading to creation of pressure gradient
What are the 2 main pressures and one ohter pressure that determine airflow into and our of lungs?
atmospheric pressue (patm) and intrapulmonary pressure (Ppulm)
Intrapleural pressure
when does ppulm=patm
after expiration (step 1) and after inspiration (step 3)
when is atmospheric pressure greater than intrapulmonary pressure?
lungs increase in volume, pressure decreases inside so patm>pulm - inspiration
What are the pressures doing during expiration
Ppul is greater than patm - lung volume decreases airflow out of lungs
what are the skeletal muscles of quiet inspiration? expiration?
IN: diapghragm and ext interostals
Exp: none
what are the accessory mucsles of inspiration?
sternocleidomastoids, scalenes, pec minior, serratus ant
what are acc muscles of exp?
internal intercost, transversusb thoracis, ext oblique, rectus abdominis, internal oblique
What are three factors that influence pulmonary ventilation
1) Airway resistance
2) alveolar surface tension
3) pulmonary compliance and elastance
what is airway resistance mostly determined by? how can this be modified?
airway diametre
modified at the bronchioles - bronchodilation - increases diametre. - decreases airway resistance - increases air flow
bronchoconstriction - decreases diametre, increases airway resistance and therefore decreases air flow
The higher the surface tension inside the alveoli - the harder it is for___
How is this decreased?
alveoli to expand. Decreased by the presence of surfactant - breaks up bonds of water molecules
What is pulmonary compliance and elastance. What are three factors that determine this ?
the ease of the lungs to expand and recoil.
1) degree of alveolar surface tension
2) distensibility and elasticity of elastic tissue gives lungs the ability to stretch during inspiration and recoil during expriation
3) ability of the chest wall to expand during inspiration
what happens when compliance decreasees?
lung less able to expand, effectiveness of inspiration decreases
what happens when elastane decreases?
lungs less able to recoil and effectiveness of expiration decreases
we can measure volume of air exchnage with each breath using a ____
spirometre
what is a graph called that allows us to measure lung volumes and capacities?
pulmonary function tests
What is tidal volume? What is normal value?
amount of air inspired/expired during ventilation at rest. 500mL
What is inspiratory reserve volume? normal value?
the amount of air that can be forcefully inspired after normal inspiration. 1900-3000mL
What is expiratory reserve volume?
amount of air that can be forcibly expired after normal expiration. 1000mL
What is residual volume?
Cant be measured w spirometre. Air remaining in lungs after max expiration
what is minute ventilation? Formula
total volume of air that moves in and out of the lungs per minute - tidal volume x # of breaths per min
what is inspiratory capacity? equation?
total amount of air a person can inspire - IC = TV + IRV
What is functional Residual capacity? Formula?
Amount of air left in lungs after tidal expiration. FRC= ERV + RV
what is Vital capacity? Equation
Total amount of air that you can move in and out of your lungs. VC = TV + IRV + ERV
What is Total lung capacity?
Total amount of air that can fill the lungs
TLC = TV + IRV + ERV + RV
What is alveolar ventilation? Equation?
total volume of air reaching alveoli per minute. Va = breaths per min (f) x (Vt-VD (anatom dead space))
What is anatomic dead space? Equation?
air that never reaches alveoli, remains in conducting portion of lungs. VD = VT x 0.3
What are the 4 main parts of respiration
1) pulmonary respiration
2) Pulmonary gas exchange
3) Gas transport
4) Tissue Gas exchange
What is gas exhchange?
DIffusion of gases from one medium to another
What is Daltons law of partial pressures? Eqaution for atmospheric pressure?
Each gas in a mixture exerts its own pressure (Partial P) the total pressure in a mixture is a sum of all partial pressures. Patm = PN2 + PO2 + PCO2
What is Henry’s Law?
Degree to which gas dissolves in a liquid is porportional to both partial pressure and solubility in liquid - explains behaviour of gases in air that come in contact w water in body
OF the three gases what is the most, least soluble in blood/water
Most soluble = co2, then o2 has low solubility, N2 very low solubility despite high PN2 grad - barely any acc enters lungs
What is pulmonary Gas Exchange
DIffusion of O2 and co2 between alveoli and blood - from alveoli to blood in pulm capillaries
What has a higer partial pressure grad o2 or co2?
O2 but solubility is lower so its actual amount that diff acris round the same as CO2
What are 3 factors that affect PULM gas exchange?
1) surface area of total resp membrane (where gas exchange occurs - very high SA of lungs cause of struture and number of alveoli
2) distance for diffusion of gases - lowest possible distance due to alveoli and capillaries
3) Matching of ventilation and perfusion
- matching the amount of air reaching alveoli with the amount of blood flow
what is tissue gas exchange?
DIffusion of O2 and CO2 between systemic capillaries and cells of tissues down parital pressure gradient
three factors affecting TISSUE gas exchange?
1) surface area available for gases - depends of capillary density
2) perfusion of tissue - depends on how much blood flow getting to tissues
3) distance of diffusion - depends on type of cells gases need to get across and how close they are to capillary bed
What o2 binds to what on hemoglobin?
heme group?
How many heme groups on hemoglobin? How much oxygen can hemoglobin hold?
4 and 4
what are the 2 reactions when Hb binds to O2?
loading and unloading: Hb and o2 makes oxyhemoglobin
What is the oxygen and hemloglobin graph called?
oxygen-hemoglobin dissacitation curve
The more o2 the ____ the bond between hemoglpobin and 02
the stronger the bond (higher affinity)
in normal resting conditions each Hb molecule remains ___ saturated with o2 even in venous blood
3/4
3 factors that affect the affinity of O2-Hb binding what does it cause
decreased pH, increased PCo2, increased temperature> Right shift of disacc curve - o2 unloads more easily at tissues