A&P II EXAM 3 Flashcards
How does respiratory system maintain homeostasis?
exchange of oxygen/carbon dioxide between external and internal environments
What process in our body requires oxygen in order to generate ATP (energy)?
cellular respiration
this process releases carbon dioxide as a waste byproduct
breathing occurs through a process called ….
pulmonary ventilation
breathing in-inspiration/inhalation
breathing out-expiration/exhalation
what is #2 external respiration?
exchange between lungs and blood
what is #3 transport of gases?
cardiovascular system pumps blood between lungs and tissues
what is #4 internal respiration?
exchange between blood and tissues
internal respiration is
exchange with blood
the 4 respiratory processes are…
pulmonary ventilation, external respiration, transport of gases, internal respiration
trace a molecule of oxygen that has entered the nasal or oral cavity until it reached the alveoli of lungs.
nasal/oral cavities>pharynx>larynx>trachea>
bronchi>bronchioles>alveoli
At what point do the structures of respiratory system change from conduction zone to respiratory zone?
between terminal and respiratory bronchioles
aside from providing conduits for air to travel, what else does the conducting zone of the respiratory system do?
cleanse, humidify, and warm incoming air
Respiratory structures and functions: nose (nasal cavity and septum)
warm, filter, moisten, speech and smell
Respiratory structures and functions:
Paranasal sinuses-
speech
Respiratory structures and functions:
pharynx (including tonsils)-
passageway for air and food
Respiratory structures and functions:
larynx (including vocal folds)-
passageway (epiglottis prevent food entry)
and voice box
Respiratory structures and functions:
trachea and bronchial tree
passageway -transport air from environment to lungs
clean, warm, moisten
Respiratory structures and functions:
alveoli (including surfactant)
surfactant lowers surface tension/prevents lung collapse
-location of gas exchange
Respiratory structures and functions:
pleurae (including pleural fluid)
lubricating fluid
compartmentalize lungs
function of respiratory membrane is to allow…
is to allow gas exchange by simple diffusion and to exist as a blood-air barrier
list the 3 layers of the respiratory membrand from inside blood to inside the alveolus..
capillary endothelium
flimsy basement membrane
simple squamous epithelium (type 1 alveoli)
what additional cells exist within the alveoli and what is each of their functions?
Type 2 secrete surfactant (which decreases surface tension) and antimicrobial proteins
macrophages>phagocytize microbes
list the pleurae that surround the lung from superficial to deep. what is each layer attached to?
these are serous membranes..
i. parietal pleura-attache to chest wall
ii. pleural cavity-filled with pleural fluid (lubrication during breathing)
iii. visceral pleura attached to lung surface
the relationship between pressure and volume is known as…
Boyle’s Law
^volume up, pressure down
volume down, pressure up
intrapulmonary pressure increases or decreases to allow inspiration?
decreases
what pressure is always negative and helps to keep the lungs inflated?
intrapleural pressure Pip
a decrease in surfactant will result in a
decrease or increase in compliance?
decrease
oxygen is loaded at the —–
and unloaded at the —–
loaded at eh lungs and unloaded at the tissues
the Bohr effect weakens the bond between hemoglobin and oxygen promoting (loading/unloading) to occur?
unloading
list 2 ways that oxygen(attached to iron) is transported through blood
98.5% hemoglobin (iron) oxygen attaches to the iron
1.5% plasma (dissolves in plasma)
Blood that is 98% saturated is called ——-or O2 rich blood ?
oxygenated and contains 4 molecules of oxygen bound to each (heme group) hemoglobin
blood that is only 40-75% saturated is ——- or 02 poor blood and contains ….
deoxygenated and contains only 1-3 molecules of oxygen bound to each Hb(hemoglobin)
this blood travels through the systemic veins and the pulmonary arteries
At the tissues of the body CO2 gas is converted to a what?
bicarbonate ion HCO3-, and leaves the erythrocyte as chloride enters.
list 3 ways carbon dioxide is transported through blood…
7-10% carbon dioxide dissolves in plasma at the tissue
20% carbon dioxide binds to Hb in RBCs hemoglobin attached to amino acid in globin protein, not heme
70% carbon dioxide is transported as bicarbonate ion(HCO3-)
volume changes lead to what kind of changes which lead to air flow into or out of lungs?
pressure changes
atmospheric pressure Patm >
pressure exerted by …
gases is air outside of body
(atmosphere)
intrapulmonary pressure (Ppul) >
pressure in ..
alveoli of lungs
always equalizes with Patm.
Intrapleural pressure (Pip)
pressure in the…
pleural cavity must be less than Ppul
Boyle’s law
at constant temperature, pressure of gas
is inversely (opposite) related to volume
as volume increases, pressure decreases
Boyle’s law summarized…
as volume increases….
pressure decreases or vice versa
why does Boyle’s law occur?
in large container (largest lung volume)…
gas molecules are more spread out
(collide less=less pressure)
if container is reduced (smallest lung volume)
gas molecules are less spread out (collide more=more pressure)
quiet breathing (inspiration)
diaphragm> moves or contracts how to increase thoracic volume?
moves inferiorly
external intercostals>elevate rib cage (up and out)
quiet expiration (breathe out)
this is a passive process….
muscles relax, lungs recoil.
muscles involved in forced breathing…
forced inspiration
neck-pect-erect
scalene-all neck muscles
pectoralis minor-all elevate rib cage
erector spinae - changes back curvature
forced expiration
internal intercostals>
abdominal muscles >
depresses rib cage (down and IN)
pushes diaphragm superiorly to decrease thoracic volume
Inspiration (quiet) diaphragm and intercostal muscles….
contract
rib cage moves up and out (parallel parking)
it increases thoacic cavity and lung volume
inspiration
as volume increase…
pressure decrease
Ppul drops below Patm (this is constant w/ventilation)
Pip decreases also
inspiration.
gases move down pressure gradient meaning..
high outside to low inside
(air enters lungs) called inhalation
it ends when Ppul returns to (equal to) Patm
1.(TV)TIDAL VOLUME> is
air inhaled or exhaled at rest (quiet)
- inspiratory reserve volume (IRV)>
- expiratory reserve volume (ERV)>
air inhaled above
air exhaled below
=forced breathing
- residual volume (RV)>
- vital capacity (VC)>
air left in lungs after complete exhale
-TV + IRV + ERV(total amount you inhale and exhale)
surfactant is…
detergent-like substance secreted from alveolar type 2 cells
lung collapse is prevented with…
- surfactant>reduces cohesiveness of water in alveoli of water in alveoli
- negative intrapleural pressure>works against natural tendency of lungs to recoil
- residual volume>keeps alveoli open
lung compliance is…
stretch or expansion of lungs
lung compliance measure the changes in lung volulme over the changes in…
lung pressure
factors affecting lung compliance…
- elasitcity (distensibility)> C Is reduced by scar tissue from infections
- alveolar surface tension >C IS REDUCED by decreased surfactant
lung compliance.
you want high elasticity and…
low tension!!!
or surfactant increases
like from exercise or being young
Dalton’s law> says that…
total pressure is sum of partial pressure
respiration (aside from ventilation) involves
blood transportation gases
total pressure>is
pressure of all gases in air
partial pressures> is
inidividual (each) of each gas
differences in partial pressures of atmospheric gases and alveolar gases:
atmospheric Po2(HIGHER) > alveoli lower Po2 so …
O2 moves into alveoli
Henry’s law>
gases dissolve in liquid (plasma) in proportion to partial pressures (still move from high to low)
with external and internal respiration, gases move by …
diffusion (high to low pressure to reach equilibrium)
external respiration>
exchange between alveoli and blood
why does this happen
greater partial pressure in oxygen P o2 is in alveoli. So 02 diffuses into blood(lower pressure in blood)
greater partial pressure in CO2 is in bloood so CO2 diffuses into alveoli of lungs and is then exhaled
internal respiration>
exchange between blood and tissues.
Why does this happen?
Greater partial pressure O2 is in blood, so 02 diffuses into tissues(cells).
so CO2 diffuses into blood and is later exhaled
oxygen transport in blood:
98.5 % oxygen binds to
1.5% is
hemoglobin with RBCs
dissolved in plasma
each hemoglobin (a protein) has how many peptide chains and binds and carries how many oxygen molecules?
It has 4 peptide chains
it binds and carries 4 oxygen molecules( 1 oxygen per iron)
loaded HB =
Hb+ O2=HbO2 which is oxyhemoglobin
meaning it is saturated if it’s loaded
oxygen saturation
saturation=
how much oxygen is bound to hemoglobin in blood
oxygen saturation:
greater O2 pressure allows
greater saturation
Oxygenated (O2 rich) blood:
within pulmonary veins and systemic arteries is
4 oxygen bound to Hb
Hb is 98% saturated with O2
deoxygenated (O2-poor) blood
within systemic veins and pulmonary arteries is
1-3 oxygen bound to Hb (partially saturated)
Hb is only 40-75% saturated with O2
Inactive tissues need less oxygen(less cell respiration) so less…
less unloading due to high O2 partial pressure in tissues.
Hb remains mostly saturated (75%)
Active tissues need more oxygen (more cell respiration) so more…
unloading due to low O2 partial pressure in tissues
Hb is least saturated after visiting active tissues (40%)
oxygen unloading:
hemoglobin is less willing to bind (LOAD) oxygen in lungs when…
increase in blood CO2 partial pressure
-increase in blood temperature
-increase in H+ or blood acidity
*all three affect loading/unloading by changing Hb shape
These factors increase Hb “unloading “ of O2 in the capillaries (Bohr effect)
Co2 transport in blood:
carbon dioxide combines with water forming …
carbonic acid dissociates into hydrogen and bicarbonate.
bicarbonate ions can be generated in …
plasma or RBC(faster in RBC due to enzyme carbonic anydrase)
chloride shift is…
negative chloride ions counterbalance negative bicarbonate ions entering or leaving RBC
medulla sets…
respiratory rhythm
ventral respiratory group (VRG)
this is quiet breathing, not forced…it does three things…
- sets rhythm eupnea (12-15 breaths /min) at rest
- breathe in -inspiratory neurons>stimulate phrenic and intercostal nerves( take in O2)-stimulate diaphragm to contract -intercostal muscles
- expiratory neurons -breathe out-inhibit inspiratory neurons, causing relaxation of muscles
Ventral respiratory groups
inspiratory and expiratory groups alternate
control of respiratory muscles
DRG Dorsal Respiratory Group does what?
integrates input from stretch and chemo receptors
-communicates with VRG to modify rhythm
PRG Pontine Respiratory Group
Pons modifies medullary neurons how?
it smooths VRG transition between inspiration and expiration
depth: determined by how much
respiratory groups stimulate nerves
Greater stimulation=
greater force of muscle contraction > greater depth of breathing
respiratory rate: determined by how long inspiratory groups are active…
which means..
longer they’re active >slower breathing (longer rate)
rate and depth change based on sensory input from receptors
central chemoreceptors are where?
within brainstem
peripheral chemoreceptors are where?
in aorta and carotid arteriesa
all chemoreceptors are sensitive to changes in
CO2, O2, H+
Influence of carbon dioxide partial pressure 3 things…
- most controlled respiratory chemical
- high levels of CO2 lead to increased H+ and decreased pH
- leads to an increase in rate and depth of breathing
(opposite for low levels of CO2)
influence of pH
perioheral chemoreceptors detect what
decrease in pH
pH does down so high in H+(acidity) leads to increased rate of breathing and depth
influence of oxygen partial pressure
decrease in oxygen has what effect?
only has a slight affect on ventilation unless extreme decrease occurs
respiratory disorder:
emphysema which is…
alveolar walls are damaged which makes air sacs which makes less surface are for gas exchange
respiratory disorder:
COPD which is..
chronic obstructive pulmonary diseases
respiratory disorders
chronic bronchitis which is …
excess mucus production causes chronic cough? which blocks gas exchange
homeostatic imbalances:
pneumonia which is
alveoli filled with fluid due to viral or bacterial infection which disrupts gas exchange
homeostatic imbalances:
asthma which is…
constriction of bronchioles (sometimes due to allergen) affects ventilation
