ch 16 Flashcards
function of resp system
respiration
gas exhange
comminication
olfaction
acid base balance
conducting zone
most air
birng air to lungs
trachea
bronchus
respiratory zones
alvioli for gas exhange
Squamous (type I) alveolar
cells
Simple squamous epithelium
flat n stuff, good for gas passing thru
Great (type II) alveolar cells
- Produce pulmonary surfactant (more sure nothing disrupt water bond) keep avioli open
Alveolar macrophages (dust
cells)
- Clean the lungs
typical respiratory membrane made of
1.Squamous alveolar cells
2.Shared basement membrane
3.Endothelium of capillary
parietal pleura
lines the thoracic wall
visceral pleura
covers the lungs.
intrapleural
space
The parietal and visceral
pleura are normally
pushed together, with a
potential space between
called the
Boyle’s Law
At a constant temperature,
volume of a gas is inversely
proportional to pressure
p1v1=p2v2
Atmospheric pressure:
pressure of air outside the body,
760 mm Hg at sea level
Intrapulmonary or intra-alveolar pressure:
pressure in the
lungs
Intrapleural pressure:
pressure within the intrapleural
space (between parietal and visceral pleura); contains a
thin layer of fluid to serve as a lubricant
thoracic wall expands while lungs try to collapse (neg)
Transpulmonary or transmural pressure:
pressure
difference across the wall of the lung
pos pressure, press lungs against thoracic wall
Inspiration pressure (inhalation):
Intrapulmonary pressure
is lower than atmospheric pressure
Around −1cmH2O (air move in)
subatmospheric or negative pressure
Pressure below that of the atmosphere
Expiration pressure (exhalation):
Intrapulmonary pressure
is greater than atmospheric pressure.
Around +1cmH2O (air move out)
Quiet Inspiration
– Flatten diaphragm and elevate thoracic cage to
increase thoracic volume
Forced Inspiration -
Greatly increase thoracic volume
Quiet Expiration
– Passive process, muscles relax and lungs recoil
no energy needed
Forced Expiration
– Increases abdominal pressure
* Valsalva Maneuver (forced expire again closed shit)
at rest intrapulonary p and intrapleural p
pulm- same as atmo
pleural- -5
inspiration intrapulonary p and intrapleural p
pulm -1
plerual -8
expiration intrapulonary p and intrapleural p
pulm +1
plerual -5
Bronchodilation—
- Epinephrine and sympathetic stimulation
increase airflow?
Bronchoconstriction caused by
- Histamine, parasympathetic nerves, cold air, and
chemical irritants - Anaphylactic shock and asthma
will decrease
Pulmonary compliance:
ease with which the lungs
can expand
Change in lung volume per change in transpulmonary
pressure
ΔV/Δ
Elasticity:
Lungs return to initial size after being stretched
(recoil
how can lung be stretchy
Lungs have lots of elastin fibers
why are lung always under elastic tension
stuck to thoracic wall
Tension increases during - and is reduced by -
inspiration
elastic recoil during expiration
Surfactant
- Amphiphilic liquid of phospholipids and hydrophobic protein
- Reduces surface tension bn water molecules by reducing the number of hydrogen bonds between water molecules
- Prevents collapse of an alveolus
Infant respiratory distress syndrome (IRDS)
- Premature babies
- Lack surfactant
ventilation perfusion coupling
you want this to match to be efficient
usually .8
when theres too little oxy, what happens
vasoconstriction
what happens when there hella oxy
vasodilation, increased ventilation
response to reduced perfusion
decrease blood flow
constriction of bronchioles
decrease airflow
response to increased perfusion
increased blood flow
incresed air flow
dilation of bronch
Dalton’s Law
Total atmospheric pressure is the
sum of the contributions of the
individual gases
atmospheric pressure at sea level
760 mm
why will gas diffuse into blood
erm pressure gradients
Henry’s Law
At the air–water interface, for a given temperature, the amount of gas that dissolves in water is determined by its solubility in water & its partial pressure in air
Oxygen transport by what
- 98.5% bound to hemoglobin- bc something with bonds idk
- 1.5% dissolved in plasma
Carbon dioxide transport how
- 90% of CO2 is hydrated to form carbonic acid
- CO2 + H2O → H2CO3 → HCO3- + H+
- Then dissociates into bicarbonate and hydrogen ions
- 5% is bound to proteins
- 5% is dissolved in plasm
Hemoglobin
—molecule specialized for oxygen
transport
- Oxyhemoglobin (HbO2)
—O2 bound to hemoglobin
- Deoxyhemoglobin (Hb)—
hemoglobin with no O
oxygen bound to hemoglobin wiht increase with
partial pressure
where is hemoglobin fully saturated
in arteries
what percent of oxy in saturated in veins
75% ish
for 100 ml of blood, how much o2
20%? girl idk
what effects oxygen absorption curve
temperature (at higher temps, easier to unload oxy)
pH (low pH, easier to unload)
bohr effect
when ph decreases, its easier to unload oxygen
Voluntary breathing controlled by
motor cortex of frontal lobe of
the cerebrum
Breaking point:
when CO2 levels rise to a point where
automatic controls override one’s will
Involuntary breathing controlled form
from respiratory control
centers of the medulla oblongata and pons
what controls breathing
Motor neurons form brainstem to diaphragm (phrenic n.) and other respiratory muscles
pontine respiratory center
smooths the respiratory pattern
ventral respiratory group
rythem generator and intergrator
dorsal respiratory group
takes in sensory info to adjust breathing rate
chemorecpetros in body
Monitor pH, PCO2
and PO2
of
CSF and blood
Central
chemoreceptors in
the medulla
oblongata
Peripheral
chemoreceptors in
carotid and aortic
arteries
Eupnea breathing
—relaxed, quiet breathing
* Characterized by tidal volume 500 mL and the respiratory rate of
12 to 15 bpm
Apnea
—temporary cessation of breathing
with increase co2 what happens to ph
decreases bc theres more h+ ions n stuff
Dyspnea
—labored, gasping breathing; shortness of breath
Hyperpnea
—increased rate and depth of breathing in
response to exercise, pain, or other conditions
Hyperventilation
—increased pulmonary ventilation in excess of metabolic demand
Hypoventilation
—reduced pulmonary ventilation leading to an increase in blood co2
Kussmaul respiration
—deep, rapid breathing often induced by acidosis
Respiratory arrest
—permanent cessation of breathing
Orthopnea
—dyspnea that occurs when person is lying
down
Tachypnea
—accelerated respiration
what does the rate and depth of breathing maintain
ph-7.4
pco2-40 mmhg
po2- mmhg
Acidosis
—blood pH lower than 7.35
Alkalosis
—blood pH higher than 7.45
Hypocapnia
— less than 37 mmHg (normal 37 to 43 mmHg)
* Most common cause of alkalosis
too basic
Hypercapnia
— greater than 43 mmHg
* Most common cause of acidosis
too acidic
Direct effects of Co2
- increased CO2 at beginning of exercise may directly
stimulate peripheral chemoreceptors and
trigger increased ventilation more quickly than central
chemoreceptors
Chronic hypoxemia,
PO2 less than 60 mm Hg, can significantly
stimulate ventilation
Hypoxic drive:
respiration driven more by low PO2 than by CO2 or pH
Hypoxia
—a deficiency of oxygen in a tissue or the inability to use oxygen
Hypoxemic hypoxia
—state of low arterial
Ischemic hypoxia
—inadequate circulation of blood
Anemic hypoxia
-Due to anemia resulting in the inability to blood to carry
adequate oxygen
