Chapter 20 - Respiratory System Flashcards
xrespiratory system
system of tubes that delivers air to and from the lungs
functions of the respiratory system
gas exchange, pH balance, olfaction, communication
effectors of pH balance
urinary system, CO2 in blood
olfaction
sense of smell
how does the respiratory system contribute to communication
speech, vocalization, and the larynx
passage of air through the RS
nose, pharynx, larynx, trachea, bronchi, alveoli
pharynx is also called the
throat
the larynx is also called the
voicebox
trachea is also called
windpipe
functions of the nose
warms, cleanses, humidifies air, olfaction, voice resonation
nasal mucosa
mucosa lining the nasal cavity
types of epithelium in the nose
respiratory and olfactory epithelium
respiratory epithelium
ciliated pseudostratified columnar epithelium
purpose of goblet cells in respiratory epithelium
to produce mucus
purpose of cilia in respiratory epithelium
move mucus toward pharynx for swallowing
olfactory epithelium
sensory cells that lines part of the roof of the nasal cavity and septum
purpose of cilia in olfactory epithelium
immobile to bind to odorants
pharynx
muscular funnel extending from the nasal cavity to larynx
the pharynx is a passage way for
food and air
the larynx is made of
cartilage
larynx location
anterior to esophagus
superior to trachea
larynx function
keeps food and water out of airway
phonation
phonation
sound production
superior vestibular fold
closes the larynx is swallowing
inferior vocal fold is also called
vocal cords
the inferior vocal folds
opening between vocal cords
glottis
vocal cords that produce sound
the inferior vocal folds are part of the
glottis
trachea
a ridged tube anterior to the esophagus
tracheal cartilage
c-shaped hyaline cartilage rings
important tracheal cartilage feature
open side of rings face the esophagus to allow the esophagus to expand
mucociliary escalator
cleans the air using goblet cells and mucus
the trachea is lined with which type of tissue
respiratory epithelium
bronchi
small airways leading to the alveolar duct and alveoli
lung parenchyma
lung functional tissue composed of alveoli and brochioles
bronchi composition
crescent-shaped hyaline cartilage
the bronchi lumen is lined with
respiratory epithelium
muscularis mucosae
smooth muscle that contracts/relaxes to regulate air flow
bronchioles
branches of bronchi
bronchiole lumen is lined by
ciliated cuboidal epithelium
bronchioles branch into
alveolar ducts and alveoli
alveoli
site of gas exchange with capillaries in the lungs
alveoli size and number
70 m2 of surface area, 150 million in a lung
types of alveolar cells
Type I, Type II, dust cells
type I alveolar cells
squamous cells that make up most of the alveoli lining
type II alveolar cells
round cuboidal cells that repair the alveolar epithelium and secrete pulmonary surfacant
alveolar dust cells
alveolar macrophages that phagocytize dust particles
most numerous type of cell in the lung
dust cell
respiratory membrane
barrier between the alveoli and blood in lungs
why is the respiratory membrane thin
to allow fast gas exchange
layers of the respiratory membrane
Type I Alveolar cells, endothelial capillary cells, a shared basement membrane
alveolar gas exchange
swapping of O2 and CO2 across the respiratory membrane
alveolar gas exchange is driven by
diffusion of partial pressure gradients
alveolar gas exchange brings what gas in and what out of blood
O2 into blood and CO2 out of blood
loading
moving of gas into blood
unloading
moving of gas out of blood
pulmonary ventilation
repetitive cycle of inspiration and expiration
pulmonary ventilation is also known as
breathing
respiratory cycle
one complete inhalation and expiration
hyperventilation
increased breathing rate in excess of metabolic demand
hyperventilation causes
excess CO2 expulsion creating arterial constriction and fainting
quiet respiration
effortless, automatic beathing while at rest
quiet respiration is also called
eupnea
forced respiration
deep, potentially rapid breathing under voluntary control
what drives air movement between lungs and outdoors
pressure gradient
inspiration pressure
lung pressure < atmospheric pressure
expiration pressure
lung pressure > atmospheric pressure
boyles law
gas volume is inversely proportional to its volume
increase in lung volume means what about pressure
decrease in lung pressure
respiration muscles
help lungs expand and contract to change volume
main muscle of respiration
diaphragm
diaphragm contraction does what
enlarges thoracic cavity
diaphragm relaxation
compresses lungs
what muscle helps with eupnea
internal and external intercostal muscles
accessory muscles function
act in forced respiration to contract harder
accessory muscles
sternocleidomastoid, scalene, pectoralis, serratus anterior, erector spinae, abdominal muscles
pleurae
serous membranes lining lungs and thoracic cavity
parietal pleura attach to
ribs and thoracic wall
visceral pleura attach to
lungs
intrapleural space
thin space filled with serous fluid
steps of inspiration
1) diaphragm contracts and flattens
2) intercostal muscles elevate ribs and pull pleurae upward
3) alveoli stretch outward and lungs expand
4) air enters
how many mL of air enters/exits the lungs
500 mL
is expiration passive/inpassive
entirely passive
steps of expiration
1) respiratory muscles relax
2) thoracic cage goes through elastic recoil
3) recoil compresses lungs
4) air flows out
tidal volume
normal amount of air flowing in/out of lungs
forced breathing is controlled by
the cerebrum
automatic breathing is controlled by
the brainstem
voluntary breath control steps
1) motor cortex of cerebrum sends efferent signals
2) corticospinal tract bypasses brainstem to neurons in spinal cord
and stimulate accessory muscles
when are voluntary breathing controls overriden
when CO2 levels are too high
brainstem respiratory centers in the medulla
ventral and dorsal respiratory groups
ventral respiratory group
primary generator of respiratory rhythm
the VRG generates how many breaths per minute
12
dorsal respiratory group
modifies rate and depth of breathing based on external input
pontine respiratory group
sends efferent signals to VRG and DRG to modify breathing rate to sleep, exercise, etc
blood chemials
O2, CO2, and pH
which blood chemical has the largest effect of breathing rate
pH
acidosis
blood pH less than 7.35
acidosis is caused by
hypercapnia (high co2)
acidosis is corrected by
hyperventilation
alkalosis
blood pH above 7.45
alkalosis is caused by
hypocapnia (low co2)
alkalosis is corrected by
hypoventilation
gas transport in lungs
process of carrying gasses in the blood from alveoli to systemic tissues and vice versa
oxygen transport is mostly in ____, but also _____
hemoglobin (98.5%), plasma (1.5%)
hemoglobin saturation
100%:
50%:
100%: 4 O2 bound
50%: 2 O2
CO2 is transported as
carbonic acid or bicarbonate (90%), bound to proteins (5%), in plasma (5%)
H2CO3
carbonic acid
HCO3
bicarbonate
CO2 binds to an amino group to form
carbaminohemoglobin
Co2 reacts with and combines with what molecules and also converts back constantly
carbon dioxide + water -> carbonic acid -> bicarbonate + helium ion
atmospheric pressure
760 mmHg
atmospheric air composition
78% N, 20.9% O2, 0.04% Co2, 0-4% water vapor
Dalton’s law
total atmospheric pressure is the sum of the partial pressure of individual gases
partial pressure
contribution to total air pressure due to a single gas
atmospheric air is also called
inhaled air
partial pressure calculation
percentage x total pressure
water vapor partial pressure difference in alveolar air
10x higher than atmospheric air because of humidification of mucous membrane
residual air
air that remains in lungs after expiration
alveolar air mixing with residual does what to O2 and Co2
O2 is diluted to 65% and CO2 is enriched by 130x
systemic gas exchange function
blood unloads O2 and loads CO2 at systemic capillaries
what happens to loaded Co2 is systemic gas exchange
diffuses into blood and RBCs from the tissue
carbonic anhydrase
enzyme that generates bicarbonate through catalyzation to produce movement of Co2 in systemic gas exchange
chloride shift
enters the RBC to ensure the conversion of Co2 to bicarbonate by forcing bicarbonate to leave the cell
what happens to the hydrogen ion as a result of the chloride shift
binds to hemoglobin
how is O2 loaded into tissues in systemic gas exchange
hydrogen ion binds to oxyhemoglobin to reduce its affinity for O2, allowing 22% of O2 to be released
utilization coefficent
percentage of O2 delivered to tissue by hemoglobin
venous reserve
amount of O2 remaining in the blood after systemic capillary exchange
alveolar gas exchange function
blood unloads CO2 and loads O2 at the pulmonary capillaries
process of O2 loading in alveolar gas exchange
O2 diffuses into blood and CO2 binds to hemoglobin
where specifically is PO2 high
the pulmonary capillaries`
how is Co2 unloaded in RBCs during alveolar gas exchange
helium ion dissociates from hemoglobin and attaches to bicarbonate
reverse chloride shift
bicarbonate diffuses back into RBCs to exchange with Chloride
chloride shift occurs in _____ gas exchange, reverse chloride shift occurs in ___ gas exchange
systemic, alveolar
how is CO2 unloaded from plasma in alveolar gas exchange
using a reverse chloride shift reaction to allow Co2 and carbamino to diffuse out of the plasma
what does hemoglobin adjust O2 unloading to
metabolic tissue needs
what does a decrease in ambient PO2 do to gas exchange
active tissue has a lower PO2, causing more O2 to be released from hemoglobin
what does a decrease in ambient pH do to gas exchange
active tissue has a higher Co2, which lowers blood pH, which favors O2 release from hemoglobin
Bohr Effect
lower blood pH causes more O2 to be released
what does an increase in body temperature do to gas exchange
active tissue increases body temperature, which favors O2 release from hemoglobin
what does BPG bind to and why
To hemoglobin to promote O2 release
what produces BPG and why
RBCs produce in response to stimuli
Haldane Effect
Co2 loading is adjusted to meet needs by lowering oxyhemoglobin to allow more Co2 to be transported
