Respiratory System (Exam 2) Flashcards
includes the pulmonary arteries and veins, the thoracic cage, the lungs, and the respiratory tract
respiratory system
includes the nose and nasal cavity, the pharynx, the larynx, the trachea, and the bronchial tree
respiratory tract
the terminal structures of the respiratory tract, tiny air sac arranged in grapelike clusters through which gases are exchanged
alveoli
paired spongy organs in the thoracic cavity that consist of millions of alveoli
lungs
pharynx is also called
the throat
the larynx is also called
the voice box
the trachea is also called
the windpipe
includes the passageways from the nasal cavity to the larynx
upper respiratory tract
includes the passageways from the trachea to the respiratory tract’s terminal structures, the alveoli
lower respiratory tract
the conduits through which air travels on its way in and out of the body as it is inspired, or inhaled, and expired, or exhaled
conducting zone
air is filtered, warmed, and moistened as it travels through the many passages of the
conducting zone
where gases are exchanged
respiratory zone
the process that provides the body’s cells with oxygen and removes the waste product carbon dioxide
respiration
What are the four separate processes respiration includes?
1) pulmonary ventilation
2) pulmonary gas exchange
3) gas transport in the blood
4) tissue gas exchange
the movement of air in and out of the lungs
pulmonary ventilation
the movement of gases between the lungs and the blood
pulmonary gas exchange
the movement of gases through the blood
gas transport
the movement of gases between the blood and the tissues
tissue gas exchange
moisten, warm, and filter the inspired air; house olfactory receptors; and enhance voice resonance
the nose and nasal cavity
the nasal cavity extends from and is divided by?
- extends from the anterior nares to the posterior nares
* divided into right and left portions by the nasal septum
what is the nasal cavity lined with?
with respiratory mucosa, a portion of the roof of the nasal cavity is line with olfactory mucosa
what are the three divisions of the pharynx?
- nasopharynx
- oropharynx
- laryngopharynx
- lies posterior to the nasal cavity
- lined with pseudostratified ciliated columnar epithelium
- functions to warm, humidify, and filter the inspired (like the pharynx)
- extends from the posterior nares to a part of the soft palate, uvula
nasopharynx
- located posterior to the oral cavity
- serves as a passageway for both food and air
- lined with nonkeratinized stratified squamous epithelium
- extends from the uvula to the tip of the larynx
oropharynx
- extends from the hyoid bone to the esophagus
- serves as a passageway for both food and air
- lined with nonkeratinized stratified squamous epithelium to prevent abrasion from food
laryngopharynx
- protects the airway and produces sound
- keeps food and liquids out of the rest of the respiratory tract
- lined with nonkeratinized stratified squamous epithelium
larynx
what are the nine pieces of cartilage the larynx is framed with?
- epiglottis
- thyroid cartilage
- cricoid cartilage
- the paired arytenoid
- corniculate
- cuneiform cartilages
seals off the larynx during swallowing to prevent food or liquid from entering the respiratory tract
epiglottis
what are the two sets of mucosal folds that the larynx contains?
- vestibular folds
* vocal folds
- also called the false vocal cords
* function in closing off the glottis during swallowing
vestibular folds
also called the true vocal cords
vocal folds
vibrate to produce sound when air is passed over them
elastic vocal ligaments
the largest piece of the larynx’s framework, forming its anterior and superior walls
* attached superiorly to the hyoid bone and inferiorly to the cricoid cartilage by fibrous membranes
thyroid cartilage
known as the Adam’s apple
thyroid cartilage
- inferior to the thyroid cartilage
* attached to it by a thin membrane called the cricothyroid ligament
cricoid cartilage
site for a procedure sometimes performed on a choking victim, called cricothyroidotomy
cricoid cartilage
Proper functioning of the respiratory system is critical in maintaining?
Acid-base balance in the extracellular fluid, this system controls one of the primary buffer systems in the body
the respiratory system synthesizes an enzyme involved in the production of
angiotensin-II
involved in maintaining acid-base homeostasis and is also critical in maintaining blood pressure and fluid homeostasis
angiotensin-II
secrete mucus
goblet cells
- triangular pieces of cartilage that are involved in sound production
- they attach to the vocal folds and the intrinsic muscles of the larynx
arytenoid cartilages
- function in sound production
* small pieces capped on the arytenoid cartilages
corniculate cartilage
- found in the lateral wall of the larynx
* help to support the epiglottis
cuneiform cartilage
- delivers this air to the lower structures of the respiratory tract
- hollow tube about 2cm in diameter and about 10-12cm long
trachea
- walls consist of a mucosa composed of respiratory epithelium
- contains C-shaped rings of hyaline cartilage to keep the airway open
trachea
a series of progressively smaller tubes that terminate in tiny alveoli, the structures of gas exchange
bronchial tree
where does the bronchial tree begin?
with the right and left primary bronchi
the smallest passageways of the bronchial tree are the
bronchioles
the last branches of the conducting zone are the
terminal bronchioles
what do terminal bronchioles lead to?
respiratory bronchioles, which begin the respiratory zone and lead to alveolar ducts
To get to the alveoli, our inhaled air had to pass through?
nares(anterior and posterior)—-> nasal cavity—-> nasopharynx—> oropharynx—> laryngopharynx—> larynx—> trachea—> primary bronchi—> secondary bronchi—> tertiary bronchi—> multiple branches of bronchi—> bronchioles—> terminal bronchioles—> respiratory bronchioles—> alveolar ducts—> alveolar sacs
majority of alveoli are located in groups called
alveolar sacs
each round, thin-walled alveolus has three cell types that include
- type I alveolar cells
- type II alveolar cells
- alveolar macrophages
- squamous cells that make up about 90% of the cells in the alveolar wall
- exceedingly thin, which permits rapid diffusion of gases across their cell membranes
type I alveolar cells
- small cuboidal cells that make up about 10% of the cells in the alveolar wall
- secrete surfactant
type II alveolar cells
helps to reduce the surface tension on the alveoli
surfactant
- phagocytes derived from cells formed in the bone marrow
- clean up debris in the alveoli
- directly involved with an agent that causes a potentially serious respiratory infection
alveolar macrophages
the very thin type I alveolar cells help make up what is known as
the respiratory membrane
the barrier through which gases must diffuse
the respiratory membrane
the respiratory membrane has three major parts which include
- type I alveolar cells
- basal lamina
- capillary endothelial cells
the lobes of the lung are divided into
bronchopulmonary segments
each lung is enclosed by?
pleural cavity
filled with serous fluid, which reduces friction during ventilation
pleural cavity
depends on pressure gradients that drive inspiration and expiration
pulmonary ventilation
states that a gas under constant temperature, the pressure and volume are inversely related. this means that as the volume of a container increases, its pressure decreases. as the volume of a container decreases, its pressure increases
Boyle’s law
increase the volume of the lungs
inspiratory muscles
the main inspiratory muscle is?
the diaphragm
the other inspiratory muscle is?
external intercostal muscles
expiration during normal quiet breathing is passive due to?
the elastic recoil of the lungs
as the lungs recoil, what happens to the volume of the lungs?
the volume decreases
when he inspiratory muscles relax what two things happen?
- the diaphragm resumes its original dome shape, which pushes up on the lungs
- the elastic tissue in the lungs recoils, and the lungs snap back into a smaller size
help keep the alveoli inflated and prevent obstruction of the airways
nonrespiratory movements
What three pressures are at work during the process of ventilation?
- atmospheric pressure
- intrapulmonary pressure
- intrapleural pressure
the pressure exerted by the air around us
atmospheric pressure
the pressure with the alveoli. it varies during inspiration and expiration, but it always eventually equilibrates with atmospheric pressure
intrapulmonary pressure
the pressure within the pleural cavity. it also varies with inspiration and expiration, but it is normally less than the intrapulmonary pressure, a state that prevents the lungs from collapsing
intrapleural pressure
During inspiration, the volume of the lungs increases, causing a decrease in?
intrapulmonary pressure below atmospheric pressure
During expiration, the volume of the lungs decreases, causing an increase in?
intrapulmonary pressure above atmospheric pressure
What three physical factors determine the effectiveness of pulmonary ventilation?
- airway resistance
- alveolar surface tension
- pulmonary compliance
defined as the impedance to air flow, and any increase in airway resistance decreases the effectiveness of pulmonary ventilation
airway resistance
defined as the attraction created by hydrogen bonding between water molecules that tends to collapse the alveoli
alveolar surface tension
refers to the ability of the lungs to stretch.
pulmonary compliance
if pulmonary compliance decreases what occurs?
the lungs are less able to expand, and the effectiveness of pulmonary ventilation decreases
lung function may be assessed using measurements taken with?
spirometer
relaxation of the bronchial smooth muscle
bronchodilation
when the smooth muscle contract it is called
bronchoconstriction
Pulmonary compliance is determined by three factors which include?
- degree of alveolar surface tension
- distensibility of elastic tissue in the lungs
- ability of the chest wall to move
Three volumes in the lungs can be measured, they include?
- tidal volume (TV)
- inspiratory reserve volume (IRV)
- expiratory reserve volume (ERV)
the amount of air inspired or expired during normal, quiet ventilation
tidal volume
in the average healthy adult, the tidal volume is about?
500 ml of air
the air that remains in the conducting zone airways is said to be?
in the anatomical dead space
Out of a 500 ml tidal inspiration which portion is involved in gas exchange and which portion fills the anatomical dead space?
350 ml in gas exchange
150 ml fills anatomical dead space
the volume of air that reaches the alveoli multiplied by the breaths per minute, averages about 4.2.liters per minute
alveolar ventilation rate
refers to the volume of air that can be forcibly inspired after a normal tidal inspiration
*averages 2100-3300 ml of air, which is dependent on a person’s gender and size
inspiratory reserve volume (IRV)
refers to the amount of air that can be forcibly expired after a normal tidal expiration
*averages about 700-1200 ml of air
expiratory reserve volume (ESV)
a fourth pulmonary volume, which cannot be assessed by spirometry, is called
residual volume
the air that remains in the lungs even after the most forceful expiration
residual volume (RV)
two or more of the pulmonary volumes can be combined to create what are called?
pulmonary capacities
the four pulmonary capacities are?
- inspiratory capacity
- functional residual capacity
- vital capacity
- total lung capacity
the total amount of air that a person can inspire after after a tidal expiration
- equal to the tidal volume plus the inspiratory reserve volume
- can be measured using spirometry
inspiratory capacity
the amount of air that is normally left in the lungs after a tidal expiration
*the sum of the ERV and the IRV
functional residual capacity
represents the total amount of exchangeable air, or the total amount of air that can move in or out of the lungs
*equals the sum of tidal volume, inspiratory reserve volume (IRV), and expiratory reserve volume (ESV)
vital capacity
represents the total amount of exchangeable and nonexchangeable air in the lungs
* it is the total of all of the pulmonary volumes (IRV, TV, ERV, and RV.
total lung capacity
states that the total pressure of a gas mixture is equal to the sum of the partial pressures of the individual gases
Dalton’s law of partial pressures
states that the degree to which a gas dissolves in a liquid is proportional to its pressure and its solubility in that liquid
Henry’s law
the exchange of gases in which oxygen diffuses from the alveoli to the blood, and carbon dioxide diffuses from the blood to the alveoli
pulmonary gas exchange
effectiveness depends on the surface area of respiratory membrane, the thickness of the respiratory membrane, and the match between ventilation and perfusion
pulmonary gas exchange
Hemoglobin binds and releases O2 via two reactions known as
loading and unloading reactions
oxygen from alveoli binds to hemoglobin in the pulmonary capillaries during
loading
hemoglobin in the systemic capillaries releases oxygen to tissue cells during
unloading
Hemoglobin’s ability to load and unload depends on which two factors?
- the PO2 in the lungs or tissues
* the tightness with which hemoglobin binds oxygen, also called the affinity, or the bond strength , of hemoglobin
the percent of hemoglobin bound to oxygen is called
percent saturation of Hb
What is one of the main determinants of the percents saturation of Hb is?
the PO2 of the blood and tissues
the higher the PO2 of the blood, the more?
loading reaction is favored, because more O2 molecules are available to bind to Hb
the relationship between PO2 and percent saturation of Hb is shown in the?
oxygen-hemoglobin dissociation curve
these values are on the left-hand side of the graph
percent O2 saturation of Hb
along the bottom of the graph is the partial pressure of oxygen in the blood
blood PO2
Four main factors can change the affinity of Hb for oxygen by altering Hb’s shape
- temperature
- the pH of the blood
- P CO2
- BPG (bisphosphoglycerate)
a key factor that allows people to live at higher altitudes or with poor pulmonary function, both situations result in lower in PO2 levels and less saturation of Hb with oxygen
BPG
Carbon dioxide is transported in blood in three ways
- dissolved in plasma (7-10%)
- bound to Hb (20%)
- bicarbonate ions (70%)
In erythrocytes, carbon dioxide is converted to bicarbonate by being?
combined with water in a reaction catalyzed by the enzyme carbonic anhydrase
one of the primary buffer systems in the body is?
the carbonic acid-bicarbonate buffer system
What occurs when PCO2 increases?
raises carbonic acid and lowers blood pH
What occurs when PCO2 decreases?
lowers carbonic acid and raises blood pH
groups of neurons in the medulla of the brainstem maintain?
eupnea
sets the basic pattern of ventilation
respiratory rhythm generator
consists of both inspiratory neurons that stimulate the inspiratory muscles and expiratory neurons that stimulate the accessory muscles of expiration
ventral respiratory group (VRG)
consists mostly of inspiratory neurons that stimulate the inspiratory muscles
dorsal respiratory group (DRG)
respond to changes in hydrogen ion concentrations and PCO2 of the CSF
central chemoreceptors
Other mechanisms that influence pulmonary ventilation include?
- peripheral chemoreceptors in the aotic
* carotid bodies that respond to the PO2 of the arterial blood
decrease pulmonary compliance (ability to stretch)
*decreases the effectiveness of inspiration, inspiratory capacity, vital capacity, and total lung capacity
restrictive lung disease
increase airway resistance
obstructive lung diseases
defined as persistent airway obstruction that is not fully reversible
chronic obstructive pulmonary disease (COPD)
an obstructive disease in which airways are hyperresponsive to a trigger of some sort
*bronchoconstriction, airway inflammation, and increased secretion of excessively thick mucus occurs
asthma
refers to tumors that arise from the epithelium of the lung tissue
lung cancer
