Respiratory system Flashcards
Body cells require continuous supply of
oxygen
Major role of RS
is to supply the body with the oxygen it needs and dispose of carbon dioxide
Pulmonary ventilation
The movement of air into and out of the lungs.
Pulmonary ventilation is simply called
ventilation or breathing
External respiration
Gas exchanges to and from the pulmonary circuit blood that occur in the lungs
Transport of respiratory gases
Transport of respiratory gases between the lungs and tissue cells of the body using blood as the transport vehicle
Internal respiration
Exchange of gases to and from the blood capillaries of the systemic circulation
oxygen loading and carbon dioxide unloading occurs in
External respiration
oxygen unloading and carbon dioxide loading occurs in
internal respiration
Tasks of the respiratory system
Pulmonary ventilation and external respiration
upper respiratory system structures
nose
pharynx
larynx
air generally passes into the respiratory tract through the
and enters
nostrils
nasal cavity
another name for nostrils
nares
air then flows posteriorly over 3 pairs of lobelike structures
inferior, superior and middle nasal conchae
inferior, superior and middle nasal conchae increase the
air turbulence
as the air passes through the nasal cavity, it is warmed, moistened and filtered by the
nasal mucosa
when air flows directly beneath the superior part of the nasal cavity may stimulate
the olfactory receptors in the mucosa of that region
nasal cavity is surrounded by the
paranasal sinuses in the frontal, spenoid, ethmoid and maxillary bones
paranasal sinuses act as
Their mucus
resonance chambers in speech
warms and moisten the incoming air
nasal passages are separated from the oral cavity below by a
parition composed anteriorly of the hard plate and posteriorly by the soft plate
oral and nasal cavities are joined temporarily
pharynx
when air enters via mouth, it moves into the
pharynx
another name of pharynx
throat
pharynx connects the nasal and oral cavities to the
larynx and esophagus inferiorly
lies posteriorly to the nasal cavity
nasopharynx
nasopharynx serves only as an air passage because
it lies above the soft plate
above nasopharynx
pharyngeal tonsils, paired masses of lymphoid tissue
allow middle ear pressure to become equalized to atmosphere pressure, drain into the nasapharynx
pharyngotympanic or auditory tubes
lies posteriorly to the oral cavity
oropharynx
oropharynx extends from the
soft plate to the epiglottis of the larynx inferiorly
oropharynx serves as a common
conduit for food and air
lateral walls of oropharynx are the
palatine tonsils
covers the base of the tongue
lingual tonsil
like the oropharynx, accommodates both ingested food and air
laryngopharynx
laryngopharynx extends to the
larynx
larynx, common pathway divides into
respiratory and digestive channels
from the laryngopharynx, air enters the
lower respiratory passageways by passing through the larynx into the trachea below
another name for larynx
voicebox
larynx is made uo of
9 cartilages
largest cartilage are the
shield shaped thyroid cartilage
anterior protrusion of thyroid cartilage is called
adam’s apple
more inferior ring shaped cartilage
cricoid cartilage
all laryngeal cartilages are composed of;
except for
hyaline cartilage
epiglottis
define epiglottis
flaplike elastic cartilage superior to the opening of the larynx
epiglottis forms a lid over the larynx when we;
swallow
if anything other than air enters the larynx
a cough reflex attempts to expel the substance
cough reflex only works when the person is
conscious
mucous membrane of the larynx is thrown into a pair of folds called the;
vocal folds or true vocal cord, which vibrate with expelled air for speech
the slitlike passageway between the vocal folds is called the
glottis
air entering the trachea travels down its length;
to the level of the;
There passageways divides into the
11ch
5th thoracic vertebra
right and left main or primary bronchi
trachea is lined with a ciliated
mucus secreting epithelium
mucus are produced by
goblet cells
the cilia propel;
away from lungs and throat, where it can be
spat out or swallowed
walls of trachea is are reinforced with
C shaped cartilages, with the incomplete portion of the rings facing toward the esophagus
the solid portions reinforce the trachea walls to keep its passageways
open regardless of the pressure changes that occur during breathing
main bronchi plunge into their respective lungs at an indented area called the
hilum
inhaled foreign objects are more likely to become lodged in here
right main bronchi
bronchi divides further into smaller and smaller branches called
bronchioles
bronchioles have a terminal branche called
respiratory bronchioles
all but the tiniest branches have
cartilage in their walls, usually oin the form of small plates of hyaline cartilage
as the respiratory branches get smaller and smaller, the relative amount of
smooth muscles in their walls increases and the amount of cartilage declines and finally disappears
continuous branching of the respiratory passageways in the lungs is often called to as the
respiratory tree
respiratory bronchioles in turn subdivided into
alveolar ducts
alveolar ducts end in
alveolar sac, resemble a cluster of grapes
describe alveoli
tiny ballonlike expansion along the alveolar sacs
alveoli are composed of
a single thin layer of squamous epithelium overlying a wispy connective tissue layer
external surfaces of the alveoli are
densely spiderwebbed with pulmonary capillaries
together, the alveolar and capillary walls and their fused basement membranes form the
respiratory membrane
gas exchanges occur by
across;
referred to as
simple diffusion
respiratory membrane, the alveolar sacs, alveolar ducts and respiratory broncioles
respiratory zone structures
all other respiratory passageways serve as;
are called
access or exit routes to and from these gas exchange chambers
conducting zone structures
each lung is connected to the mediastinum by
a root containing its vascular supply and bronchial attachments
all structures distal to the primary bronchi are inside
the lungs
deep to the clavicle
lung’s apex
rests of the diaphragm
base
medial surface of the left lung has a
recess that accommodates the heart
divides the lungs into a number of lobes
fissure
2 in the left lung and 3 in the right
lungs are mostly;
elastic connective tissue, which allows then to recoil passively during expiration
each lung is enclosed in a double layered serous membrane sac called
pleura
attached to the thoracic walls and diaphragm
parietal pleura
outer layer of lungs
parietal pleura
inner layer of the lungs
visceral pleura
2 pleura layers are separated by the
pleural cavity
pleural layers produce
lubricating serous fluid that causes them to adhere closely to one another, holding the lungs to the thoracic wall and allowing them to move easily against one another during the movements of breathing
includes larynx, trachea with attached lungs, the heart, and portions of the major blood vessels found in the mediastinum
sheep pluck
advantage of using a fresh pluck
is that it changes color (becomes more red) as hemoglobin in trapped RBCs becomes loaded with oxygen
a “lid” for the larynx:
epiglottis
shaped like a signet ring:
cricoid
connects the larynx to the primary bronchi
trachea
site of tonsils
pharynx
food passageway posterior to the trachea
esophagus
covers the glottis during swallowing of food
epiglottis
contains the vocal cords
larynx
pleural layer lining the walls of the thorax
parietal pleura
site from which oxygen enters the pulmonary blood
aveolus
connects the middle ear to the nasopharynx
opening of auditory tubes
opening between the vocal folds
glottis
increases air turbulence in the nasal cavity
concha
separates the oral cavity from the nasal cavity
palate
function of cilia
Sweep (debris-laden) mucus superiorly away from lungs
Why does oxygen move from the alveoli into the pulmonary capillary blood?
Because the partial pressure of oxygen is greater
in the alveoli; therefore, it moves according to the laws of diffusion into the pulmonary blood
What structural characteristics of the alveoli make them an ideal site for the diffusion of gases
Thin walls, extremely large surface area.
pulmonary ventilation has 2 phases
inspiration
expiration
when inspiratory muscles contract
size of the thoracic cavity increases
what cause the increase in the superoinferior volume
the diaphram moves from its relaxed dome shaped to a flattened position
external intercostals lift the rib cage
increasing the anteroposterior and lateral dimentions
lowers the air pressure inside the lungs
increase in intrapulmonary volume
during expiration, the inspiration
muscles relax and the elastic lung tissue recoils
both intrathoracic and intropulmonary volumes decrease during
expiration
as the gas molecules within the lungs are forced closer together
intrapulmonary pressure rises above atmospheric pressure
produce variations in respiratory volumes
a person’s size, sex, age and physical condition
respiratory volumes are measured with an apparatus called
a spirometer
2 types of spyrometers
handheld dry or wheen
wet spirometer
the more sophisticated wet spirometer consists of a
plastic or metal bell that sir can be added to or removed from and which rests in a rectangular or cylindrical tank
in nonrecording spirometers
an indicator moves as air is exhales and only expired air volumes can be measured directly
the neural centers that control respiratory rhythm and depth are located in the
medulla and pons
medulla initiates the basic
rate and rhythm
what can modify the rate and depth of respiration
talking, yawning, coughing and exercise
changes in co2 blood levels act directly on the
medulla control centers
changes in PH and oxygen levels are monitored by
chemoreceptor regions in the aortic and carotid bodies, which in turn send input to the medulla
describe pneumograph
an apparatus that records variations in breathing patterns, is the best means of observing respiratory variations
coiled rubber hose that is attached around the thorax
chest pneumograph
Under what internal conditions does air tend to flow into the lungs?
↑ thoracic volume, and
↓pressure.
Under what internal conditions does air tend to flow out of the lungs? Explain why this is so.
↑thoracic volume.
The diaphragm moves inferiorly, increasing the superior-inferior dimension; the ribs swing up and out, increasing the lateral and anterior/posterior dimensions.
Activation of the diaphragm and the external intercostal muscles begins the inspiratory process. What effect does contraction of these muscles have on thoracic volume, and how is this accomplished
↑thoracic volume. The diaphragm moves inferiorly, increasing the superior-inferior dimension; the ribs swing up and out, increasing the lateral and anterior/posterior dimensions.
What temporary physiological advantage is created by the substantial increase in chest circumference during forced inspiration?
Increases the thoracic volume more; therefore, creates a greater negative internal pressure, causing the gases to rush in quickly. Also, more “fresh” air reaches the alveoli
The presence of a partial vacuum between the pleural membranes is integral to normal breathing movements. What would happen if an opening were made into the chest cavity, as with a puncture wound?
Destroys the partial vacuum in the pleural space and the lung on the affected side collapses.
Which of the respiratory sounds is heard during both inspiration and expiration?
Bronchial
Which is heard primarily during inspiration?
Vesicular
Where did you best hear the vesicular respiratory sounds?
Hear over most of the lung area
Why does hyperventilation produce apnea or a reduced respiratory rate?
Hyperventilation washes CO2 out of the blood. Since
CO2 is the major chemical stimulus for inspiration, the desire or drive to breathe is decreased.
Why does rebreathing breathed air produce an increased respiratory rate?
CO2 (exhaled) accumulates in the bag; this stimulates increased force/rate of respiration
Where are sensory receptors sensitive to changes in O2 levels in the blood located?
Aortic bodies in the aortic arch and
carotid bodies at the bifurcation of the common carotid artery
What is the primary factor that initiates breathing in a newborn infant?
↑ levels of CO2 in the blood.
