Lesson 13/14 Exam 4 Flashcards
respiratory system
organ system that takes in air and expels it from the body
respiration refers to
ventilation of the lungs
function of the respiratory system
- gas exchange
- communication
- olfaction
- acid base balance
- blood pressure regulation
- blood and lymph flow
- platelet production
- blood filtration
- expulsion of abdominal contents
gas exchange in the respiratory system
O2 and CO2 exchanged between blood and air
communcation in the respiratory system
speech and other vocalization
olfaction is
sense of smell
acid base balance in respiratory system
influences pH of body fluids by eliminating CO2
blood pressure regulation in respiratory system
assists with synthesis of angiotensin II
angiotensin II
hormone that regulates blood pressure
blood and lymph flow in respiratory system
breathing creates pressure gradients between thorax and abdomen that promotes flow of lymph and blood
platelet production in respiratory system
more than half of platelets are made by megakaryotes in lungs
blood filtration in respiraotry system
lungs filter small clots
expulsion of abdominal contents i respiratory system
breath holding assists in urination, defacation, and childbirth
principle organs of the respiratory system
- nose
- pharynx
- larynx
- trachea
- bronchi
- lungs
conducting zone
- passages that serve only for airflow
- nostrils through major bronchioles
respiratory zone
regiosn that participate in gas exchange
upper respiratory tract
airway from nose through larynx
lower respiratory tract
regions from trachea through lungs
nose
- warms, cleasnes, and humidifies inhaled air
- detects odors
- serves as resonating chamber that amplifies voice
the nose extends from
nostrils to posterior nasal apeture
nostrils aka
nares
posterior nasal apeture aka
choanae
facial part of the nose is shaped by
bone and hyaline cartilage
nasal septum
divides nasal cavity into right and left nasal fossae
vestibule
small dilated chamber just inside nostrils lined with stratified squamous epithelium
guard hairs aka
vibrissae
guard hairs
stiff hairs that block insects and debris from entering nose
chamber behind vestibule occupied by
superior, middle, and inferior nasal conchae
nasal conchae project
from lateral walls toward septum
meatus
narrow air passage beneath each concha
narrowness and turbulence ensure
most air contacts mucous membranes to clean, warm, and moisten the air
nasal mucosa covered by
respiratory epithelium
respiratory epithelium
ciliated pseudostratified columnar epithelium
ciliated cells
have motile cilia that propel mucus posteriorly toward pharynx to be swallowed
_____ produce most mucus in nasal respiratory epithelium
goblet cells
goblet cells are supplemented by
mucous glands in lamina propria
olfactory epithelium
- located at roof of each nasal fossa
- immobile cilia bind odoarant molecules
olfactory glands secrete ___
serous fluid
why do olfactory glands secrete serous fluid
to assist in the diffusion of odor molecules to receptors on the cilia
pharynx
muscular funnel extending about 5in from posterior nasal apertures to larynx
muscles of the pharynx assist in
swallowing and speech
what are the three regions of the pharynx
- nasopharynx
- oropharynx
- laryngopharynx
nasopharynx
posterior to nasal apertures and above soft palate
nasopharynx receives ___ and contains ____
- auditory tubes
- pharyngeal tonsil
what is the purpose fo the 90° downward turn in the nasopharynx?
to trap large particles
oropharynx
space between soft palate and epiglottis
what tonsils are located in the oropharynx
palatine
laryngopharynx
posterior to larynx from epiglottis to cricoid cartilage
larynx
cartilaginous chamber about 1.5in long
larynx primary function
- keep food and drink out of airway
- involved in sound production
epiglottis
flap of tissue that guards superior opening of larynx
what happens to the epiglottis when swallowing?
extrinsic muscles pull larynx upward and tongue pushes epiglottis down
what is the reason for the epiglottis closing?
closes airway and directs food to esophagus behind it
_____ play greater role in keeping food and drink out of the airway
vestibular folds
___ cartilages make up framework of larynx
nine
what are the first three cartilages of the larynx
- epiglottis
- thyroid
- cricoid
epiglottis cartilage
- most superior
- spoon-shaped supportive plate of epiglottis
thyroid cartilage
- shield-shaped and largest
- contains laryngeal prominence
laryngeal prominence aka
adam’s apple
what causes adam’s apple to grow
testosterone
cricoid catilage
- ring like shape
- connects larynx to trachea
vestibular folds
two folds on internal wall of larynx that extend from thyroid cartilage to arytenoid cartilages
vestibular folds function
close larynx during swallowing
vestibular fold supported by
vestibular ligaments
vocal folds
- produce sound when air passes between them
- contain vocal ligaments
vocal ligaments covered in
stratified squamous epithelium
why are vocal ligaments covered in stratified squamous epithelium
to ensure they can endure vibration and contact
glottis
vocal cords and opening between them
how many layers of muscle are in the larynx?
two; superficial and deep
extrinsic muscles of larynx
- superficial layer of muscles connecting larynx to hyoid bone
- elevate larynx during swallowing
intrinsic muscles
abduct or adduct vocal cords depending on direction of rotation
air forced between adducted cords creates
high pitch sound
lower pitched sounds are audible when
cord are more slack
how do adult male cords compare to female
- usually longer and thicker
- vibrate more slowly
- produce lower pitched sound
loudness is determined by
the force of air passing between vocal cords
what transforms crude sounds from the vocal cord into words
actions of the pharynx, oral cavity, tongue, and lips
trachea
- tube that connects larynx to bronchi
- windpipe
structure and location of trachea
- rigid 4.5in long and 1in diameter
- anterior to esophagus
- supported by 16-20 c shaped rings of hyaline cartilage
why is the trachea supported by cartilage
prevent collapse during inhalation
why are opening of cartilage on trachea facing posteriorly
allows esophagus to expand as swallowing food passes by
carina
internal median ridge on the lowermost tracheal cartilage
the trachea is lined with
ciliated pseudostratified columnar epithelium
the trachea contains what types of cells
- mucus secreting cells
- ciliated cells
- stem cells
mucociliary escalator
- mechanism for debris removal
- mucus traps inhaled particles, upward beating cilia moves mucus to pharynx to be swallowed
tracheotomy
to make a temporary opening in the trachea and insert a tube to allow airflow
tracheotomy prevents
asphyxiation due to upper airway obstruction
potential problems of a tracheotomy include
- inhaled air bypasses nasal cavity and is not humidified
- if left for long, will dry out mucus membrane
- become encrusted and interfere with clearance of mucus from tract thereby promoting infection
intubation
- when patient is on ventilator
- air is introduced directly into trachea
air must be __ and __ to prevent respiratory tract damage
filter and humidified
what are the landmarks of the lung
- base
- apex
- costal surface
- mediastinal surface
- hilum
base of lung
broad concave portion resting on diaphragm
apex of lung
tip that projects just above the clavicle
costal surface of lung
pressed against the ribcage
mediastinal surface of lung
face medially toward heart
hilum of lung
slit through which the lung receives the main bronchus, blood vessels, lymphatics, and nerves
structures near hilum constitute
root of lung
are the lungs symmetrical?
no
right lung has a ___ volume than left lung
greater
characteristics of the right lung
- shorter than left
- three lobes
why is the right lung shorter than the left
liver rises higher on the right
horizontal fissure of right lung separates ____
superior and middle lobes
oblique fissure of right lung separates ____
middle and inferior lobes
characteristics of left lung
- tall and narrow
- indentation to accommodate heart
- had two lobes
why is the left lung tall and narrow?
heart tilts toward the left and occupies more space on this side of mediastinum
cardiac impression
indentation in left lung to accommodate heart
what separates the two lobes of the left lung
oblique fissure
bronchial tree
branching system of air tubes in each lung
the bronchial tree extends from
main bronchus to terminal bronchioles
how many terminal bronchioles are there
65000
right main bronchus is ___ than left main bronchus
wider and more verticle
aspirated foreign objects lodge more in the ____ than the ___
right than the left
main bronchi divide into
lobar bronchi
how many lobar bronchi branches are there in the right lung
three
how many lobar bronchi branches are there in the left lung
two
lobar bronchi branch into
segmental bronchi
main bronchi supported by
rings of hyaline cartilage
cartilage rings of main bronchus transition to
crescent-shaped plates in lobar and segmental bronchi
all bronchi are lined with
ciliated pseudostratified columnar epithelium
what happens to cells and epithelium are progress distally towards bronchioles
cells grow shorter and epithelium thinner
lamina propria has abundance of
mucus glands and lymphoid nodules
all divisions of bronchial tree have large amount of
elastic connective tissue
what does elastic connective tissue in bronchial tree do?
contributes to recoil during respiration
muscularis mucosae
- mucosa of bronchial tree with well-developed layer of smooth muscle
- contracts or relaxes to constrict or dilate airway
bronchodilation and stim
- increase in diameter of bronchus or bronchiole
- epinephrine and sympathetic stim
bronchoconstriction and stim
- decrease in diameter of bronchus or bronchiole
- histamine, parasym nerve, cold air, chemical irritants
bronchioles
continuations of airway that ack supportive cartilage and are 1mm or less in diameter
pulmonary lobule
portion of lung ventilated by one bronchiole
bronchioles have what type of tissue
ciliated cuboidal epithelium
each bronchiole branches into ___ terminal bronchioles
50-80
terminal bronchioles
- final braches of conducting zone
- measure 0.5mm or less in diameter
terminal bronchioles do not have
mucous glands or goblet cells
terminal bronchioles do have
cilia that move mucus by mucociliary escalator
each terminal bronchiole gives off two or more
respiratory bronchioles
respiratory bronchioles have ___ budding off them
alveoli
____ considered beginning of respiratory zone
respiratory bronchioles
how many alveolar ducts come off of respiratory bronchioles
2-10
alveolar ducts
- elongated thin-walled passages with alveoli along their walls
- end in alveolar sacs
alveolar sacs
clusters of alveoli around a central space
alveoli
microscopic air pouches in the lung each about 0.2-0.5mm in diameter
how many alveoli in each lung
480 million
what is the surface area of the alveoli in the lungs
70 m^2
cells of the alveoli
- squamous alveolar cells
- great alveolar cells
- alveolar macrophages
squamous alveolar cells
- type 1
- thin cells allow rapid gas diffusion between air and blood
____ cover 95% of alveolus surface area
type 1 squamous alveolar cells
great alveolar cells
- type 2
- cuboidal cells
- repair alveolar epithelium when squamous cells are damaged
what covers the last 5% of alveolar surface
type 2 cells
type 2 cells secrete
pulmonary surfactant
pulmonary surfactant
mixture of phospholipids and proteins that coats the alveoli and prevents them from collapsing during exhalation
how does surfactant prevent alveoli from collapsing
reduces surface tension
alveolar macrophages
- dust cells
- wander lumens of alveoli and connective tissue between them
- keep alveoli free from debris by phagocytizing dust particles
why do millions of dust cells die each day
ride up mucociliary escalator to be swallowed and digested with their load of debris
____ most numerous of all cells in lung
alveolar macrophages
respiratory membrane
thin barrier between alveolar air and blood
each alveolus surrounded by
basket of capillaries supplied by pulmonary artery
three layers of respiratory membrane
- squamous alveolar cells
- endothelial cells of blood capillary
- shared basement membrane
pulmonary circuit
- pulmonary trunk
- pulmonary arteries
- lobar arteries
- capillaries surrounding alveoli
- pulmonary veins
pulmonary circuit function
unload CO2 from blood so it can be exhaled and pick up O2 from inhaled air
systemic blood supply in lungs
bronchial arteries and veins
bronchial arteries of lung systemic blood supply
- arise form aorta
- supply lung tissue with blood supply
bronchial veins in lung systemic blood supply
drain this blood into azygos vein of thorax
right to left shunt
- some bronchial venous blood mixes with pulmonary venous blood
- dilutes oxygen content somewhat before it reaches the left atrium
to prevent fluid accumulation in the lungs
alveoli are kept dry by low blood pressure in capillaries
average blood pressure in alveoli
10 mmHg
low blood pressure in alveoli means what?
- reabsorption overrides filtration and keeps the alveoli free of excess fluid
- prevents rupture of respiratory membrane
lung has more extensive ____ than any other organ
lymphatic drainage
pleura
serous membrane that lines thoracic wall and forms surface of lung
visceral pleura
forms surface of the lung
parietal pleura
adheres to mediastinum, inner surface of rib cage, and superior surface of diaphragm
pleural cavity
- potential space between pleurae
- contains film of pleural fluid
is there usually room between membrane of pleura
no
pleural effusion
pathological seepage of fluid into the pleural cavity
causes of pleural effusion
- congestive heart failure
- pneumonia
- pulmonary embolism
functions of pleurae and pleural fluid
- reduction of friction
- creation of a pressure gradient
- compartmentalization
reduction of friction in pleura
allow lungs to move with minimal friction
creation of pressure gradient in pleura
pressure gradient assists with lung inflation
compartmentalization of pleura
prevents spread of infection from one organ in mediastinum to others
breathing
repetitive cycle of inspiration and expiration
respiratory cycle
one complete breath
quiet respiration
- breathing while at rest
- effortless and automatic
forced respiration
- deep and rapid breathing
- during exercise or playing instrument
flow of air in and out of lungs depend on
pressure difference between air within lungs and outside body
____ change lung volumes and create differences in pressure relative to atmosphere
respiratory muscles
principle respiratory muscles
diaphragm and intercostals
prime mover of respiration
diaphragm
diaphragm moving respiration
- contraction flattens diaphragm enlarging thoracic cavity and pulling air into lung
- relaxation allows diaphragm to bulge upward again, compressing lungs and expelling air
diaphragm accounts for ___ of airflow
two thirds
internal and external intercostals
- located between ribs
- contribute to enlargement and contraction of thoracic cage
accessory muscles of respiration act mainly in
forced respiration
deep inspiration uses
- sternocleidomastoid
- scalenes
- pectoralis minor
- serratus anterior
normal quiet inspiration uses
diaphragm and external intercostals
normal quiet expiration
energy saving passive process achieved by elasticity of lungs and thoracic cage
forced expiraion uses
- rectus abdominus
- internal intercostals
- external obliques
why are abdominal muscles used for forced expiration
increases abdominal pressure pushing viscera up against diaphragm increasing thoracic pressure