Lesson 13-14a Part 1 - The Respiratory System Flashcards
Slides 1-53
respiratory system
organ system that takes in air and expels it from the body
respiration
refers to ventilation of the lungs (breathing)
functions of the respiratory system part 1 (5)
- gas exchange
- communication
- olfaction
- acid/base balance
- blood pressure regulation
functions of the respiratory system part 2 (4)
- blood and lymph flow
- platelet production
- blood filtration
- expulsion of abdominal contents
functions of the respiratory system: gas exchange
O2 and CO2 exchanges between blood and air
functions of the respiratory system: communicaiton
speech and other vocalization
functions of the respiratory system: olfaction
sense of smell
functions of the respiratory system: acid/base balance
influences pH of body fluids by eliminating CO2
functions of the respiratory system: blood pressure regulation
assists with synthesis of angiotensin II
angiotensin II
a hormone that regulates blood pressure
functions of the respiratory system: blood and lymph flow
breathing creates pressure gradients between thorax and abdomen that promote flow of lymph and blood
functions of the respiratory system: platelet production
more than half of platelets are made by megakaryocytes in the lungs (not bone marrow)
functions of the respiratory system: blood filtration
lungs filter small clots
functions of the respiratory system: expulsion of abdominal contents
breath-holding assists in urination, defecation, and childbirth
principal organs of the respiratory system (6)
- nose
- pharynx
- larynx
- trachea
- bronchi
- lungs
conducting zone
passage that serve only for airflow (no gas exchange)
the conducting zone is through…
nostrils through major bronchioles
respiratory zone
region that participate in gas exchange
the respiratory zone is through…
alveoli and nearby structures
upper respiratory tract
airway from nose through larynx
lower respiratory tract
regions from trachea through lungs
functions of the nose (3)
- warms, celeanses, and humidifies inhaled air
- detects odors
- serves as a resonating chamber that amplifies the voice
the nose extends from..
the nostril to posterior nasal apertures
nostrils aka
nares
posterior nasal apertures aka
choanae
the facial part of the nose is shaped by _____ and _____ cartilage
bone, hyaline
nasal septum
divides nasal cavity into right and left nasal fossae
vestibule
small, dilated chamber just inside nostrils
the vestibule is lined with…
stratified squamous epithelium
guard hairs (vibrissae)
stiff hairs that block insects and debris from entering the nose
the chamber behdin vestibule occupied by three folds of tissue called…
superior, middle, and inferior nasal conchae (turbinates) that project from lateral walls toward septum
meatus
narrow air passage beneath each concha
_____ and _____ ensure the most air contact mucous membrane to clean, warm , and moisten the air
narrowness, turbulence
nasal mucosa is covered by…
respiratory epithelium
respiratory epithelium is..
ciliated pseudostratified columnar epithelium
ciliated cells
have motile cilia that propel the mucus posteriorly toward the pharynx to be swallowed
goblet cells
produce most of the mucus, supplemented by mucous glands in lamina propria
olfactory epithelium
involved in the sense of smell
where is the olfactory epithelium?
located at the roof of each nasal fossa
the olfactory epithelium contains what kind of cells? that do what?
immobile cilia that bind odorant molecule
olfactory glands secrete…to assist…
serous fluid to assist diffusion of order molecules to receptors on the cilia
pharynx
muscular funnel extending from the posterior nasal apertures to the larynx
three regions of the pharynx
- nasopharynx
- oropharynx
- laryngopharynx
nasopharynx
posterior nasal apertures and above the soft palate
the nasopharynx contains…(2)
auditory tubes and contains the pharyngeal tonsil
oropharynx
space between soft palate and epiglottis
laryngopharynx
posterior to larynx, from epiglottis to cricoid cartilage
where does the esophagus begin?
the laryngopharynx
larynx
cartilaginous chamber functioning to keep food and drink out of the airway
what is commonly called the ‘voice box’?
the larynx
epiglottis
flap of tissue that guards superior opening of the larynx
at rest, how is the epiglottis positioned?
almost vertically
during swallowing, how does the larynx move?
extrinsic muscles pull the larynx upwards
during swallowing, how does the epiglottis move?
the tongue pushes it down to meet the larynx
what do the larynx and epiglottis function together to do?
closes airways and directs food to esophagus behind it
_____ folds of the larynx play greater role in keeping food and drink out of the airway
vestibular
_____ cartilages make up the framework of larynx
nine
first three cartilages of the larynx
- epiglottic cartilage
- thyroid cartilage
- cricoid cartilage
epiglottic cartilage
most superior; spoon-shaped supportive plate in epiglottis
thyroid cartilage
shield-shaped and largest cartilage
where is the laryngeal prominence?
the thyroid cartilage
- aka Adam’s apple
why is the laryngeal prominence larger in men?
testosterone stimulates the growth
cricoid cartilage
ring-shaped that connects the larynx to trachea
two folds of the larynx
vestibular and vocal
vestibular folds
play no role in speech but close the larynx during swallowing
the vestibular folds are supported by…
vestibular ligaments
vocal folds (vocal cords)
produce sound when air passes between them
the vocal cords contain…
vocal ligaments
vocal ligaments
suited to endure vibration and contact
vocal ligaments are covered with…
stratified squamous epithelium
glottis
the vocal cords and the opening between them
extrinsic muscles
superficial layer of muscles connecting the larynx to the hyoid bone
what is the function of the extrinsic muscles?
elevate the larynx during swallowing
intrinsic muscles
abduct or adduct vocal cords, depending on direction of rotation
when are high pitched sounds produced by the intrinsic muscle?
air is forced between the adducted (taut) cords
when are low pitched sounds produced by intrinsic muscles?
occurs when the cords are more slack
adult male vocal cords, when compared to female cords…(3)
- usually longer and thicker
- vibrate more slowly
- produce lower-pitched sound
how is loudness determined?
by the force of air passing between the vocal cords
vocal cords produce crude sounds that are formed into words by the actions of…(4)
- pharynx
- oral cavity
- tongue
- lips
trachea
tube that connects larynx to bronchi
what is commonly called the windpipe?
trachea
where is the trachea located?
anterior to the esophagus
how is the trachea supported?
16-20 C-shaped rings of hyaline cartilage
what do the tracheal cartilage do?
prevent collapse during inhalation
openings in the tracheal cartilage rings faces _____ toward the esophagus
posteriorly
what do the openings in the tracheal cartilage do?
allows the esophagus to expand as swallowed food passes by
what muscle spans the openings in the rings?
trachealis
what is the function of the trachealis?
contracts (parasym) or relaxes (sym) to adjust airflow
carina
lowest tracheal cartilage with an internal median ridge
the trachea is lined by…
ciliated pseudostratified columnar epithelium
the trachea has these three types of cells
mucus-secreting, ciliated, and stem cells
mucociliary escalator
mechanism for debris removal; mucus traps inhaled particles, and 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
what does a tracheotomy prevent?
asphyxiation due to upper airway obstruction
potential problems of a tracheotomy include: (3)
- inhaled air bypasses the nasal cavity and is not humidified
- if left for too long, will dry out mucous membranes
- became encrusted and interfere with clearance of mucus from the tract, thereby promoting infection
intubation
when a patient is on a ventilator, air is introduced directly into the trachea
what must happen to air being used in a intubation?
must be filtered and humidified to prevent respiratory tract damage
lung
a conical organ
base of the lung
broad, concave portion resting on the diaphragm
apex of the lung
tip that projects above the clavicle
costal surface of the lungs
pressed against the ribcage
mediastinal surface of the lungs
faces medially toward the heart
the hilum of the lung
slit through which the lungs receives the main bronchus, blood vessels, lymphatics, and nerves
structures near the hilum constitute the _____ of the lung
root
which lung has greater volume?
the right lung
why is the right lung shorter than the left?
because the liver rises higher on the right
three lobes of the right lung
superior, middle, and inferior lobes
horizontal fissure
separates the superior and middle lobes of the right lung
oblique fissure
separates the middle and inferior lobes of the right lung
why is the left lung tall and narrow?
the heart tilts toward the left and occupies more space on this side
cardiac impression
indentation to accommodate the heart in the left lung
two lobes of the heart
superior and inferior lobes
what are the two lobes of the left lung separated by?
a single oblique fissure
bronchial tree
a branching system of air tubes in each lung
which main bronchus is wider and more vertical?
the right
which bronchus has aspirated foreign object lodged in it more commonly?
the right
each bronchial tree extends from the _____ bronchus to ______ bronchioles
main, terminal
each main bronchi are divided into…
lobar (secondary) bronchi
a lobar bronchus serves…
each lobe of each lung
the left main bronchus gives off two branches…
superior and inferior lobar bronchi
the right main bronchus gives off three branches…
superior, middle, and inferior lobar bronchi
lobar bronchi branch into…
segmental (tertiary) bronchi
how many segmental bronchi are in the right lung?
10
how many segmental bronchi are in the left lung?
8
what are the main bronchi support by?
rings of hyaline cartilage
the hyaline cartilage supporting the main bronchi transition into…
crescent-shaped plates in the lobar and segmental bronchi
all bronchi are lined with…
ciliated pseudostratified columnar epithelium
cells grow shorter and the epithelium of the lungs thinner as you progress towards the _____
bronchioles
mucosa-associated lymphoid tissue (MALT)
lamina propria with an abundance of mucous glands and lymphoid nodules
all divisions of the bronchial tree have large amounts off….
elastic connective tissue
what does the elastic connective tissue of the bronchial tree contribute to?
recoil during respiration
the mucosa has a well-developed layer of smooth muscle called the….
muscularis mucosae
muscularis mucosae
contracts or relaxes to constrict or dilate the airway regulating air flow
bronchodilation
increase in diameter of bronchus or bronchiole
_____ and _____ stimulation increase airflow
epinephrine, sympathetic
bronchioconstriction
decrease in diameter of bronchus or bronchioles
what decreases airflow? (4)
- histamine
- parasympathetic nerves
- cold air
- chemical irritants
bronchioles
continuations of the airway that lack supportive cartilage and are 1mm or less in diameter
pulmonary lobule
portion of the lung ventilated by one bronchiole
bronchioles have these two things
- ciliated cuboidal epithelium
- well-developed layer of smooth muscle
each bronchiole branches into 50-80…
terminal bronchioles
what are the final branches of the conducting zone?
terminal bronchioles
terminal bronchioles lack…(2)
mucous glands and goblet cells
terminal bronchioles move mucous by…
cilia that move it by the mucociliary escalator
terminal bronchiole gives off two or more smaller _____ _____
respiratory bronchioles
respiratory bronchioles have _____ budding from their walls
alveoli
what is considered the beginning of the respiratory zone? why?
respiratory bronchioles because their alveoli participate in gas exchange
each respiratory bronchiole divides into 2-10 _____ _____
alveolar ducts
alveolar ducts
elongated, thin-walled passages with alveoli along their walls
alveolar ducts end in _____ _____
alveolar sacs
alveolar sacs
clusters of alveoli around an atrium (central space)
alveoli
microscopic air pouches in the lungs, each about .2-.5 mm in diameter
cells of alveoli (2)
- squamous (type I) alveolar cells
- great (type II) alveolar cells
- alveolar macrophages (dust cells)
squamous (type I) alveolar cells
thin cells that allow rapid gas diffusion between air and blood
what cell type covers 95% of alveolar surface area?
squamous (type i) alveolar cells
great (type II) alveolar cells
cuboidal cells that cover the remaining 5% of alveolar surfaces
what do great alveolar cells do?
repair the alveolar epithelium when squamous cells are damaged
what do type II alveolar cells secrete?
pulmonary surfactant
pulmonary surfactant (2)
- mixture of phospholipids and proteins that coats the alveoli and prevents them from collapsing during exhalation
- reduced surface tension of the alveoli
what is the most numerous cell in the lungs?
alveolar macrophages (dust cells)
what happens to dust cells after phagocytizing dust particles?
they ride up the mucociliary escalator to be swallowed and digested with their debris
alveolar macrophages (dust cells)
keep alveoli free from debris by phagocytizing dust particles
where do alveolar macrophages wander?
lumens of alveoli and connective tissue between them
respiratory membrane
thin barrier between the alveolar air and blood
each alveolus is surrounded by..
a basket of capillaries supplied by the pulmonary artery
three layers of the respiratory membrane
- squamous alveolar cells
- endothelial cells of blood capillaries
- their shared basement membranes (between the alveolar cells and capillary endothelium)
lungs receive both ____ and ____ blood supplies
pulmonary, systemic
pulmonary circuit pathway (5)
pulmonary trunk –> pulmonary arteries –> lobar arteries –> capillaries surrounding alveoli –> pulmonary veins
what does the pulmonary circuit serve to do? (2)
(1) unload CO2 from blood so it can be exhaled and (2) pick up O2 from inhaled air
where does gas exchange occur?
the respiratory membrane
systemic blood supply to the lungs includes (2)
- bronchial arteries
- bronchial veins
bronchial arteries
arise from aorta, supply lung tissue with blood
bronchial veins
drain blood from the lungs to the azygos vein of the thorax
right to left shunt (lungs)
some bronchial venous blood mixes with pulmonary venous blood, diluting the O2 content somewhat before it reaches the left atrium
why is it important to prevent fluid build up in the lungs?
gasses diffused too slowly through liquid to sufficiently aerate the blood
how do the lungs prevent fluid build up? (3)
- alveoli are kept dry by lower blood pressure in capillaries
- reabsorption overrides filtration and keeps alveoli free of excess fluid
- lungs have more extensive lymphatic drainage than any other organ in the body
pleura
serous membrane that lines the thoracic wall and forms the surface of the lung
visceral pleura
forms the surface of the lung
parietal pleura
adhere to the mediastinum, inner surface of the rib cage, and superior surface of the diaphragm
pleural cavity
potential space between pleurae
is there normally space between the membranes of the pleura?
no, but it contains a film of slippery pleural fluid
pleural effusion
pathological seepage of fluid in the pleural cavity
causes of pleural effusion (3)
- congestive heart failure
- pneumonia
- pulmonary embolism
functions of pleurae and pleural fluid (3)
- reduce friction
- creation of a pressure gradient
- compartmentalization
functions of pleurae and pleural fluid: reduced friction
allows lungs to move with minimal friction
functions of pleurae and pleural fluid: creation of a pressure gradient
pressure gradient to assist with lung inflation
functions of pleurae and pleural fluid: compartmentalization
prevents spread of infection from one organ in the mediastinum to others
breathing is a repetitive cycle of _____ and _____
inspiration, expiration
respiratory cycle
one complete breath, inspiration and expiration
quiet respiration
breathing while at rest, effortless and automatic
forced respiration
deep or rapid breathing, such as during exercise or playing an instrument
flow of air in and out of lungs depends on…
a pressure difference between air within the lungs and outside the body
respiratory muscles do what?
change lung volume and create differences in pressure relative to the atmosphere
principal muscles of respiration (2)
diaphragm and intercostal muscles
who is the prime mover of respiration?
the diaphragm
what happens when the diaphragm contracts? (2)
- flattens the diaphragm
- enlarges the thoracic cavity and pulls air into the lungs
what happens when the diaphragm relaxes? (2)
- allows diaphragm to bulge upward again
- compresses the lungs and pushes air out
what accounts for two-thirds of airflow?
the diaphragm
what assists the diaphragm in respiration?
internal and external intercostal muscles
what contribute to the enlargement and contraction of the thoracic cage during respiration?
internal and external intercostal muscles
what contributes to the remaining third of airflow in the lungs?
internal and external intercostal muscles
accessory muscles of respiration act mainly in _____ respiration
forced
deep inspiration also uses these muscles (4)
- sternocleidomastoid
- scalenes
- pectoralis minor
- serratus anterior
normal quiet inspiration uses…(2)
the diaphragm and external intercostal muscles
normal quiet expiration uses…(2)
- nothing
- energy saving passive process achieved by the elasticity of the lungs and thoracic cage
forced expiration uses these muscles (2)
- rectus abdominis
- internal intercostals
forced expiration (2)
(1) greatly increased abdominal pressure pushing viscera up against the diaphragm, (2) increasing thoracic pressure, forcing air out
