Chapter 22: Respiratory Flashcards
The respiratory system consists of what?
A system of tubes that delivers air to the lungs
What two systems work together to deliver oxygen to the tissues and remove carbon dioxide?
Respiratory and cardiovascular
What two systems collaborate to regulate the body’s acid–base balance?
Respiratory and urinary systems
List the 8 main functions of respiration
1) Gas exchange
2) Communication
3) Olfaction
4) Acid-Base balance
5) Blood pressure regulation
6) Blood and lymph flow
7) Blood filtration
8) Expulsion of abdominal contents
Describe the purposes of the first 4 functions of respiration: gas exchange, communication, olfaction, and acid-base balance
1) Gas exchange: O2 and CO2 exchanged between blood and air
2) Communication: speech and other vocalizations
3) Olfaction: sense of smell
4) Acid-Base balance: influences pH of body fluids by eliminating CO2
Describe the purposes of the last 4 functions of respiration: blood pressure regulation, blood and lymph flow, blood filtration, and expulsion of abdominal contents
1) Blood pressure regulation: help make angiotensin II
2) Blood and lymph flow: breathing creates pressure gradients
3) Blood filtration: lungs filter small clots
4) Expulsion of abdominal contents: breath-holding assists in urination, defecation, and childbirth(Valsalva maneuver)
List and describe 4 main zones of the respiratory system
1) Conducting zone of respiratory system: Nostrils through bronchioles
2) Respiratory zone: consists of alveoli and other gas exchange regions
3) Upper respiratory tract: in head and neck
4) Lower respiratory tract: organs of the thorax
Describe the conducting zone of the respiratory system
-Includes those passages that serve only for airflow
-No gas exchange
-Nostrils through major bronchioles
What are the 3 functions of the nose?
1) Warms, cleanses, and humidifies inhaled air
2) Detects odors
3) Serves as a resonating chamber that amplifies voice
Where does the nose begin and end? What is the nose shaped by?
1) Nose extends from nostrils (nares) to posterior nasal apertures (choanae)
2) Shaped by bone and hyaline cartilage
What divides the nasal cavity?
Nasal septum
What are the features of the nasal cavity?
Superior, middle, and inferior nasal conchae, each with a meatus beneath it
Define meatus and describe its purposes
-Defined as a narrow air passage beneath each concha of the nasal cavity
-Its narrowness and turbulence ensure that most air contacts mucous membranes
-Cleans, warms, and moistens the air
What type of tissue lines most of the nasal cavity?
Respiratory epithelium; specifically ciliated pseudostratified columnar epithelium
Describe mucous formation and movement in the nose
(what creates it and what propels it)
Goblet cells secrete mucus and cilia propel the mucus posteriorly toward pharynx; then swallowed
What are the 3 regions of the pharynx?
1) Nasopharynx
2) Oropharynx
3) Laryngopharynx
Describe the nasopharynx (what is it, what does it contain, and what does it do?)
1) Posterior to nasal apertures and above soft palate
2) Receives auditory tubes and contains the pharyngeal tonsil
3) Passes only air, lined with pseudostratified columnar epithelium
Describe the oropharynx (where is it, what does it contain, and what does it do?)
1) The space between soft palate and epiglottis
2) Contains lingual and palatine tonsils
3) Passes air, food, and drink and is lined by stratified squamous epithelium
Describe the laryngopharynx (where is it, what begins there, what does it do?)
1) From the epiglottis to cricoid cartilage
2) Esophagus begins at that point
3) Passes air, food, and drink and is lined by stratified squamous epithelium
What region(s) of the pharynx passes only air and is lined by pseudostratified columnar epithelium?
Nasopharynx
What region(s) of the pharynx pass air, food, and drink and are lined by stratified squamous ?
Oropharynx and laryngopharynx
Muscles of the pharynx assist in what two functions?
Swallowing and speech
Define the larynx (voice box) and its primary function
1) A cartilaginous chamber about 4 cm (1.5 in.) long
2) Its primary function is to keep food and drink out of the airway and sound production
What are the two structures found in the larynx?
Epiglottis and vestibular folds of the larynx
Define the epiglottis
A flap of tissue that closes airway and directs food to esophagus behind it
What do the vestibular folds of the larynx do?
Play greater role in keeping food and drink out of the airway
How many cartilages make up the framework for the larynx?
9 (6 paired and 3 unpaired)
List and describe the 3 solitary and relatively large cartilages of the larynx
1) Epiglottic cartilage: spoon-shaped supportive plate in epiglottis; most superior one
2) Thyroid cartilage: largest, laryngeal prominence (Adam’s apple); shield-shaped
-Testosterone stimulates growth, larger in males
3) Cricoid cartilage: connects larynx to trachea, ring-like
List the 3 small pairs of cartilages found in the larynx
1) Arytenoid cartilages (2)
2) Corniculate cartilages (2)
3) Cuneiform cartilages (2)
Ligaments suspends larynx from the _____ and hold it together
hyoid
The interior wall of the larynx has two folds on each side; name them
1) Superior vestibular folds
2) Inferior vocal cords
Describe the superior vestibular folds
-Play no role in speech
-Close the larynx during swallowing
Describe the inferior vocal cords
-Produce sound when air passes between them
-Covered with stratified squamous epithelium
-Glottis: the vocal cords and the opening between them
Define glottis
the vocal cords and the opening between them
Describe sound production in the larynx (what causes it, what happens when cords are taut and slack?)
1) Air is forced between vocal cords, it vibrates them
-When cords are taut, high-pitched sounds
-When cords are slack, low-pitched sounds
Why do adult males have lower voices?
-Adult male vocal cords are usually longer and thicker
-Vibrate more slowly, which means lower-pitched sounds
What is loudness of a voice determined by?
The force of air passing between the vocal cords
Define and describe the trachea (what is it, where is it, what supports it?)
1) A rigid tube about 12 cm (4.5 in.) long and 2.5 cm (1 in.) in diameter
2) Anterior to esophagus
3) Supported by 16 to 20 C-shaped rings of hyaline (*) cartilage that prevent collapse
Describe why the C-shaped rings of the trachea are shaped the way they are
-The opening in the rings faces posteriorly toward esophagus
-This gap in the C allows room for the esophagus to expand as swallowed food passes by
What are the 3 layers of the trachea?
1) Mucosa
2) Middle tracheal layer (submucosa)
3) Adventitia
Describe the mucosa layer of the trachea
-Made of ciliated pseudostratified columnar epithelium
-Mucociliary escalator
What happens at the end of the trachea?
End of trachea forks into right and left main (primary) bronchi.
Define the base and apex of a lung
1) Base: broad concave portion resting on diaphragm
2) Apex: tip that projects just above the clavicle
Define the costal and mediastinal surfaces of the lungs
1) Costal surface: pressed against the ribcage
2) Mediastinal surface: faces medially toward the heart
Define the hilum and describe it (what surface is it on and what is it, and what does its general area make up?)
-A slit on the mediastinal surface through which the lung receives the main bronchus, blood vessels, lymphatics, and nerves
-These structures near the hilum constitute the root of the lung
Describe the shape of the right lung and list its lobes
1) Shorter than left lobe
2) Has three lobes: superior, middle, and inferior
-separated by horizontal and oblique fissure
Describe the shape of the left lung, name and describe its indentation, and list its lobes
1) Tall and narrow
2) Has an indentation called cardiac impression (cardiac notch is anterior portion of cardiac impression)
3) Has two lobes: superior and inferior
-separated by a single oblique fissure
List the order of airflow of the bronchial tree (8 steps)
1) Trachea
2) Primary (Main) Bronchi
3) Secondary (Lobar) Bronchi
4) Tertiary (Segmental) Bronchi
5) Bronchioles (smaller than 1 mm in diameter)
6) Terminal Bronchioles (end of conducting division)
7) Respiratory Bronchioles (start of respiratory division)
8) Alveolar ducts to Alveoli
Define the bronchial tree
A branching system of air tubes reaching from main bronchus to 65,000 terminal bronchioles
Describe the main (primary) bronchi and the differences between the right and left
-Main bronchi enter the lungs and are supported by C-shaped hyaline cartilage rings
-The right main bronchus slightly wider and more vertical than left
-Aspirated (inhaled) foreign objects are lodged in the right main bronchus more often than in the left
Describe the lobular (secondary) bronchi (what do they enter, what supports them, and how many right and left lobes?)
-They enter the lobes and are supported by cartilage plates
-Three right lobar (secondary) bronchi: superior, middle, and inferior
-Two left lobar bronchi: superior and inferior
Name the left and right secondary bronchi
-Three right lobar (secondary) bronchi: superior, middle, and inferior
-Two left lobar bronchi: superior and inferior
Describe the segmental (tertiary) bronchi (what do they enter and are supported by, how many are there on each side, and what’s a feature of these bronchi?)
1) They enter segments and are supported by cartilage plates
2) 10 on right, 8 on left
3) Bronchopulmonary segment: functionally independent unit of the lung tissue
Define the bronchopulmonary segment
A functionally independent unit of the lung tissue associated with the segmental (tertiary) bronchi
Describe all bronchi in general (what are they lined with, what do they all have, and what regulates their airflow?)
-All bronchi are lined with ciliated pseudostratified columnar epithelium
-Have MALT (mucosa-associated lymphoid tissue)
-Have a large amount of elastic connective tissue that contributes to the recoil that expels air from lungs
-Smooth muscle layer regulates airflow
What does the pulmonary artery do? What does the bronchial artery do?
1) Pulmonary artery branches follow the bronchial tree on their way toward (*) the alveoli
2) Bronchial artery from aorta services bronchial tree with systemic blood
Describe bronchioles
-1 mm or less in diameter
-Each bronchiole enter a Pulmonary lobule
-No cartilage support
-Divides into 50 to 80 terminal bronchioles
Describe terminal bronchioles
-Final branches of conducting zone
-Have no mucous glands or goblet cells but still have cilia
-Each terminal bronchiole gives off two or more smaller respiratory bronchioles
Describe the respiratory bronchioles and what they end in
-Have alveoli budding from their walls
-Considered the beginning of the respiratory zone
-Divide into 2 to 10 alveolar ducts
-End in alveolar sacs
There are ___ ________ alveoli in each lung, providing about ____ m2 of surface for gas exchange
150 million; 70m2
What are the 3 types of alveoli cells?
1) Squamous (type I) alveolar cells
2) Great (type II) alveolar cells
3) Alveolar macrophages (dust cells)
Describe squamous (type 1) alveolar cells
-Thin cells that allow for rapid gas diffusion between alveolus and bloodstream
-Cover 95% of alveolus surface area
Describe great (type II) alveolar cells
-Round to cuboidal cells that cover the remaining 5% of alveolar surface
-Repair the alveolar epithelium when the squamous (type I) cells are damaged
-Secrete pulmonary surfactant
Describe alveolar macrophages (dust cells)
-Wander the lumens of alveoli and the connective tissue between them
-Keep alveoli free from debris by phagocytizing dust particles
-100 million dust cells die each day as they ride up the mucociliary escalator to be swallowed and digested
Each alveolus surrounded by a basket of capillaries is supplied by the ________ artery
pulmonary
Define the respiratory membrane of alveoli and list the 4 things it’s made of
-A thin barrier between the alveolar air and blood.
-Consists of:
1) Squamous alveolar cells
2) Endothelial cells of blood capillary
3) Their shared basement membrane
4) Very thin film of moisture inside the alveolus
What is important to prevent in alveoli?
-Important to prevent fluid from accumulating in alveoli
-Gases diffuse too slowly through liquid to sufficiently aerate the blood
In what 3 ways does the body prevent excess fluid from building up in the alveoli?
1) Low capillary blood pressure (and overall low pulmonary circuit blood pressure) results in low filtration; prevents rupture of delicate respiratory membrane
2) Excess liquid easily reabsorbed by blood capillaries
3) Lungs have a more extensive lymphatic drainage than any other organ in the body
What are the two pleurae of the lungs called and where are they? What is the potential space between them called?
1) Visceral pleura: serous membrane that covers lungs
2) Parietal pleura: adheres to mediastinum, inner surface of the rib cage, and superior surface of the diaphragm
-Pleural cavity: potential space between pleurae
Describe the pleural cavity
It’s a potential space between the pleurae; normally no room between the membranes, but contains a film of slippery pleural fluid
Name and describe the 3 functions of pleurae and pleural fluid
1) Reduce friction
2) Create pressure gradient
-Lower pressure than atmospheric pressure; allows the two layers to stick to each other (assists lung inflation)
3) Compartmentalization
-Prevents spread of infection from one organ to another
Define a respiratory cycle
One complete inspiration (inhaling) and expiration (exhaling)
What are the two main types of respiration?
Quiet respiration vs. Forced respiration
Flow of air in and out of lung depends on there being what?
A pressure difference between air within lungs and outside body
What do respiratory muscles do? (2 things)
1) Change lung volumes
2) Create differences in pressure
Name the prime mover and synergists of inhalation
1) Prime mover: Diaphragm
2) Synergists: External intercostals and scalenes
What muscle is responsible for approximately 66-75% of inhalation?
Diaphragm