Chapter 23 - The Respiratory System - Part 2 Flashcards
What are the 3 large extrapulmonary airways associated with the lungs?
the trachea, and the right and left primary bronchi
The trachea is also known as….
the windpipe
The trachea branches at the T5 vertebra to form…
the right and left primary bronchi
The epithelium of the trachea is continuous with that of the….
larynx
What is the function of the tracheal cartilages?
to stiffen the tracheal walls and protect the airway. they prevent the trachea from collapsing or overexpanding as pressures change in the respiratory system
Each tracheal cartilage is ___ shaped
C
Are the tracheal cartilages continuous?
no
WHY are the tracheal cartilages not continuous?
so that the posterior tracheal wall can easily distort when you swallow, allowing large masses of food to pass through the esophagus
Trachealis muscle is a band of what kind of muscle?
smooth muscle
trachealis muscle along with a _____ connect…..
elastic ligament connect each end of tracheal cartilage
Contraction of the trachealis muscle ______ the diameter of the trachea
reduces
Contraction of the trachealis muscle ______ the diameter of the trachea
reduces
This narrowing of the trachea does what?
increases the tube’s resistance to airflow
Sympathetic stimulation ______ the diameter of the trachea
increases
Sympathetic stimulation increases the diameter of the trachea. What does this help with?
makes it easier to move large volumes of air along the respiratory passageways
The trachea branches within the ____ and into the ______
the trachea branches within the MEDIASTINUM and into the LEFT AND RIGHT PRIMARY BRONCHI
what structure separates the right and left primary bronchi?
An internal ridge called the carina
Like the trachea, the primary bronchi contain C shaped rings. But what is the difference?
in the primary bronchi, the C shaped rings overlap and they dont overlap in the trachea
The right primary bronchus supplies the ____ while the left primary bronchus supplies the ____
right lung, left lung
Which is larger in diameter - the right or left primary bronchus?
the right primary bronchus is larger in diameter
Since the right primary bronchus is larger in diameter than the left, what function does it serve?
most foreign objects find their way into the right bronchus rather than the left
What is the name of the groove which provides access for entry for the pulmonary vessels, nerves, and lymphatics?
the hilium of the lung
List functions of the trachea
-transports air between the larynx and primary bronchi
-Cilia and the mucus produced by epithelial cells protect the respiratory tree by trapping inhaled debris and sweeping it towards the pharynx where it is removed through coughing or swallowing
Why are the cartilages that reinforce the trachea C-shaped?
To allow space for expansion of the esophagus when food or liquid is swallowed
If food accidentally enters the bronchi, in which bronchus is it more likely to lodge? why?
The right bronchus because it is slightly larger and more vertical than the left broncus
the right and left lungs are surrounded by the left and right….
pleural cavities
the lungs have distinct ____ that are separated by deep fissures
lobes
How many lobes does the right lung have?
3 - superior, middle, and inferior
The 3 lobes of the right lung are separated by..
the horizontal and oblique fissures
How many lobes does the LEFT lung have?
2 lobes - superior and inferior
The 2 lobes of the left lung are separated by…
the oblique fissure
Between the right and the left lung…
-Which is broader
-Which is longer
Explain why
broader = right lung because most of the heart and great vessels project into the left thoracic cavity
longer = left lung because the diaphram rises on the left side to accomodate the mass of the liver
the primary bronchi and their branches form the….
bronchial tree
Each TERTIARY bronchus branches several times within a bronchiopulmonary segment, forming many ______
bronchioles
Do the walls of bronchioles have cartilage?
NO
The walls of bronchioles are dominated by.,
smooth muscle tissue
In functional terms, bronchioles are to the respiratory system as….
arterioles are to the cardiovascular system
Changes in the diameter of the bronchioles control…
the resistance to airflow and the distribution of air in the lungs
What controls the diameter of the bronchioles?
the autonomic nervous system
SYMPATHETIC activation leads to….
bronchodilation
PARASYMPATHETIC stimulation leads to….
bronchoconstriction
Which takes place during allergy reactions such as anaphylaxis—
bronchodilation or bronchoconstriction?
bronchoconstriction
Anaphylaxis occurs in response to HISTAMINE which is released by which 2 cells?
mast cells and basophils
In which condition is there excessive stimulation of the smooth muscles which can almost completely prevent airflow along the terminal bronchioles?
asthma
Where does the “conducting zone” end?
at the terminal bronchioles
the alveoli are the “___ ____” found within the lungs
air sacs
Each alveolus is associated with an extensive network of _____ surrounded by a network of ____
Each alveolus is associated with an extensive network of CAPILLARIES surrounded by a network of ELASTIC FIBERS
What is the function of the elastic fibers that surround the network of capillaries?
to help maintain the relative positions of the alveoli and respiratory bronchioles.
When the elastic fibers recoil during exhalation, they reduce the size of the alveoli and help push air out of the lungs
What plays a key role in keeping the alveoli open?
surfactant
Where does gas exchange occur at the alveoli?
at the respiratory membrane
Alveolar macrophages are also called ___ cells
dust cells
Type 1 alveolar cells are sites of….
gas diffusion
Type 2 alveolar cells are also called…
septal cells
Which type of alveolar cell produces surfactant?
type 2
Surfactant _____ surface tension in the liquid coating the alveolar surface
reduces
Surface tension creates a…
barrier that keeps small objects from entering the water, but it also tends to collapse small air bubbles
Does surfactant keep the alveoli open or closed?
open and reduces the surface tension
Gas exchange occurs across the ______ of the alveoli
respiratory membrane
The respiratory membrane has ___ layers
3 layers
Name the 3 layers of the respiratory membrane
- Squamous epithelial cells lining the alveolus
- The endothelial cells lining an adjacent capillary
- The fused basement membranes that lie between the alveolar and endothelial cells
Why does diffusion proceed very rapidly across the respiratory membrane?
because the distance between alveolar air and blood is very short and oxygen and carbon dioxide are both very small, lipid-soluble molecules
Name the disease that causes an inflammation of the lobules of the lung which causes fluid to leak into the alveoli, and the respiratory bronchioles to swell
pneumonia
Give an example of when pneumonia would become more likely?
if the respiratory defenses have already been compromised by other factors
How many circuits nourish lung tissue?
2
one supplies the respiratory portion of the lungs and the other supplies the conducting portion of the lungs
What would happen to the alveoli if surfactant were not produced?
The alveoli would collapse as a result of surface tension in the thin layer of water that moistens the alveolar srfaces
Trace the path that air takes in flowing from the glottis to the respiratory membrane
Air passing through the glottis flows into the larynx and through the trachea. From there, air flows into a primary bronchus, which supplies the lungs. In the lungs, the air passes to bronchi, bronchioles, a terminal bronchiole, a respiratory bronchiole, an alveolar duct, an alveolar sac, an alveolus, and ultimately to the respiratory membrane
The respiratory exchange surfaces RECEIVE blood from…
arteries of the pulmonary circuit
Do the pulmonary arteries carry oxygenated or deoxygenated blood?
deoxygenated
the pulmonary veins deliver blood to …
the left atrium of the heart
What is the name for the main type of cell found in the inside lining of blood vessels, lymph vessels, and the heart?
endothelial cells
Endothelial cells of the alveolar capillaries provide for…
gas exchange
The endothelial cells of the alveolar capillaries are the primary source of…
ACE (angiotensin-converting enzyme)
What does ACE do?
converts angiotensin 1 to angiotensin 2. This enzyme plays an important role in regulating blood volume and blood pressure
Blood pressure in the PULMONARY CIRCUIT is usually…
low
Blood pressure in the pulmonary circuit is usually low. What could this lead to?
pulmonary vessels can easily become blocked by small blood clots, fat masses, or air bubbles in the pulmonary arteries
The entire cardiac output goes to…
the lungs
What does the term pulmonary embolism mean?
occurs when a large emboli gets stuck in an artery of the lung, stopping blood flow to a group of lobules or alveoli
What will happen if a pulmonary embolism is in place for several hours?
the alveoli will permanently collapse
What will happen if the blockage of a pulmonary embolism occurs in a major pulmonary vessel rather than a minor branch?
pulmonary resistance increases. This places extra strain on the right ventricle of the heart, which may be unable to maintain cardiac output, and congestive heart failure may result
the thoracic cavity has the shape of a…
broad cone
The walls of the thoracic cavity are the…
The floor of the thoracic cavity is the….
walls=the rib cage
floor=the muscular diaphragm
The 2 pleural cavities are separated by….
the mediastinum
each lung is surrounded by a single ____ cavity. Each ___ cavity is lined by a….
each lung is surrounded by a single PLEURAL CAVITY. each pleural cavity is lined by a serous membrane called the pleura
Describe the anatomy of the pleura serous membrane
2 layers
The parietal pleura covers the inner surface of the thoracic wall
the visceral pleura covers the outer surfaces of the lungs, extending into the fissures between the lobes
what is the anatomical relationship between the parietal pleura and visceral pleura?
they’re usually in close contact. PLEURAL FLUID is produced by both pleurae and provides lubrication and reduces friction between the parietal and visceral surface as we breathe
what is the term “thoracentesis”
the sampling procedure of obtaining samples of pleural fluid by inserting a long needle between the ribs
sample is examined for bacteria, blood cells, or abnormal components
what is the name for the painful condition in which the normal coating of pleural fluid does not prevent friction between the pleural surfaces?
pleurisy
Which arteries supply blood to the conducting portions and respiratory exchange surfaces of the lungs?
The pulmonary arteries supply blood to the exchange surfaces of the lungs. (pulmonary circulation)
The bronchial arteries, carotid arteries, and the thyrocervical trunks supply the conducting portion of the respiratory system (systemic circulation)
List the functions of the pleura
the pleura is a serous membrane that secretes pleural fluid, which lubricates the opposing parietal and visceral surfaces to prevent friction during breathing
explain the term “ventilation-perfusion coupling”
vasoconstriction occurs in response to hypoxia. this diverts blood from poorly ventilated areas to well ventilated areas
