Exam 2: 20 Feb 25 Anatomy And Function Of The Respiratory System Flashcards
What is the diaphragm’s role in the respiratory system?
The diaphragm’s contraction creates negative pressure, drawing air into the lungs
The diaphragm is the main muscle of ventilation and has two leaflets that work together.
Why is the right lung larger than the left lung?
The right lung is slightly larger due to the space taken up by the heart
The heart’s position creates a cardiac notch in the left lung.
What are the two types of pleura surrounding the lungs?
- Visceral pleura
- Parietal pleura
Visceral pleura covers the lungs, while parietal pleura lines the thoracic cavity.
What is tidal volume?
Tidal volume is 500 cc
It represents the amount of air inhaled or exhaled during normal breathing.
Define functional residual capacity (FRC).
Functional residual capacity is 3 liters
FRC is the volume of air remaining in the lungs after a normal expiration.
What is the normal respiratory rate?
The normal respiratory rate is 12 breaths per minute
This rate can vary based on age, fitness, and health status.
What is transpulmonary pressure?
Transpulmonary pressure is the difference between alveolar pressure and intrapleural pressure
It is crucial for maintaining lung inflation.
List the three perfusion zones in the lungs.
- Zone one (always off)
- Zone two (intermittent)
- Zone three (continuous)
Zone four is mentioned but not universally accepted.
What happens during positive pressure ventilation?
Increased alveolar pressure can compress blood vessels, affecting blood flow distribution
It may increase workload on the right side of the heart.
What is the role of accessory muscles in ventilation?
Accessory muscles assist the diaphragm during stress or exercise
These include scalene muscles and intercostal muscles.
Fill in the blank: The respiratory cycle involves a _______ second inspiration and a _______ second expiration.
4; 4
There is typically a 1-second pause in between breaths.
What is atelectasis?
Atelectasis refers to lung collapse
It can occur due to blockage of air passages or pressure from outside the lung.
Explain the importance of arterial and alveolar variables in blood gas analysis.
Understanding these variables is crucial for assessing gas exchange and respiratory function
They help in diagnosing conditions like hypoxia and hypercapnia.
True or False: The diaphragm is the only muscle involved in ventilation.
False
While the diaphragm is the main muscle, accessory muscles also assist during increased demand.
What is the significance of the central tendon of the diaphragm?
The central tendon supports the heart and provides a platform for diaphragm movement
It is made of connective tissue and does not attach to bone.
What are some terms related to breathing difficulties?
- Dyspnea
- Apnea
- Stridor
- Orthopnea
These terms describe various respiratory conditions and symptoms.
What is the primary function of the phrenic nerve?
The phrenic nerve innervates the diaphragm
It originates from the cervical plexus and is essential for breathing.
What is the role of gravity in lung perfusion?
Gravity affects blood flow distribution, with higher blood flow in lower lung regions
This is important for efficient gas exchange.
Fill in the blank: The normal intrapleural pressure is _______ cm H2O.
-5
This negative pressure is essential for lung inflation.
What are the major lung volumes and capacities?
- Tidal volume
- Total lung capacity
- Vital capacity
- Functional residual capacity
These measurements are important for pulmonary function tests.
What are the main plexuses involved in regional anesthesia?
Cervical plexus and brachial plexus
These plexuses consist of large groups of nerves located in the neck and shoulder area.
What is one reason for using regional blocks in anesthesia?
To minimize opioid use and avoid general anesthesia in patients unfit for it
Patients with compromised lung function may not tolerate general anesthesia well.
What is a major concern when performing regional anesthesia in the neck area?
Risk of affecting the phrenic nerve
The phrenic nerve is crucial for diaphragm function and breathing.
How many generations of airways are there in the respiratory system?
About 24 generations
Starting from the trachea (generation zero) to the alveoli.
What is the primary function of bronchioles?
Conducting air without gas exchange
Bronchioles are part of the conducting zone in the respiratory system.
What term describes the zones where gas exchange occurs in the respiratory system?
Respiratory zones
This includes alveoli and terminal alveolar sacs.
Fill in the blank: The term ________ describes a person not breathing at all.
Apneic
What does the term dyspnea refer to?
Respiratory distress or feeling of not getting enough air
It is commonly experienced in various respiratory conditions.
What is the definition of orthopnea?
Difficulty breathing when lying down
Patients may breathe normally in an upright position but struggle when supine.
True or False: Hyperventilation refers to insufficient ventilation for metabolic demands.
False
Hyperventilation is excessive ventilation beyond metabolic needs.
What is cyanosis and what does it indicate?
A bluish discoloration due to deoxyhemoglobin
It indicates a significant amount of deoxygenated hemoglobin in the blood.
What do hypoxia and hypoxemia describe?
Hypoxia refers to low oxygen at the tissue level; hypoxemia refers to low oxygen in the arterial blood
Hypoxia is localized, while hypoxemia is a systemic issue.
What does the term atelectasis refer to?
Collapse of a portion or region of a lung
It can occur due to infection or other respiratory issues.
What unit is used to measure intrathoracic pressure?
Centimeters of water
This unit provides greater resolution for low thoracic pressures compared to millimeters of mercury.
How is the content of oxygen in arterial blood measured?
Oxygen content includes both oxygen attached to hemoglobin and dissolved in solution
Normal arterial blood has about 20 mls of O2 per deciliter.
Fill in the blank: The abbreviation for arterial blood gas is ________.
PaO2
What does the term compliance refer to in respiratory physiology?
The ability of lung tissue to stretch and expand
High compliance indicates easier expansion, while low compliance indicates stiffness.
What is the tidal volume for a typical adult during normal breathing?
About half a liter
This is the amount of air inhaled or exhaled during a normal breath.
What is the relationship between compliance and elastance?
Compliance is inversely related to elastance
Low compliance indicates high elastance and vice versa.
What is the normal tidal volume for a healthy adult?
Half a liter
Tidal volume refers to the amount of air that goes in and out with each breath.
What is the total lung capacity for a healthy adult?
Six liters
This is the maximum amount of air the lungs can hold.
How much air does each lung hold in a healthy adult?
Three liters
Total lung capacity is divided between the two lungs.
Define functional residual capacity (FRC).
Three liters
FRC is the amount of air remaining in the lungs after a normal expiration.
What happens to the air in the lungs when a person holds their breath?
They can hold their breath for a couple of minutes due to the reservoir of air in the lungs
This air helps stabilize blood gases.
What is the expiratory reserve volume (ERV) for a healthy 20-year-old?
One and a half liters
ERV is the volume of air that can be forcibly exhaled after a normal tidal expiration.
What is the residual volume (RV)?
One and a half liters
RV is the amount of air that remains in the lungs after maximal exhalation.
What is the inspiratory reserve volume (IRV) for a healthy 20-year-old?
Two and a half liters
IRV is the amount of air that can be inhaled beyond a normal tidal volume.
Define vital capacity.
The total amount of air that can be exhaled after a maximal inhalation
This includes tidal volume, ERV, and IRV.
What is the inspiratory capacity (IC)?
Three liters
IC is the maximum amount of air that can be inhaled from the end of a normal expiration.
What is the normal respiratory rate for a healthy adult?
12 breaths per minute
This rate is based on a respiratory cycle lasting five seconds.
What is the thoracic pressure in between breaths?
Negative five centimeters of water
This pressure helps facilitate the inflow of air during inspiration.
During inspiration, what happens to thoracic pressure?
It drops to negative seven and a half centimeters of water
This creates a vacuum that pulls air into the lungs.
How long does a normal respiratory cycle take?
Five seconds
This includes two seconds for inspiration, two seconds for expiration, and one second in between.
What is the flow rate of inspired air at its peak during a normal breath?
Point five liters per second
This occurs at the halfway point of inspiration.
What happens to the air flow rate during expiration?
It peaks at the halfway point and then tapers off
Expired air flow is measured as positive.
What is atelectasis?
Collapse of regions of the lungs
This can occur when lung volumes are too low.
FRC is a combination of which two volumes?
Expiratory reserve volume (ERV) and residual volume (RV)
FRC is essential for maintaining stable blood gases.
What is the role of the three liters of air in the lungs?
Helps stabilize blood gases and holds airways open
This reservoir is critical for efficient gas exchange.
What occurs to lung volumes when a person lies down?
Some air is squeezed out of the lungs
This is due to the weight of the stomach pushing the diaphragm up.
What happens to pressure during inspiration?
Pressure decreases, pulling air into the chest.
This process occurs over the course of two seconds.
When does peak air flow inspiration rate occur?
Halfway into inspiration, at the one second mark.
This corresponds to the point where alveolar pressure is the lowest.
What is the alveolar pressure at one second into inspiration?
Negative one centimeter of water.
It starts at zero and goes negative before returning to zero.
What happens to alveolar pressure during normal breathing?
It is zero centimeters of water between breaths.
This is in comparison to the outside environment.
What occurs when the diaphragm contracts?
Alveolar pressure becomes more negative, pulling air into the lungs.
The pressure starts off at negative five and becomes more negative.
What is transpulmonary pressure?
The difference between pleural pressure and alveolar pressure.
It is a key factor in determining airflow into the lungs.
What happens during expiration?
The diaphragm relaxes, making alveolar pressure positive, pushing air out.
This process relies on the elastic recoil of lung tissue.
What is the role of elastic recoil in expiration?
It helps push air out of the lungs without using muscle effort.
Abnormal amounts of recoil can lead to breathing difficulties.
When does expired air flow rate peak?
About halfway through expiration.
This corresponds to the highest alveolar pressure.
What are the three zones of pulmonary blood flow?
Zone 1: No blood flow, Zone 2: Intermittent blood flow, Zone 3: Continuous blood flow.
These zones are influenced by gravity and vascular pressures.
What characterizes Zone 2 of lung perfusion?
Intermittent blood flow depending on pulmonary blood pressure.
Arterial pressure is greater than alveolar pressure, which is greater than venous pressure.
What is the condition for Zone 3 blood flow?
Continuous blood flow throughout the cardiac cycle.
Arterial pressure is always higher than venous and alveolar pressures.
What happens in Zone 1 of lung perfusion?
There is no blood flow.
This occurs in healthy individuals; in unhealthy individuals, Zone 1 may exist.
What happens when the pressures in the lungs equilibrate during inspiration?
Alveolar pressure returns to zero.
This occurs after air is sucked into the lungs.
What is the significance of transpulmonary pressure?
It determines airflow into the lungs.
Transpulmonary pressure is affected by pleural pressure.
True or False: The alveolar pressure is always lower than the environmental pressure during inspiration.
True.
This negative pressure is what allows air to be sucked into the lungs.
Fill in the blank: The tidal volume is abbreviated as _______.
VT
Tidal volume refers to the amount of air inhaled or exhaled in a normal breath.
What is the effect of gravity on lung perfusion?
It determines which parts of the lungs receive the most blood flow.
Blood flow is typically higher at the base of the lung.
What is the primary risk location for zone one blood flow in the lung?
The top of the lung
This area has lower vascular pressures, making perfusion more difficult.
What conditions define zone one in terms of blood flow?
If alveolar pressure is higher than both arterial and venous blood pressures
This causes capillaries to be compressed, preventing blood flow.
What effect does positive pressure ventilation have on lung blood flow?
It can compress blood vessels, increasing workload on the right side of the heart
This can lead to altered blood flow distribution patterns.
How does blood flow through the lung vary by location?
Higher blood flow occurs further down in the lung
This is due to higher vascular pressure and lower pulmonary vascular resistance.
What is the average blood flow rate through the lungs?
Five liters per minute
Most of this blood flow occurs in the lower parts of the lung.
What is zone four in the context of lung perfusion?
An area at the very base of the lung where blood flow is slightly less due to vessel compression from gravity
This zone is sometimes not included in all textbooks.
What happens to blood flow at the base of the lung due to gravity?
There is slightly less blood flow due to compression of blood vessels
This phenomenon is referred to as zone four.
What is the typical fluctuation of alveolar pressure during normal breathing?
Fluctuates between negative one and one centimeter of water
This fluctuation creates a range around zero during normal breathing.
True or False: The lungs are suspended in the chest and supported at the base.
True
This description highlights the anatomical relationship between the lungs and the diaphragm.
In what position is the risk for zone one blood flow highest?
Upright position
This position leads to lower vascular pressures at the top of the lungs.
Fill in the blank: The average blood flow through the lungs is _______ liters per minute.
five
What is the primary function of the cardiopulmonary system?
To facilitate gas exchange between the body and the environment
This involves the lungs for oxygen intake and carbon dioxide removal.
What anatomical structures are involved in the cardiopulmonary system?
Heart and lungs
The heart pumps blood, while the lungs facilitate gas exchange.
What is the role of the diaphragm in respiration?
To assist in the expansion and contraction of the lungs
The diaphragm is a major muscle involved in breathing.
Which muscles are primarily responsible for inspiration?
Scalene muscles
The scalene muscles include anterior, middle, and posterior scalene.
What are the key respiratory terms related to breathing patterns?
- Eupnea
- Dyspnea
- Apnea
- Stridor
- Bradypnea
- Tachypnea
- Orthopnea
- Hyperpnea
- Hyperventilation
These terms describe various states of breathing.
What does hypoxia refer to?
Decreased amount of O2 at the level of a tissue
This condition can lead to cellular dysfunction.
What is the significance of pulmonary vascular resistance (PVR)?
It affects pulmonary blood flow and gas exchange efficiency
PVR is influenced by factors like blood vessel recruitment and distention.
What is atelectasis?
Collapse of functional lung units
This condition can occur due to various reasons, including obstruction or fluid accumulation.
What is the normal value for alveolar ventilation?
4,200 mL/minute
This value indicates the amount of fresh air reaching the alveoli per minute.
What is the formula for transpulmonary pressure?
P_TP = P_A - P_IP
This equation helps to understand lung inflation.
What are the West perfusion zones?
- Zone 1: Always off
- Zone 2: Always on
- Zone 3: In-between
These zones describe the distribution of blood flow in the lungs.
What does hypercapnia indicate?
Excessive CO2 in blood (arterial)
This condition can result from respiratory failure or hypoventilation.
What is the primary role of hypoxic pulmonary vasoconstriction (HPV)?
To redirect blood flow away from underventilated alveoli
This mechanism is unique compared to other vascular beds.
Fill in the blank: The partial pressure of oxygen in dry atmospheric gas is approximately _______.
159.0 mmHg
This value is based on the concentration of oxygen in the atmosphere.
What is the significance of the Starling capillary equation?
It describes the forces governing fluid movement across capillary membranes
This equation is important for understanding pulmonary capillary dynamics.
What is the normal alveolar P_AO2?
100 mmHg
This reflects the oxygen pressure in the alveoli after equilibration.
True or False: Alveolar compliance is typically higher at the top of the lung than at the bottom.
False
Alveolar compliance is generally lower at the top due to gravity effects.
What are the main components of laryngeal cartilage?
- Hyoid Bone
- Thyroid Cartilage
- Cricoid Cartilage
- Epiglottis
These structures provide support and flexibility to the larynx.
What is the definition of hyperoxia?
O2 levels above normal in tissues/organs
This condition can lead to oxygen toxicity if excessive.
What is a key function of the interstitial hydrostatic pressures?
Regulates fluid movement in and out of capillaries
This is influenced by atmospheric pressure and other factors.
