Physiology Exam Review #4 Flashcards
What do all body processes directly or indirectly require?
ATP
What does most ATP synthesis require and produce?
Requires oxygen; produces carbon dioxide
A system of tubes that delivers air to the lungs
The respiratory system
Which gases diffuse into and out of the blood?
Oxygen diffuses into the blood, and carbon dioxide diffuses out
Which systems work together to deliver oxygen to the tissues and remove carbon dioxide?
Respiratory and cardiovascular systems - disorders of the lungs directly affect the heart and vice versa
What are the respiratory and cardiovascular systems considered jointly as?
The cardiopulmonary system
Which systems collaborate to regulate the body’s acid-base balance?
The respiratory and the urinary systems
A term used to refer to ventilation of the lungs (breathing)
Respiration
What are the functions of respiration?
- Gas exchange: oxygen and carbon dioxide exchanged between blood and air
- Communication: speech and other vocalizations
- Olfaction: sense of smell
- Acid-Base balance: influences pH of body fluids by eliminating carbon dioxide
- Blood pressure regulation: by helping in synthesis of angiotensin II
- Blood and lymph flow: breathing creates pressure gradients between thorax and abdomen that promote flow of lymph and blood
- Expulsion of abdominal contents: breath-holding assists in urination, defecation, and childbirth
Increasing pressure in the thorax cavity
Valsalva maneuver
Which zone gets air to the respiratory zone
The conducting zone
Which tract is in the head and neck (nose through larynx)
Upper respiratory tract
Which tract is in the thorax (trachea through major bronchioles)
Lower respiratory tract
Which zone is the site of gas exchange
Respiratory zone
The alveoli and respiratory bronchioles are located in which zone?
The respiratory zone
What are the functions of the conducting zone?
- Transports air to the respiratory zone
- Voice production in the larynx as air passes over the vocal folds
- Warms, humidifies, filters, and cleans the air
What does the mucus secreted by cells of the conducting zone do?
The mucus traps small particles
What is it called when mucus moves along the cilia that beat in a coordinated fashion to the pharynx - this is where it can be cleared by swallowing or expectorating
Mucociliary escalator
What is the process called when mucus is taken to the pharynx to be cleared by swallowing or expectorating
Mucociliary clearance
In which disease does the mucociliary escalator not function properly due to the fact that abnormal mucus is too thick for the cilia to properly clear
Cystic Fibrosis
Which preventable cause damages cilia and reduces mucociliary clearance
Smoking
These have air sacs in the lungs where gas exchange occurs
Alveoli
How many alveoli are there?
300 million
What is the purpose for having so many alveoli?
To provide a large surface area (760 square feet) to increase diffusion rate
What is one-cell layer thick but has great tensile strength (the ability to expand without ripping or popping)
Alveoli
What forms clusters at the ends of respiratory bronchioles
Alveoli
What keeps the alveoli clean
Resident macrophages - they may engulf carbon dust
Which type of alveolar cell has 95 to 97% surface area where gas exchange occurs
Type I
Which type of alveolar cell secretes pulmonary surfactant and reabsorbs sodium and water, preventing fluid buildup
Type II
Movement of air from higher to lower pressure, between the conducting zone and the terminal bronchioles, occurs as a result of what
The pressure difference between the two ends of the airways
Which cavity contains the heart, trachea, esophagus, and thymus within the central mediastinum
The thoracic cavity
What fills the rest of the thoracic cavity
The lungs
What lines the thoracic wall
The parietal pleura
What covers the lungs
The visceral pleura
What is the potential space between the parietal and visceral pleura
The intrapleural space
What contains a thin layer of fluid, secreted by the parietal pleura
The intrapleural space
What was formed as a filtrate from blood capillaries in the parietal pleura and is drained into lymphatic capillaries
The thin layer of fluid within the intrapleural space
What is the main function of the fluid within the intrapleural space
To serve as a lubricant so that the lungs can slide relative to the chest during breathing
A dome-shaped skeletal muscle of respiration that separates the thoracic and abdominal cavities
The diaphragm
Cavity below the diaphragm that contains the liver, pancreas, gastrointestinal tract, spleen, genitourinary tract, and other organs
The abdominopelvic cavity
Which physical property of the lungs allows them to expand when stretched, and ease to which they expand under pressure
Lung compliance
Which physical property of the lung is reduced by factors that produce a resistance to distention such as infiltration of connective tissue proteins in pulmonary fibrosis
Lung compliance
Which physical property of the lungs allow them to return to initial size after being stretched, and is the result of them to have lots of elastin fibers
Lung elasticity
Which physical property of the lung is always happening since they are stuck to the thoracic wall
Elastic tension
Tension ____ during inspiration and is ____ by elastic recoil during expiration
Increases, reduced
Which physical property of the lung is related to the resistance of distension and exerted by fluid secreted on the alveoli
Surface tension
- A surface active agent
- Secreted into the alveoli by type II alveolar cells
- Consists of hydrophobic protein and phospholipids
- Reduces surface tension between water molecules
- More concentrated as alveoli get smaller during expiration
- Prevents collapse
- Allows a residual volume of air to remain in lungs
Surfactant
Consists of a repetitive cycle of inspiration (inhaling) and expiration (exhaling)
Breathing (pulmonary ventilation)
One complete inspiration and expiration
Respiratory cycle
Type of respiration that happens at rest, is effortless, and automatic
Quiet respiration
Type of respiration that is deep, rapid breathing, such as during exercise
Forced respiration
What does the flow of air in and out of the lung depend on
Depends on a pressure difference between air within the lungs and outside the body
Which muscles change lung volumes and create difference in pressure relative to the atmosphere
The respiratory muscles
What is the prime mover of respiration
The diaphragm
___ flattens diaphragm, enlarging thoracic cavity and pulling air into lungs
Contraction
____ allows diaphragm to bulge upward again, compressing the lungs and expelling air
Relaxation
Which organ accounts for two-thirds of airflow
The diaphragm
Which muscles of respiration act mainly in forced respiration
Accessory muscles
An energy-saving passive process achieved by the elasticity of the lungs and thoracic cage
Normal quiet expiration
As muscles relax, structures recoil to original shape and original (smaller) size of thoracic cavity, which results in _____
airflow out of the lungs
What raises the pressure within the alveoli above the atmospheric pressure and pushes the air out
The decrease in lung volume
Greatly increased abdominal pressure pushes viscera up against diaphragm increasing thoracic pressure, forcing air out
Forced expiration
Which expiration is important for “abdominal breathing”
Forced expiration
Mechanisms of breathing - volume of thoracic cavity (and lungs) increases vertically when diaphragm contracts (flattens) and laterally when parasternal and external intercostals raise the ribs
Inspiration
If the thoracic and lung volume increase and then intrapulmonary pressure decreases, then air goes ___
in
Mechanisms of breathing - volume of thoracic cavity (and lungs) decreases vertically when diaphragm relaxes (dome) and laterally when external and parasternal intercostals relax for quiet expiration or internal intercostals contract in forced expiration to lower the ribs
Expiration
If the thoracic and lung volume decreases and then intrapulmonary pressure increases, then air goes ___
out
Subject breathes into and out of a device that records volume and frequency of air movement on a spirogram
Spirometry
What pulmonary function test can measure lung volume and capacities and can diagnose restrictive and obstructive lung disorders
Spirometry
Lung volume - amount of air expired or inspired in each breath of quiet breathing (normal/relaxed breathing)
Tidal volume
Lung volume - amount of air that can be forced out after tidal volume
Expiratory reserve volume
Lung volume - amount of air that can be forced in after tidal volume
Inspiratory reserve volume
Lung volume - amount of air left in lungs after maximum expiration
Residual volume
Lung capacity - maximum amount of air that can be forcefully exhaled after a maximum inhalation
Vital capacity
Lung capacity - amount of gas in the lungs after a maximum inspiration
Total lung capacity
Lung capacity - amount of gas that can be inspired after a normal expiration
Inspiratory capacity
Lung capacity - amount of air in lungs after a quiet expiration
Functional residual capacity
As fresh air is inhaled, it is mixed with air in the ____
anatomical dead zone
This area comprises the conducting zone of the respiratory system and is where no gas exchange occurs
The anatomical dead space/zone
Inspiratory reserve volume + expiratory reserve volume + tidal volume
Vital capacity
Residual volume + expiratory reserve volume
Functional residual capacity
Tidal volume x breaths per minute (approximately 6L/min)
Total minute volume
In which disorder is vital capacity reduced but forced expiration is normal, there is decreased compliance, inhalation is restricted, and it makes it difficult to fill lungs with air
Restrictive disorders
In which disorder is vital capacity normal but forced expiration is reduced, there is decreased elastance, and is due to lung damage or narrowing of airways, which makes it difficult to fill lungs with air
Obstructive disorders
This is an obstructive disorder that has symptoms of dyspnea and wheezing. Obstruction of air flow caused by inflammation, mucus secretion, and constriction of bronchioles.
Asthma
This obstructive disorder is caused by chronic inflammation, narrowing of the airways, and alveolar destruction, which includes emphysema and chronic obstructive bronchiolitis.
COPD (chronic obstructive pulmonary disorder)
Inflammation from COPD involves which cells
Neutrophils and cytotoxic T cells
What may develop from COPD that could eventually lead to failure of the right ventricle
Cor pulmonale - pulmonary hypertension with hypertrophy
Which restrictive disorder accumulates fibrous tissue in the lungs when alveoli are damaged, may be due to inhalation of small particles, and is also known as black lung
Pulmonary fibrosis
Total atmospheric pressure is the sum of the contributions of the individual gases
Dalton’s law
The separate contribution of each gas in a mixture
Partial pressure
What percentage of nitrogen constitutes the atmosphere
78.6%
The swapping of oxygen and carbon dioxide across the respiratory membrane
Alveolar gas exchange
At the air-water interface, for a given temperature, the amount of gas that dissolves in the water is determined by its solubility in water and its partial pressure in air
Henry’s law
What does unloading carbon dioxide and loading oxygen involve?
Erythrocytes
At rest, how long does a RBC spend in alveolar capillaries
0.75 seconds
In strenuous exercise, how long does a RBC spend in alveolar capillaries
0.3 seconds
What is the normal pressure gradient of oxygen
PO2 = 104 mm Hg in alveolar air vs. 40 mm Hg in blood
What is the normal pressure gradient of carbon dioxide
PCO2 = 46 mm Hg in blood vs. 40 mm Hg in alveolar air