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Chapter 22 - Respiratory System

Terms in this set (168)

Function of Respiratory system
supply tissues with O2 and dispose of CO2
Respiration
Gas exchange.
Internal respiration
Respiration at the tissue level - unloading from cells in capillaries. Exchange between systemic blood vessels and tissues.
External respiration
Respiration at the level of lungs. Exchange between lungs and blood.
Gas Transport
via blood between lungs and tissues in blood vessels
Pulmonary ventilation
moving gas in and out of the lungs
Vibrissae
nose hairs that line the first portion of the nasal cavity
Conchae
protrude medially; function is to increase surface area
Olfactory mucosa
olfactory receptors line superior nasal conchae
Respiratory mucosa
line rest of the cavity
mucous, defensins, lysosomes against microbes
What are the functions of the conchae and mucosa?
1. inhale- warm, moisten and filter air
2. exhale- reclaim heat and moisture
What triggers sneezing?
when the respiratory mucosa is irritated
Major organs of the respiratory system
-Nose, nasal cavity, paranasal sinuses.
-Pharynx
-Larynx
-Trachea
-Bronchi and their branches
-Lungs and aveoli
Respiratory zone
Site of gas exchange. Composed of respiratory bronchioles, alveolar ducts, and alveolar sacs (clusters of alveoli).
Conducting zone
Conduits to gas exchange sites.
Respiratory muscles
Diaphragm and other muscles that promote ventilation. Inhalation is an active process that depends on muscles (exhalation is passive).
Functions of the nose (5)
1. Provides an airway for respiration.
2. Moistens and warms the entering air.
3. Filters and cleans inspired air (nose hairs!)
4. Serves as a resonating chamber for speech.
5. Houses olfactory receptors.
Regions of the nose
1. External nose: Root, bridge, dorsum nasi, and apex - also philtrum and nares (nostrils)
2. Nasal cavity: In and posterior to the external nose, divided by a midline nasal eptum.
Roof of nasal cavity (Bones)
Ethmoid and sphenoid
Floor of nasal cavity (bones)
Hard and soft palates.
Paranasal sinuses
In frontal, sphenoid, ethmoid, and maxillary bones.

Lighten the skull and help to warm and moisten the air.
What causes sinus headaches?
drainage block which means air is absorbed in bone, it creates a vacuum
Pharynx
Muscular tube that connects to the nasal cavity and mouth superiorly and larynx and esophagus inferiorly. The throat.

From the base of the skull to the level of the 6th cervical vertebrae.
Nasopharynx
Air passageway posterior to the nasal cavity. Soft palate and uvula close nasopharynx during swallowing.

Psuedostratified epithelium
adenoid tonsils
Oropharynx
Passageway for food and air from the level of the soft palate to the epiglotis.

Stratified squamous
Lingual and palatine tonsils
Laryngopharynx
Passageway for food and air - extends to larynx, where it is also continuous with the esophagus.
Larynx
Attaches to the hyoid bone. Helps to close glottis during swallowing.
Functions of the larynx
Functions
1. Provides a patent airway
2. Routes air and food int proper channels.
3. Voice production.
Cartilage of larynx
Type: hyaline cartilage

1. Thyroid Cartilage
2. Cricoid cartilage
- arytenoid cartilage
- corniculate cartilage
- cuneiform cartilage
Epiglottis
elastic cartilage, serves to cover the air passage when we are swallowing
Glottis
space between vocal cords
False vs. True vocal cords
false- structural
true- makes sound
Composition of vocal cords
elastic connective tissue
Attachment of vocal cords
thyroid cartilage and arythenoid cartilage
Sound production
vibration of TRUE vocal cords
Pitch
length and tension of VC
Volume
force of air through glottis
Pharynx/sinuses/nasal/oral cavity
amplifiers of sound
Language production
tongue, lips, palate, teeth, shape of oral cavity
Glottis closure
sphincter closes to prevent air passage (cough and sneeze)
Valsava maneuver- definition and function
increases abdominal pressure by glottis closure
1. empty rectum
2. stabilize trunk while lifting
3. transient bp changes
Trachea
Windpipe, from the larynx into the mediastinum.
Walls of trachea
1. Mucosa: Ciliated pseudostratified epithelium with goblet cells.
2. Submucosa: Connective tissue with seromucous glands.
3. Adventita: Outermost layer made of connective tissue that encases the C-shaped rings of hyaline cartilage. It's function is to keep the air way open
Trachealis
contracts to produce more force when coughing
Posterior surface of trachea
soft; esophagus can expand into trachea to allow for food/water to go down
Tracheotomy
form opening below larynx if obstructed/damaged, which allows for air flow
Carina
last tracheal cartilage

highly embedded with neurons, that is why if particles touch it then you will cough
Secondary bronchi
2 on left
3 on right
Tertiary bronchi
8 on left
10 on right
How many orders of branching is there?
23 orders
Bronchioles
<1 mm in diameter
With branching of passage:
cartilage decreases
PS ciliated columnar decreases
by bronchioles = no cartilage (all smooth muscle), cuboidal ET, few cilia and goblet cells
Order of flow in the respiratory zone
terminal bronchioles, respiratory bronchioles, alveolar ducts, alveoli
Volume of respiratory zone
about 300 million alveoli in lungs which accounts for most of the volume in the lungs
Surface area of the respiratory zone
alveoli = massive increase in surface area, increased SA = increase gas exchange

40 SQUARE METERS
Air-blood barrier
fused wall of alveoli and capillary
Alveolar walls
1. Type 1 cells- simple squamous ET
2. Allow gas movement by simple diffusion
Surfactant
Type II, detergent-like substance that disrupts surface tension so alveoli remain open after expiration
Features of respiratory membrane
Smooth muscle and elastic fibers- allows expansion but limits overfilling

Alveolar pores- equalized pressure

Macrophages- keep surfaces clean
Bronchea
Right main bronchus is wider, shorter, and more vertical than the left. Foreign objects usually go to right bronchus for this reason.
Alveoli
Account for most of the lungs volume; main site of gas exchange.
Lungs
Occupy all of the thoracic cavity except for the mediastinum. Left lung is smaller, separated into two lobes by an oblique fissure. Right lung has three lobes separated by oblique and horizontal fissures.
Blood supply to lungs...
1. for oxygenation- pulmonary artery and vein carry blood to and from the heart/lungs
2. for lung tissue nourishment- bronchial artery arises directly from aorta to enter lung tissue, bronchial veins anastomose with pulmonary vein
Pleural lining
thin, double layered serosal membrane
Parietal pleura
lines cavity of lungs
Visceral pleura
lines outside of lungs
Pleural space
contains fluid and allows membranes to slide past each other
Pleurisy
inflamed lining, painful due to friction
Pulmonary ventilation as a mechanical process
depends upon: volume changes
volume changes lead to: pressure changes
pressure changes lead to: air flow
The loudness of a person's voice depends on...
Force with which air rushes across vocal folds.
Type II aveoli cell function
Secrete surfactant.
Air moves out of the lungs when the pressure inside the lungs is...
Greater than the pressure in the atmosphere.
Forces promoting lung collapse
elasticity of lungs and surface tension of alveolar surfactant
Forces promoting lung expansion
elasticity of chest wasll an low Pip
Surfactant helps to prevent the alveoli from collapsing by...
Interfering with the cohesiveness of water molecules, thereby reducing the surface tension of alveolar fluid.
Pneumothorax
extra air in plureal space, pressure differential removed so lung collapses
Hemothorax
blood in pleural space
What maintains the patency (openness of the trachea?
Cartilage rings
Interpulmonary pressure is the...
Pressure within the aveoli of the lungs, it fluctuates with breathing and always eventually equalizes with Patm
"in a mixture of gases, the total pressure is the sum of the individual partial pressures of gases in the mixture" paraphrases ________.
Dalton's law
Two factors on which expiration depends
the recoil of elastic fibers that were stretched during inspiration and the inward pull of surface tension due to the film of alveolar fluid
Inspiration sequence of events
Expiration sequence of events
Muscles utilized in forced expiration: active (internal intercostals and abdominal muscles)
The relationship between the pressure and volume of gasses is given by...
Boyle's Law (P1V1 = P2V2)
Henry's law
when mixture of gasses in contact with a liquid, each gas will dissolve in liquid in proportion to its partial pressure
the amount of gas that will dissolve in a liquid also depends upon solubility
CO2- most soluble
O2- 1/20th as soluble
N- practically insoluble in plasma
Intrapulmonary pressure, intrapleural pressure and volume of breath
The greatest natural resistance to airflow in the lungs is the...
medium sized bronchi
Constricted or obstructed bronchioles can prevent...
...
Asthma attacks
pulmonary ventilation

primary reactions:
1. constriction of airways
2. inflammation of airways
3. increased mucous production
Triggers for asthma
many
Treatment for asthma
bronchodilators (epinephrine is a natural bronchiodilator, it reduces resistance and allows for better breathing during fight or flight)
Homeostatic imbalances that reduce lung compliance...
- deformities of thorax
- ossification of the costal cartilage
- paralysis of intercostal muscles
What is ventilation and perfusion?
ventilation: the amount of gas reach the alveoli
perfusion: the amount of blood flow circulation by a alveoli
Ventilation-perfusion coupling
these 2 factors are tightly regulated to maintain efficient gas exchange- this coupling is regulated by vasoconstriction/dilation of arterioles (if alveolar CO2 increases then bronchioles dilate, if alveolar O2 increase then arterioles dilate)
Internal and external respiration gas exchange is driven by...
pressure gradients
Hemoglobin
98.5% of O2 in blood
Factors that affect Hb's affinity for oxygen..
1. PO2- about 25% of O2 bound to Hb released to tissues, if more O2 is needed, move O2 dissociates from Hb
2. Blood temp increases, decrease in Hb's affinity for O2
3. Blood pH decreases, lowers affinity for O2 (Bohr affect)
4. Pco2- with increase CO2 particle pressure, affinity for O2 decreases
5. BPG concentration- by product of glycolysis is and increase in BPG, which leads to a decrease in affinity for O2
6. Cigarette smoking
CO2 + H2O
products of a combustion reaction
H2CO3
Carbonic Acid
H + HCO3
...
For gas exchange to be efficient, the respiratory membrane must be ________.
0.5 to 1 micrometer thick
With the Bohr effect, more oxygen is released because a(n) ________.
decrease in pH (acidosis) weakens the hemoglobin-oxygen bond
The most powerful respiratory stimulus for breathing in a healthy person is ________.
Increase in carbon dioxide.
Nerve impulses from ____ will result in inspiration
The ventral respiratory group.
In the plasma, the quantity of oxygen in solution is....
Only about 1.5% of the oxygen carried in dissolved form.
Is respiratory rate lowest in newborn infants?
Nope.
Which of the choices below describes the forces that act to pull the lungs away from the thorax wall and thus collapse the lungs?
A) the natural tendency for the lungs to recoil and the surface tension of the alveolar fluid
B) compliance and transpulmonary pressures
C) the natural tendency for the lungs to recoil and transpulmonary pressures
D) compliance and the surface tension of the alveolar fluid
A
Which of the following does not influence the increase in ventilation that occurs as exercise is initiated?
A) psychic stimuli
B) decrease in lactic acid levels
C) proprioceptors
D) simultaneous cortical motor activation of the skeletal muscles and respiratory center
B
19) Which of the following is not a form of lung cancer?
A) adenocarcinoma
B) Kaposi's sarcoma
C) small cell carcinoma
D) squamous cell carcinoma
B
Which of the following is not an event necessary to supply the body with O2 and dispose of CO2?
A) pulmonary ventilation
B) blood pH adjustment
C) internal respiration
D) external respiration
B
21) Which of the following is not true of the respiratory tract from the medium bronchi to the aveoli?
A) Cartilage gradually decreases and disappears at the bronchioles.
B) Resistance to air flow increases due to the increase in cross-sectional diameter.
C) Proportionally, smooth muscle decreases uniformly.
D) Lining of the tubes changes from ciliated columnar to simple squamous epithelium in the alveoli.
B
Which of the following determines lung compliance?
Alveolar surface tension
Total volume is air....
Exchanged during normal breathing.
Which of the choices below determines the direction of respiratory gas movement?
A) solubility in water
B) partial pressure gradient
C) the temperature
D) molecular weight and size of the gas molecule
B
Possible causes of hypoxia include...
Too little oxygen in the atmosphere.
The lung volume that represents the total volume of exchangeable air is the ________.
Vital capacity
Because the lungs are filled with fluid during fetal life, which of the following statements is true regarding respiratory exchange?
A) Respiratory exchanges are made through the ductus arteriosus.
B) Respiratory exchanges are not necessary.
C) Respiratory exchanges are made through the placenta.
D) Because the lungs develop later in gestation, fetuses do not need a mechanism for respiratory exchange.
Respiratory exchanges are made through the placenta.
28) Which of the following is not a stimulus for breathing?
A) rising carbon dioxide levels
B) rising blood pressure
C) arterial Po2 below 60 mm Hg
D) arterial pH resulting from CO2 retention
Rising blood pressure.
Respiratory control centers are located in...
medulla and pons
The amount of air that can be inspired above the tidal volume is called....
Inspiratory reserve
31) Which statement about CO2 is incorrect?
A) Its concentration in the blood is decreased by hyperventilation.
B) Its accumulation in the blood is associated with a decrease in pH.
C) More CO2 dissolves in the blood plasma than is carried in the RBCs.
D) CO2 concentrations are greater in venous blood than arterial blood.
More CO2 dissolves in the blood plasma than is carried in the WBCs.
Oxygen and carbon dioxide are exchanged in the lungs and through all cell membranes by...
Diffusion
The auditory tube drains into the...
Nasopharynx.
The larynx contains...
A thyroid cartilage.
35) Which respiratory-associated muscles would contract if you were to blow up a balloon?
A) diaphragm would contract, external intercostals would relax
B) internal intercostals and abdominal muscles would contract
C) external intercostals would contract and diaphragm would relax
D) diaphragm contracts, internal intercostals would relax
Internal intercostals and abdominal muscles would contract.
How is the bulk of carbon dioxide carried in blood?
As the bicarbonate ion in the plasma after first entering the red blood cells.
37) Which of the following is not found on the right lobe of the lung?
A) middle lobe
B) cardiac notch
C) horizontal fissure
D) oblique fissure
Cardiac notch
38) Which of the choices below is not a role of the pleura?
A) allows the lungs to inflate and deflate without friction
B) helps divide the thoracic cavity into three chambers
C) helps limit the spread of local infections
D) aids in blood flow to and from the heart because the heart sits between the lungs
Aids in blood flow to and from the heart.
39) Which of the following correctly describes mechanisms of CO2 transport?
A) 710% of CO2 is dissolved directly into the plasma
B) 20% of CO2 is carried in the form of carbaminohemoglobin
C) as bicarbonate ion in plasma
D) attached to the heme part of hemoglobin
Attached to the heme part of hemoglobin.
40) Factors that influence the rate and depth of breathing include ________.
A) thalamic control
B) voluntary cortical control
C) stretch receptors in the alveoli
D) composition of alveolar air
Voluntary cortical control
41) Which of the following provide the greatest surface area for gas exchange?
A) alveolar sacs
B) alveoli
C) respiratory bronchioles
D) alveolar ducts
Alveoli
42) The respiratory membrane is a combination of ________.
A) respiratory bronchioles and alveolar ducts
B) alveolar and capillary walls and their fused basement membranes
C) atria and alveolar sacs
D) respiratory bronchioles and alveolar sacs
Alveolar and capilary walls and their fused basement membranes.
Gas emboli may occur because a...
Diver holds his breath upon ascent.
Inspiratory capacity is...
The total amount of air that can be inspired after a tidal expiration.
Which center is located in the pons?
Pontine respirator group?
The nose serves all the following functions except ________.
A) as a passageway for air movement
B) as the initiator of the cough reflex
C) warming and humidifying the air
D) cleansing the air
B
A premature baby usually has difficulty breathing. However, the respiratory system is developed enough for survival by ________.
A) 17 weeks
B) 24 weeks
C) 28 weeks
D) 36 weeks
C
48) Which of the following statements is true regarding the respiratory rate of a newborn?
A) The respiratory rate of a newborn is slow.
B) The respiratory rate of a newborn varies between male and female infants.
C) The respiratory rate of a newborn is approximately 30 respirations per minute.
D) The respiratory rate of a newborn is, at its highest rate, approximately 40-80 respirations per minute.
D
Select the correct statement about the neural mechanisms of respiratory control.
A) The pons is thought to be instrumental in the smooth transition from inspiration to expiration.
B) The dorsal respiratory group neurons depolarize in a rhythmic way to establish the pattern of breathing.
C) The pontine respirator group (PRG) continuously stimulates the medulla to provide inspiratory drive.
D) The ventral respiratory group is contained within the pons.
A
Which of the choices below is not a factor that promotes oxygen binding to and dissociation from hemoglobin?
A) partial pressure of oxygen
B) temperature
C) partial pressure of carbon dioxide
D) number of red blood cells
D
The factors responsible for holding the lungs to the thorax wall are ________.
A) the smooth muscles of the lung
B) the diaphragm and the intercostal muscles alone
C) the visceral pleurae and the changing volume of the lungs
D) surface tension from pleural fluid and negative pressure in the pleural cavity
D
The erythrocyte count increases after a while when an individual goes from a low to a high altitude because the ________.
A) temperature is lower at higher altitudes
B) basal metabolic rate is higher at high altitudes
C) concentration of oxygen and/or total atmospheric pressure is higher at higher altitudes
D) concentration of oxygen and/or total atmospheric pressure is lower at high altitudes
D
Most inspired particles such as dust fail to reach the lungs because of the ________.
ciliated mucous lining in the nose
Which of the following is not possible?
A) Gas flow equals pressure gradient over resistance.
B) Pressure gradient equals gas flow over resistance.
C) Resistance equals pressure gradient over gas flow.
D) The amount of gas flowing in and out of the alveoli is directly proportional to the difference in pressure or pressure gradient between the external atmosphere and the alveoli.
B
Select the correct statement about the physical factors influencing pulmonary ventilation.
A) A decrease in compliance causes an increase in ventilation.
B) A lung that is less elastic will require less muscle action to perform adequate ventilation.
C) As alveolar surface tension increases, additional muscle action will be required.
D) Surfactant helps increase alveolar surface tension.
C
Select the correct statement about oxygen transport in blood:
D
Which of the disorders below is characterized by destruction of the walls of the alveoli producing abnormally large air spaces that remain filled with air during exhalation?
C
Which of the following does not influence hemoglobin saturation?
D
Inspiration
Gases flow into the lungs. An active process.
Expiration
Gases exit the lungs. Normally a passive process - but doesn't have to be, forced expiration is active using abdominal and internal intercostal muscles.
Atmospheric pressure
Pressure exerted by the air surrounding the body - 760 at sea level.
Respiratory pressure
Described relative to atmospheric pressure. Negative is less than atmospheric pressure. Positive results in exhalation.
Intrapulmonary pressure
Pressure within the aveoli - always eventually equalizes with atmospheric pressure. Positive on exhale.
Interpleural pressure
Pressure in pleural cavity - fluctuates with breathing, but always negative or lungs would collapse.
Atelectasis
Lung collapse due to plugged bronchioles, which leads to a collapsed alveoli OR wound that admits air into pleural cavity (pneumothorax)
Boyle's law
The relationship between the pressure and volume of gas. Pressure varies inversely with volume
Physical factors influencing pulmonary ventilation
Airway resistance
Alveolar surface tension
Lung compliance
Airway resistance
Friction is major nonelastic source of resistance to gas flow. Resistance is usually insignificant because of large airway diameters. As resistance rises, breathing becomes more strenuous.
Alveolar surface tension
Attracts liquid molecules to one another at a gas-liquid interface - resists any force that tends to increase the surface area of the liquid.
Tidal volume
Amount of air inhaled or exhaled with each breath under resting conditions.
Surfactant
Detergent like lipid produced by type II alveolar cells- reduces surface tension and discourages alveolar collase. Insufficient quantity in premature infants causes infant respiratory distress symptom (it's produced at 28 weeks).
Inspiratory reserve volume
Amount of air that can be forcefully inhaled after a normal tidal volume inhalation.
Expiratory reserve volume
Amount of air that can be forcefully exhaled after a normal tidal volume exhalation.
Residual volme
Amount of air remaining in the lungs after forced exhalation.
Total lung capacity
Maximum amount of air contained in lungs after a maximum inspiratory effort.
Vital capacity
Maximum amount of air that can be expired after a maximum inspiratory effort.
Inspiratory capacity
Maximum amount of air that can be inspired after a normal expiration.
Functional residual capacity
Volume of air remaining in the lungs after a normal tidal volume expiration.
THIS SET IS OFTEN IN FOLDERS WITH...