Ch 23 Respiratory System
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Ch 23 Respiratory System
23 Respiratory System
Ch 23 Respiratory System
Name the structures which comprise the respiratory system.
Which structures are considered to be part of the upper respiratory system ?
Comprised of the nose and the pharynx
Which structures are considered to be part of the lower respiratory system ?
Compare the function of the conducting portion of the respiratory system to that of the respiratory portion of the respiratory system.
Series of tubes that will carry air from the nose to the lungs
What are the two main portions of the nose ?
Describe the structure of the external nose.
Framework made of cartilage & bone
covered with muscle and skin
Lined with mucous membrane
What are the external nares ?
What are the functions of the internal structures of the external nose ?
Take in Air
Warm/ filter/ moisten air
resanince chamber (for speech)
Describe the structure of the internal nose.
Inferier to the nasal bone
Superier to the mouth
Lined with muscle and mucous membrane
What are the internal nares ?
Opening into the back of the nose (into pharynx)
What structures open (drain) into the internal nose ?
Naso lacrimal ducts
Where is the vestibule of the nose ?
Right side of the external nares
Briefly describe the structure and function of the nasal septum.
Partition that divides the nasal cavity into left and right halves
What is the function of the olfactory epithelium ? Where is it located ?
Contains olfactory receptors
Upper portion of nasal cavity in mucous membrane & in concay
What is the pharynx ?
Extends from nose to larynx and epiglotous.
What are the functions of the pharynx ?
Passage way for air and food
Used for speech and vocalization
What are the three regions of the pharynx ? Briefly describe the location of each of the
Name the structures which open into the nasopharynx.
Goes from soft palate to hyoid
from level of hyoid to larynx to esophagus.
What are the functions of the nasopharynx ?
Passage way for air
Equalize pressure between pharynx & inner ear
What is the fauces ?
Opening from mouth into pharynx
What are the functions of the oropharynx ?
Passage way for air, food, and drinks
What are the functions of the laryngopharynx ?
Passage way for air, food, and drinks
What two structures does the larynx connect ?
Pharynx to trachea
What is the common name for the larynx ?
Describe the structure and the function of the epiglottis.
Leaf like structure
Made mostly of cartilage
Covered by epithelium
Why is the epiglottis important ?
Covers respiratory system during swallowing
Directs food to esophigous
Prevents food from entering airways
Describe the structures that comprise the glottis.
ventricular folds (outside)
Describe the structure and function of the two sets of folds which are present in the larynx.
: Holding breath. Actions involving a lot of exhale
: Vibrate when making a sound
Anatomically speaking, what must you do in order to increase the volume of the sound you make ?
Increase the amount of air going through vocal chords
Anatomically speaking, what must you do in order to increase the pitch of the sounds you are making ?
Change the tension of the vocal chords
In addition to the vocal cords, what other structures are involved in speech ?
What is the common name for the trachea ?
Where is the trachea in relation to the esophagus ?
In front of esophagus
What structures does the trachea connect ?
Larynx to bronchi
Describe the appearance of the hyaline cartilage bands within the trachea. What does their peculiar shape accommodate? What is their function ?
Keeps trachea open
Allows esophagus to expand during swallowing process
At its base, the trachea splits to form the right ____________
____________ and the left ___________ ______________, which go to the
At its base, the trachea splits to form the right __primary bronchi___and the left ___primary bronchous ___, which go to the
What is the carina ?
Rigid at the site where the trachea divides
Describe the subdivisions of the primary bronchi to become the terminal bronchioles.
Divide to form secondary bronchi
Secondary to trachea
Trachea primary to bronchi secondary bronchi
Terciary bronchi --> Bronchiole --> to terminal bronchiole
Describe how the distribution of cartilage and smooth muscle changes throughout the bronchial tree.
Decrease cartilage (keep tubes open)
Increase smooth muscle
Describe the general location and shape of the lungs.
Cone shaped in thorasic cavity
Describe the two layers of pleura.
Visceral Pleura (on organs)
Parietal Pleura (lines wall of chest cavity)
Where is the pleural cavity ? What does it contain ?
Space between visceral & pleura
What is the function of pleural fluid ?
What happens at the hilus ?
Bronchi enter lung at hilus
So does anything going to lung
What is the function of the fissures in the lungs ?
Deep groves that divide each lung into groves
Describe the relationship between bronchopulmonary segments and alveolar ducts.
Primary Bronchus (goes to)
Terminal Bronchioles (lobule)
What is an alveolus ?
Cup shaped pouch that surrounds an alveolar duct
What type of cells make up the walls of the alveoli ?
Simple squamous (thin so good for gas exchange)
What is the function of surfactant ? Where is it produced ?
Lowers the surface tension of alveoli
Makes walls slipery so alveoli don't colapse when exhale
Septal cells in alveoli
What occurs at the respiratory membrane ? What are the constituents of the respiratory
Exchange of gasses (oxygen, carbon dioxide)
Pulminary capillaries & alveoli
List and define the three basic steps of respiration.
1. Pulmonary Ventilation
2. External Respiration
: Lungs (exchange of gasses)
What causes air to flow into the lungs ? What causes air to flow out of the lungs ?
-Air enters lungs when pressure in lungs is less then the pressure in atmosphere
-Air enters atmosphere when pressure in lungs is more then the pressure in atmosphere
Besides differences in pressure between the atmosphere and the lungs, what other factors may influence the rate of airflow ?
Surface tension of alveoli fluid
What is Boyle’s Law ?
Volume of a gas varies inversely with its pressure
What must occur within the body in order to decrease the air pressure inside the alveoli ?
Increase the size of the lungs
What muscles are utilized in order to expand the volume of the lungs ?
What happens to the pleurae when the thoracic cavity expands?
Stick to the wall of the thorasic cavity
When rib goes out so do lungs
Why is expiration considered to be a passive process ?
No muscular contraction is required
Exhaling due to elastic recoil
What two forces contribute to elastic recoil ?
Elastic fibers around alveoli connect
Inword pull of suface tension due to fluid of alveoli
When does exhalation become active ? What muscles are involved in active exhalation ?
With exercise & wind insturments
Use internal intercostals, abdominal muscles
Define tidal volume.
What is the average tidal volume for humans ?
Volume of air that would be moved in one breath (inhale and exhale)
Does all the air inhaled during one breath actually reach the alveoli ?
No only about 70%
Define the inspiratory reserve volume. What is the average inspiratory reserve for humans ?
Additional amount of air that could be inhaled by taking a big breath
Define the expiratory reserve volume. What is the average expiratory reserve for
Amount that you could forcefully exhale following a normal inhale and exhale
Define residual volume.
What is the average residual volume for humans ?
Air that remains in the lungs following a forceful exhale
Define minimal volume.
How is minimal volume used in forensic science ?
Part of residual volume remaining in lungs after thorax was open
Trying to find out if babies are born dead or still born
How do you calculate inspiratory capacity ?
How much the individual can inhale
How do you calculate functional residual capacity ?
How much is left in the lungs after a normal exhale
How do you calculate vital capacity ?
How much air an individual can move
If did a max inhale followed by a max exhale
How do you calculate total lung capacity ?
How much air lungs can hold
Why are these various lung volumes and/or capacities useful from a diagnostic perspective ?
Indicate emphysema (lung disease)
->always do forceful inhale
->overdeveloped chest muscles
By what mechanism is oxygen exchanged between the alveolar air and the pulmonary blood ?
->need a concentration gradient high pressure to low pressure
What is Dalton’s Law ?
Behavior of gas in a mixture
Each gas in a mixture exerts it's own pressure as if no other gasses were present
What is the partial pressure of a gas ? How is it calculated ?
Pressure of a specific gas in a mixture
Multiply % of gas in mixture by total pressure in mixture
What is the partial pressure of oxygen in inhaled air ?
What is the partial pressure of carbon dioxide in inhaled air ?
.04% Carbon Dioxide
How does the partial pressure of a gas affect its movement across cell membranes ?
How do the partial pressures of oxygen and carbon dioxide in inhaled air compare with that of alveolar air ?
Oxygen that partial pressure alveolar air is less
More carbon dioxide in alveolar air compared to inhaled air
What is Henry’s Law ?
The quantity of a gas that will disolve in a liquid is propotional the partial pressure of the gas and its solubility
How much nitrogen gas is dissolved in plasma at sea level? Why ?
Its solubility is very low
What causes deep sea divers to experience the rapture of the depths ?
Breathing in nitrogen under high pressure
What causes decompression sickness ? How can decompression sickness be avoided ?
Extra nitrogen come out of blood to fast
Come up slowly
Describe the process of hyperbaric oxygenation. What type of disorders is this process used to treat ?
Increasing the pressure of oxygen in the atmosphere
Increases oxygen going into blood
Anarobic Infections: carbon monoxide poisoning, trauma, near drowning
Explain why more oxygen will diffuse into your blood as it goes through the pulmonary capillaries if you are exercising.
Oxygen will go from high pressure to low pressure
lung --> blood
Use the concept of partial pressures to explain why oxygen diffuses into the tissues as it goes through the systemic capillaries.
Oxygen leaves blood and go to tissues of foot
Briefly discuss each of the four major factors which affect the rate of pulmonary and systemic gas exchange.
Partial pressure difference of gasses
Surface area available for gas exchange
Diffusion differences (distance)(edimial)
Molecular weight, solubility of gasses
Why do people develop high altitude sickness when they travel up into relatively high mountains ?
Pressure of oxygen change
Does oxygen dissolve easily in water ? How much oxygen is transported in plasma ?
No low solubility
Only about 15% oxygen inhaled is moving in plasma
Attached to hemoglobin in red blood cells
In what form is most oxygen transported in the blood ?
Binded to red blood cells
What component of hemoglobin binds to oxygen ? What metal is an important part of this component ?
Hehe: non protein part (Iron)
How many molecules of oxygen can one hemoglobin molecule carry ?
What is the percent saturation of hemoglobin ?
How many oxygen's being carried on hemoglobin
What is the most important factor that determines how much oxygen will bind to a hemoglobin molecule ?
Higher pp more oxygen bind
Lower pp oxygen detaches
Why is more oxygen released from hemoglobin as it passes through the capillaries of exercising tissues as compared to resting tissues ?
Resting partial pressure 40
Exercising partial pressure lower
More oxygen come off hemoglobin molecule in exercising tissue
How does acidity affect the affinity of hemoglobin for oxygen ? How is this beneficial during periods of exercise ?
As acidity increases affinity of hemoglobin for oxygen decreases
Lactic acid make tissues more acid hemoglobin release more oxygen
How does temperature affect the affinity of hemoglobin for oxygen ? How is this beneficial during periods of exercise ?
As temperature increases
Affinity of hemoglobin for oxygen decreases
Cause more oxygen to go into the tissues
Name some chemicals which decrease the affinity of hemoglobin for oxygen.
How does fetal hemoglobin differ from adult hemoglobin in its affinity for oxygen ? Why is this beneficial ?
Fetal hemoglobin has a few different amino acids
Fetal hemoglobin has more affinity for oxygen
Oxygen is slightly more attracted to fetal hemoglobin
How does carbon monoxide affect the oxygen-carrying capability of hemoglobin ?
Carbon Monoxide is more attached to hemoglobin, more then oxygen
Need oxygen to make ATP
Name the three forms in which carbon dioxide is carried in the blood. Discuss the relative abundance of each form.
7% Carbon Dioxide - Dissolved in Plasma
23% Carbon Dioxide - Carried on Hemoglobin Molecule
70% Carbon Dioxide - Bicarbonate Ion
Describe the chemical reaction which occurs when carbon dioxide reacts with water in the presence of carbonic anhydrase.
70% Carbon Dioxide will react with water
Make Carbonic Acid
Breaks down to form bicarbonate ion
How does the accumulation of carbon dioxide in the blood affect the pH of the blood ?
More hydrogen ions, more acid in blood
Lower the pH more acidity blood
Summarize gas exchange and transport in the lungs and in tissue.
Bicarbonate hook back with hydrogen
Makes carbonic acid (H2CO3)
Makes Carbon Dioxide (CO2) that you exhale
Name the three areas in the brain stem which control the rhythm of respiration.
What are the two areas within the medullary rhythmicity center ?
Briefly describe the function of the medullary rhythmicity center during quiet breathing. How does it change during forceful breathing ?
: Inspatory area turned on 2 sec (Diaphragm, intercostals), then off for 3 sec
: Inspatory signals expatory center
Briefly describe the function of the pneumotaxic area.
Control the transition (end inhale start exhale)
Turn off inhalation (allows you to exhale)
Briefly describe the function of the apneustic area.
Sends stimulatory messages to inspitory system
Can you voluntarily control your breathing rate? Why is this advantageous ?
Yes, Cortical center (can control inspitory system)
can hold breath (under water, bad gasses)
Can a little kid really hold his breath until he dies ? Why ?
Level of Carbon Dioxide in blood overrides
Pass out and inspitory center turns on
What are chemoreceptors ?
Sensory neurons that respond to certain chemicals
Where are central chemoreceptors located ? To what chemicals are they responsive ?
In brain (near medulla)
Monitor levels of carbon dioxide and hydrogen+ in arebral spinal fluid
Where are peripheral chemoreceptors located ?To what chemicals are they sensitive ?
Near a blood vessel (aorta, corotic)
Carbon Dioxide, Hydrogen Ion, Oxygen
How do the central and peripheral chemoreceptors respond to increased levels of carbon dioxide or H+ in the blood ?
Signals inspitory system
Increase the rate of respiration
How do the chemoreceptors respond to decreased levels of carbon dioxide in the blood ?
Do not respond
Lets inspitory system set pace
What are proprioceptors ? How do proprioceptors affect breathing rate ?
Located in joints/muscles
Monitor movement of joints/muscles
Signals inspitory center with change of movement
Where are the baroreceptors which affect breathing rate located ? What happens when they become stretched?
Pressure receptors in bronchi of lungs
Respond when they get stretched (Inhale)
Identify several other factors that contribute to the regulation of the breathing rate.
Limbic Area of the brain (Anxiety, Anticipation)
Increase temperature, Increase Breath rate
sharp pain (deep breath --> apnea)
Chronic Pain (Increase respiration rate)
Irritation of airways (apnea --> cough)
Blood pressure increases (respiration rate decreases)
Stretch anal sphincter (Increase respiratory rate)
How does exercise affect ventilation ?
Breathing rate increases right when move (changes in neuro system)
Breathing rate increases more when continue to move more (Increase oxygen, Increase Carbon Dioxide, Increase temperature)
Breathing rate increases more when continue to exercise (Lactic acid and carbon dioxide in blood)