Bio 203 Module 8- Respiratory
asthmatic airways
"triggers" can cause an asthma attack or exacerbate ongoing symptoms - pollen, weeds, grasses, dust, smog, odors, strong emotions, etc.
avian lungs
- air sacs allow for unidirectional flow across the respiratory surface - lung is stiff and undergoes very little change in volume throughout - air capillaries of parabronchi serve as site of gas exchange - counter-current exchange- air flow is in the opposite direction of blood flow
tracheal system of insects
- does not rely on a circulatory system for gas exchange (open circulatory system is used for gas exchange) - air enters and exits via spiracles, which open to the exterior - tracheae branch extensively and carry air deep within the animal's body - body movements compress air sacs - tracheae located close to mitochondria and skeletal muscles - this system limits the size of insects!
At sea level, air pressure is 760 mm Hg and the partial pressure of oxygen is _____ mm Hg. At higher elevations, air pressure is reduced, and the partial pressure of oxygen is ______ (lower / the same / higher) even though the percent of oxygen in the air is ______ (lower / the same / higher).
160, lower, the same
counter current exchange
2 substances (blood & water) flowing in opposite directions of each other that maximize a gradient for exchange
At what partial pressue of oxygen, in mm Hg, would the average hemoglobin molecule be bound to two O2 molecules? Enter your answer as a number. Do not enter letters or symbols.
35
A healthy young adult takes 12 breaths per minute, and inhales 500 mL of air with each breath, and has 150mL of dead space in the respiratory tract. What is this person's Alveolar Ventilation Rate (in mL/min)? Enter your answer as a number. Do not enter letters or symbols.
4200
A healthy young adult takes 12 breaths per minute, and inhales 500 mL of air with each breath. What is this persons Total Pulmonary Ventialtion Rate (in mL/min)? Enter your answer as a number. Do not enter letters or symbols.
6000
If the partial pressure of oxygen were 60mm Hg, what percent of the binding sites on the hemoglobin would be occupied by oxygen?
85
At an oxygen partial pressure of 30mm Hg, approximately what percent of the myoglobin molecules would be bound to a single O2 molecule? Enter your answer as a number. Do not enter letters or symbols.
90
negative pressure breathing
A breathing system in which air is pulled into the lungs when the lung volume is expanded. air flow depends on differences in pressure
closed circulatory system
A circulatory system in which the oxygen-carrying blood cells never leave the blood vessels; one or more hearts serve as a transport medium between cells and a specialized respiratory system
mammalian lungs
Branch extensively and their entire volume is filled with bubble like structures called "Alveoli." anatomically localized- bridged by circulatory system dense network of capillaries w very short diffusion distances
Regarding oxygen transport and hemoglobin, which of the following statements are TRUE? A: The P50 value of hemoglobin is a constant value inherent to the protein B: A higher affinity for oxygen makes it easier to deliver O2 to target tissues C: Oxygen is more likely to dissociate from hemoglobin at a high temperature D: Both A and B are correct, C is incorrect E: A, B, and C are all correct
C: Oxygen is more likely to dissociate from hemoglobin at a high temperature
For a healthy individual, which of the following statements is/are TRUE? (assume tidal volume = 500 mL, respiratory rate = 12 breath/min): A: Residual volume refers to the air remaining in the lungs at the end of a normal (tidal volume) expiration B: Breathing faster increases both pulmonary and alveolar ventilation C: Taking deeper breaths (increasing tidal volume) can increase alveolar ventilation but does not change dead space volume D: Both A and B are correct, C is incorrect E: A, B, and C are all correct
C: Taking deeper breaths (increasing tidal volume) can increase alveolar ventilation but does not change dead space volume
You have reached the summit of Mt. Kilimanjaro! You'd like to celebrate butnow you have a headache and feel unusually fatigued. At this elevation(5,895 meters)...: A: Ventilation rate is increased compared to resting at sea level B: Arterial PO2 is lower because the driving force for O2 to diffuse into bloodis reduced C: Peripheral chemoreceptor afferents fire more frequently due todecreased PO2 in CSF D: Both A and B are correct, C is incorrect E: A, B, and C are all correct
D: Both A and B are correct, C is incorrect
muscles of inspiration
active process diaphragm- always active; contracts on inspiration external intercostals- required for forceful breathing only
terrestrial animal respiratory systems
advantages (air medium): - higher O2 concentration - O2 and CO2 diffuse faster in air - air is easier to move (ventilation requires less energy) disadvantages: - loss of water by evaporation - respiratory surface may be folded into body
Aquatic Animal Respiration
advantages: - resp. surfaces stay moist - water is not lost by evaporation disadvantages: - O2 concentration is low - exchange must be very effecient
pneumothorax
air in the pleural cavity caused by a puncture of the lung or chest wall (lung collapses to unstretched size)
ventilation
any method of increasing contact between the respiratory medium and the respiratory surface ** usually requires energy examples: - ciliated surfaces - paddle-like appendages to push water over gills - swimming to increase water flow over gills
environmental reservoirs of oxygen
atmosphere (21% O2) bodies of water
red blood cells shape
biconcave discs created by cytoskeleton Contributes to: 1. hemoglobin is positioned close to cell membrane, reducing diffusion distance of oxygen 2. allows RBC to bend and twist while negotiating tight passageways 3. Birds have biconvex (football shaped) RBCs
coordinate covalent bond
binds one iron atom reversibly to one molecule of oxygen in a hemoglobin molecule
systemic capillaries
capillaries in all the body tissues where gas exchange occurs internally (internal respiration)
forces of the pleural cavity
chest wall- tries to pull wall outwards lung- inward pull
hemocyanins
copper binds oxygen - anthropods: three protein subunits - mollusks: two protein subunits
partial pressure gradient
determines the direction of respiratory gas movement
Fick's Law of Diffusion
diffusion through a membrane is directly proportional to the surface area and concentration gradient and inversely proportional to the thickness of the membrane and its resistance ** the most important factor is the pressure gradient
pleural sac
double-walled, closed sac that separates each lung from the thoracic wall - pleural fluid keeps the lung adhered to the chest wall
gills
evaginations of the body surface (epidermis) absorb dissolved O2 from an aqueous respiratory medium and excrete CO2 gas exchange maximized by: - large surface area - counter-current exchange - ventilation (increased water flow over gills)
oxygen-hemoglobin dissociation curve
graph that describes the relationship of partial pressure to the binding and disassociation of oxygen to and from heme
maternal vs fetal hemoglobin
hemoglobin F in the fetus allows a stronger binding to oxygen than maternal hemoglobin
hemoglobin
iron-containing heme group (protoporphyrin IX) binds oxygen. Carries 98% of blood oxygen in humans. four protein subunits -> each contains one heme group. One iron atom at the center of each heme group binds one O2 molecule ** Four O2 per Hb
When plasma travels through a systemic capillary, most the of the CO2 entering the plasma
is converted to bicarbonate ions.
clinical management of asthma
maintenance medicines rescue medicines
vital capacity
maximum volume of air that can be moved into and out of the lungs (4600 mL) TV + IRV + ERV
The cells that respond to changes in blood gas concentration and generate the respiratory rhythm are found in several nuclei in the _____________________.
medulla oblongata
respiratory muscle
mixed muscles; composed for fast-twitch and slow-twitch fibers diaphragm: - 55% type I - 21% type IIa - 23% Type IIb other respiratory muscles contain 60% or more type I fibers this makes them well equipped to sustain continuous rhythmic contractions over long periods of time
Beta2-Adrenergic Agonists
most effective bronchodilator agents inhaled, short acting relieve symptoms of ongoing asthma episode- albuterol inhaled, long acting are maintenance meds- salmeterol
bicarbonate buffer system
most important buffer system that keeps blood pH from changing drastically
oxygen transport in blood
most oxygen attach to hemoglobin to form hemoglobin (98%). A small dissolved part is carried into the plasma (2%)
maintenance medicine (asthma)
must be used on a regular schedule glucocorticoids- reduce inflammation and hyperreactivity in airways (ex: fluticasone (steroid)) long acting beta 2-andrenic receptor antagonists- relax smooth muscles of the airways (ex: salmeterol)
structure of respiratory system
nose, pharynx, larynx, trachea, bronchi, lungs, diaphragm
muscles of expiration
passive process diaphragm- relaxes on expiration internal intercostals- required for forceful breathing only
respiratory drive
physiological drive to breathe
Law of LaPlace
pressure is directly proportional to surface tension and inversely proportional to radius of alveolus reason that surfactant reduces surface tension
alveolar pressure
pressure within the lungs
intrapleural pressure
pressure within the pleural cavity (always negative to prevent chest collapse!)
partial pressure of a gas
proportion of pressure of entire gas that is due to presence of the individual gas gradient is the driving force for diffusion!!
respiratory pigments
proteins in blood cells that carry gases; hemoglobin and hemocyanins
surfactant
reduces surface tension in the alveoli - the surface tension of pure water opposes lung inflation - mixture of proteins and phospholipids disrupts the cohesive forces of water - more concentrated in smaller alveoli, which equalized the pressure in small and large alveoli - released by type II alveolar cells
rescue medicines
relax airway muscles, reversing bronchospasm and making it easier to breathe (ex: albuterol)
myoglobin
resp pigment found in muscle cells that rely on aerobic metabolism and where O2 used most quickly; higher O2 affinity single polypeptide chain and one heme group (compared to four in hemoglobin) ** O2 reserve in muscles
cutaneous respiration
respiration through the skin; small or thin animals use body surface for gas exchange - no respiratory or circulatory systems - O2 diffuses very slowly through water - all cells must be close to respiratory surface (<1 mm)
respiratory systems in echinoderms
sea stars have external papulae that function as gills for gas exchange cilia in inner and outer surfaces beat in opposite directions, allow for counter-current gas exchange
Type II alveolar cells
secrete surfactant
Type I alveolar cells
simple squamous cells where gas exchange occurs; allow rapid diffusion through thin membranes
coupled respiratory and circulatory systems
step 1: exchange between respiratory medium and circulatory system step 2: exchange between circulatory system and interstitial fluid bathing cells circulatory system transports gases to and from tissues throughout the body ** driven by pressure gradients
Total Lung Capacity (TLC)
sum of all lung volumes (TV + IRV + ERV + RV)
pulmonary capillaries
surround the thin tissue membranes of the alveoli; site of gas exchange in blood
newborn respiratory distress syndrome (NRDS)
symptoms produced as a result of an insufficient amount of pulmonary surfactant being produced to reduce the alveolar surface tension to manageable levels can be prevented by corticosterioids given to the mother to acelerate fetal lung development
cooperativity
the binding of oxygen causes a conformational change in Hb so subsequent O2 molecules will bind with greater affinity.
Inspiratory Reserve Volume (IRV)
the maximal amount of additional air that can be drawn into the lungs by determined effort after normal inspiration (3000 mL)
external respiration
the movement of gases between the environment and the body's cells Main functions: - gas exchange (O2 in, CO2 out) - acid-base balance
cellular respiration
the process by which cells use oxygen to produce energy from food (anaerobic + aerobic)
capacity
the sum of two or more lung volumes
tidal volume
the volume of air moved in and out of the lungs during normal, quiet breathing 500 mL
total pulmonary ventilation
the volume of air moved into and out of the lungs each minute (ventilation rate) x (tidal volume)
dry powder inhaler
types of breath-activated delivery methods for inhaled medications
Hyperventilation
ventilation of the lungs beyond normal body needs
hyopventilation
ventilation of the lungs that does not fulfill the body's gas exchange needs
dead space
volume of air remaining in the airways at the end of each expiration (150 mL) consequence of bidirectional flow through airways mixes with fresh air during inhalation part of residual volume
Which of the following sensory systems can produce a change in respiratory rhythm in response to an increase in the partial pressure of carbon dioxide in plasma (either directly or indirectly) (select one or more) ? Question options: - Chemoreceptors in the aortic arch - Chemoreceptors in the carotid body - Stretch receptors in the carotid sinus - Stretch receptors in bronchi and bronchioles - Chemoreceptors in the ventral respiratory group
- Chemoreceptors in the aortic arch - Chemoreceptors in the carotid body - Chemoreceptors in the ventral respiratory group
Fill in the blanks with the correct words. 1. During inspiration, intra-alveloar pressure is __________ atmospheric pressure. 2. The intra-alveolar pressure when the diaphragm contracts is ________________ the intra-alveolar pressure when the diaphragm relaxes. 3. The tidal volume is ______________ the amount of fresh air that reaches the alveoli plus the dead space volume 4. The partial pressure of carbon dioxide in the blood leaving the lungs via the pulmonary vein is ______________ the partial pressure of carbon dioxide in the alveolar air. 5. At normal partial pressures in the capillaries, the percent of carbon dioxide in the blood that is bound to hemoglobin is ___________________ the percent of oxygen in the blood that is bound to hemoglobin. 1. less than 2. equal to 3. greater than
1. During inspiration, intra-alveloar pressure is less than atmospheric pressure. 2. The intra-alveolar pressure when the diaphragm contracts is less than the intra-alveolar pressure when the diaphragm relaxes. 3. The tidal volume is equal to the amount of fresh air that reaches the alveoli plus the dead space volume 4. The partial pressure of carbon dioxide in the blood leaving the lungs via the pulmonary vein is equal to the partial pressure of carbon dioxide in the alveolar air. 5. At normal partial pressures in the capillaries, the percent of carbon dioxide in the blood that is bound to hemoglobin is less than the percent of oxygen in the blood that is bound to hemoglobin.
For each of the following, complete the statement with the appropriate matching answer. (assume normal healthy adult human) 1. Following deep breathing in and out of a small paper bag, respiratory drive will ____________. 2. Following deep breathing of room air, the partial pressure of oxygen in plasma will ____________. 3. Following deep breathing of room air, plasma oxygen content will ____________. 4. Following deep breathing of room air, respiratory drive will ____________. 5. Following deep breathing in and out of a small paper bag, plasma carbon dioxide content will ____________. 6. Following deep breathing of room air, the partial pressure of carbon dioxide in plasma will ____________. A. increase B. decrease C. be the same or change very little
1. Following deep breathing in and out of a small paper bag, respiratory drive will increase. 2. Following deep breathing of room air, the partial pressure of oxygen in plasma will increase. 3. Following deep breathing of room air, plasma oxygen content will be the same or change very little. 4. Following deep breathing of room air, respiratory drive will increase. 5. Following deep breathing in and out of a small paper bag, plasma carbon dioxide content will decrease 6. Following deep breathing of room air, the partial pressure of carbon dioxide in plasma will increase.
CO2 transport in blood
10% dissolved in plasma 20% bound to Hb 70% bicarbonate ** CO2 is dissolvable in water (and blood plasma)
A healthy young woman is breathing at 12 breaths per minute with a tidal volume of 500 ml. Which of the following statements is correct if she changes her breathing pattern to 15 breaths per minute with a tidal volume of 400 ml? (assume a dead space volume of 150 ml)
Alveolar Ventilation Rate will decrease.
spirometer
An instrument for measuring the air entering and leaving the lungs. upon inspiration, air moves into the lungs. The volume of the bell decreases and he pen rises on the tracing
Lung Volumes and Capacities
Average pair of lungs can hold up to 6 liters of air. Tidal volume Residual volume Inspiratory capacity (IC)
Which of the following statements is/are correct?: A: Inspiration at rest involves contraction of both the diaphragm and external intercostals B: Expiration is passive at rest and active during strenuous activity C: Contraction of the internal intercostals expands the ribcage D: Both (a) and (b) are correct and (c) is incorrect E: Statements (a), (b) and (c) are all correct
B: Expiration is passive at rest and active during strenuous activity
During expiration in mammals...
Elastic recoil of the lungs increases intra-alveolar pressure until it is greater than atmospheric pressure.
(T/F) In the gills of marine fish, counter-current exchange is not necessary because oxygen is exceptionally soluble in saltwater.
False
(T/F) The majority (98%) of O2 in blood is transported bound to hemoglobin. This bound O2 is directly responsible for the partial pressure of O2 in blood.
False
True/False: All parts of the airwayare capable of gas exchange
False
True/False: Intrapleural pressure remains constant over the course of a breath (inhalation and expiration)
False
Fill in the blanks with the correct words. 1. A drop in plasma pO2 will _________________ central chemoreceptor firing rate. 2. Increasing the pCO2 of blood will ______________CSF pH. 3. Decreasing arterial pO2 from 100mm Hg to 99 mm Hg will _______________ the firing rate of mammalian peripheral chemoreceptors. 4. Increasing the pCO2 of blood will _____________ blood pH. 5. During hyperventilation, pCO2 will __________________. 6. Increasing CSF [H+] will ______________ firing of central chemoreceptors. 1. increase 2. decrease 3. have little or no effect on
Fill in the blanks with the correct words. 1. A drop in plasma pO2 will have little to or effect on central chemoreceptor firing rate. 2. Increasing the pCO2 of blood will decrease CSF pH. 3. Decreasing arterial pO2 from 100mm Hg to 99 mm Hg will have little or no effect on the firing rate of mammalian peripheral chemoreceptors. 4. Increasing the pCO2 of blood will decrease blood pH. 5. During hyperventilation, pCO2 will decrease. 6. Increasing CSF [H+] will increase firing of central chemoreceptors.
sickle cell disease
Genetic disorder in which red blood cells have abnormal hemoglobin molecules and take on an abnormal shape. Glutamate is replaced by Valine at postion 6 of the beta chain. Can obstruct blood flow; may increase resistance to malaria
Choose the correct answer to complete the statement: Air moves out of the lungs because...
Intrathoracic pressure increases during expiration.
control of ventilation
Primary control centers for breathing located in the medulla and the pons Chemoreceptors (stimulated by acidic pH, and PaCO2) Irritant receptors: epithelium of conducting airways Stretch receptors: protective
During breathing in humans, which of the following does NOT contribute to Vital Capacity?
Residual Volume
Expiratory Reserve Volume (ERV)
The additional volume of air that can be forcibly exhaled after normal exhalation (1100 mL)
myoglobin dissociation curve
The curve is much steeper due to a much higher oxygen affinity as muscles need lots of oxygen for respiration.
Residual Volume (RV)
The volume of air remaining in lungs after maximum (forced) exhalation (1200 mL) ** the lungs cannot be completely emptied of air
alveolar ventilation
The volume of air that reaches the alveoli per minute. (volume of fresh air per breath reaching alveoli) x (number of bpm) *** Need to consider dead space (volume of fresh air per breath reaching alveoli)= (breath volume - dead space)
(T/F) During normal quiet breathing, intrapleural pressure is negative during both inspiration and expiration.
True
True/False: Inspiring a larger volume of air does not affect the driving force for gasexchange
True
gases in solution
When temperature remains constant ,the amount of a gas that dissolves in a liquid depends both on the solubility of gas in the liquid & partial pressure of the gas.
