Name the 5 functions of the respiratory system
1. Regulation of blood pH. -- RS can change blood pH by changing blood carbon dioxide.
2. Production of chemical mediators. -- angiotensin-converting enzyme is produced in lungs and is important to blood pressure regulation.
3. Voice production -- air mov
describe the nasopharynx
lined with pseudostratified ciliated columnar epithelium with goblet cells. Debris-labed mucus from nasal cavity is moved through the nasopharynx and swallowed. Two auditory tubes from the middle ears open into to the nasopharynx.
Describe the oropharynx
Air, food and drink pass through. Moist stratified squamous epithelium protects it from abrasion. palatine and lingual tonsils.
Describe the laryngopharynx
Food and drink pass through here and on to the esophagus. Small amount of air is swallowed as well. Too much air can cause excess gas in stomach and belching. lined with stratified squamous epithelium.
What makes up the upper respiratory tract?
external nose, nasal cavity, and pharynx.
What makes up the lower respiratory tract?
larynx, trachea, bronchi and lungs.
Describe the Larynx cartilage.
Three are unpaired. The thyroid cartilage and cricoid form most of the larynx. The epiglottis covers the opening of the larynx during swallowing. Six of the cartilages are paired. The vocal folds attach to the arytenoid cartilages.
What is the function of the Larynx?
maintains an open air passageway, regulates the passage of swallowed materilas and air. produces sounds, and removes debris from the air.
How are sound waves produced in the Larynx?
vocal folds vibrate when air passes through the larynx. Tightening the folds produces sounds of different pitches by controlling the length of the fold. which is allowed to vibrate.
Describe Alveoli
small, air-filled chambers where gas exchange between the air and blood takes place. As the respiratory bronchioles divide to form smaller repsiratory bronchioles, the number of attached alveoli increases.
Describe type I and type II pneumocytes
Type I is thin squamous epithelial cells that form 90% of the alveolar surface and where most of the gas exchange takes place here. Type II are round cube-shaped secretory cells that produce surfactant, which makes it easier for the alveoli to expand duri
What is surfactant?
mixture of lipoproteins produced by type II pneumocytes. They form a monomolecular layer over the surface of the fluid within the alveoli to reduce the surface tension.
What makes up the membrane and what happens there?
formed by the alveolar walls and surrounding pulmonary capillaries with some contributions to by the respiratory bronchioles and alveolar ducts. This is where gas exchange between the air and blood takes place.
List the muscles of inspiration
diaphragm, external intercostals, pectoralis minor, and scalenes.
List the muscles of exspiration
muscles that depress the ribs and sternum, such as internal intercostals, and transverse thoracis, which are assisted by the abdominal muscles.
explain the steps of inspiration and exspiration
During inspiration the diaphragm contracts downward, muscle contract and pull upward and increase the size of the thoracic cavity and decreases the pressure inside. As a result air rushes in and fills the lungs.
During exspiration the diaphragm relaxes, v
Describe how "bucket handle motion" and "pump-handle motion" increase and decrease the size of the thoracic volume.
Elevation of the rib in the "bucket-handle" movement increases thoracic volume laterally. As the rib is elevated, rotation of the rib in the "pump-handle" movement increases thoracic volume anteriorly.
Explain Boyle's Law and discuss how it applies to ventilation.
P=k/V where P is pressure, k is a constant and v is volume. Body temperature is a constant. Boyle's law states that, in the thoracic cavity or an alveolus, pressure is inversely proportional to volume. As volume increases, pressure decreases and the oppos
Explain Dalton's Law and discuss how it applies to gas diffusion at the respiratory membrane.
The partial pressure of a gas in a mixture of gases is the percentage of the gas in the mixture. Gases move from areas of higher to lower partial pressure. The greater the difference in partial pressure between two points, the greater the rate of gas move
Explain Henry's Law and discuss how it applies to gas diffusion at the respiratory membrane.
The concentration of a gas dissolved in a liquid is equal to the partial pressure of the gas over the liquid times the solubility coefficient of the gas.
Only a small amount of gases in air dissolves in fluid linging the alveoli. Carbon Dioxide, is 24 tim
What happens at the end of expiration?
intra-alveolar pressure is equal to barometric air pressure and there is no air movement. Palv = 0
What happens during inspiration?
increased thoracic volume results in increased alveolar volume and decreased intra-alveolar pressure. Barometric air pressure is greater than intra-alveolar pressure, and air moves into the lungs. Pb > Palv
What happens during end of inspiration?
intra-alveolar pressure is equal to barometric air pressure and there is no air movement. Palv = Pb
What happens during expiration?
Decreased thoracic volume means decreased alveolar volume and increased intra-alveorlar pressure. Intr-alveolar pressure is greater than barometric air pressure, and air moves out of the lungs.
What is Pleural pressure (Ppl)?
Pressure in the pleural cavity. When pleural pressur is less than intra-aveolar pressure, the alveoli tend to expand.
During inspiration, pleural pressure decreases because thoracic volume _________.
increases
As inspiration begins, intra-avolar pressure decreases below barometic air pressure because the decreased pleural pressure causes alveolar volme to __________.
increase
During inspiration, air flows into the lungs because intra-alveolar pressure is _______ than barometric air pressure.
lower
During expiration, pleural pressure ________ because thoracic volume decreases.
increases
As expiration begins, intra-alveolar pressure increases above barometric air pressure because the increased pleural pressure causes alveolar volume to _________.
decrease
During expiration, air flows out of the lungs because intra-alveolar pressure is ______ than barmoetric air pressure.
greater
What would happen without surfactant in inspiration and expiration?
Without surfactant in inspiration and expiration the force prduced by surface tension can be as high as 30mm Hg.
What is compliance?
A measure of the ease with which the lungs and thorax expand.
What is the compliance of the thorax and lungs in a normal person?
0.18 L/mm Hg
A lower compliance means that it is harder to expand the lungs and thorax.
Name some conditions that decrease compliance
pulmonary fibrosis,
Name some conditions that result in the collapse of the alveoli
infant respiratory distress syndrome and pulmonary edema
Name some conditions caused by restricted air flow
asthma, bronchitis and lung caner.
What is Spirometry?
The process of measuring volumes of air that move into and out of the respiratory system.
What is the spirometer?
device used to measure these pulmonary volumes.
What is Tidal volume?
volume of air inspired or expired with each breath. As you sit and breath normally. 500 mL
What is Inspiratory reserve volume?
amount of air that can be inspired forcefully after inspiration of the tidal volume. Take a deep breath as far as you can.
What is expiratory reserve volume?
amount of air that can be forcefully expired after expiration of the tidal volume. Pushing all the air out that you can.
What is residual volume?
volume of air still remaining in the respiratory passages and lungs after the most forceful expiration.
What is pulmonary capacities?
the sum of two or more pulmonary volumes.
Inspiratory capacity, functional residual capacity, vital capacity, and total lung capacity.
What is inspiratory capacity?
tidal volume plus the inspiratory reserve volume, which is the amount of air a person can inspire maximally after a normal expiration. Take an inspiratory capacity before jumping into water so that you can stay in longer.
What is functional residual capacity?
expiratory reserve volume plus the residual volume, which is the amount of air remaining in the lungs at the end of a normal expiration.
What is Vital capacity?
the sum of the inspiratory reserve volume, the tidal volume and the expiratory reserve volume, which is the maximum volume of air a person can expel from the respiratory tract after a maximum inspiration. after you take a deep breath in (TLC)and you let o
What is total lung capacity?
sum of inspiratory and expiratory reserve volumes plus the tidal volume and the residual volume. Take a deep breath.
What is forced expiration volume?
the patient inspires maximally and then exhales maximally into a spirometer and the volume of air expired at the end of the test is the vital capacity.
What is anatomical dead space?
formed by the nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, and terminal bronchioles.
What is the physiological dead space?
the anatomical dead space plus the volume of any alveoli in which gas exchange is less than normal.
What is partial pressure?
The pressure exerted by each type of gas in a mixture.
Explain how Dalton's Law can show that the partial pressure of oxygen in alveolar air is around 104 mm Hg
Because oxygen in the alveolar air is 13.6%of the volume of alveolar air pressure, the partial pressure resulting from from oxygen is 0.136 x 760.
what are the 3 reason's why the compositions of alveolar air and expired air are not identical to the composition of atmospheric air?
1. air entering the respiratory s. during inspiration is humidified.
2. oxygen diffuses from the alveoli into the blood and CO2 diffuses from the pulmonary capillaries into the alveoli.
3. air within the alveoli is only partially replaced with atmospheric
According to Henry's Law, how do partial pressure and solubility of a gas affect its concentration in a liquid?
If the partial pressure of a gas in the air is greater than in the liquid, gas molecules diffuse into the liquid. If pp of a gas in the air is less than in the liquid, gas molecules diffuse out of the liquid. If pp is air is equal there is no diffusion.
Describe the 4 factors that affect the diffusion of gases through the respiratory membrane.
1. Respiratory membrane thickness -- increased thickness causes decreased rate of diffusion. Thickness causes pulmonary edema.
2. Diffusion Coefficient -- a measure of how easily a gas diffuses into and out of a liquid or tissue.
3. Surface Area -- total
What deceases are caused by inflammation of the lung tissues?
Tuberculosis, pneumonia, or silicosis.
Even people in "good health" may have trouble breathing at high altitudes. Explain how this can happen, even when ventilation of the lungs increases.
At high altitudes, the atmospheric Po2 results in a decrease in alveolar Po2 and less oxygen diffusion into lung tissues. If arterioles are sensitive to decreased oxygen levels constriction of the arterioles reduces blood flow through the lungs, and the a
Describe the partial pressure of oxygen and carbon dioxide in the alveoli, lung capillaries, tissue capillaries, and tissues
The Po2 in the alveoli is 104 mm Hg. Carbon Dioxide is 40 mm Hg and is continually removed from the alveoli as air is expired. Blood coming from heart in the pulmonary capillaries has a Po2 of 40 and a Pco2 of 45, therefor oxygen diffused from the air in
Explain the oxygen - hemoglobin dissociation curve
the percent saturation of hemoglobin in the blood at different blood Po2 values.
In Co poisoning, Co binds to hemoglobin, and decreases the uptake of oxygen by hemoglobin. When Co binds to hemoglobin dissociation curve shifts to the left. How does this shift affect the ability of tissues to get oxygen?
Curve normally shifts to the right in tissues. The shift of the curve to the left caused by CO reduces hemoglobin's ability to releases oxygen to tissues. Shift to the left may slightly increase the hemo ability to pick up oxygen, but this effect is offse
Explain the Bohr effect.
In the tissues, As pH decreases, Pco2 increases, or temperature increases the curve shifts to the right, resulting in an increased release of oxygen.
In the lungs, as pH increases, Pco2 decreases, the curve shifts to the left, resulting in an increased ab
Explain why it is necessary to have fetal hemoglobin that has a greater affinity for oxygen than maternal hemoglobin.
Fetal hemo is 50% greater than maternal. Fetal hemo is different because it oxygen-hemo dissociation curve is to the left of the maternal curve. fetal hemo can hold on more tightly to oxygen. BPG does not cause fetal hemo to release oxygen.
What is 2,3-bisphosphoglycerate (BPG)?
binds to hemo reducing its affinity for oxygen, which increases its ability to release oxygen.
How does movement of CO2 from fetal blood into maternal blood increase the movement of oxygen from maternal blood into fetal blood?
As a result of this movement, pH inside maternal red blood cells decreases, affinity of maternal hemo for oxygen decreases, and more oxygen is released (right shift). Movement of CO2 from fetal blood into maternal blood decreases CO2 levels inside fetal b
Name the 7 steps of gas exchange in the tissues
1. In tissues CO2 diffuses into the plasma and into red blood cells. Some remains in plasma.
2. In blood cells, CO2 reacts with water to form carbonic acid (H2CO3) in a reaction of enzyme carbonic anhydrase (CA).
3. Carbonic acid dissociates to form bicar
Name the 7 steps of gas exchange in the lungs
1. in lungs CO2 diffuses from RBC and plasma into the alveoli.
2. Carbonic anhydrase catalyzes the formation of CO2 and H2O from H2Co3.
3. Bicarbonate ions and H+ combine to replace H2Co3.
4. In the chloride shift electrical neutrality is maintianed by th
What is the Haldane effect?
CO2 ability to bind to hemo is affected by the amount of oxygen bound to hemo. The smaller the amount of oxygen bound to hemo, the greater the amount of CO2 able to bind to it. and vice versa.
What are the two sections of the medullary respiratory center and what is their function?
The dorsal respiratory group and the ventral respiratory group. they are bilaterally paired and cross-communicate so that respiratory movemnets are symmetrical. Dorsal group is most active inspiration but some are active during expiration. responsible for
What is the pontine respiratory group and it's function?
collection of neurons in the pons. some active only durig inspuration and some during ex. or both. hahs connections with the medullary respiratory center plays a role in switching between inspiration and expiration.
Recall how the brain, chemoreceptors, Hering - Breuer reflex, proprioceptors, and skin receptors can effect breathing.
Speech, emotion, voluntary control of breathing, and action potentials in motor pathways have both increase and decrease ventilation.
Medullary chemoreceptors have increase ventilation.
Carotid and aortic body chemoreceptors have increase ventilation.
Her
How do pH and CO2 effect respiration?
Medullary chemoreceptors detect the increase in blood pH and this causes a decrease in breathing which causes increase blood CO2. Blood pH decreases and restores homeostasis. When blood pH decreases the Medullary chemoreceptors dectect athe decrease and t
How does a decrease in blood pH affect respiratory rate?
a decrease in blood pH causes a increase in breathing.
How does a decrease in carbon dioxide affect respiratory rate?
a decrease in CO2 causes a decrease in breathing.
What is hypoxia?
a decrease in oxygen below its normal values.
Why must arterial PO2 change significantly before it affects respiratory rate?
consider the oxygen-hemo dissociation curve. Because the s shape of the curve, at any Po2 above 80 mm Hg nearly all of the hemo is saturated with oxygen.
Arrange from highest to lowest PO2
(1) PO2 of pulmonary veins
(2) PO2 of pulmonary artery
(3) PO2 of alveolar air
3,1,2