Respiratory System Review Guide

What exactly is positive cooperativity in regards to hemoglobin and its buddy oxygen?

-As the PO2 increases the hemoglobin molecule acquires at least one molecule of O2. -The binding of one molecule of O2 to hemoglobin causes a conformational change in the hemoglobin that INCREASES THE AFFINITY of the remaining subunits for oxygen.

What gas in the CSF do central chemoreceptors in the medulla respond to? What happens to the depth and rate of breathing when the levels of this blood gas are high?

-Carbon Dioxide -breathe faster

What is the major muscle associated with breathing? What are some of the accessory muscles? Make sure to identify which accessory muscles are more important for inhalation vs. exhalation.

-Diaphragm: contraction draws air into lungs. 75% of normal air movement -external intercostal muscles Accessory muscle of Inhalation: sternocleidomastoid muscle, scalene muscles, pectoralis minor muscle, and serratus anterior muscle Accessory muscle of exhalation: internal intercostal muscles, transversus thoracis muscle, external oblique muscle, rectus abdominus, and internal oblique muscle

List AND describe the respiratory defense system components. Don't forget to include the mucociliary escalator!

-Each day approx. a quart of mucus containing lysozyme is secreted to trap particles and kill bacteria -Defensins (natural antibiotic) are secreted to kill microbes -Nasal cavity exposure to unpleasant stimuli (infection) increases production of mucus. ex: "common cold" -Nasal mucosa richly supplied w/ nerve endings, irritating particles trigger sneeze to blow irritants out (100 MPH) -Nasal cavity, cilia sweep mucus with trapped debris toward pharynx to be swallowed. -Lower respiratory system, cilia move mucus upward toward pharynx: Mucociliary escalator

List AND describe the basic functions of the respiratory system.

-Gas exchange between air/blood -Moving air to/from exchange surfaces of lungs (simple squamous epithelium) -Protecting surfaces -Dehydration, temp. changes, pathogen invasion -Producing communication sounds -Facilitating olfaction

Describe the protective reflexes from the airways and the lungs.

-Irritant receptors in respiratory mucosa: Stimulate vagal afferents (approach) to medulla, results in bronchoconstriction or coughing (protective mechanism) -Stretch receptors in airways - inflation reflex: Excessive inflation triggers reflex; Stops inspiration -Chemoreceptor Reflexes: Respiratory centers are strongly influenced by chemoreceptor input from CN 9 and CN 10

What are the two respiratory centers of the medulla? Draw some sort of diagram or flowchart showing how these two centers allow a person to breathe "quietly." Then draw another diagram or flowchart showing how these two centers function to allow a person to breathe forcefully.

-Medulla oblongata sets the pace of respiration 1. Dorsal Respiratory Group (DRG) -Inspiratory center -Functions in quiet and forced breathing 2. Ventral Respiratory Group (VRG) -Inspiratory AND expiratory center -Functions only in forced breathing Quiet Breathing: -Brief activity in the DRG: Stimulates inspiratory muscles -DRG neurons become inactive: Allowing passive exhalation

Describe the mechanism by which the nose warms and humidifies air.

-Mucus humidifies air inhaled 1. Air in: -Swirls around, picks up heat and evaporated water from nasal mucus -Protects delicate respiratory surfaces from being effected 2. Air out: -Warmer air 'warms' nasal mucus and water condenses back into the mucus -Breathing through your nose helps prevent heat loss and water loss

What is the difference between the nasopharynx, oropharynx, and laryngopharynx?

-Nasopharynx: only air passage, soft palate and uvula block while swallowing -Oropharynx: both food and air pass -Laryngopharynx: just below epiglottis

What is the normal composition of air?

-Nitrogen (N2) about 78.1% (Inert) -Oxygen (O2) about 20.9% (percentage is the same at sea level and at a higher elevation). -Water vapor (H2O) about 0.5% -Carbon dioxide (CO2) about 0.04%

Compare and contrast pulmonary ventilation, external respiration, and internal respiration.

-Respiratory System: 1. Pulmonary ventilation: movement of air into and out of lungs - gases continually changed 2. External respiration: Gas exchange between blood and lungs -Circulatory system: 1. Internal respiration: (O2 dump and CO2 uptake) gas exchange between systemic blood and cells

Summarize the Haldane effect.

-The Haldane effect describes how OXYGEN concentrations determine hemoglobin's affinity for carbon dioxide. Oxygen is going to drive carbon dioxide off of the hemoglobin. -High oxygen concentrations enhance the unloading of carbon dioxide -low oxygen concentrations promote loading of carbon dioxide onto hemoglobin -oxygen causes the change in carbon dioxide levels

Draw the relationship of the structures that comprise the respiratory membrane and relate this to the speed of diffusion of blood gases.

-The thin membrane of alveoli where gas exchange takes place -Three Layers of the Respiratory Membrane 1. Squamous epithelial cells lining the alveolus 2. Endothelial cells lining an adjacent capillary 3. Fused basement membranes between the alveolar and endothelial cells -diffusion: across respiratory membrane is very rapid because distance is short and gases (O2 and CO2) are lipid soluble

Compare the roles of Type I vs. Type II Pneumocytes.

-Tiny, moist, multi-lobed air sacs made of simple squamous cells (called Type I Pneumocytes) -Thin wall allows air exchange with thin-walled capillaries of circulatory system. -Type II Pneumocyte -Produces Surfactant - decreases surface tension in the alveoli -The contractive tendency of the surface of a liquid that allows it to resist an external force -Premature infants that lack surfactant suffer from respiratory distress syndrome

Compare and contrast the structures of the upper and the lower respiratory systems.

-Well, the primary difference is the location of the infection. Infections can be caused by a number of things, including bacteria, disease, and viruses. Frequently, pharmacists and doctors are able to better understand the nature of the conditions. -An upper respiratory tract infection would include infection of the nose, nasal cavity, nasal and paranasal sinuses, and the larynx and pharynx. -A lower respiratory tract infection would include infection of the trachea, bronchi or bronchial tree, and the lungs or pleural cavity.

Use Henry's Law to explain why a person SCUBA diving might get the bends if they ascend to the surface of the water too quickly.

-When gas under pressure comes in contact with liquid: gas dissolves in liquid until equilibrium is reached (the more pressure you put on a gas, the more gas you can get in a liquid) -At a given temperature: amount of a gas in solution is proportional to partial pressure of that gas -The actual amount of a gas in solution (at given partial pressure and temperature): Depends on the solubility of that gas in that particular liquid

What happens to the level of activity in the respiratory centers in the brainstem when oxygen demand increases?

-cardiac output and respiratory rates increase under neural control. Have both voluntary and involuntary components

What is the epiglottis? How does it "work?"

-during swallowing, the epiglottis tips downward to cover the larynx and protect the airway

What is Boyle's Law? Does it describe a direct or inverse relationship? Explain!

-if you decrease the volume of a gas, its pressure will rise. If you increase the volume of a gas, its pressure will fall. (Indirect relationship) -air will flow from higher pressure to lower pressure (diffusion)

What exactly is pneumonia?

-inflammation of lobules. -causes fluid to leak into alveoli -compromises function of respiratory membrane -CPAP (breathing treatments), albuterol, antibiotics

What are the two respiratory centers of the pons?

-pons modify the rate and depth of respiration 1. Apneustic Center (the inhibitor) -Provides continuous stimulation to its DRG center 2. Pneumotaxic Centers (inhibits the inhibitor) -Inhibit the apneustic centers -Promote passive or active exhalation

Use the oxyhemoglobin dissociation curve to explain how a person can be at a higher altitude and still have a relatively decent percent oxygen saturation of their hemoglobin.

-relates the saturation of Hb to partial pressure of oxygen. -Hb changes shape each time a molecule of oxygen is bound -each oxygen bound makes next oxygen binding easier -allows Hb to bind oxygen when oxygen levels are low -at a partial pressure of approximately 25 mmHg, Hb is still 50% saturated -partial pressure of oxygen saturation will be less in blood

How do terminal bronchioles and respiratory bronchioles differ?

-respiratory bronchioles: arise form terminal bronchioles which end in alveolar sacs with alveoli covering like grapes on a bunch -terminal bronchioles: smallest, less than .5mm in diameter

Summarize how exercise will affect the oxyhemoglobin dissociation curve.

-shift curve to the right: 1. decrease pH (more acidic) 2. increase temperature 3. increase PCO2 (carbon dioxide) -muscle tissue's demand for oxygen will increase and Hb will let go of its bound oxygen more readily

What is the normal volume of inspiration during quiet breathing?

-spirometry measures how fast and how much air you breathe out. -tidal volume: 500 mL

Diagram, on the molecular and cellular level, the Bohr Effect and how it produces a lower pH in metabolically active tissues.

-the effect of pH on the hemoglobin saturation curve. Decreases pH and moves the curve to the right. -Caused by increasing levels of CO2: 1. Remember CO2 is going to be present around cells that are metabolically active (increase in CO2 ) 2. CO2 diffuses into RBC 3. An enzyme called carbonic anhydrase, catalyzes reaction with H2O 4. Produces carbonic acid (H2CO3): -Carbonic acid (H2CO3) dissociates into hydrogen ion (H+) and bicarbonate ion (HCO3-) -Some hydrogen ions diffuse out of RBC, lowering pH, while other hydrogen ions are buffered by the hemoglobin in the RBC -Carbon dioxide dictates where oxygen is going to go (where it is needed most)

Which two cranial nerves are involved with the peripheral chemoreceptors? What blood gas do they both respond to? What happens to the depth and rate of breathing when the levels of this blood gas are low?

1. CN 9 (glossopharyngeal nerve) - from carotid bodies -stimulated by changes in blood pH or PO2 2. CN 10 (vagus nerve) -from aortic bodies -stimulated by changes in blood pH or PO2 -If blood gases are low then you are going to breathe slower

Use the concept of partial pressures of gases to explain how gases are exchanged at the level of the alveoli and in peripheral tissues.

1. Gas exchange in lungs: -Blood arriving to lungs in pulmonary arteries has: low PO2 and high PCO2 -The concentration gradient causes: O2 to enter blood and CO2 to leave blood -Rapid exchange allows blood and alveolar air to reach equilibrium -high pressure to low pressure 2. gas exchange in peripheral tissues: -PO2 40 mm Hg -PCO2 45 mm Hg -Concentration gradient in peripheral capillaries is opposite of lungs: CO2 diffuses into blood and O2 diffuses out of blood

What are the three functions of the larynx?

1. Provide open airway 2. Switching mechanism for food and air 3. Voice production (houses vocal cords)

List AND describe the four processes of the respiratory system, making sure to compare and contrast internal and external respiration.

1. Pulmonary ventilation: movement into and out of the lungs 2. External respiration: between the lungs and the blood 3. Internal respiration: between the blood and the cells 4. Transport of respiratory gases: between the lungs and the cells

Describe or draw, in detail, the bronchiole tree.

1. The Conducting Zone: -Rt. & Lt. Primary (Mainstem) Bronchi: formed by division of trachea Rt. side is wider, shorter and more vertical than Lt. -Secondary Bronchi: 3 on right and 2 on left, each goes to one lobe of lung -Tertiary Bronchi: divide further into 4th order, 5th order - 23rd order bronchi -Bronchioles: (no cartilage) under 1mm in dia, have layer of SMOOTH MUSCLE! -Terminal Bronchioles: smallest, less than 0.5mm in dia. 2. The Respiratory Zone: presence of thin-walled air sacs = alveoli -Respiratory Bronchioles arise from terminal bronchioles which end in alveolar sacs w/ alveoli covering like grapes on a bunch

Why do we have smooth muscle in bronchioles?

1. To assist exhalation: This theory postulates contraction of these smooth muscles might assist with exhalation. Yet Mitzner concludes that, "However, the magnitude of such an effect, if it exists, must be quite small and of little physiologic significance. Gas exchange in the lung can be performed quite well with fully relaxed airway smooth muscle." 2. To aid expectoration (spitting up phlegm): Again, peristalsis might help move secretions from the lower airway to the upper airway to help you cough it up. Yet, evidence shows that cilia (small hair like structures in your lungs) work like an escalator to bring up mucus, and then you cough it up. There is no evidence that smooth muscles have any use in coughing up junk from your lungs. 3. Protecting the lungs: Believe it or not, your lungs are supposed to be sterile. Contracting of bronchial smooth muscle might prevent substances from entering the lungs. However, to maintain life, an organism must breath. And, to draw in air, lung muscles must be relaxed. If contracted for an extended time to "protect the lungs" one would not ventilate, and would therefore die. Thus, this theory holds little merit.

List AND describe the three ways in which carbon dioxide is transported in the blood, making sure to clearly illustrate the role of carbonic anhydrase!

1. converted to carbonic acid (most important) 2. bound to hemoglobin within red blood cells: CO2 is not bound to the iron/heme. CO2 binds to the globin chains (alpha and beta chains) 3. dissolved in plasma -carbonic anhydrase catalyzes reaction with H2O -70% of CO2 is converted to carbonic acid. It is the acid that results from carbon dioxide (acts like an acid). Made by carbonic anhydrase.

What are the three cartilages associated with the larynx?

1. corniculate cartilage 2. cuneiform cartilage 3. epiglottis (elastic cartilage)

Compare and contrast hypercapnia and hypocapnia.

1. hypercapnia: an increase in arterial CO2 -hypoventilation (abnormally low respiratory rate) -allows CO2 buildup in blood -stimulates chemoreceptors in the medulla oblongata to restore homeostasis. Respiratory rate should go up. 2. hypocapnia: a decrease in arterial PCO2 -hyperventilation results in abnormally low PCO2 -stimulate chemoreceptors to decrease respiratory rate

What is the significance of the trachea having cartilaginous rings?

15-20 rings, they keep the airway open

Review the structure of hemoglobin (Hb)

4 heme groups attached by iron rings, 4 oxygen molecules can bind to one hemoglobin in a reversible reaction Factors that can affect it: -P O2 if blood, blood pH, Temperature, metabolic activity within RBCs

Explain how anatomical dead space relates to Alveolar Ventilation.

Anatomic Dead Space: -Only a part of respiratory minute volume reaches alveolar exchange surfaces. -Volume of air remaining in conducting passages is Anatomic Dead (not contributing to getting oxygen into bloodstream) Space -NO gas exchange! -Alveolar Ventilation: Amount of air reaching alveoli each minute. Calculated as: Alveolar Ventilation = (Tidal Volume - Anatomic Dead Space) X Respiratory Rate

Lower Respiratory Tract includes...

Bronchial tree Bronchi Bronchioles Alveolar ducts/sacs Alveoli Surfactant Lungs Pleura

Relate bronchodilation and bronchoconstriction in terms of asthma and the main treatment for an acute asthma attack. Don't forget to include which receptors are involved!

Bronchodilation: dilation of bronchial airway; caused by sympathetic ANS activation and it reduces resistance Bronchoconstriction: constricts bronchi; can be caused by parasympathetic ANS activation, histamine release or asthma (chronic inflamed hypersensitive smooth muscle in bronchiole passage Asthma responds to albuterol which binds to beta 2 receptors causing bronchodilation

Where exactly does the carbon dioxide bind to hemoglobin when forming carbaminohemoglobin?

Carbon dioxide binds to the globin proteins (alpha and beta chains) not to the iron in the heme group

What is the significance of the cardiac notch?

Cardiac Notch: the notch in the anterior border of the superior lobe of the left lung that accommodates the pericardium.

What is the function of the trachealis muscle?

Controlled by ANS -Sympathetic; increases diameter

What role does surfactant play? Where is it found? What problems could an absence of surfactant result in?

Decreases surface tension in the alveoli, has a tendency of a surface of a liquid that allows it to resist an external force, it is found coating the alveoli and the absence of surfactant could cause respiratory distress because alveoli resist stretching, reduce SA and recoil following stretching (premature infants)

Use Dalton's Law to explain the idea of partial pressures.

Each gas contributes to the total pressure in proportion to its number of molecules

What does FEV describe?

Forced Expiratory Volume: % of vital capacity exhaled/time. Healthy adult: 75-80% in 1 second -FAST

Take some time and go back to make sure that you understand what it is going on in the capillaries of the alveoli and the capillaries of peripheral tissues in regards to gas exchange. You need to know the details, not just that oxygen and carbon dioxide are exchanged!

Haldane Effect Oxygen: loaded in the lungs Carbon Dioxide: unloaded in the lungs Oxygen in peripheral tissues: unloaded Carbon Dioxide: loaded in the peripheral tissues Bohr Effect: 7% CO2 in plasma, 93% in RBC (23% in hemoglobin)

What is the significance of the hilum of the lung?

Hilum: Hila, or lung roots, are relatively complicated structures that consist mainly of the major bronchi and the pulmonary arteries and veins. The hilum of the lung is found on the medial aspect of each lung, and it is the only site of entrance or exit of structures associated with the lungs.

How many lobes are there in each lung? What are they? Where would you find the apex of the lung? How about the base?

In the right lung there are three lobes. In the left lung there are two lobes. The apex of the lungs are on the most superior part of the lungs and the base is the most anterior part of the lungs.

31. In terms of pressure differences, explain how lung volume decreases and increases when a person inspires AND expires. You should take some time on this one and make sure to address the following terms:

Inspiration (inhalation): contracts, enlarging thoracic cavity Expiration: diaphragm relaxes. Air is exhaled by elastic recoil of lungs/tissues lining thoracic cavity and abdominal musclesa. a. Intrapulmonary (intralveolar pressure): intrapulmonary pressure decreases. Lungs expand with visceral pleura b. Visceral and parietal pleura c. Intrapleural pressure: intrapleural pressure decreases. As volume of thoracic cavity increases, visceral pleura clings to parietal pleura d. Transpulmonary pressure: Transpulmonary pressure: intrapleural minus intrapulmonary pressure e. Sucking vs. pushing: outside air is pushing air into lungs. f. Lung tissue compliance

What is pulmonary ventilation?

Movement of air in and out of the lungs, no gas exchange

Explain the importance of the nasal conchae and nasal meatuses.

Nasal Conchae: The nasal conchae are covered with a mucus-secreting mucous that moistens and warms the entering air and helps cleanse it of debris. The scroll-shaped conchae increase the turbulence of air flowing through the nasal cavity. This swirling forces more of the inhaled air into contact with the warm, damp mucous and encourages trapping of airborne particles (dust, pollen, bacteria) in the sticky mucus. Nasal Meatus: A nasal meatus is a nasal passage of the nasal cavity, of which there are three; the superior meatus, middle meatus and inferior meatus

Upper Respiratory Tract includes...

Nose (nostrils) Mouth Pharynx Epiglottis Larynx Trachea

Describe the locations AND function(s) of the sinuses.

Paranasal sinuses: Frontal, sphenoidal, ethmoid and maxillary -Lighten the skull -Warm and moisten air -When passages connecting sinuses and nasal cavity are blocked w/ mucus, the air is absorbed by the mucosa, causing a partial vacuum = sinus headache

Provide AND explain the equation for Pulmonary Ventilation.

Pulmonary ventilation=respiratory rate X tidal volume -respiratory rate: the number of breaths per minute (heart rate) -tidal volume: the volume of air moved per breath

List AND describe ALL of the respiratory volumes AND respiratory capacities. I would draw out the spirogram vs. just staring at it and convincing yourself that you know it!

Respiratory Volumes: 1. Tidal Volume (TV): the amount of air moving into and out of the lungs with each breath 2. Inspiratory Reserve Volume (IRV): air in excess of tidal inspiration that can be inhaled with maximum effort 3. Expiratory Reserve Volume (ERV): air in excess of tidal expiration that can be exhaled with maximum effort 4. Residual Volume (RV): air remaining in lungs after maximum expiration, presents alveoli collapse Respiratory Capacities: 1. Inspiratory Capacity (IC): total amount of air that can be inspired after tidal expiration (TV + IRV) 2. Functional Residual Capacity (FRC): combined residual & expiratory reserve volumes (ERV + RV). The amount of air remaining in lungs after tidal expiration. 3. Vital Capacity (VC): total amount of exchangeable air (TV + IRV + ERV) 80% of TLC = 6000 - 4200mL 4. Total Lung Capacity (TLC): sum of all lung volumes (TV + IRV + ERV + RV)

If a person were to aspirate (inhale) a hot dog, which lung would it be more likely to enter? Why?

Right lung because the R primary bronchi is more of a straight shot from the trachea and into the lung

How do the respiratory zone and conducting zone differ?

The conducting zone consists of a series of interconnecting cavities and tubes both outside and within the lungs. The respiratory zone consists of tubes and tissues within the lungs where gas exchange occurs.

Describe the anatomical location of the trachea to the esophagus.

The esophagus lies first behind the trachea and then behind the left atrium. The trachea is anterior to the esophagus.

Explain why hyperventilation leads to hypocapnia.

There is an abnormally low PCO2 (hypocapnia)

What is the importance of the bicarbonate/chloride exchanger in the membrane of a RBC?

To control how many hydrogen ions get into the plasma in order to control how much pH drops

Draw AND explain the pleural layers in the lung.

Visceral Layer: covers, protects and cushions lungs, lines the lungs themselves Parietal Layer: lines the inside of the thoracic cavity -the space between the layers is the pleural space which is occupied by pleural fluid

Draw out AND label an oxyhemoglobin dissociation curve illustrating how oxygen unloading is affect by the following:

a. Increase in temperature: more oxygen is released. Oxygen-hemoglobin saturation curve shifts to the right b. Decrease in temperature: less oxygen is released. Curve shifts to the left c. Increase in pH: less oxygen is released. Curve shifts to the left d. Decrease in pH: more oxygen is released. The oxygen-hemoglobin saturation curve shifts to the right.

Describe the differences (in structure and function) between bronchi, bronchioles, and alveoli? Which one has smooth muscle? What is the significance of this?

bronchi- have cartilage, no smooth muscle bronchioles- have smooth muscle, have no cartilage alveoli- deflated sac of single cell epithelium where the gas exchange between blood and oxygen and CO2 occurs

Explain why people breathe into a paper bag if they are hyperventilating and cannot slow down their respiratory rate?

increase the CO2 levels

What two regions of the brainstem are the respiratory centers located in?

pons and medulla oblongata

If a tissue has a high oxygen reserve, how is hemoglobin going to respond in terms of giving up its oxygen?

the amount of O2 released depends on interstitial PO2 -inactive tissues have a higher PO2 so less O2 will be unloaded in tissues that aren't doing that much work