What is the order of air going through the respiratory tract?
- 1. Nasopharynx
- 2. Pharynx
- 3. Epiglottis
- 4. Larynx
- 5. Vocal cords
- 6. Trachea
- 7. CARINA
- 8. Main Stem Bronchus
- 9. Bronchi
- 10. Bronchiole
- 11. Respiratory Bronchioles
- 12. Alveolar Ducts
- 13. Alveolar Sacs
What makes up the upper respiratory tract?
What makes up the lower respiratory tract?
- Primary bronchi
What covers the lungs?
- 2 layers of pleura
- Visceral (inside)
- Parietal (outside)
What is between the two layers of pleura?
- Potential space
- Allows lungs to expand
What is generated by the intercostals muscles and diaphragm constriction?
- Negative pressure
- Makes body suck in air
What is the role of the epiglottis?
During swallowing, prevents food from going into the trachea and instead directs it to the esophagus, which is posterior.
What is the role of the sinuses?
- 1. Heat and humidify air
- 2. Resonate voice
- 3. Lighten weight on skull
- 4. Cushioning effect when blow to the face
What are the different types of sinuses?
- Frontal sinus
- Ethmoid sinus
- Maxillary sinus
Where is the frontal sinus located?
Above the eyes
Where is the ethmoid sinus located?
Sides of the nose
Where is the maxillary sinus located?
Under the eyes
Where are the sinuses located? What is special about the structure?
- Within the upper respiratory tract
- Paired structures
Where does gas exchange occur in the respiratory system?
What is the function of the vocal cords?
They vibrate, modulating the flow of air being expelled from the lungs during phonation
What makes up the basement membrane of an alveolar sac?
- 2 cells are required for exchange of gas at the alveolar membrane: The Alveolar Type 1 Cells and the Capillary Endothelial Cells
- Type 2 alveolar cells produce surfactant and are NOT involved in the passive diffusion of oxygen and carbon dioxide
Where are Type 1 cells found in the respiratory system?
What is the function of Type 1 cells?
Diffusion of oxygen and carbon dioxide
Where are Type 2 cells found in the respiratory system?
In the lungs
What is the function of Type 2 cells?
- Produce surfactant
- Reduces the surface tension of the moisture that covers the alveolar walls
- No role in diffusion
In what structure are the bronchiole pharmacologic receptors located?
Smooth muscle surrounding the bronchiole tubes
What is the innervation of the bronchiole pharmacologic receptors and their functions?
- Sympathetic (beta 2 receptors): dilate
- Parasympathetic (M3 cholinergic): constrict
What is one respiratory cycle?
One breath in, one breath out
What does I to E ratio mean?
Time breathing in versus time breathing out
What is the normal I to E ratio?
What I to E ratio is present in asthma?
What I to E ratio is present in hypoventilation?
What is RR?
- Respiratory rate
- The number of breathing cycles per minute
What is the normal RR?
How does RR vary by age?
- Faster as infant, young child
- By about age 16, to normal range
Take a breath in and blow it out
The movement of air in and out of the lungs
- Transfer gases through the cell membrane
- Move oxygen into cells and carbon dioxide out of cells
Carry oxygen through the body (via hemoglobin)
How does Alveolar pressure differ from Atmospheric pressure during inhalation?
Inhalation: Expansion of the thoracic cage reduces alveolar pressure below atmospheric pressure, so air moves into the lungs
How does Alveolar pressure differ from Atmospheric pressure during exhalation?
Due to elastic recoil in a normal state, the Palv will > Patmospheric. Exhalation that requires forced skeletal muscle contraction occurs when forcing a breath out such as using a peak flow meter, blowing up a balloon, performing an FEV1, or during an asthma attack. Here Palv also is > Patmospheric , so there is air flow out.
What is transpleural pressure (Pip)?
Pip (transpleural pressure) = pressure between the pleural and outside chest
What must occur to generate a negative Pip?
- Diaphragm and inspiratory intercostals contract
- Thorax expands
Define dead space.
Air not contacting an alveolar sac
Define tidal volume.
- Amount of air moved in the airways in a single breath
Define residual volume.
- How much air is left over in the lungs following maximal exhalation
Define vital capacity.
How much air goes in/out in a maximal force breath
Define total lung capacity.
- Total amount of air the lung can accommodate
- VC + RV
- Amount of air that is forcibly exhaled in one second
- Should be a majority of the air
What is minute ventilation?
How much air flows or is exchanged in one minute
What is the difference between Minute ventilation and Alveolar ventilation?
- Alveolar ventilation= minute ventilation – dead-space ventilation
- Alveolar ventilation is how much air actually makes to the alveolus
Describe pulmonary compliance.
A measure of the lung’s “stretchability”
What occurs if pulmonary compliance is abnormally high?
- The lungs might fail to hold themselves open
- Prone to collapse
What occurs if pulmonary compliance is abnormally low?
The work of breathing is increased
What is surfactant?
A compound that lowers the surface tension of a liquid
What is the function of a surfactant in the lungs?
- Lowers hydrostatic pressure/surface tension
- Increases lung compliance
- Makes lungs easier to expand
- Allows alveoli’s to stay open
What happens to the amount of surfactant secretion during a deep breath?
When is the production of surfactant done in fetal lungs?
- Late in gestation
- Neonatal infants cannot produce surfactant, leading to respiratory distress
Where in the alveolar sac is surfactant found?
Lining the type 1 cells, in the inner surface of the alveolus
What is pulmonary surfactant made of?
Phospholipids and protein
Describe the diffusion direction and pressure changes found at the alveolar / capillary membrane and at the tissue / capillary membrane.
- Diffusion of oxygen into (toward the blood) the cells
- Outward (toward the alveolar air) diffusion of carbon dioxide
- Pressure change from higher to lower after diffusion
What is the main form of oxygen in systemic arterial blood?
Bound to hemoglobin
What is the main form of carbon dioxide in systemic arterial blood?
As bicarbonate HCO3- (ionic form of CO2)
How might oxygen and carbon dioxide concentrations be affected during hyperventilation?
- Increasing respiratory efforts and increasing minute ventilation
- Breathing off lots of CO2 so the equation pushes right and as a result H+ ion decreases and thus blood pH increases
How might their concentrations be affected during hypoventilation?
- SLOWING down your respiratory efforts so the Minute Ventilation is decreased
- Arterial P CO2 will rise and thus push the carbonic anhydrase equation to the left
- Causing an increase in H+ ion concentration and lowering blood pH
What is the carbonic anhydrase equation?
H+ + HCO3- = H2CO3 = H20 + CO2
What is narcosis?
Coma due to carbon dioxide intake
What is asphyxiation?
Death by lack of oxygen
What is the oxygen content in air?
What is the oxygen content when administering CPR? Is this enough to sustain life?
Describe the basic structure of hemoglobin.
- Contains 4 protein subunits (called globins)
- 2 Alpha subunits, 2 Beta subunits
- Each subunit has one Heme group
Where does oxygen bind to hemoglobin?
Each Heme group binds one O2 molecule at the Fe++ atom
How many molecules of oxygen bind 1 heme group and 1 Hb molecule?
- Heme: one O2 molecule
- Hb: four O2 molecules
Explain the Oxygen – Hb dissociation curve?
As the concentration of oxygen increases, the percentage of hemoglobin saturated with bound oxygen increases until all of the oxygen-binding sites are occupied (100% saturation)
What is the abbreviation for oxygenated hemoglobin?
What is the abbreviation for deoxygenated hemoglobin?
How does the presence of hemoglobin affect oxygen diffusion at the alveolar / capillary membrane?
Hemoglobin binds the O2, and thus makes more O2 diffuse to the blood because the gradient is still lower in the blood (unbound O2)
What are the five measurements in a blood gas analysis?
- 1. Arterial blood pH
- 2. Partial pressure of oxygen
- 3. Partial pressure of carbon dioxide
- 4. Oxygen saturation
- 5. Bicarbonate
What is the abbreviation for the partial pressure of oxygen?
What is the abbreviation for the partial pressure of carbon dioxide?
What is the abbreviation for oxygen saturation?
What is the abbreviation for bicarbonate?
What is acidosis?
Blood pH is less than 7.35
What is alkalosis?
Blood pH is greater than 7.45
What is hypoxemia?
PaO2 is less than 70mmHg
What is hypercarbia?
PaCO2 is greater than 60mmHg
What is hypocarbia?
PaCO2 less than 30mmHg
What is desaturation?
Hb-O2 is less than 90%
What is the difference between arterial and venous blood with respect to PCO2, PO2 & Oxygen Saturation?
- Arterial blood: PaCO2= 40mmHg PaO2=100mmHg Oxygen saturation=near 100%
- Venous blood: PaCO2= 46mmHg PaO2=40mmHg Oxygen saturation less than 75%
What is a noninvasive modality to measure oxygenation and how does it work?
- Pulse oximetry machine
- Calculates the Hb-O2 amount by sensing its wavelength
- Different wavelengths of Hb-O2 and Hb
What are the three chemosensory controls of respiration?
Arterial oxygen pressure (P O2), arterial carbon dioxide pressure (P CO2) and blood pH
Where are their chemosensory controls of respiration receptors located?
Aortic and carotid bodies sense changes in these 3 chemical parameters and send that afferent information to the DRG / VRG respiratory control center located in the medulla oblongata. The Pons has more respiratory control from inputs from the cerebral cortex (such as fright, excitement, muscle movement)
What cranial nerves function as their afferents regarding the chemosensory controls of respiration?
CN9 and CN10
Where in the CNS is the respiratory control center located?
- In the brainstem
- Medulla: input for chemosensory afferent input and efferent output to diaphragm and intercostals muscles
- Pons: regulatory role in I/E transitions
What are Kussmaul Respirations?
Deep hyperventilation to blow off CO2
What is the clinical finding associated with Kussmaul Respirations?
How does rising PCO2 affect blood pH?
As PaCO2 rises, pH blood lowers
What are the ABCs of resuscitation?
Describe the appropriate position of the head for assuring an open airway in an unconscious individual.
- “Sniffing Position”
- Neck neutral and chip up; mandible moved forward
What is cyanosis?
Bluing of the skin
Under what physiologic conditions will cyanosis be visible?
When 1/3 of Hb is present as Deoxy-Hb
What are the four vital signs?
What are three types of oxygen delivery systems for a breathing patient?
- Nasal cannula
- Face mask
How much additional oxygen can be provided in each oxygen delivery system?
- Nasal Cannula: 7%
- Face Mask: 19%
- Mask/Reservoir: 39%
What is the risk of ventilating an 80kg adult with a pediatric ambu bag?
Will only ventilate dead space, no ventilation actually exchanging in the alveoli
What is the risk of ventilating a 3kg neonate with an adult ambu bag?
Pop lungs, way too much air for the neonates lungs
What are the two means to deliver positive pressure ventilation?
- Bag/mask ventilation
- Intubation and ventilator
What is intubation?
- The placement of a tube inserted into the trachea
- Serves as an open passage through the upper airway
- Permits air to pass freely to and from the lungs in order to ventilate the lungs
- Can be connected to ventilator machines to provide artificial respiration
Where is the proper anatomic location for placing an ETT (endotracheal tube)?
- Below clavicles
- Above carina
Describe a hospital “code”.
- Full cardiopulmonary arrest or rapid decline in vital signs
- Patient needs immediate stabilization to prevent death
What would be the pharmacist’s role in a “code”?
- Drawing up meds (epinephrine)
- Making sure correct dose
What are the standard resuscitation drugs that can be delivered via an ETT?
- Inhaled (anesthetics, steroids)
Describe a pneumothorax. What are its major physiologic complications?
- Partial or complete collapse of a lung due to filling the thorax with air between the visceral and parietal pleura
- Elevates intrathoracic pressures leading to impaired lung ventilation and impaired lung perfusion
What are the major physiologic complications of pneumothorax?
- Rapidly alter respiratory dynamics
- Elevated pressure leads to severe hypoxemia and death due to inadequate ventilation, oxygenation, venous return to heart
What are the major considerations for placement of an ETT?
- General anesthesia
What types of medications are utilized in a rapid sequence intubation?
- 1. Sedative/hypnotic
- 2. Skeletal muscle paralytic
- 3. Atropine/lidocaine
What are the mechanisms in asthma that lead to decreased caliber of bronchial lumen?
- 1. External smooth muscle contraction (broncho-constriction)
- 2. External bronchial wall edema
- 3. Intra-lumical inflammation and mucous plugging
What pharmacologic receptors are involved in the mechanisms of asthma?
- 1. Sympathetic (Beta2): dilation
- 2. Parasympathetic (Cholinergic): constriction
What inflammatory mediators are involved in the mechanisms of asthma?
Use of corticosteroids, antihistamines, leukotriene inhibitors
What role does a mast cell have in the inflammatory response?
Responsible for synthesizing mediators of inflammation
What is the effect of sympathetic receptors regarding asthma?
What is the effect of parasympathetic receptors regarding asthma?
What is the value of using FEV1 and PEF measurements in the diagnosis and management of asthma?
- Can help a patient decide if there is a need for medication or doctor’s visit
- Especially a quick acting bronchodialator
Why is asthma primarily an expiratory problem?
Because bronchial lumen is already narrowed, greater intrathoracic pressure is needed to exhale air (more positive pressure)
Name common triggers of asthma?
- EVERYTHING can trigger!
- Acute respiratory infections
- Weather changes
- Air quality
- Inhalant irritants
What is an asthma care plan?
Helps patients decide whether their breathing is good, or needs medication, or needs medical attention
What types of medications could be utilized in an asthma care plan?
- Routine control medications in green zone
- In yellow/red zone, use of fast acting bronchodilators (Maxair/Albuterol)
Calculate pack years of a person smoking one pack per day for 10 years.
10 pack years
What is the risk of lung cancer, regarding pack years?
Over 20, significant increase in cancer
What are other non-cigarette exposure risks for lung cancer?
How does smoking affect the non-cigarette exposure risks for lung cancer?
What is the different between metastatic and primary lung cancer?
- Metastatic: started in another organ; breast, colon, prostate
- Primary lung cancer: started in lung (airway tumors usually present)
What are the cellular origins of lung cancer?
- Neuro/endocrine origin
- Epithelial origin
- Pleural origin
Describe physiologic consequences of a pulmonary tumor.
- Hemoptysis (coughing up blood)
- Shortness of breath
- Weight loss
Why is lung cancer so fatal?
- Obstruct larger and small airways
- Restrict lung expansion
- Induce lung collapse
- Hemorrhage into airways
- Reduce effective surface area for diffusion
- Fluid/blood accumulation in pleural space
What is influenza?
Viral infection of the respiratory tract
What is sinusitis?
Bacterial infection of the sinuses
What is bronchitis?
Bacterial/viral infection of the bronchi
What is pneumonia?
Bacterial/viral infection of the lungs
How do pharmacologic treatments vary with respect to viral and bacterial etiologies of common respiratory infections?
- Viral: fluids, rest
- Bacterial: antibiotics
Why not give antibiotics to everyone with a respiratory infection?
- Drug resistance
- Unwanted side effects
- Kill of natural flora
- Allergies great in antibiotics
What are the five major functions of the kidney?
- 1. Regulation of water, inorganic ion balance, and acid-base balance
- 2. Removal of metabolic waste products from the blood
- 3. Removal of foreign chemicals from the blood
- 4. Gluconeogenesis
- 5. Production of hormones/enzymes (erythropoietin, Renin, Vitamin D)
What are the three basic processes in the kidney that determine what is excreted from the body and what stays?
- 1. Filtration
- 2. Secretion
- 3. Reabsorption
Describe glomerular filtration.
Movement of fluid and solutes from the glomerular capillaries into Bowman’s space
What cannot be filtered through glomerular filtration? Why?
- Proteins and protein-bound substances
- Cannot be filtered due to the small pore size and negative charge of the membrane (repels proteins)
Describe tubular secretion.
- Transport or diffusion of solutes from the peritubular capillaries into the tubules
- Addition of solutes into fluid
- Waste products, when filtration didn’t get rid of enough
Describe tubular reabsorption.
- Transport or diffusion of materials from the filtrate into the tubules
- Materials that the body wants to keep
Describe a substance that is filtered and secreted but not reabsorbed.
- Plasma that enters nephron is completely cleared of the substance
- Examples: toxins, metabolic wastes
Describe a substance that is filtered and partially reabsorbed.
- A certain fraction is excreted, sometimes subject to physiological control
- Examples: inorganic ions (sodium, potassium, calcium)
Describe a substance that is filtered and completely reabsorbed.
- Kidney has no effect on levels of these substances
- Examples: glucose, other nutrients
In what locations can nephrons be? Describe each.
- Juxtamedullary—near the border with medulla, loops of Henle go deep into medulla
- Cortical—corpuscle and most of loop in cortex
What is the importance of a juxtamedullary location?
- Only 15%
- Important function in generating osmotic gradient
What is the equation for the amount of something excreted by the kidneys?
Amount excreted = amount filtered + amount secreted – amount reabsorbed
What allows the formation of glomerular filtrate in Bowman’s capsule?
Sum of opposing pressures: hydrostatic pressure from the heart favors filtration, osmotic and hydrostatic pressure of the filtrate oppose it
What is the normal rate of filtration?
How can filtration rate be adjusted?
Changing the radius of the arterioles
How can you decrease GFR?
- Constrict afferent arterioles
- Dilate efferent arterioles
How can you increase GFR?
- Dilate afferent arterioles
- Constrict efferent arterioles
What structures make up the filter of the kidneys?
Glomerulus (capillary endothelium, basement membrane, podocyte foot processes)
What is in filtrate?
- Urea, wastes
- Inorganic ions
What is excluded in the filtrate?
- Nutrients that are needed by the body
What is clearance of the kidneys?
Amount of plasma from which a substance is completely removed
What is the normal clearance of glucose?
0, all is reabsorbed
How is glucose clearance different in diabetics? Why?
- Reabsorption is finite, maximum can be reached
- Plasma glucose concentration saturates transporters, with excess glucose remaining in the tubules
How can clearance of creatinine or inulin be used to measure GFR?
- Completely or almost completely cleared
- Clearance equal to GFR
How can clearance be used to determine whether a substance is secreted or reabsorbed?
- If a substance has a clearance greater than GFR, secreted
- If clearance is less than GFR, reabsorbed
How does the bladder filling reflex work?
- PSNS inhibited, detrusor muscle relaxed
- SNS input keeps internal sphincter contracted (closed)
- Somatic motor input keeps external sphincter closed
How does the micturition reflex work?
- 1. Afferents detect stretch of bladder wall
- 2. PSNS activated, detrusor muscle contracts
- 3. SNS inhibited, opens internal sphincter
- 4. Somatic motor input can be voluntarily inhibited to allow urine release
Can the output of water, salt, etc., change? Why?
- Extreme sweating, diarrhea, salty meals