Exam 3 Material Flashcards
Symptoms & Factors Involved Airway Obstruction: Asthma
-Airway walls are inflamed
-During an asthma attack, mucosal walls are thickened, air is trapped in alveoli, and smooth muscles are constricted.
-Wheezing, breathlessness, chest tighness, coughing. Increased at night and early AM
Symptoms & Factors Involved Airway Obstruction: Croup
-Acute laryngotracheobronchitis
-Usually viral
-Common in youth 6mos-5yrs
-Seal-like barking cough
Symptoms & Factors Involved Airway Obstruction: COPD
-Hypersecretion of mucus and chronic productive cough
-Inspired irritants increase mucus production along with the size and number of mucus glands
-Wheezing, chronic cough, breathlessness
Symptoms & Factors Involved Airway Obstruction: Emphysema & Bronchitis
-Abnormal, permanent enlargement of the gas exchange in airways accompanied by destruction/rupture of alveoli. Loss of elastic recoil in the lungs
-Cough, difficulty breathing, wheezing
-Bronchitis: Inflammation of bronchi. Can be acute or chronic
Airway Function Tests: FEV1
-Bronchial hyperreactivity testing.
-The fall in forced expiratory volume, in one second, provoked by inhaling increased concentrations of histamine or methacholine
Airway Function Tests: PEF
-Peak Expiratory Flow
-Measures maximum flow of forced expiration.
-This increases as we age
Immune response to allergens: Dendritic cells, T-cells, B-cells, Plasma Cells, Mast Cells, Neutrophils, Eosinophils
-Dendritic cells are located in the lining of the respiratory tract; first exposure to allergen. Antigen-presenting cell
-T-cells are activated, release IL-4 –> B-cells are then released by IL-4
-B-cells turn into plasma cells and produce IgE antibodies against the allergen
-IgE binds to the surface of mast cells and is irreversibly bound. On 2nd exposure to allergen, antibodies bind to IgE on mast cells, mast cells degranulate and release histamine, prostaglandins, leukotrienes
-Neutrophils & Eosinophils rush to the area due to a foreign substance being present, further exacerbating inflammation
Mediators released in early & late stages of asthma and their effects
Early stages: Histamine & Prostaglandins. Cause immediate bronchoconstriction from muscular contraction and vascular leakage
Later Stages: Leukotrienes. Liberated from the lungs during inflammation. Cause bronchospasm, mucus secretion, microvascular permeability, and airway edema
ANS & it’s effects on airway diameter
What role do the SNS and PNS play?
-Airway is innervated by nerves in the PNS, SNS, as well as NANC
-Normal resting tone of the airway smooth muscle is maintained by vagal stimulation
-SNS: Bronchiolar smooth muscle is relaxed when B2 cells are stimulated; however, the PNS system will fire in response causing constriction of the airway
-We see more of a response from circulating catecholamines than from direct innervation of the vagus nerve
MOA, SABA & LABA, Toxicity
Beta 2 Agonists
Short Term Relievers- Asthma & COPD
-Bronchodilators
-Nebulized Epi & Isoproterenol: Non-specific for beta cells. Can cause tachycardia and arryhthmias
-Albuterol (SABA): B2 selective. Aerosol. Takes effect in 30 mins, lasts 3-4 hours
-Salmeterol/Formotorol (LABA): B2 Selective. Aerosol. Lipid soluble, lasts 12 hours. Only 10-20% delivered due to droplet size
Toxicity: Skeletal muscle tremors
MOA? Toxicity?
Methylxanthines
Short term relievers- Asthma & COPD
-Inhibits PDE & adenosine receptors resulting in mild bronchodilation
-Theophylline: Most effective methylxanthine, found in natural tea.
-Toxicity: CNS stimulation, (+) chronotropy and ionotropy in heart, tremors
Muscarinic (M3) Antagonists
Short Term Relievers- COPD
-Bronchodilators
-Atropine: Given IV
-Ipratropium Bromide: Inhaled, can combine with B2 agonists
-Titroprium: Inhaled, long acting
-No CNS effects
Corticosteroids & Glucocorticoids
Long Term Controllers- Asthma
-Glucocoritcoids: Inhibit immune response by blocking DNA transcription/translation
-Cortico: Reduce bronchial activity, increase airway caliber, reduce frequency of exacerbations
-S/E: Increased risk of osteoporosis, slow growth rate in children, oropharyngeal candida & other opportunistic infections
Leukotriene Pathway Inhibitors
Long Term Controllers- Asthma
-Inhibit 5-Lipoxygenase: Zileuton
-Inhibit synthesis of leukotriene: -ukast
-Both improve aspirin induced asthma
Renal Corpuscle
Parts of the Nephron
-Glomerulus & Glomerular Capsule; In the medulla
-Filtration
Transporters in this area?
Proximal Convoluted Tubule
Parts of the Nephron
Reabsorption of 65% of Na+, K+, Ca++, Mg++
85% of NaHCO3-
Nearly all glucose and amino acids
Primary Xporters: NHE3, carbonic anhydrase, SGLT2
Proximule Tubule, Straigh Segments
Parts of the nephron
Secretion and reabsorption of organic acids and bases, including uric acid and diuretics
Thin Descending Loop & Thick Ascending Loop
Parts of the nephron
Descending loop: Passive reabsorption of water
Ascending loop: Active reabsorption of 15-25% of filtered Na+, K+, and Cl-. Secondary reabsorption of Ca++ and Mg ++
Distal Convoluted Tubule
Parts of the nephron
Active reabsorption of 4-8% of filtered Na+, Cl-, and Ca++ reabsorption under PTH control
What is secreted here?
Cortical Collecting Tubule
Parts of the Nephron
2-5% Na+ reabsorption coupled with K+ and H+ secretion
Medullary Collecting Duct (End of Nephron)
Parts of the nephron
Water reabsorption under vasopressin control
Macula Densa Cells
Monitors the osmolality and volume of the fluid in the distal tubule.
Transmits that information to the JG cells.
Located in vascular pole of the renal corpuscle
Juxtaglomerular Apparatus & GFR Regulation
-GFR regulation is done through adjusting BP:
-Altering capillary surface rea
-Controling arteriole diameter
-Autoregulation & Hormonal Regulation: RAAS
-Neuronal Regulation: NE and Epi release
Function of NHE3 & Carbonic Anhydrase in Na and HCO3- reabsorption
-NaHCO3 reabsorption is initiated by the action of the Na+/H+ Exchanger (NHE3)
-This system allows Na+ to enter the cell from the tubular lumen in exchange for an H+ from inside the cell (Na+ moves in, H+ moves out)
-Na+/K+/ATPase pump pumps reabsorbed Na+ back into the interstituem in order to main a low intracelluar Na+ concentration
-Secreted H+ & HCO3- combine to form carbonic acid –> broken down into CO2 & H2O by carbonic anhydrase
HCO3- reabsorption is dependent upon the activity of carbonic anhydrase
Inhibition of what at the loop?
Loop Diuretics
-Inhibition of the Na+/K+/Cl- (NKCC2) transporter in the ascending Loop of Henle. Na+ is pushed down and absorbed into the collecting duct, causing excess potassium to be secreted
-Hypokalemic metabolic alkalosis
-Sulfa drugs. Caution with sulfa allergies
-Lasix, Bumex, Ethacrynic Acid
Carbonic Anhydrase Inhibitors
-Inhibition of carbonic anhydrase in the PCT, meaning carbonic acid is not broken down into HCO3- & CO2
-Currently used for glaucoma, mountain sickness, edema w/ alkalosis
-Toxicity: Metabolic acidosis, renal stones
Potassium Sparing Diuretics
-Aldosterone Receptor Antagonists
-Spironolactone: Blocks aldosterone receptors
-Amiloride: Inhibits Na+ flux through ion channels in luminal membrane
Potassium Wasting w/ Diuretics
Potassium wasting occurs because of an increase in Na+ (w/ HCO3-) being driven to the collecting duct. This creates a lumen-negative electrical potential, causing an increase in K+ secretion