Respiratory B Flashcards

Question

#3 Lung compliance - stretch/ expandability Expandability of the lungs, when does it change? Normally high due to collagen to elastin ratio, more elastin in lungs How is it diminished?

Answer 1

-change in lung volume with a given change in pressure - Relates to effort required to distend the lungs -Distensibility of the lung tissue (connective tissue) - Alveolar surface surfactant -Nonelastic scar tissue (fibrosis) -Reduced production of surfactant -Decreased flexibility of the thoracic cage

Answer 2

- Help lungs return to their pre-inspiratory volume, get back to resting state Connective tissue in the lungs * Elastin / Collagen Alveolar surface tension * Increases tendency of alveoli to recoil

Answer 3

- Volume of air entering/leaving lungs during a single quiet breath, 500 ml - air left in lungs - ~1200 mL - Maximum air you can move - ~ 5/6 L, (= IRV+TV+RV) - extra air that can be added to inspiration/expiration if the breath is deeper: Inspiratory – 3L, Expiratory – 1L

Answer 4

- activity of lungs graph - test, used to asses someones respiratory status inspired air that doesn’t contribute to gas exchange. Anatomical and alveolar

Answer 5

-total amount of gas flow into or out of the respiratory tract in one minute -gas forcibly expelled after taking a deep breath -the amount of gas expelled during specific time intervals of the FVC, air in first second usually

Answer 6

High compliance, Low recoil Difficult to breathe out, easier in * Less “fresh air” each breath -Eg. Emphysema, Asthma Chronic bronchitis - Primarily caused by smoking Break-down of collagen/elastin in septal walls -Loss of lung recoil, harder to breath out (over-inflated) Increased tar and mucous production -Decreased surface area for gas exchange, out of breath

Answer 7

Response to chronic irritants -Smoking or pollutants Inflamed airways, leading to igh production of mucous Decreases airway diameter Irritants trigger cough reflex and bronchoconstriction

Answer 8

Hard to breathe in, easy to breathe out -Hard to hold air in long enough for gas exchange -Eg. Asbestos exposure Increased fibroids More collagen Lungs become stiffer Inflammation and scarring

Answer 9

Exchange oxygen and CO2 between the alveolar air and blood and tissues *External respiration (alveoli to blood) *Internal respiration (blood to tissues) Gas exchange is by simple diffusion *Need a concentration gradient *gas will move from higher partial pressure lower partial pressure oxygen (0.21) vs nitorgen (0.79) x sea level number. fraction always stays same. difference is barometric

Answer 10

The partial pressure of each gas is directly proportional to its percentage in the mixture *Fraction of oxygen in air = 21% *Fraction of nitrogen in air = 79% *Carbon dioxide and other gases are less than 1% of the air

Answer 11

- Gas exchanges in the lungs -Humidification of air -Mixing of alveolar gas that occurs with each breath -Partial pressure gradients and gas solubilities -Ventilation-perfusion coupling Structural characteristics of the respiratory membrane

Answer 12

Concentration gradient Diffusion distance Solubility Surface area * alveoli Rate of gas transfer across the alveoli is governed by Fick’s law of diffusion

Answer 13

0.5 to 1 um thick Large total surface area (40 X that of skin) Thicken if lungs become waterlogged (edema), and gas exchange ↓ ↓ surface area with emphysema walls of adjacent alveoli break down

Answer 14

Partial pressure gradient for O2 in lungs is steep -Venous blood Po2 = 40 mm Hg -Alveolar Po2 = 104 mm Hg Partial pressure gradient for CO2 in the lungs is less steep: -Venous blood Pco2 = 46 mm Hg -Alveolar Pco2 = 40 mm Hg BUT CO2 is 20 times more soluble in plasma than oxygen CO2 diffuses in equal amounts with oxygen

Answer 15

Partial pressures and diffusion gradients are reversed compared to external respiration -Po2 in tissue is always lower than in systemic arterial blood -Po2 of venous blood is 40 mm Hg and Pco2 is 45 mm Hg Ventilation: amount of gas reaching the alveoli Perfusion: blood flow reaching the alveoli Ventilation and perfusion must be matched (coupled) for efficient gas exchange

Answer 16

Carbon Dioxide - Bronchioles ↑ CO2 causes bronchiole dilation ↓ CO2 causes bronchoconstriction Oxygen – Alveoli ↑ O2 causes vasodilation ↓ O2 causes vasoconstriction 1.5% dissolved in plasma 98.5% loosely bound to each Fe of hemoglobin (Hb) in RBCs 4 O2 per Hb

Answer 17

At level of gas exchange surface (where the PO2 is 100 mmHg) – Hb quickly becomes saturated with oxygen At the level of the tissue (where the PO2 is 30-40 mmHg) – Hb unloads 25-30% of its oxygen – which diffuses into tissue

Answer 18

- Po2 -Temperature -Blood pH -Pco2 - Concentration of DPG (*) -influenced by factors like temperature, pH, and organic phosphate concentration - fetal has higher affinity then maternal meaning - colder temp, higher blood ph, lower blood PCO2, higher affinity

Answer 19

- Not enough oxygen (eg. High altitude) * Too few RBCs * Abnormal or too little Hb * Blocked or poor circulation * Metabolic poisons * Pulmonary disease * Carbon monoxide Binds Hb and doesn’t let go Blocks sites from oxygen

Answer 20

7 to 10% dissolved in plasma 20% bound to globin of hemoglobin (carbaminohemoglobin) 70% transported as bicarbonate ions (HCO3–) in plasma

Answer 21

-CO2 combines with water to form carbonic acid (H2CO3), which quickly dissociates -HCO3– quickly diffuses from RBCs into the plasma -The chloride shift occurs: outrush of HCO3– from the RBCs is balanced as Cl– moves in from the plasma -HCO3– moves into the RBCs and binds with H+ to form H2CO3 -H2CO3 is split by carbonic anhydrase into CO2 and water -CO2 diffuses into the alveoli

Answer 22

If ventilation is hindered (e.g. emphysema), CO2 may build-up * CO2 combines with water (carbonic acid equation) H+ will also build up, this will drop pH - If breathing can’t be corrected, the kidney will actively work to correct H+ levels E.g. Hyperventilation Fast breathing will cause excessive loss of CO2 * Also loss of H+ This will cause the body to be alkalotic Seen in high altitude conditions as well

Answer 23

-Eg. High acid (low pH) due to exercise or a kidney or buffer problem -Will trigger faster breathing to help reduce CO2 * Will reduce H+ Low H+ Breathing will slow down to try and build H+ and CO2 levels More in Urinary system – stay tuned!

Answer 24

-Caused by viruses -Antibiotics not effective infection of the lungs * May be caused by bacteria or viruses * High mortality rate in seniors * Treatment depends on cause -bacterial infection that scars the lungs * May be active with symptoms, or dormant and will reactivate later * Treatment: antibiotics poisoning by bacterial toxin * Toxin consumed in improperly preserved foods * Causes paralysis of skeletal muscles including intercostals and diaphragm * Respiratory failure