Cell Bio 3

Question 1

2 essential fxns of lungs. hypo vs hyperpnea

Answer 1

breathing, circ. distensibility; shallow or slow breathing vs inc breathing to meet demand (like exer or needing O2); sign of refractory sepsis

Question 2

hb O2 sat vs hypoxemia vs hypoxia. causes of hypoxia?

Answer 2

%age of hb bound to O2 vs low O2 in arterial blood, <60mmHg & dec O2 sat; low PaO2 vs low O2 in tissue. hypoxemia, anemia, CO, cyanide, blood flow/cardiac output

Question 3

components of upper vs lower resp tract. where do cough receptors reside?

Answer 3

columnar, ciliated cells, goblet cells; conduction zone -> trachea + bronchi/oles, humidify air, particle deposits, mucociliary clear (cilia terminate in condxn zone) vs special resp epith; resp zone -> resp bronchioles + alveoli, lg surface area for gas exchange. post wall of trachea & pharynx

Question 4

resp passages = coated in what? for what?

Answer 4

mucus, periciliary fluid, surfactant. keep surface moist, trap small particles, dec surface tension

Question 5

what kind of cells = found in mucociliary clearance system?

Answer 5

goblet cells secreting mucus, club/clara cells in bronchioles secreting GAG to protect bronchiole lining, pseudostratified ciliated columnar epith secreting periciliary fluid

Question 6

type I vs II vs III vs macs vs mast cells of alveolar cells (pneumocytes from embryo)

Answer 6

elong, gas exchange; more susceptible to toxins vs cuboidal, surfactant by lamellar bodies, progenitor of type I to restore dmged barrier, prolif at 24wks vs brush cells throughout airway, assoc w/ nn vs kill bacteria, make cytok & ROS -> toxic to type II vs hist, sero for immunity

Question 7

how do lungs get blood/O2 (which vessels)? where does blood get oxygenated?

Answer 7

bronchial a for nourishment, pulm a/v for blood. pulm capillaries

Question 8

is inspiration vs expiration active or passive w/ what mechanism? mm for forced inspiration vs expiration?

Answer 8

active by impulses from resp center in brainstem to diaphragm & ext intercostal mm (T1-11) vs passive by passive relax diaphragm, lung recoil via mechanoreceptors in lung & chest wall and chemoreceptors in carotids. SCM, scalenes vs int intercostals & abd mm like in emphysema d/t loss recoil

Question 9

relationship b/w lung & chest wall. fxns of surfactant

Answer 9

lung wants to close, chest wall wants to open; find equil to maximize gas exchange. dec surface tension & capillary filtration forces, prevent atelectasis -> prevent alveolar edema; inc alveolar opening & pulm compliance

Question 10

factors affecting gas exchange vs compliance

Answer 10

too much dead space = not good, compliance/elastance, dec area of diffusion/fick’s law, fluid in lungs/PNA, perfusion (blood clot), not enough diff in pressure/vol vs tissue itself (elastin, collagen, A1AT), surface tension & lining of alveoli (collapsing pressure/Law of LaPlace = 2T/r)

Question 11

pathogenesis vs major probs of ARDs. what hormone produces surfactant? tx?

Answer 11

premies have no surfactant -> pink fibrin rich hyaline mem -> unopened alveoli d/t inc surface tension -> dec compliance -> harder recoil, atelectasis, pulm edema vs thick mem -> gas exchange harder, hyaline mem = sticky -> inc alveolar collapse after ea breath -> hard to reopen to breathe -> need PEEP. stress, no insulin -> cortisol -> surfactant. exogenous surfactant, corticoids, pos pressure

Question 12

emphysema vs fib w/ causes?

Answer 12

too floppy, can’t ctx -> high compliance; smoking, A1AT, pollution vs too stiff, can’t stretch -> high elastance; occupation, sarcoid, drugs, rads, RA & sclerosis, genetics

Question 13

causes of pulm edema

Answer 13

inc hydrostat pressure (MI, mitral sten), dec colloid osmotic pressure (hypoalbumin), inc capillary permeability (rads, ARDs, NO), dec interstitial pressure (hyperinflation, pneumothorax), lymphatic insufficiency (blocked lymph drain)

Question 14

4 major + 1 sites for ctrlling respiration

Answer 14

1. dorsal/ventral resp centers in the medulla; apneustic & pneumotaxic centers in pons
2. central chemoreceptors in CSF
3. periph chemoreceptors in the carotids, aortic bodies, blood
4. mechanoreceptors in lungs & joints
5. cerebral cortex (like breathing during swallowing, hypo/hypventilate)

Question 15

Hering Breuer reflex

Answer 15

lung stretch receptors sense distended lungs/airway -> prolong expiratory time -> dec breathing rate

Question 16

dorsal/insp center vs ventral/expi center

Answer 16

ctrl basic rhythm & freq, CN9/10/phrenic, ctrlled by apneustic/taxic centers vs for exer since nml expiration = passive

Question 17

apneustic vs pneumotaxic centers

Answer 17

lower pons; turn on inspiration by prolong AP -> ctx diaphragm vs upper pons; turn off inspriation by limiting AP, tidal vol, RR; still nml breathing

Question 18

central vs periph chemoreceptors. what about COPD pts?

Answer 18

pH: CO2 diffuse into BBB -> become H+ -> diffuse out of CSF & bind to central chemoreceptors -> inc breathing vs C/O2, pH; <60mmHg O2 -> inc PCO2 & H+ -> CN9/10 relay to DRG -> medullary insp center regulates minute ventilation. dec sensitivity to PCO2 b/c chronic CO2 rtn -> hypoxemia -> resp drive

Question 19

resp drive or response to PCO2 change can dec if you’re what? (3)

Answer 19

hyperventilating, drugs/anesthesia, inc work of breathing/COPD

Question 20

biggest problem w/ anesthesia?

Answer 20

resp depression, alter gas exchange dec FRC -> dec elastic recoil -> atelectasis. preO2 w/ 80% O2 when inducing anesthesia, raise FRC enough not to cause atelectasis, PEEP or CPAP to keep alveoli open

Question 21

OSA vs central sleep apnea. conseq of sleep apnea?

Answer 21

closure upper airway during insp, resp effort; transient hypoxemia/hypercapnia vs cess of resp drive to resp mm, no resp effort. hypoxic vasoconstrict, sympathetic stim -> pulm HTN, R heart fail

Question 22

biots vs Cheyne Stokes vs Kussmaul

Answer 22

quick shallow insp -> silent -> rpt, etc; poor prog b/c dmged pons d/t stroke, trauma, pressure, opioids vs deeper faster breathing -> silent/apnea w/ cres-diminuendo pattern vs deep labored breathing, hyperventilation; common for ketoacidosis & renal fail to get rid of H+

Question 23

changes of breathing in exer

Answer 23

no change in arterial PC/O2 or pH, V/Q = 1; Hb-O2 to the right. O2 consumption, ventilation rate, venous PCO2, cardiac output inc. physiologic dead space dec

Question 24

anatomic vs physiological shunts. what would V/Q be? O2 in fib or stren exer = ___-limited

Answer 24

venous blood shunted to arterial blood w/o gas exchange -> buildup CO2 -> central chemoreceptors -> inc ventilation; PaO2 improve if given 100% O2 vs no ventilation -> hypoxic vasconstriction; PaO2 doesn’t improve if 100% O2 given. V/Q = 0. diffusion limited

Question 25

main sxs of CF

Answer 25

thick mucus plug, dehydrated mucus, cough + phlegm, dec mucociliary clear; dec Cl- secretion, inc Na & H2O reabsorption

Question 26

polycythemia vs anemia vs CO poison. O2 content vs O2 sat vs PO2 vs SaO2

Answer 26

total O2 inc (more Hb), PO2 = same vs total O2 dec (less Hb), PO2 = same vs total O2 & O2 sat dec, PO2 & Hb conc same. dissolved/PO2 & bound vs amt of O2 bound to Hb vs dissolved in blood vs amt of Hb saturated (regardless of what’s bound)

Question 27

4 ways to get bronchiectasis. chronic bronchitis inc risks of what? how to tx bronchitis? silicosis? barrel chest & inc AP diameter means?

Answer 27

CF, Kart (defect in dynein cilia, sinusitis, infertile), aspergillus for asthma & CF, tumor/foreign body. infxn by mucus plug, cor pulm, cyanosis. bronchodil, steroids. sand/rock -> impaired macs, promote apop -> inc risk of TB, PAH, COPD, lung ca. emphysema