med physio quiz 4

internal vs external respiration

internal = supply O2 and remove CO2 from body

external = delivery of O2 and removal of Co2 from cells

upper and lower respiratory

upper = nasal cavity —> pharynx —> larynx

• air getting humidified

lower = trachea —> primary bronchi —> lungs

where are lungs contained

pleural cavity

right vs left lung lobes

right = 3 lobes

left = 2

pleuristy

inflammation of pleural cavity

pleural effusion

fluid accumulation in cavity

mucociliary elevator

lines the lower respiratory tract

• carrying pathogens and foreign particles toward pharynx where it is swallowed or coughed out

goblet cell

secret mucin

conducting vs respiratory zone

CONDUCTING

• cilia = yes

• smooth = yes

• cartilage = trachea

  • patchy in bronchi

RESPIRATORY

• no cilia

• some/no smooth

• no cartilage

when does resistance decrease

after 4th branching

type I vs type II

type I = simple squamous, gas exchange

• more common and dont replicate

type II = secrete surfactant

• help regenerate type I

inspiration

1. diaphragm moves down and rib pull chest outward

2. lung pressure < ATM —> air from out into lung

physiological dead space

anatomic dead space + alveolar dead space

• alveolar = air present but no perfusion (no blood supply)

anatomic vs physiological age

healthy: physiological = anatomic

older/lung disease: physiological > anatomic

• more unperfused alveoli

alveolar ventilation formula

[ (tidal volume) - (physiologic dead space) ] x respiratory rate

partial pressure

pressure a single gas in a mixture would exert if it occupied the entire volume by itself

P_AO2 vs P_ACO2 vs P_aO2 vs P_aCO2

P_AO2 = partial pressure of O2 in alveoli

P_ACO2 = partial pressure of CO2 in alveoli

P_aO2 = partial pressure of CO2 in blood

P_aCO2 = partial pressure of CO2 in blood

ventilation and CO2

inverse relationship

what keeps parietal and visceral pluerua together

the cohesiveness of water molecules —> neg pressure in intrapleural space

• lungs = collapsing force thoracic cavity = expadning force

what prevents lung collapse

transmural pressure gradient = difference bw alveolar pressure and intrapleural pressure

what other muscles are involved in ventilation

diaphragm

sternocleidomastoid

internal intercostal muscles

compliance

delta V / delta P

pulmonary fibrosis

lungs become less compliant —> lung expansion decreased and pressure decrease —> inspiration harder

alveolar surface tension

provides elastic recoil during expiration but also decreases compliance

surfacant in lungs

reduces surface tension —> lungs compliant and reduce force needed to create volume change

• prevents collapse of small alveoli (atelectasis)

surfactant def

acts on the surface of a structure to disrupt surface tension —> oppose collapsing or aggregation

• mostly lecithins

surfactant other uses in pharm

stabilize emulsions or suspension

cystic fibrosis

abnormal surfactant

• mucus in airways interfere with surfactant distribution

• inflammation can damage surfactant protein

vital capacity

IRV + TV + ERV

FEV1

FORCED EXPIRATORY VOLUME

volume you can force out of lung in one sec

FVC

FORCED VITAL CAPACITY

volume forced out in total

what helps diagnose asthma

FEV1

Obstuctive lung disease

FEV / FVC IS LESS THAN 0.7

PEFR

peak expiratory flow rate

• home spirometric test to assess asthma severity

GREEN = 80 - 100% OF PR

YELLOW = 50 - 80% - DOCTOR IF MORE THAN 24 HRS

RED = < 50% - DOCTOR NOW

if no surfactant

collapsing pressure in small alveoli > large alveoli

—> air out of small into larger one

asthma

inflammation and narrowing airways

• triggered by allergens, irritants, exercise, cold air, infections

asthma symptoms

1. SOB

2. wheezing

3. chest tightness

4. coughing (night/morning)

5. difficulty breathing

diagnosis asthma

1. pulmonary test = spirometry to measure lung function and airway obstruction

2. peak flow meter = track lung function at home

why wheezing happens law

faster moving fluid exert less pressure

wheezing pathway

1. constricted airway

2. air must flow faster to get out

3. exert lower pressure

4. airway lumen decreases

5. critical narrowing slows airflow (wheezing)

6. air exerts higher pressure

7. airway reopens

albuterol

beta 2 selective agonist —> dilate airway

what causes bronchodilation

1. CO2

2. sympathetic - norepinephrine = weak on b2

3. eprinephrine - strong beta 2 agonist released by adrenal medulla

** beta 2 = Gs = SMOOTH relax

what causes bronchoconstriction

1. O2

2. parasympathetic - Ach - muscarinic M3 = Gq

3. histamine

obstructive

greater resistance and harder expiration

drugs for asthma

1. beta adrenergic agonist

2. corticosteroids = affects transcription factors but SLOW

PO2 does what when traveling down

1. decreases in trachea bc water vapor displaces O2

2. in alveoli: decreases further bc further mixed with residual air from previous breaths

amount of gas transferred relationship

diretly proportion = area, diffusion constant, difference in partial pressure

• constant is proportional to gas solubility but indirectly to molecular weight

inverse = thickness

CO2 vs O2 solubility

CO2 higher = transfer faster

emphysema

collapse of alveoli bc of collagen loss

• one large sac = lower SA and gas exchange

pulmonary fibrosis

thicken alveolar walls bc of excess collagen

• affects thickness

chronic obstructive pulmonary disorder

1. bronchitis

2. emphysema

3. infection

what can hemoglobin carry

1. CO2

2. proton

3. carbon monoxide

types of hemoglobin

1. Hb A = adult, most common A2B2

2. Hb A2 = adult, A2DELTA 2

3. Hb F = fetal, present first year of life, high affinity for O2

• ALPHA2

1. Hb S = less common, valine replace by glutamic acid, less affinity

• A2B2

carboxyhemologin

carbon monoxide binds to Hb and occupies binding sites

solution = 100% oxygen

methemoglobin

poor at binding oxygen and releasing oxygen to tissues

solution = methylene blue