BRS Review Quick Facts

Question 1

in restrictive lung disease like fibrosis, what is the FEV1/FVC ratio like?

Answer 1

increased

Question 2

compliance equation

what is it measuring?

Answer 2

C = V/P

distensibility of the lungs and chest wall

Question 3

how is compliance related to elastance and stiffness?

what is another way to measure compliance?

Answer 3

inversely related to both

slope of pressure-volume curve

Question 4

what is the lung compliance in a patient with emphysema?

what happens to the FRC?

Answer 4

compliance is INCREASED, tendency for the lungs to collapse is decreased

higher FRC

Question 5

characteristics of neonatal respiratory distress syndrome?

Answer 5

lack of surfactant
atelectasis, difficulty reinflating the lungs (bc of DEC compliance)
hypoxemia due to DEC V/Q

Question 6

where is the major site of airway resistance?

Answer 6

medium-sized bronchi

Question 7

what pathology is associated with high lung volumes?

Answer 7

patients with increased airway resistance (asthma), learn to breathe w/high lung volumes to offset high airway resistance

Question 8

what can reduce resistance to air flow?

increase it?

Answer 8

Helium gas

deep-sea dive

Question 9

what is fick’s law equation?

Answer 9

V = DL x delta P

V= volume of gas transferred/min
DL = lung diffusing capacity
delta P = partial pressure difference of gas

Question 10

when does DL increase?

decrease?

Answer 10

exercise bc more capillaries open and thus more surface area

emphysema (dec s.a.), fibrosis and edema (inc diffusion dist.)

Question 11

Increasing CO2 does what to pH?
how does this shift the Hb/O2 curve?
when does this happen and for what reason?

Answer 11

decreases pH
right shift
during exercise, facilitating offloading of O2 to the tissues, where it is needed

Question 12

what is hypoxemia?

what causes it?

Answer 12

DEC in arterial PO2

dec PAO2, diffusion defect, V/Q defect, R–>L shunts

Question 13

what is hypoxia?

what causes it?

Answer 13

DEC O2 delivery to the tissues

DEC blood flow ,hypoxemia, DEC hemoglobin [ ], CO and CN poisoning

Question 14

what does DEC O2 delivery to the kidneys cause?

Answer 14

production of hypoxia-inducible factor 1alpha

which will make EPO

Question 15

in the lungs, what does hypoxia cause?

Answer 15

vasoconstriction

Question 16

what is the DRG responsible for?

where do inputs come from?
outputs?

Answer 16

inspiration

CN 9 and 10 via peripheral chemoreceptors
phrenic nerve to the diaphragm

Question 17

what is the VRG responsible for?

when is it activated?

Answer 17

expiration

exercise

Question 18

what does the pneumotaxic center do?

located where?

Answer 18

inhibits inspiration

upper pons

Question 19

what do increases in PCO2 and H+ do to breathing?

Answer 19

stimulate it

Question 20

what does arterial [H+] increases do?

Answer 20

stimulate carotid peripheral chemoreceptors directly

in metabolic acidosis, breathing rate is increased (hyperventilation) bc arterial [H+] is INC and pH is DEC

Question 21

how are lung stretch receptors activated?

what happens when lung stretch receptors are stimulated

Answer 21

distention of the lungs

produce a reflex DEC in breathing frequency (Hering-Beuer reflex)

Question 22

where are J receptors located?

activated how?
what is the response?

Answer 22

alveolar walls, next to capillaries

engorgement of pulmonary capillaries, ie left heart failure
causes rapid shallow breathing

Question 23

where are irritant receptors located?

stimulated how?

Answer 23

bw airway epithelial cells

noxious substances (dust and pollen)

Question 24

In obstructive lung disease such as COPD and asthma what is the FEV1/FEC ratio like?

Answer 24

Decreased