Unit 3 Flashcards
where does gas exchange in the lungs occur
at alveoli
pneumothorax
host in chest wall, air into the pleural space
what does negative alveolar pressure mean
air flows into the lungs
what does positive alveolar pressure mean
air flows out of lungs
what happens in increased inspiration
contract external intercostal muscles, contract accessory muscles in the neck
what happens during increased expiration
contract internal intercostal muscles
what is FEV1/FVC
how much total forced expiration occurs in the first second
what is normal FVC
5L
what is normal RV
1L
what is normal TLC
6 L
what is normal FEV1/FVC
80%
what are the defining characteristic of an obstructie disorder
increaed RV and decreased FEV1/FVC
what type of disease is emphysema
obstructive
what happens in emphysema
loss of alveoli, difficulty getting air out of the lungs
what are the defining characteristics of a restrictive disorder
decreased TLC
what type of disease is fibrosis
restrictive, scar tissue in lung
* difficulty getting air into the lungs
where is the most important resistance in the lungs, why?
bronchioles, they have smooth muscle so the resistnace can be regulated
what does the parasymp NS do to airway resistance
ACh acting on mACH receptors causes constriction
what does the symp NS do to airway resistance
Ep acting on beta2 receptors causes airway dilation
what happens at high altitude
there is a decrease in total pressure
perfusion-limmited
diffusing capacity is limited by blood flow
diffusion-limited
diffusing capacity is limited by rate of diffusion
diffusing capacity of O2 is
perfusion limited
what are the 3 benefits of recruitment and distension
- decreased resistance causes decreased pressure
- decreases velocity of blood flow so more time for gas exchange
- increases surface area for gas exchange
effect of hypoxia
always want to match air flow and blood flow
dissolved O2
- defines PO2
- detected by chemoreceptors
- used by cells
Bohr effect
when there are high levels of CO2 binding to Hb there is less O2 bound to Hb
pulmonary stretch receptors
inhibitory, dont stop normal inspiration but stop overinflation of lungs
chemoreceptors
stimulatory, detect increase in CO2, H+, and decrease in O2
proprioceptors
stimulatory, dectect increase in muscle activity and joint movement
what regulates breathing - decreased O2 or increased CO2
increased CO2
things that stimulates central chemoreceptors
increased CO2 in blood
increased H+ in the interstitial fluid in the brain
things that stimulate peripheral chemoreceptors
increased CO2 in blood
increased H+ in blood
decreased O2 blood
clearance
volume of plasma/minutes needed to exrete the quantity of a substance appearing in the urine in a minutes time
inulin
is filtered, not reabsorbed, and not secreted
PAH is
filtered, not reabsorbed, completely secreted
glucose is
filtered, completely reabsorbed, not secreted
diabetes mellitus
glucose in urine, increse in urine volume
proximal convoluted tubule absorption
70% of K+, Na+, H2O reabsorbed
proximal convoluted tubule secretion
100% PAH
loop of henle descending limb reabsorbs
H2O
loop of henle ascending limb reabsorbs
Na+ and Cl- NOT WATER
distal convoluted tubule reabsorbs
Na+ and Cl- NOT WATER
aldosterone increases
- protein synthesis
- Na+/K+ pumps
- Na+ reabsorptino
- K+ secretion
ADH increases
H2O reabsorption
where is ADH made and released
hypothalamus, posterior pituitary
what stimulates ADH release
high osmolarity in extracellular fluid
low blood volume
what is inhibited during urination
alpha motor neuron to voluntary sphincter (sphincter relaxes)
what is stimulated during urination
parasymp NS to detrusser muscle (destrusser contracts)
what stimulates the renin-angiotensin-aldosterone system
low extracellular fluid volume
what does ANP do
lower blood pressure
what do ADH, aldosterone, and angiotensin II all do
increase blood pressure
what is the importance of concentrating urine
- conserving water
- can concentrate urine to the concentration of the intersitial fluid of the inner medulla
what decreases ADH release
alcohol
countercurrent multiplication
- H2O reabsorbed from the descending loop of henle
- Na+, Cl-, but not H2O, reabsorbed from the asending limb of the loop of Henle
- Can create a 200 mOsm concentration gradient
- Creates concentrated interstitial fluid of the inner medulla
Regulation of pH
buffers (within seconds)
respiratory system (within minutes)
renal system (days)
acidosis is described by
increased H+
alkalosis is described by
decreased H+
what is respiratory acidosis
high CO2
* cause: decreased ventilation, severe asthma
what is metabolic acidosis
low HCO3-
* cause: kidney failure, diarrhea, exercise
what is respiratory alkalosis
low CO2
* cause: increased ventilation - high altitude
what is metabolic alkalosis
high HCO3-
* cause: abuse of antacids, vomiting
granular cells
release renin
macula densa cells
detect increase in Na, Cl- in filtrate
does constricting the afferent or efferent arteriole decrease filtration
afferent
does constricting the efferent or afferent arteriole increase filtration
efferent
vitamin D3
involved in calcium regulation
activation occurs in proximal tubule cells
erythropoeitin
stimulates production of RBCs in bone marrow
