D11-D12 Flashcards
(69 cards)
What is the major difference in the pulmonary system?
it is a low pressure system with little smooth muscle
What is an important characteristic of the pulmonary blood vessels?
the large capillary bed surrounding each alveoli
How long is blood in the capillaries?
about 3/4 of a sec
What is the volume of blood in the pulmonary vessels at any one time?
1 liter
What is the volume of blood in the capillaries?
100 ml
What is the pulmonary capillary pressure?
about 10 mmHg
What is the oncotic pressure of the plasma?
25 mm Hg
What does the pressure gradient in the capillaries favor in terms of movement of fluids?
from alveoli to the capillaries
At what pressure does pulmonary congestion and edema happen?
more than (>25 mmHg)
What disease gives a chronic and progressive rise in pulmonary capillary pressure resulting in a backup in the lungs?
mitral stenosis
What causes pulmonary vessels to constrict?
decrease in PO2
Where is angiotensin I converted to angiotensin II?
The lungs (but comes from the heart)
HyPOventilation increases what and decreases what?
increases arterial PCO2 to make carbonic acid and decreases ph
HyPERventilation increases what and decreases what?
increases ph and decreases pco2
Why is CO2 called a volitile acid?
Because it can be removed by ventilation
What are acids generated by metabolic pathways called and where are they disposed of?
fixed acids and are disposed of by the kidneys
What is associated with respiratory acidosis occur?
hypoventilation (high PCO2 levels)
What is associated with respiratory alkalosis?
hyperventilation (low arterial PCO2 levels)
What causes metabolic acidosis?
increased lactic acid production from exercise or loss of alkali from diarrhea
What causes metabolic alkalosis?
from acid loss that would occur from vomiting
Where are the cell bodies of the motor neurons that innervate the respiratory muscles?
C3-5 (keeps diaphragm alive)
What is the main nerve that makes the diaphragm function?
phrenic nerve
Where does control come from during automatic control of ventilation?
central chemoreceptors in the brainstem and peripheral chemoreceptors
What controls voluntary control of ventilation?
higher centers of the brain