Physiolgy Flashcards
Primary force for absorption
Capillary osmotic pressure
Hydrostatic and osmotic pressure at the arteriole end of capillaries
Hydrostatic: 34mmHg
Osmotic: 28mmHg
Hydrostatic and osmotic pressure at the venue end of capillaries
Hydrostatic: 14mmHg
Osmotic: 28mmHg
Tissue pressure hypothesis of auto regulation
Increased tissue perfusion pressure -> increased tissue blood volume->increased filtration to extravascular space -> increased tissue turgor pressure -> decreased perfusion pressure
Myogenic hypothesis of auto regulation
Increased perfusion pressure -> increased vessel wall stretch -> increased intrinsic contractile response -> decreased perfusion pressure
Metabolic hypothesis of auto regulation
Decreased perfusion pressure -> increased accumulation of metabolic vasodilator substances ->decreased pre capillary resistance -> increased perfusion pressure
Two major sensing systems that monitor arterial blood pressure
Carotid sinus Baroreceptors
Aortic arch Baroreceptors
Part of the brain that receives information from Baroreceptors and body sensors
Medulla
What are the two main effector systems that the medulla sends signals to
Heart
Peripheral vasculature
Primary force for filtration
Capillary hydrostatic pressure
Systolic arterial pressure
Max pressure developed prior to ventricular relaxation
Diastolic arterial pressure
Minimum pressure developed prior to ventricular ejection
Normal LA pressure doesn’t go above?
6mmHg
In left heart failure, can reach 40-50 causing pulmonary hypertension causing the RV to have increased work
If LA reaches 30mmHg, gets pulmonary edema
Pulmonary vs systemic capillaries
Pulmonary has lower pressure (7vs17)
Pulmonary interstitial fluid more negative (-5 to-8 vs -3)
Pulmonary capillaries more leaky, protein escapes making interstitial oncotic pressure higher
What pulmonary capillary pressure will cause sudden death
Greater than 25- above safe level of 28 (so greater than 53)
If pressure is 40 but has built over time, lungs can compensate by increasing lymphatic ability over a period of two weeks