Blood Stuff
EPO is released in the
kidneys
Myogenic controls
local vascular smooth muscle responds to changes in MAP to keep perfusion constant to avoid damage to tissue
systemic blood pressure
-Pumping action of heart generates blood flow -Pressure results when flow is opposed by resistance
elastic rebound
Arterial walls Stretch during systole Rebound (recoil to original shape) during diastole Keep blood moving during diastole
blood pressure falls
Increase cardiac output Cause peripheral vasoconstriction
respiratory pump
Inhalation and exhalation of the lungs expand and compress veins to return blood to the heart.
Autoregulation
causes immediate, localized homeostatic adjustments to blood flow
Renin
hormone secreted by the kidney; it raises blood pressure by influencing vasoconstriction (narrowing of blood vessels)
Angiotensin 2 causes
-vasoconstriction -aldosterone increase -ADH release -increase thirst
tissue perfusion is affected by
Blood flow, blood pressure, peripheral resistance and blood volume
ADH responds to
Dangerously low blood pressure and circulating angiogestin 2 Reduces water loss at kidneys
MAP and pulse pressure _____ with distance from heart
Decrease
Venous Pressure and Venous Return
Determines the amount of blood arriving at right atrium each minute Low effective pressure in venous system
local vasoconstrictors
Examples: prostaglandins and thromboxanes Released by damaged tissues Constrict precapillary sphincters Affect a single capillary bed
Atrial natriuretic peptide (ANP)
Leads to reduction in blood volume and pressure Strengthens the bodies response to almost drone Promotes the kidneys to excrete more water and sodium Reduces stress on the heart causing vasodilation
resistance depends on
Length of the vessel Diameter vs sold I lagoon and vasoconstriction
Blood pressure can be calculated by
Mean arterial pressure(MAP)
arterial blood pressure
Measure of the pressure exerted by the blood as it flows through the arteries. Maintains bloodflow
Low venous resistance is assisted by:
Muscular pump of peripheral veins (moving)
EPO stimulates
RBC production Increase in blood volume and viscosity
endocrine mechanisms
Releases hormones that enhance short-term adjustments and that direct long-term changes in cardiovascular performance.
carotid sinus
Respond to blood pressure, Carotid Body responds to partial pressures of O2/CO2, supplied by glossopharyngeal nerve
Angiotensin II
Responds to fall in renal blood pressure Stimulates: Aldosterone production ADH production Thirst Cardiac output and peripheral vasoconstriction Enhances blood volume
Erythropoietin (EPO)
Responds to low blood pressure and low oxygen in the blood
Hormones have
Short term or long term effects on cardiovascular regulation
turbulence
Swirling action that disturbs smooth flow of liquid Occurs in heart chambers and great vessels Atherosclerotic plaques cause abnormal turbulence
carotid artery
The major artery that supplies blood to the head and brain.
systolic pressure
The pressure generated by the left ventricle during contraction
Renin starts
a cascade reaction resulting in the production of angiogestin 2
local vasodilators
accelerate blood flow at tissue level -low O2 or high CO2 levels -low pH (acids) -nitric oxide (NO) -high K+ or H+ concentrations -chemicals released by inflammation (histamine) -elevated local temperature
vasomotor center
adjusts blood vessel diameter for blood pressure regulation
pressure is highest in the
aorta
Largest drop off in pressure is at the
arterioles
neural mechanisms adjust
cardiac output and resistance to maintain blood flow
Tissue perfusion
carries O2 and nutrients to tissues and organs Blood flow to the tissues
Chemoreceptors
chemical sensors in the brain and blood vessels that identify changing levels of oxygen and carbon dioxide Detects changes in ph, O2, and CO2 Low oxygen or high CO2 cause increased cardiac output and blood pressure Produces coordinating cardiovascular and respiratory activities
Sympathetic vasoconstruction
constructs the smooth muscle in the walls of veins
Control of vasodilation of skeletal muscle and brain tissue
controlled by the release of nitric oxide
cardioinhibitory center
controls the parasympathetic neurons that slow the heart rate
blood pressure rises
decrease cardiac output Cause peripheral vasodilation
pulse pressure
difference between systolic and diastolic pressure
capillary blood pressure
filters water and small molecules from the plasma
Vascular resistance
friction between blood and blood vessel walls
cardioacceleratory center
increases cardiac output through sympathetic nerves
Cardiovascular centers
monitor arterial blood pressure
renal mechanisms
most potent, but require hours to days to effect pH changes
cardiac center of medulla oblongata
regulates heart's rate and strength of contraction
vasomotor center controlled by
release of norepinephrine
antidiuretic hormone (ADH)
released by the posterior pituitary (neurohypophysis) controls how much fluid leaves the body in the urine and causes reabsorption of water from the kidney tubules
indirect renal mechanism
renin-angiotensin-aldosterone mechanism Drop in blood pressure signals kidney cells to release renin
neural mechanisms
respond quickly to changes at specific sites
arterial blood pressure will rise and fall with
systole and diastole
blood viscosity
thickness of blood
Baroreceptor reflex
uses stretch receptors found within the walls of carotid, aortic, and right atrium
Too much blood causes
vasoconstiction
increase blood pressure
vasoconstriction
decrease in blood pressure
vasodilation
too little blood causes
vasodilation