part 7 Flashcards
The renal-blood fluid system for regulating blood pressure uses what?
The Kidneys.
What part of the kidneys and what other system is involved with the renal-blood fluid system?
the nephron and the renin-angiotensin system.
How fast and effective is the renal-blood fluid system at regulating blood pressure?
slow but a VERY high gain Some say it is infinite because it removes fluid from body.
The renal-blood fluid system is the _______ mechanism.
Ultimate
Renal -blood fluid system relies on a phenomenon known as what?
Diuresis.
What is Diuresis?
Formation of Urine.
What is pressure diuresis?
increase arterial blood pressure and increase water disposal.
What is pressure natriuresis?
increase arterial blood pressure and increase salt disposal.
The renal-blood fluid mechanism is due to what?
Pressure
Explain how drinking water increases urine?
increase extracellular fluid increase blood volume, this increases mean systemic blood pressure, and this increases venous return, and this increases cardiac output, This increases arterial BP and this increases pressure diuresis.
What is harder to do pressure diuresis or pressure natriutesis?
Pressure natriuresis. Excreting salt is harder that water.
What are 2 long term determinants of long-term arterial pressure?
- Level of water and salt intake. 2. Behavior of kidneys.
What are factors in kidney behavior that effects the renal-blood fluid system?
addition of hormonal controls and abnormal nephrons.
What will the chronic renal output curve look like?
it is a very very sharp curve that shows salt intake or output is directly related to extracellular fluid volume.
What will angiotensin do to the kidneys?
Makes them retain salt and water.
What will angiotensisn do to the adrenal glands?
increase aldosterone secretion which increases salt and water retention in the kidneys.
What is hypertension (#’s)?
Systemic blood pressure greater than or equal to 140 and/or diastolic blood pressure that is less than or equal to 90.
What is primary and secondary hypertension?
Primary- origins of hypertension are unknown. Secondary- origins of hypertension are known.
What is a diuretic?
A drug that makes the kidneys make more urine.
Short term systems that regulate blood pressure do what?
Alter the cardiac output and alter the peripheral resistance.
Long term systems that regulate blood pressure do what?
Alter the volume of blood in the vascular compartment.
What type of disorder is renal artery stenosis?
a vascular stenosis to the kidneys.
What is renal artery stenosis usually due to?
atherosclerosis.
Renal artery stenosis is a secondary hypertension called what?
Renal vascular hypertension.
What are the symptoms of intermittent claudication?
Intermittent pain in the lower extremities during exercise.
Intermittent claudication is associated with what?
Poor diet, lack of exercise and smoking.
Blood circulation through the body is due to what 3 factors?
- nature of blood flow. 2. blood flow determinants. 3. The heart.
What organs receive over 1 liter of blood per minute?
Kidneys, and GI tract.
What happens to blood flow in the left coronary artery with ventricle systole and diastole?
Systole- decreases flow as the ventricle contracts. Diastole- increases flow as the ventricle relaxes.
What are 2 controls of flow thorugh the coronary arteries?
- vasodilation of sympathetic fibers. 2. local metabolic factors from cardiac myocytes cause vasodilation.
What causes cardiac muscle to vasodilate with a sympathetic stimuli?
Beta 2 receptors.
What causes the cardiac muscles to vasodilate from metabolic factors?
release of CO2 and H+, and adensoine.
What are the consequences of an obstruction in the coronary artery?
myocardial ischemia
What is the term used for a chest pain from myocardial ischemia?
Angina pectoris.
Is angina pectoris a heart attack?
no it seldomly involves permanent damage.
What is Coronary artery disease caused by?
atherosclerosis which comes from high fat diets, genetic predispositions and lack of exercise.
What is the test used to evaluate the degree of a coronary artery inclusion?
Angiography
Besides having restricted flow with coronary artery disease what else happens?
Often have a damaged epithelial lining.
What happens to arteries when they have damaged epithelial lining?
They lack the normal responsiveness to vasoactive agents and tend to spasm. Also the clotting system is promted.
What is the term used for death of cardiac muscle tissues?
Myocardial infarction.
Myocardial ischemia can progress to what?
Myocardial infarction.
What will determine how much the cardiac output is damaged with a myocardial infarction?
The amount of myocardial death.
A heart attack is aka?
coronary, or myocaridal infarction.
What happens to blood in coronary arteries with a heart attack and why?
it declines because the cardiac output is low.
What happens to myocardium around the site of infarction?
We get hyper-excitable patches of myocardium that can become the pacemaker and cause fibrillation.
What is a cardiac tamponade?
A rupture of the infarction due to thinning and systolic stretch.
How effective can CPR performed right be at maintaining cardiac output?
30% which is good enough until defibrillation can be done.
Healing from a heart attack can happen when?
There is a development of collateral microvasculature and hypertrophy of surrounding myocardium.
How much blood goes to skeletal muscles at rest and how much during strenuous exercise?
Rest- 4 ml/min/100g. Active- can be as high as 80 ml/min./100g.
How is flow to skeletal muscles changed during contraction and relaxation?
Contraction- flow goes down because of compression. Relaxation- flow increases.
What ways will blood flow be controlled to skeletal muscles?
- sympathetic fiber innervation. 2. Local metabolic factors.
Of the controls of blood flow to skeletal muscles which one is the greatest factor?
Local metabolic factors.
Will sympathetic fibers to skeletal muscles cause vasoconstriction or vasodilation for blood vessels?
Both.
How can sympathetic fibers going to vasculature of skeletal muscle cause both vasoconstriction and vasodiliation?
It depends on the receptors if the vessels have Alpha-1 receptors then they will vasoconstrict, but if they have beta-2 adrenergic receptors they will vasodilate.
How will local metabolic factors control flow of blood to an area?
They will cause a vasodilation when the area produces CO2 and H+ so more blood can come there and remove the metabolic waste.
what will mass sympathetic discharge do?
Increase cardiac output and wide-spread vasoconstriction which leads to better delivery of blood.
What area of the body is given the highest priority for blood?
The cerebral circulation.
What is blood flow like in the brain?
It is constant at 700 ml/min.
Can the brain hold more blood?
No there is no room.
What part of the body is least tolerant to ischemia?
The brain.
What happens when there is a cerebral blood vessel blockage?
Cerebral stroke aka cerebrovascular accident.
What will often precede a cerebral stroke?
Transient ischemic attack.
How is blood flow controled to the brain?
Just one way through local metabolic factors from neurons.
CSF is turned over how much every day? How much csf is there at a given time?
500 ml/day and there are only 150ml at a time.
What is the difference between csf and normal plasma?
csf has increased na2+, and decreased glucose and K+
What part of the body is given the lowest priority for blood?
The splanchnic circulation.
Blood flows from Stomach and small intestines to where through what?
To the liver through the portal system.
How is blood flow controled to the GI tract?
- Local metabolic factors. 2. Nervous innervation by sympathetic fibers.
What control system of blood flow for the GI tract is the most powerful?
The local metabolic factors are powerful, but they can be profoundly overridden by sympathetic innervation.
What will sympathetic innervation to the GI tract do?
Causes vasoconstriction.
What will parasympathetic innervation to the GI tract do?
It will cause glandular activity that will cause vasodilation.
What is another name for a ischemia to the GI tract?
Abdominal cramps.
Excess fluid can accumulate in the peritoneal compartment in a condition known as what?
Ascites.
Where will blood that comes to the liver come from?
25% from the hepatic artery, and 75% from the hepatic portal vein.
How is blood flow controlled to the liver?
By local intestinal factors.
What can the spleen do?
It can store up to about 50 ml of concentrated RBCs.
What will cause the spleen to release the storage of RBCs?
Strong sympathetic stimulation.
What is the normal role of the spleen?
To cleanse blood of old blood cells.
How much blood flows to the kidneys?
1100 ml/min.
How is blood flow controlled to the kidneys?
It is rather steady, but sympathetic innervation produces vasoconstriction and a drop in flow.
How much of blood flow can go to the skin?
0-30 % of cardiac output.
What happens to blood flow to the skin when core temperature is high?
Vasodilation and sweating.
What happens to blood flow to the skin when core temperature is low?
Vasoconstriction and no sweating.
How is blood flow to the skin controlled?
just nervous innervation by sympathetic fibers.
Why is blood flow to the skin not dependant on local metabolic factors?
integument gets about 10 times more flow than it would generally need to remove local metabolic factors.
What will sympathetic innervation to arteries in the skin cause?
Vasodilation and vasoconstriction.
Cold temperatures will also release what and from where?
epinephrine release from adrenal gland.
What will innervate sweat glands?
Cholinergic sympathetic fibers.
What happens to smooth muscle that is vasoconstricting arteries in the skin when they get too cold?
They get paralysis and stop vasoconstricting and this results in a vasodilation and this will send lots of blood to the cold area and warm it up, but can lower core body temperature very fast.
What is the term used for the condition when smooth muscle stops vasoconstricting arteries of the skin and core body temperature can go down fast?
Exposure.
What is the term used for when tissue freezes and dies?
Frostbite.
What is intermittent claudication due to?
Atherosclerosis affecting arteries of the legs.
What causes pain in intermittent claudication?
it is an ischemic pain due to loss of circulation and drainage.
Why willl intermittent claudication only hurt people when they are walking?
That is when they need more blood that they cant get because of the atherosclerosis.
Circulatory shock is a life-threatening condition due to what?
Widespread, inadeuate blood flow.
What happens to blood pressure with circulatory shock?
It can increase or decrease.
What happens to metabolism with circulatory shock?
it decreases.
What happens to muscle strength and mental function with circulatory shock?
They both decrease.
The blood pressure in the system is created primarily from what?
The heart.
What determines cardiac output?
Venous return.
