Hypertension (EXAM 1) Flashcards
What nervous system drive blood pressure?
Sympathetic NS
What does RAAS stand for?
Renin Angiotensin Aldosterone System
What does the RAAS system do?
Regulates long term blood pressure and extracellular volume
Angiotensionogen
Release by LIVER in response to low blood pressure and changes in blood volume ( Na level)
Low fluid volume stimulates the kidney to release RENIN which causes the liver to convert ANGIOTENSINOGEN to ANGIOTENSIN I
Sionogen (Pre cursors to something)
Angiotensin I
Travels to LUNG where it is converted to Angiotensin II by ACE (Angiotensin Converting Enzyme)
Angiotensin II
Acts on the ADENAL GLANDS to cause release of ALDOSTERONE (causing fluid retention)
Angiotensin II is a POTENT Vasoconstrictor
This process causes the nephron in the kidney to retain fluid and B/P goes up
The RAAS System
System that regulates long term blood pressure and extracellular volume
First ANGIotensionogen is released by the LIVER due to low blood pressure and changes in blood volume
The low fluid volume stimulates the kidney to release RENIN which causes liver to turn angiontensinogen into angiontensinogen I
Angiotensin I travles to lungs where ACE converts it into Angiotensin II
Angiotensin II acts on ADRENAL GLANDS to cause release of ALDOSTERONE causing fluid retention
Angiotensin II is a potent vasoconstrictor
RAAS System etc
Also activated when kidneys have decreased renal perfusion—release of renin to start the process
RAAS problem
Some people have a hypersensitivity to angiotensin II or are high secretors of Renin
Chronic Stress can elevatue Angiotensin II
Other mechanism affecting blood pressure: Arterial baroreceptors
-Receptors in the carotid sinus, aorta, and left ventricle.
-Receptors sense blood pressure, can alter BP by altering HR
-Can also impact vasodilation and vasoconstriction
Other mechanisms affecting blood pressure: Vascular Autoregulation (TISSUE LEVEL)
-Helps maintain consistent levels of tissue perfusion
-Regulates based on mean arterial pressure (MAP)
-Alters the resistance (diameter) in arterioles
-This mechanism helps keep CONSISTENT blood pressure at the tissue levels despite changes that are occurring in other mechanisms
Blood Pressure Catagories
Normal: < 120 and <80
Elevated: 120-129 and <80
HBP 1: 130-139 and 80-89
HBP 2: 140 or Higher and >90
HTN Crisis: >180 and >120
Primary Hypertension
-90-95% of cases (Essential HTN)
-Occurs when there is NO specific known cause of hypertension (Idiopathic)
Why does Primary HTN occur?
Occurs from complicated interactions of genetics and environment and involving several neurohormonal effects
Over active SNS
Over active RAAS
Natriuretic peptides
Risk factors for Primary Hypertension
Smoking
Sodium intake
Age
Lifestyle
Hyper-lipidemia
Stress
Family history
Insulin resistance
High Alc
