Flashcards in Hypertension Deck (72)
What equation tells you what arterial pressure is?
cardiac output times total peripheral resistance
What is the role of the reticular substance in regulation of circulation?
lateral and superior portions involved in excitation
medial and inferior portions are involved in inhibtion
What is the role of the hypothalamus in circulation?
posterior lateral portions cause mainly excitation
anterior portion can cause excitations or inhbition
What is the role of the motor cortex on nervous regulation of circulation?
exciation or inhibition
what threee areas of the brain are involved in the regulation of the circulation?
What is the vasomotor center?
located bilaterally in the reticular substance of the medulla and lower third of the pons
What is the vasoconstrictor area "C-1" anterolateral upper medulla do?
What is the role of vasodilator area "A-1" anterolateral lower medulla?
inhibits C-1 area
What is the role of sensory area "A-2" bilateral in nucleus tractus solitarii: receive sensory signal from vagus and glossopharyngeal from barorecepotrs. ?
C-1 and A-1 areas
What is the cardiac center do?
heart rate and contractility
What are innervated by sympathetic system?
sympathetic nerve fibers innervates all vessels except capillaries and precapillary sphincters and some meta arteriorles
What is mainly controled by parasympathetic nervous system?
mainly important in control of heart rate via the vagus nerve
What is the effect of total spinal anesthesia on blood pressure?
drops it significantly
What does alpha 2 sympathetic activation do on a sympathetic never?
ihibit norepinephrine release
What does activation of alpha 1 sympathetic receptors sdo?
What type of system is a baroreceptor pressure control system?
negative feedback control system?
What is the equation for G the strength of feedback
G=correction of error signal/error(abnormalilty still remianing)
What is hte range of hte effect of carotid sinus barorecptors?
pressures between 60 and 180 mmHg
Where is hte baroreceptor reflex most sensitive?
What occurs as the pressure increases in the carotid baroreceptor as far as nerve impules goes?
increase in number of impulees form carotid sinus resulting in inhibtion of vasoconstrictor and activation of vagal center
What occurs at the resetting of baroreceptors?
thought to prevent refelx from controling as a control system for changes in pressure that last more than a day
What splits angiotensinogen?
renin and splits it to angiotensin I
What splits angiotensin I?
ACE to angiotensin II; leading to aldosterone release and sodium retention
What splits kininogen?
kallikrein to bradykinin
What does bradykinin do?
cause nitric oxcde release; prostaglandin synthesis and vasodilation sodium excretion
What splits active bradykinin?
ACE inactivates bradykinin
How is hypertension diagnosed?
average of at least 2 readings per visit obtaned at 3 seperate visits each 2 to 4 weeks apart
What is the second leading cause of end stage renal disease?
with high normal being associated with a 3 times risk of future development of ESRD
What are some exogenous causes of hypertension?
Cocaine,ethanol, amphetamines, decongestants