HTN Physiology Flashcards
Describe primary and secondary HTN
Primary: idiopathic, there is no recognizable cause for their HTN.
Secondary: d/t some underlying dz.
- renal dz
- endocrine disorder
- obstructive sleep apnea
- pheochromocytoma
- thyroid problem
- aortic coarctation
- Birth control pills
- Cold medicines
- OTC pain relievers
- Rx drugs
- illegal drugs (cocaine, amphetamines)
- alcohol abuse/chronic use
Physiological mechanisms involvement in primary HTN
- autonomic nervous system
- cardiac output
- Peripheral resistance
- Renin-angiotensin-aldoserone system
- Other factors:
- -ANP, Bradykini, Endothelin, Endothelial derived relaxing factor)
Blood pressure is dependent upon what two factors?
-CO * Peripheral resistance
Systolic Blood Pressure definition
-systolic pressure is the force that blood exerts on the artery walls as the heart contracts to pump out the blood.
High systolic pressure is a greater risk factor than diastolic pressure for heart, kidney, and circulatory problems and for death in middle-aged adults, true or false?
True.
Aside: the wider the spread between the systolic and diastolic measurements, the greater the danger.
Diastolic Blood Pressure definition
the measurement of force as the heart relaxes to allow the blood to flow into the heart.
What is a high predictor of heart attack and stroke in young adults?
high diastolic pressure
What is Mean Arterial Pressure (MAP) ? How do you calculate it?
- the average arterial blood pressure during a single cardiac cycle
Calculation:
-MAP = (COxSVR) - CVP
Arterial Pulse Pressure
- what is this?
- what does it indicate?
What is this: the difference between the systolic and diastolic readings during ejection.
Indications:
- indicator of stiffness and inflammation in the blood-vessel walls.
- the greater the difference between systolic and diastolic numbers, the stiffer and more injured the vessels are thought to be.
What is peripheral vascular resistance?
-the resistance to flow that must be overcome to push blood through the circulatory system?
What is systemic vascular resistance?
the resistance offered by the peripheral circulation.
Neural Mechanism on BP
- Autonomic Nervous system mechanisms
- Central Nervous System mechanisms
ANS:
- Intrinsic: baroreceptors and chemoreceptors
- extrinsic: pain, cold, isometric exercises
- Higher neural control: sympathetic & parasympathetic
CNS:
-change in mood or emotion
Where is the most important baroreceptor for regulating arterial pressure located?
-carotid sinus
Where are the most important chemoreceptors located? They communicate with the vasomotor center and induce widespread _____.
carotid bodies and aorta
-they communicate with the vasomotor center and can induce widespread vasoconstriction
What role does the sympathetic and parasympathetic system play in vascular function?
- sympathetic can stimulate both arteriolar constriction and dilation, maintains normal blood pressure
- parasympathetic contributes to the regulation of heart function, but has little control over the blood vessels.