Exam 4 Flashcards
(28 cards)
What is the #1 modifiable risk factor to prevent CVD?
Hypertension
What risks increases as blood pressure increases?
-MI
-HF
-Stroke
-Renal disease
-Retinopathy
What ethnic group has the highest prevalence of hypertension?
African Americans
How does HTN effect African Americans?
-Increased “resistant htn”
-Develops younger ages
-More prevalent in women
-More aggressive (leads to severe end-organ damage)
-Highest death rate
How does HTN effect Hispanics?
-Less likely to receive tx
-Lowest rates of BP control
-Lowest rates of awareness of HTN and tx
How does HTN effect men?
Most at risk before early middle age
How does HTN effect women?
- 2-3x more likely with oral contraceptive use
-Preeclampsia can be an early sign of CVD
-Most at risk >64
-Harder to control in older women
What is the definition of blood pressure?
Force exerted by blood against walls of blood vessels
How does BP regulation work?
-Involves both systemic factors and peripheral vascular effects
-Important to maintain tissue perfusion during activity and rest
-The function of cardiac output (CO) and systemic vascular resistance (SVR)
-CO = SV x HR
What factors influence BP?
-Sympathetic NS
-Vascular endothelium
-Renal system
-Hormonal (endocrine system)
What happens to the Sympathetic NS when BP drops?
It activates & increases HR and cardiac contractility
What senses decreased BP in the sympathetic NS?
Baroreceptors
What do baroreceptors do when BP is low?
-Send message to vasomotor center in brainstem
-Leads to efferent nerves innervating cardiac and vascular smooth muscle cells
What happens after the activation of the SNS in response to low BP?
-Vasoconstriction in peripheral arterioles
-Renin is released from kidneys
-Increases CO and SVR
What happens after baroreceptors send a message to the nerves and muscle cells?
-Parasympathetic NS in stimulated
What does the stimulation of the PNS cause?
-Decreased HR (vagus nerve)
-CO decreases
-Results in decreased BP
Where is Norepinephrine released from?
The SNS nerve endings
What does norepinephrine do?
Activates receptors in the SA node, myocardium, and vascular smooth muscle
**Response depends on receptors present
What type of receptors do smooth muscle of blood vessels have?
a-adrenergic and b-adrenergic receptors
What is a-1?
Vasoconstriction
-Increased contractility ( +inotropic)
What is a-2?
Vasoconstriction
-Inhibits release of norepinephrine
What is b-1?
Increased:
-Contractility
-HR
-Conduction
-Renin secretion
What is b-2?
Vasodilation
What does dopamine do?
Vasodilation
