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Flashcards in Reg of BP Deck (12):
1

Formula for BP

BP=CO*TPR

2

Formula for CO

CO=SV*HR

3

What regulates CO?

1. Volume (Na)

2. HR (symp/para)

3. Force of contraction (symp)

4

What regulates Vascular Resistance?

1. Vasoconstriction (NE+, Angiotensin+, NO-)

2. Structural changes- remodeling/hypertrophy

5

What systems regulate BP? 2 Major+4 minor

1. Autonomic Nervous System

2. Renin-Angiotensin System

3. Chemoreceptors in Carotid/Aortic bodies

4. Centrally located chemoreceptors

5. Antidiuretic hormone

6. Low pressure baroreceptors: veins, atria, PA

6

How is the autonomic nervous system regulated?

Parasymp: decreases HR

Symp: increases CO & peripheral resistance via increase in HR and contractile force; increases renin from kidneys

Baroreceptors do feedback

7

What is the baroreceptor reflex?

Located in internal carotids, senses stretch

increase in BP --> increase in stretch --> decrease symp/ increase para

Bleeding, standing --> decrease in stretch --> decrease para, increase symp

8

What is the renin-angiotensin-aldosterone system?

Regulated by kidnes, leads to increased Na and H2O retention

A image thumb
9

What are the effects of Angiotensin II?

1. Adrenal cortex: stimulates synthesis & secretion of aldosterone (which acts on renal distal tubule collecting duct to increase Na reabsorption)

2. Vasoconstriction of arterioles

3. Directly stimulates Na/H exchange in kidneys

4. Hypothalamus: increases thirst, antidiuretic hormone (ADH)

5. Increases contractility and ventricular hypertrophy

10

What stimulates renin secretion?

Decreased renal perfusion (mechanoreceptors)

Decreased Na+

Sympathetic activity

11

How is ADH stimulated? What are its effects?

Stimulated by angiotensin II & increase in serum osmolarity

Affects V1 receptors on vasc sm muscle--> vasoconstriction and V2 renal collecting ducts --> increased H2O reabsorption

12

How do the low pressure baroreceptors work?

Activated by increase in blood volume which increases venous/atrial pressure

Effect is to increase ANP which leads to relaxation of vascular smooth muscle & increasing blood flow to kidneys so water and salt can be excreted

Low pressure baroreceptors also increase HR (bc increased CO --> increased renal perfusion & Na/H2O excretion) and decrease antidiuretic hormone