Regulation of Blood Pressure and Cardiac Function Flashcards
Responsible for Vascular Adjustments?
Change in tone of smooth muscle tissue
Vasodilators work on Arterioles, Veins, or Both?
Only on Arterioles
Sympathetic nerves release?
Norepinephrine
Receptors for Norepinephrine
Alpha-1 Adrenergic Receptors
Effect of Norepinephrine on Vascular Smooth Muscle
Vasoconstriction
The Brain, Heart, and Skeletal Muscles blood flow closely follow what?
Metabolic Rate
Skin and Kidney blood flow is regulated by?
Sympathetic Nerves (Rather than metabolic rate as the others are)
Functions of Blood Flow (6)
- Delivery of Oxygen
- Delivery of Nutrients (Glucose)
- Removal of CO2
- Removal of H Ions
- Maintenance of Proper Concentration of other Ions
- Transport of Hormones
Local Blood Flow Regulation is regulated by? In organs, these are regulated by?
- Muscular arteries and large arterioles
2. In organs by metarterioles and endothelial cells of capillaries
Vasodilator Theory
Endothelial tissue produce a vasodilator substance in response to availability of O2 and Nutrients
Oxygen Lack Theory
Oxygen is required to allow muscle contraction, lack of this causes local arterioles and metarterioles to relax and dilate
Reactive Hyperemia
Transient increase in blood flow following a period of ischemia
Active Hyperemia
Increase in blood flow associated with increased metabolic activity (Such as in exercise)
Vasoconstrictor Agents (4)
Norepinephrine and Epinephrine
Angiotensin II
Vasopressin
Endothelin
Vasodilator Agents (2)
Bradykinin
Histamine
Increase in Calcium (Constrict or Dilate)
Vasoconstriction
Increase in Potassium (Constrict or Dilate)
Vasodilation
Increase in Magnesium (Constrict or Dilate)
Powerful Vasodilation
Low pH (Constrict or Dilate)
Dilatation of Arterioles
Acetate and Citrate (Constrict or Dilate)
Mild Vasodilation
Increase in CO2 (Constrict or Dilate)
Moderate Dilation in other Parts (Especially in the Brain)
Which Vessels are Not INnervated by the Sympathetic Nervous System?
Capillaries
Pre-capillary Sphincters
Metarterioles
Most Important Part for Regulation of Circulation
Why?
Sympathetic Nervous System
Most blood vessels do not have parasympathetic innervations
What can pass the Blood-Brain Barrier
Glucose and CO2
Heart is Innervated By?
Sympathetic and Parasympathetic Nerves
Parasympathetic Nerves (Vagi) effect on the Heart?
Lowers BPM
If Heart is De-Innervated, Will it Beat Faster or Slower?
It will beat faster, unlike abrupt termination of response to vagal activity; effects of sympathetic stimulation will only slow gradually after stimulation is stopped
Location of Vasomotor Center
Medulla and Upper Pons
Vasomotor Center Transmits What Impulses
- Vagus Nerve
- Spinal Cord
- Parasympathetic
2. Sympathetic
Vasovagal Reflex
Compression of Carotid Arteries slows down HR