28 Questions
What influences arteriolar resistance according to the text?
Local and systemic control reflexes
Which mechanism adjusts blood flow directly in arterioles?
Myogenic autoregulation
What activates myosin light chain kinase (MLCK) in vascular smooth muscle?
Calmodulin
What does stretched vascular smooth muscle mechanically-gated Ca2+ channels result in?
Contraction
Which signals influence vascular smooth muscle?
Paracrine signals
What influences arteriolar resistance in heart and skeletal muscle?
Local control
What determines blood distribution to various tissues according to the text?
CNS reflexes
What does the sympathetic reflex regulate to meet homeostatic needs?
Blood flow to various tissues
What causes fluid movement out of capillaries?
Hydrostatic pressure
What causes fluid movement into capillaries?
Colloid osmotic pressure
What is the net pressure determining the direction of bulk flow?
PNET = PH - π
What is the function of the lymphatic system?
Returns fluid and proteins to the circulatory system
What is edema?
Accumulation of fluid in the interstitial space
What is the role of lymph nodes?
Contain immunologically active cells
What causes net filtration at the arterial end of capillaries?
PH > π
What causes net absorption at the venous end of capillaries?
PH < π
Which chemicals mediate vasoconstriction?
Norepinephrine, serotonin, endothelin, vasopressin, and angiotensin II
Which branch controls most vascular smooth muscle, except in the vasculature of erectile tissue?
The sympathetic branch
Which chemicals mediate vasodilation?
Epinephrine, acetylcholine, nitric oxide, bradykinin, adenosine, histamine, natriuretic peptides, and vasoactive intestinal peptide
Where are the baroreceptors located that control blood pressure?
Carotid arteries and aorta
How do most capillary exchanges take place?
By diffusion and transcytosis
What is the main function of drugs used to treat erectile dysfunction?
Prolong NO (nitric oxide) activity
Which chemicals are potent vasodilators that play a role in inflammation?
Kinins and histamine
What controls blood distribution according to the metabolic need of individual tissues?
Local control mechanisms and homeostatic reflexes
What is the relationship between capillary density and the metabolic activity of cells?
Capillary density is related to the metabolic activity of cells
What is the main method of plasma and cell material exchange across capillary walls?
Diffusion and transcytosis
What is the function of the baroreceptor reflex?
Controls blood pressure
Which blood flow stays nearly constant according to the text?
Cerebral blood flow
Study Notes
Vascular Physiology Overview
- Drugs used to treat erectile dysfunction prolong NO (nitric oxide) activity
- Nitric oxide decreases preeclampsia
- Kinins and histamine are potent vasodilators that play a role in inflammation
- Chemicals mediating vasoconstriction include norepinephrine, serotonin, endothelin, vasopressin, and angiotensin II
- Chemicals mediating vasodilation include epinephrine, acetylcholine, nitric oxide, bradykinin, adenosine, histamine, natriuretic peptides, and vasoactive intestinal peptide
- The sympathetic branch controls most vascular smooth muscle, except in the vasculature of erectile tissue
- Blood distribution varies according to metabolic need of individual tissues, governed by local control mechanisms and homeostatic reflexes
- Cerebral blood flow stays nearly constant
- The baroreceptor reflex controls blood pressure, with baroreceptors in carotid arteries and aorta producing continuous action potential to the brainstem
- Plasma and cells exchange materials across thin capillary walls, with capillary density related to the metabolic activity of cells
- Capillaries have the thinnest walls, and they are supported by basal lamina
- Most capillary exchange takes place by diffusion and transcytosis, including movement between endothelial cells and through cells, and transport of larger solutes and proteins by vesicular transport
Test your knowledge of vascular physiology with this quiz. Explore the role of various chemicals in vasoconstriction and vasodilation, the control of blood distribution, and the mechanisms of capillary exchange. See how well you understand the impact of drugs on nitric oxide activity and the function of the baroreceptor reflex in controlling blood pressure.
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