Blood Flow by the Tissues Guyton 2011 Chapter 17 Local and Humoral Control of Blood Flow by the Tissues Blood flow to different organs and tissues under basal condition Percent of CO 14 Brain ID: 934280
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Slide1
Local and Humoral Control ofBlood Flow by the Tissues
Guyton 2011 Chapter 17
Slide2Local and Humoral Control of Blood Flow by the Tissues
Blood flow to different organs and tissues under basal condition
Percent of CO
14
Brain 4Heart 2Bronchi 22Kidneys 27Liver (21) Portal (6) Arterial 15Muscle (inactive state)5Bone 6Skin (cool weather)1Thyroid gland0.5Adrenal gland3.5Other tissue100Total
ml/min70020010011001350105030075025030050251755000
ml/min/100g
50
70
25
360
95
4
3
3
1600
300
1.3
Slide3Local and Humoral Control of Blood Flow by the Tissues
Tissue blood flow control
Local
External
Acute control (seconds to minutes)Long-term (hours, days, weeks or months)NervousHormonal
Slide4Local and Humoral Control of Blood Flow by the Tissues
Acute Control of Local Blood Flow
Slide5Local and Humoral Control of Blood Flow by the Tissues
Acute Control of Local Blood Flow
Slide6Local and Humoral Control of Blood Flow by the Tissues
Acute Control of Local Blood Flow
Slide7Local and Humoral Control of Blood Flow by the Tissues
Role of Other Nutrients Besides Oxygen
Acute Control of Local Blood Flow
Slide8Local and Humoral Control of Blood Flow by the Tissues
Hyperemia
Active Hyperemia
(Functional or exercise)Reactive Hyperemia
Slide9Local and Humoral Control of Blood Flow by the Tissues
Reactive Hyperemia
Slide10Local and Humoral Control of Blood Flow by the Tissues
Active Hyperemia
(Functional or exercise)
Slide11Local and Humoral Control of Blood Flow by the Tissues
Autoregulation
Slide12Local and Humoral Control of Blood Flow by the Tissues
Increased BP
Increased Flow
Increased nutrients in ECF
Arteriolar contractionDecreased Flow-Metabolic Mechanism
Slide13Local and Humoral Control of Blood Flow by the Tissues
Metabolic mechanism
Slide14Local and Humoral Control of Blood Flow by the Tissues
Myogenic Response
Slide15Local and Humoral Control of Blood Flow by the Tissues
Extrinsic control of peripheral blood flow
Sympathetic division
Slide16Local and Humoral Control of Blood Flow by the Tissues
Other Humoral control of the circulation
Vasoconstrictor Agents
Angiotensin II
As little as one millionth of a gram can increase the arterial pressure of a human being 50 mm Hg or more.Vasopressin (ADH) Even more powerful than angiotensin II as a vasoconstrictor Most physiologists have thought that vasopressin plays little role in vascular controlEndothelinA large 21 amino acid peptideThe usual stimulus for release is damage to the endotheliumprevent extensive bleeding from arteries as large as 5 millimeters in diameter
Slide17Local and Humoral Control of Blood Flow by the Tissues
Vasodilator Agents
Nitric Oxide (NO)
Slide18Local and Humoral Control of Blood Flow by the Tissues
Bradykinin
They are form from alpha2-globulins in the plasma or tissue fluids by
kallikrein
alpha2-globulin→kallidin→bradykininkallikrein is activated by maceration of the blood, by tissue inflammation, or by other similar chemical or physical effects on the blood or tissuesinactivated by the enzyme carboxypeptidase or by converting enzymeFunctions:Arteriolar dilation Increased capillary permeability A normal role to help regulate blood flow in the skin as well as in the salivary and gastrointestinal glands.
Slide19Local and Humoral Control of Blood Flow by the Tissues
Histamine
Is released by damaged tissue, inflammation and
allergic reactions
Is derived from mast cellsFunction like Bradykinin
Slide20Local and Humoral Control of Blood Flow by the Tissues
Vascular Control by ions and Other Chemical Factor
Calcium Ion
Potassium IonMagnesium Ion Hydrogen IonAnionsAcetate and CitrateCarbon Dioxide ConcentrationMost Vasodilators or Vasoconstrictors Have Little Effect on Long-Term Blood Flow Unless They Alter Metabolic Rate of the Tissue
Slide21Local and Humoral Control of Blood Flow by the Tissues
Long-Term Blood Flow Regulation
Slide22Local and Humoral Control of Blood Flow by the Tissues
Long-Term Blood Flow Regulation
Change in “Tissue Vascularity”
Retrolental Fibroplasia
Vascularity Is Determined by Maximum Blood Flow Need, Not by Average Need
Slide23Local and Humoral Control of Blood Flow by the Tissues
Long-Term Blood Flow Regulation
Angiogenesis
Slide24Next Session
Microcirculation