Describe how local chemical cues can control blood flow through an organ
What will be an ideal response?
Local controls are changes within an organ that alter the flow of blood through that organ. Local controls change the diameter of the vessels running through them, altering resistance and flow. Local controls include metabolic changes, histamine, application of heat or cold, chemical response to sheer stress, and the myogenic response to stretch. In general, metabolic changes associated with active tissue (low oxygen levels, high levels of carbon dioxide) promote vasodilation, whereas inactive tissue factors promote vasoconstriction. Extrinsic controls include neural and hormonal factors that regulate vessel diameter, with the sympathetic system being most important. Increasing sympathetic activity causes generalized vasoconstriction.
You might also like to view...
Match the following:
1) Help prevent molecules from passing through the extracellular space between adjacent cells. 2) Type of anchoring junction. 3) Communicating junction. 4) Present in electrically excitable tissues. 5) Abundant in tissues subjected to great mechanical stress. A) Gap junctions B) Desmosomes C) Tight junctions
X-linked genes are expressed __________.
A) more often in females. B) at equal rates in the two genders. C) more often in males.
____________________________________ consist of fats and oils
Fill in the blank(s) with correct word
The type of most cells that form the strata in the epidermis are
A) adipocytes. B) keratinocytes. C) fibroblasts. D) melanocytes. E) dendritic cells.