Explain what a portal system is and give an example. How is a portal system different from the typical arrangement of vessels?
What will be an ideal response?
A portal system is a special circulation in which a capillary bed connects to another capillary bed before returning to the general circulation. An example is the hepatic portal system, in which capillaries of the digestive tract are connected to capillaries of the liver by way of the hepatic portal vein. Typically blood in a capillary bed flows through the venous system and back to the heart.
You might also like to view...
Bones are constantly undergoing resorption for various reasons. Which of the following cells accomplishes this process?
A) osteoclast B) osteocyte C) osteoblast D) stem cell
The pigment that causes one's normal skin color is ________.
What will be an ideal response?
What effect do fibers from the micturition center in the brain have on the sympathetic neurons that control the internal urethral sphincter?
a) they inhibit them b) they excite them
Branched muscle fibers and intercalated discs are characteristic of ________ muscle tissue.
A. smooth B. multinucleated C. skeletal D. cardiac E. voluntary