BIOL 2410 Lecture Notes - Lecture 32: Adrenal Medulla, Blood Sugar, Vasoconstriction

• School: University of Manitoba
• Department: Biological Sciences
• Course: BIOL 2410
• Professor: Diana Mlinar

Document Summary

Anywhere from 4-8 glands located on the posterior surface of the thyroid gland. Secreted when calcium concentration falls too low. Osteoclasts activity increases releasing calcium into the blood. Calcium is usually excreted as part of the kidney ltration function - gets brought back in. Needed for adequate calcium absorption in the intestine. Without vitamin d, calcium does not get taken up. Extracellular calcium concentration is very important for nerve cell activity, muscle contraction, blood clotting. The bulk of all bodily calcium is trapped in bone. Calcium exits the body in urine and less so in fecal matter. Calcium levels also directly impact phosphate availability. Thyroid hormone and growth hormone together stimulate bone growth. Osteoclasts create acidic environments and secrete proteases, resorbing bone matrix. As children bone deposition > bone resorption. As adolescents and young adults bone deposition = bone resorption. As adults bone deposition < bone resorption (clast greater than blast)