Endocrine System Lab Report

The Endocrine System

Erin Petriella

Anatomy & Physiology

2402 P4L

Erick Elung

02/08/2015

Introduction

The endocrine system, in conjuction with the nervous system, regulates and maintains homeostasis within the human body. Endocrine glands do this by secreting chemical messengers called hormones. The various hormones travel via the bloodstream to target cells where they then bind to specific receptors that are either located on the cells surface, or in the cells cytosol, or nucleus. Endocrine organs don't operate independently and it is common for one gland to depend on another in order to function properly. Usually negative feedback mechanisms control the stimulation and inhibition of hormones. These mechanisms ensure the regulation of hormone secretion, production, and effects on target cells. Simply put, one hormone may inhibit another, while yet another hormone stimulates the first hormone's opposite, resulting in an antagonistic effect.

Regulation by positive feedback is less common in the endocrine system. This is where an increased level of a hormone will stimulate the secretion of more of that hormone. An example of this is oxytocin. Oxytocin stimulates uterine contractions during childbirth and the raised levels of oxytocin during labor triggers the release of more oxytocin, increasing the strength of contractions for delivery. Both types of feedback are essential for endocine function.

In this exercise I will be performing experiments that illustrate ways in which certain hormones effect endocrine regulation and homeostasis. The first activity involves the mechanism of thyroid hormone in metabolism. The thyroid gland functions to maintain body temperature and metabolism, which is all the biochemical processes occuring within the body at any given moment, and is a key factor in maintaining homeostasis. This is why thyroid hormones affect nearly all cells in the body....