NUR 612 EXAM 1 PRACTICE QUESTIONS AND COMPLETE SOLUTIONS

Endocrine System System composed of various glands that can synthesize and release special chemical messengers called hormones. System works closely with the Nervous System and the Immune system to regulate and integrate body functions. Functions: Growth and development Sexual differentiation Metabolism Adaptation to an ever-changing environment Regulation of digestion Use and storage of nutrients Electrolyte and water metabolism Reproductive functions Hormones Endocrine system uses chemical substances called hormones as a means of regulating and integrating body functions. Hormones are thought of as chemical messengers produced to target a specific cell. They do NOT initiate reactions but function as a modulator of cellular and systemic responses. Function as chemical messengers Move through the blood to distant target sites of action Or, act more locally as paracrine or autocrine messengers that incite more local effects Most are present in body fluids at all times in greater or lesser amounts as needed. Characteristics A single hormone can exert various effects in different tissues. A single function can be regulated by several hormones. Types of Hormone Actions Hormones are released in one location but can have the biologic effect either in that location of release or somewhere else Endocrine Paracrine Autocrine Intracrine Endocrine Hormones are released in the circulation to act on a target organ (between remote cells) Paracrine Hormones acts locally in cells other than that produced the hormones Ex: sex steroids in ovary (between local cells) Hormones acting locally on cells other than those that produced the hormone For example, the action of sex steroids on the ovary Autocrine Hormones exert action on the cells from which they are produced ex: insulin (on the cell that produced them) Hormones exerting action on the cells from which they were produced For example, the release of insulin from pancreatic beta cells can inhibit its release from the same cells Intracrine Hormone action is within the cell that produced the hormone Mechanisms of Hormone Action Hormones interact with high-affinity receptors. These are linked to one or more effector system in the cell