Chapter 5 - Section 5.5 - Study Guide - Assess Your Learning Outcomes - Page 173: 3

**Definition of a Gland:** A gland is a specialized organ or structure in the body that secretes substances, such as hormones, enzymes, or fluids, either into the bloodstream (endocrine glands) or directly into a duct or body cavity (exocrine glands). Glands are essential components of various physiological processes and are responsible for producing and releasing specific substances that regulate bodily functions or aid in digestion, lubrication, and other functions. **Two Basic Functions of Glands:** 1. **Secretion:** The primary function of glands is to secrete specific substances. The nature of these substances varies depending on the type of gland and its location in the body. There are two main types of glands based on their secretion methods: - **Endocrine Glands:** These glands secrete hormones directly into the bloodstream. Hormones are chemical messengers that travel through the bloodstream to target cells or organs, where they regulate various physiological processes such as metabolism, growth, and homeostasis. Examples of endocrine glands include the pituitary gland, thyroid gland, and adrenal glands. - **Exocrine Glands:** Exocrine glands secrete their products into ducts or body cavities. The secretions from exocrine glands can include enzymes, mucus, sweat, saliva, and digestive juices. These substances are released either onto an epithelial surface (like the skin or mucous membranes) or into a body cavity. Exocrine glands are involved in functions like digestion, lubrication, and temperature regulation. Examples include salivary glands, sweat glands, and sebaceous glands. 2. **Regulation:** Glands play a crucial role in maintaining the body's internal environment and regulating various physiological processes. This regulation can involve controlling the balance of specific substances in the bloodstream or affecting target tissues and organs in response to changing conditions. - **Endocrine Regulation:** Endocrine glands release hormones that act as chemical messengers to regulate the activities of target cells or organs. For example, the pancreas releases insulin and glucagon to regulate blood glucose levels, and the thyroid gland secretes hormones to control metabolism. - **Exocrine Regulation:** Exocrine glands often play a role in maintaining the integrity of body surfaces and cavities. For instance, sweat glands help regulate body temperature by releasing sweat onto the skin, which evaporates and cools the body. Salivary glands aid in digestion by secreting enzymes and lubricating the oral cavity. In summary, glands are specialized structures in the body responsible for secretion, releasing substances into the bloodstream or body cavities, and regulating various physiological processes. The two basic functions of glands are secretion and regulation, and these functions can vary depending on whether the gland is endocrine or exocrine in nature.

**Definition of a Gland:** A gland is a specialized organ or structure in the body that secretes substances, such as hormones, enzymes, or fluids, either into the bloodstream (endocrine glands) or directly into a duct or body cavity (exocrine glands). Glands are essential components of various physiological processes and are responsible for producing and releasing specific substances that regulate bodily functions or aid in digestion, lubrication, and other functions. **Two Basic Functions of Glands:** 1. **Secretion:** The primary function of glands is to secrete specific substances. The nature of these substances varies depending on the type of gland and its location in the body. There are two main types of glands based on their secretion methods: - **Endocrine Glands:** These glands secrete hormones directly into the bloodstream. Hormones are chemical messengers that travel through the bloodstream to target cells or organs, where they regulate various physiological processes such as metabolism, growth, and homeostasis. Examples of endocrine glands include the pituitary gland, thyroid gland, and adrenal glands. - **Exocrine Glands:** Exocrine glands secrete their products into ducts or body cavities. The secretions from exocrine glands can include enzymes, mucus, sweat, saliva, and digestive juices. These substances are released either onto an epithelial surface (like the skin or mucous membranes) or into a body cavity. Exocrine glands are involved in functions like digestion, lubrication, and temperature regulation. Examples include salivary glands, sweat glands, and sebaceous glands. 2. **Regulation:** Glands play a crucial role in maintaining the body's internal environment and regulating various physiological processes. This regulation can involve controlling the balance of specific substances in the bloodstream or affecting target tissues and organs in response to changing conditions. - **Endocrine Regulation:** Endocrine glands release hormones that act as chemical messengers to regulate the activities of target cells or organs. For example, the pancreas releases insulin and glucagon to regulate blood glucose levels, and the thyroid gland secretes hormones to control metabolism. - **Exocrine Regulation:** Exocrine glands often play a role in maintaining the integrity of body surfaces and cavities. For instance, sweat glands help regulate body temperature by releasing sweat onto the skin, which evaporates and cools the body. Salivary glands aid in digestion by secreting enzymes and lubricating the oral cavity. In summary, glands are specialized structures in the body responsible for secretion, releasing substances into the bloodstream or body cavities, and regulating various physiological processes. The two basic functions of glands are secretion and regulation, and these functions can vary depending on whether the gland is endocrine or exocrine in nature.