Question

Glands are derived from a. nerve tissue. b. connective tissue. c. muscle tissue. d. epithelial tissue.

Short answer

Glands are derived from: d. epithelial tissue.

Step-by-step solution

Ruling out the tissues that do not give rise to glands

Glands are specialized structures that function to secrete substances within the body. They do not originate from nerve tissue, as nerves are responsible for transmitting electrical signals throughout the body. Similarly, they do not arise from muscle tissue, which is responsible primarily for movement and force generation. Lastly, they do not come from connective tissue, which provides structure and support throughout the body.

Identifying the correct tissue type

Glands are derived from epithelial tissue. Epithelial tissue lines both the internal and external surfaces of the body. They have many functions, including secretion, absorption, and protection. As glands are specialized structures involved in secretion, it makes sense that they originate from epithelial tissue.

Solution

Glands are derived from: d. epithelial tissue.

Key concepts

Glandular Function

Glands play an essential role in the body by producing and releasing substances that are crucial for various physiological processes. These substances can be hormones, enzymes, or other vital fluids.
Glands are categorized based on their function and the substances they secrete.

• Exocrine glands: These glands release their secretions onto epithelial surfaces, such as the skin or the lining of the gastrointestinal tract. Common examples include sweat glands and salivary glands.
• Endocrine glands: These glands release hormones directly into the bloodstream. The hormones then travel throughout the body to reach target organs and tissues. Notable examples are the thyroid gland and adrenal glands.

Each gland's function is tightly regulated to maintain homeostasis, ensuring the body remains in a balanced state, regardless of external changes or internal demands.

Tissue Types

The human body consists of four primary tissue types, each with distinct functions and characteristics. Understanding these tissue types helps explain how different body structures form and function.
Here is a brief overview:

• Epithelial tissue: This type covers the body's surfaces and lines organs and cavities. It is involved in protection, secretion, absorption, and filtration.
• Connective tissue: As its name suggests, this tissue connects and supports other tissues. It includes bone, blood, and adipose (fat) tissue, providing structural integrity and transportation of substances.
• Muscle tissue: Responsible for movement, muscle tissue facilitates body movements and maintains posture. There are three types: skeletal, cardiac, and smooth muscle.
• Nerve tissue: This tissue is essential for transmitting nerve impulses. It makes up the brain, spinal cord, and nerves, allowing coordination and control of body functions.

Glands are specifically made from epithelial tissue, highlighting its versatility beyond just creating barriers or surfaces.

Secretion in Glands

Secretion is a critical process in glands, involving the manufacture and release of substances necessary for the body's functioning. Two primary types of secretion methods exist:

• Merocrine secretion: Substances are secreted through exocytosis without losing cellular material. Examples include sweat glands and most exocrine glands.
• Holocrine secretion: Here, entire cells disintegrate to release their contents. This process is found in sebaceous glands associated with hair follicles, enabling the release of oils.

These secretion mechanisms reflect the diversity of glandular functions, from keeping the skin moisturized to regulating metabolism through hormonal release by endocrine glands.
Understanding secretion is vital because it explains how the body maintains a stable internal environment, known as homeostasis, by continuously producing and responding to different substances.