--- title: "Eccrine Glands | General Biology I" description: "Eccrine glands are sweat glands that release watery sweat onto skin to cool the body, a core example of thermoregulation in General Biology I." canonical: "https://fiveable.me/college-bio/key-terms/eccrine-glands" type: "key-term" subject: "General Biology I" unit: "Unit 29" --- # Eccrine Glands | General Biology I ## Definition Eccrine glands are sweat glands that open directly onto the skin and release watery sweat to help regulate body temperature. In General Biology I, they show how the nervous system and skin work together in thermoregulation. ## What It Is Eccrine glands are the main sweat glands in your skin, and in General Biology I you usually see them as the body’s cooling system. They are spread across most of the body, with especially high numbers on the palms, soles, and forehead, where heat control and gripping surfaces matter a lot. These glands make a watery sweat made mostly of water plus dissolved electrolytes such as sodium and potassium. The sweat travels through a duct and opens directly onto the skin surface. When that liquid evaporates, it carries heat away from the body, which lowers skin temperature and helps keep internal temperature from rising too far. The control pathway is what makes eccrine glands a good biology example, not just a skin feature. They are activated by the sympathetic nervous system, which is the part of the autonomic nervous system that can trigger sweating during heat stress, exercise, or emotional arousal. That is why you can sweat even when you are not thinking about it. Your body is constantly adjusting without conscious control. Eccrine glands are different from apocrine glands, which are found in more limited regions and release a thicker secretion into hair follicles. Eccrine glands do not make scent by themselves the way people often imagine sweat does. The main job of eccrine sweat is temperature control, not body odor. In a biology class, this term usually shows up when you are tracing how form supports function. Skin is not just a barrier. It is also part of homeostasis, and eccrine glands are one of the clearest examples of that idea because they connect anatomy, nervous control, and evaporation in one process. ## Why It Matters Eccrine glands connect several big General Biology I ideas at once: homeostasis, the nervous system, and how animal bodies stay stable in changing environments. When you study mammals, these glands help explain why mammals can keep body temperature within a narrow range even during activity or heat exposure. They also make thermoregulation easier to picture than abstract temperature terms alone. If your body temperature rises, sweat production increases, the sweat evaporates, and heat leaves the body. That cause-and-effect chain is the kind of process biology classes love to ask about because it shows how structure and function fit together. This term also helps separate two commonly mixed-up skin gland types. If you can tell eccrine glands from apocrine glands, you are not just memorizing vocabulary. You are showing that you can read anatomy terms carefully and link a body structure to its job. That skill comes up again when you compare glands, organs, and tissues across the course. ## Connections ### Thermoregulation Eccrine glands are one of the body’s main thermoregulation tools. When internal temperature rises, sweating lets heat escape through evaporation. This makes the term easier to understand as part of a larger homeostasis process, not just as a skin structure. In mammals, temperature control is a big reason sweating matters. ### [Sympathetic Nervous System](/college-bio/key-terms/sympathetic-nervous-system) The sympathetic nervous system activates eccrine glands without conscious control. That connection is a good example of how the autonomic nervous system responds to stress, exercise, or heat. If a question asks why you sweat when nervous or overheated, this is the pathway you trace. ### [Apocrine Glands](/college-bio/key-terms/apocrine-glands) Apocrine glands are the closest comparison because both are sweat glands, but they do not work the same way. Eccrine glands are spread widely and open directly onto the skin, while apocrine glands are more limited and usually empty into hair follicles. That difference helps you identify which gland a question is describing. ### [Mammary glands](/college-bio/key-terms/mammary-glands) Mammary glands and eccrine glands are both glandular structures in mammals, but they serve very different functions. Mammary glands produce milk, while eccrine glands produce sweat for cooling. Seeing both together can help you recognize how mammals use specialized glands for survival, feeding, and temperature control. ## On the AP Exam A quiz item might ask you to label a skin diagram, choose which gland type opens directly onto the skin, or explain why sweating lowers body temperature. In a short answer, you may need to trace the pathway from sympathetic nervous system activation to sweat release and evaporation. If a prompt compares eccrine and apocrine glands, focus on location, secretion, and function, not just memorized names. In a lab or image ID question, look for widespread distribution and ducts that open onto the skin surface. If the question uses a scenario, connect heat exposure or exercise to increased eccrine activity. ## Eccrine glands vs Apocrine Glands These are often confused because both are sweat glands, but they are not the same. Eccrine glands are found throughout most of the body, release a watery sweat, and open directly onto the skin to cool you down. Apocrine glands are concentrated in areas like the armpits and groin, empty into hair follicles, and produce a thicker secretion that is not mainly for cooling. ## Key Takeaways - Eccrine glands are the main sweat glands that help the body cool itself through evaporation. - They are found across most of the skin, with lots of them on the palms, soles, and forehead. - Their secretion is mostly water with electrolytes, and it opens directly onto the skin surface. - The sympathetic nervous system controls them, so sweating can happen without conscious effort. - In General Biology I, they are a clear example of homeostasis and thermoregulation working together. ## FAQs ### What are eccrine glands in General Biology I? Eccrine glands are sweat glands in the skin that produce watery sweat and release it directly onto the surface of the body. In General Biology I, they are used to show how mammals regulate temperature through sweating and evaporation. They are part of the body’s homeostasis system. ### How are eccrine glands different from apocrine glands? Eccrine glands are widespread, open directly onto the skin, and mainly cool the body. Apocrine glands are found in fewer areas and usually empty into hair follicles. They also produce a thicker secretion, so the two glands have different locations and functions. ### What controls eccrine glands? The sympathetic nervous system controls eccrine glands. That is why sweating can increase during exercise, heat exposure, or stress without you choosing to do it. This is a classic autonomic response in biology. ### Why do eccrine glands matter for thermoregulation? They matter because sweat evaporating from the skin removes heat from the body. That cooling effect helps prevent body temperature from rising too high. This makes eccrine glands a direct example of how anatomy supports homeostasis. ## Related Study Guides - [29.6 Mammals](/college-bio/unit-29/6-mammals/study-guide/Jc1PMN23K6krGgpo) ## About This Document Canonical Fiveable pages are available as Markdown at the same path plus `.md`. - [llms.txt](https://fiveable.me/llms.txt): index of Fiveable's sections and URL patterns - [llms-full.txt](https://fiveable.me/llms-full.txt): complete subject and unit listing - [MCP server](https://fiveable.me/mcp): call Fiveable as tools instead of fetching pages (`https://fiveable.me/api/mcp`) - [MCP server for AP teachers](https://fiveable.me/mcp/teachers): a teacher's classes, assignments and AP-rubric grading (`https://fiveable.me/api/mcp/teacher`) ## Structured Data ```json {"@context":"https://schema.org","@graph":[{"@type":"LearningResource","@id":"https://fiveable.me/college-bio/key-terms/eccrine-glands#resource","name":"Eccrine Glands | General Biology I","url":"https://fiveable.me/college-bio/key-terms/eccrine-glands","learningResourceType":"Concept explainer","educationalLevel":"AP® / High School","about":{"@id":"https://fiveable.me/college-bio/key-terms/eccrine-glands#term"},"audience":{"@type":"EducationalAudience","educationalRole":"student"},"dateModified":"2026-07-03T02:21:09.278Z","isPartOf":{"@type":"Collection","name":"General Biology I Key Terms","url":"https://fiveable.me/college-bio/key-terms"},"publisher":{"@type":"Organization","name":"Fiveable","url":"https://fiveable.me"}},{"@type":"DefinedTerm","@id":"https://fiveable.me/college-bio/key-terms/eccrine-glands#term","name":"Eccrine glands","description":"Eccrine glands are sweat glands that open directly onto the skin and release watery sweat to help regulate body temperature. 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