How are apocrine glands different from eccrine glands?

Eccrine glands and apocrine glands differ significantly in their structure, function, and distribution:

• Function and Secretion: Eccrine glands are primarily responsible for thermoregulation by secreting a dilute, water-based solution that cools the body through evaporation. In contrast, apocrine glands secrete a concentrated, fatty fluid. While often called sweat glands, apocrine glands are not involved in cooling; their secretions are broken down by skin bacteria into odorous fatty acids, likely serving a social or sexual signaling purpose.123
• Anatomy and Location: Eccrine glands open directly onto the skin surface via a duct. They are distributed across most of the human body, with the highest concentrations on the palms and soles. Apocrine glands are typically associated with hair follicles and open into them. In humans, they are restricted to specific areas such as the axillae (underarms), genital regions, and ear canals.31
• Control: Eccrine glands are controlled by the sympathetic nervous system in response to thermal or psychological stimuli. Apocrine glands are stimulated by hormonal changes during puberty and contract in response to emotional stress.132