Many of the endocrine glands have a similar basic structure, composed of clusters of secretory cells of epithelial origin. Hormones are secreted into the interstitial space whereby they are rapidly absorbed into the [[Vascular System - Anatomy & Physiology|vascular system]]. In contrast the [[Exocrine - Anatomy & Physiology|exocrine]] system utilises ducts enabling it to secrete its contents directly to its target area. | Many of the endocrine glands have a similar basic structure, composed of clusters of secretory cells of epithelial origin. Hormones are secreted into the interstitial space whereby they are rapidly absorbed into the [[Vascular System - Anatomy & Physiology|vascular system]]. In contrast the [[Exocrine - Anatomy & Physiology|exocrine]] system utilises ducts enabling it to secrete its contents directly to its target area. |