Adrenal Glands and Hormone Production

Adrenal Gland Structure

• The adrenal gland consists of two separate endocrine organs: adrenal medulla and adrenal cortex.

Adrenal Cortex Functions

• Produces steroid hormones, which are grouped into three categories:

Mineralocorticoids

• Produced by the zona glomerulosa of the adrenal cortex.

Glucocorticoids

• Produced by the zona fasciculata and, to a lesser extent, by the zona reticularis of the adrenal cortex.

Androgens

• Produced by the zona reticularis and, to a lesser extent, by the zona fasciculata of the adrenal cortex.

Steroid Hormone Structure

• Characterized by a nucleus with four rings and 17 carbon atoms.
• Additional carbon atoms are found at positions 13 (C18), 10 (C19), and 17 (C20, 21, ...).

Stereochemistry of Steroid Hormones

• Side chains above the hormone plane are called β cis, while those below the plane are called α trans.
• Double bonds are represented by Δ (Delta) with the number of the preceding carbon atom (e.g., Δ5 indicates a double bond between C5 and C6).

Drawing Steroid Structures

• Carbon positions on the steroid nucleus are numbered.
• All double bonds are shown in the structure.