Steroid hormones, derived from cholesterol, are essential for various body functions and produced in the adrenal cortex, testis, and ovary. They are lipid-soluble, allowing them to diffuse across membranes shortly after synthesis and play critical roles in metabolism, reproductive functions, and responses to stress and inflammation. Key types include glucocorticoids, mineralocorticoids, androgens, estrogens, and progestogens, each with specific biological functions.

1. Dr. P. Saranraj M.Sc., M.Phil., Ph.D., NET
Assistant Professor
Department of Microbiology
Sacred Heart College (Autonomous)
Tirupattur, Vellore District.
Mobile: 9994146964
E.mail: microsaranraj@gmail.com

2. STEROID HORMONES
 A steroid hormone is a Steroid that acts as a hormone.
 Steroid hormones are the crucial substances for the proper
functioning of body.
 Steroid hormones are produced in the adrenal cortex,
testis, ovary and some peripheral tissues.
 All steroid hormones are derived from cholesterol and
differ only in the ring structure and side chains attached
to it.
 Enzymes which produce steroid hormones from
cholesterol are located in Mitochondria and Smooth
Endoplasmic Reticulum.
 All steroid hormones are Lipid soluble and Water
insoluble. It is permeable to membranes so they are not
stores in cells.

3.  Steroid hormones are non-polar and can thus diffuse
across lipid membranes. They leave cells shortly after
synthesis.

4. TYPES OF STEROID HORMONES
1) Glucocorticoids - originate in the adrenal cortex and
affect mainly metabolism by (i) decreasing inflammation
and (ii) Increasing resistance to stress. (Eg.) Cortisol,
Corticosterone, 11 – dehydro corticosterone & Cortisone
2) Mineralocorticoids – originate in adrenal cortex and
maintain salt and water balance. (Eg.) Aldosterone
3) Androgens - Androgens originate in the adrenal cortex
and gonads and primarily affect maturation and function
of secondary sex organs (male sexual determination).
(Eg.) Testosterone

5. 4) Estrogens - originate in the adrenal cortex and
gonads and primarily affect maturation and function
of secondary sex organs (female sexual
determination). (Eg.) Estradiol and Estrone
5) Progestogens (also known a progestins) -
Progestins originate from both ovaries and placenta,
and mediate menstrual cycle and maintain
pregnancy. (Eg.) Pregnenolone and Progesterone

8. Aldosterone

9. Testosterone

10. Estradiol

11. Estrone

12. Pregnenolone

13. Progesterone

14. BIOSYNTHESIS OF STEROID HORMONES

16. FUNCTIONS OF STEROID HORMONES
 Steroid hormones plays a major role in
Carbohydrate regulation
Mineral balance
Reproductive functions
Inflammatory response
Stress response
Bone metabolism
Cardiovascular fitness
Activates DNA for Protein synthesis