Adrenal glands (suprarenal glands) are small, triangular-shaped glands located on top of the kidneys. The function of adrenal glands is to produce a handful of important hormones that help in maintaining salt balance in the blood and tissues, maintaining blood pressure, responding to stressful situations, and producing some sex hormones. The adrenal cortex produces hormones that control sex (androgens, estrogens), salt balance in the blood (aldosterone), and sugar balance (cortisol). On the other hand, the adrenal medulla produces hormones involved in the fight or flight response (epinephrine and norepinephrine).
What is Cortisol?
Cortisol is a hormone produced by the adrenal cortex. It is a steroid hormone in the glucocorticoid class. Normally when it is used as a medication, it is called hydrocortisone. This hormone is produced by many animals. Mainly, the Zona fasciculata of the adrenal cortex in the adrenal glands produces cortisol. Other tissues also produce cortisol in lower quantities. Cortisol hormone is released with a diurnal cycle. Moreover, cortisol release increases when there is stress and low blood glucose concentration.
The primary control of cortisol is by the pituitary gland peptide ACTH. ACTH controls cortisol by controlling the movement of calcium into the cortisol secreting target cells. ACTH is under the control of CRH (hypothalamic peptide corticotropin-releasing hormone), which is under nervous control. The main functions of cortisol are to increase blood sugar through gluconeogenesis, suppress the immune system, and aid in the metabolism of fat, protein, and carbohydrates. Furthermore, it also decreases bone formation. Some medical disorders are related to cortisol production, such as primary hypercortisolism (Cushing’s syndrome), secondary hypercortisolism (pituitary tumor resulting in Cushing’s disease, pseudo-Cushing’s syndrome), primary hypocortisolism (Addison’s disease, Nelson’s syndrome), and secondary hypocortisolism (pituitary tumor, Sheehan’s syndrome).
What is Epinephrine?
Epinephrine (adrenaline) is a hormone produced by the adrenal medulla. It is a hormone as well as a medication. The Polish physiologist Napoleon Cybulski first isolated adrenaline in 1895. Epinephrine is normally produced by both the adrenal glands and by a small number of neurons in the medulla oblongata. This hormone is involved in the regulation of visceral functions such as respiration.
It plays an important role in the fight to flight response by increasing blood flow to muscles, the output of the heart (by acting on the SA node), pupil dilation response, and blood sugar level. Epinephrine does this by binding to adrenergic receptors like alpha and beta receptors. Epinephrine is found in many animals and some single-celled organisms. Moreover, as a medication, epinephrine is used to treat a number of conditions, including allergic reactions like anaphylaxis, cardiac arrest, and superficial bleeding. ACTH hormone and sympathetic nervous system stimulate the synthesis of epinephrine precursors by enhancing the activity of tyrosine hydroxylase and dopamine β hydroxylase, the two key enzymes involved in catecholamine synthesis.
What are the Similarities Between Cortisol and Epinephrine?
- Cortisol and epinephrine are two hormones produced by the adrenal glands.
- Both hormones are involved in stress response.
- Both hormones can increase the blood sugar level.
- They are well regulated by the ACTH hormone.
- Dysregulation of both is associated with diseases.
What is the Difference Between Cortisol and Epinephrine?
Cortisol is a hormone produced by the adrenal cortex, while epinephrine is a hormone produced by the adrenal medulla. Thus, this is the key difference between cortisol and epinephrine. Furthermore, cortisol is a steroid hormone, whereas epinephrine is a peptide hormone.
The below infographic presents the differences between cortisol and epinephrine in tabular form for side by side comparison.
Summary – Cortisol vs Epinephrine
Cortisol and epinephrine are two hormones produced by the adrenal glands that are involved in stress response. Cortisol is a steroid hormone produced by the adrenal cortex while epinephrine is a peptide hormone produced by the adrenal medulla. So, this is the key difference between cortisol and epinephrine.
1. “Cortisol” Encyclopædia Britannica, Encyclopædia Britannica, Inc.
2. “Epinephrine (Adrenaline): What It Is, Function, Deficiency & Side Effects.” Cleveland Clinic.
1. “Cortisol-3D-balls-2” By Jynto (talk) – This image was created with Discovery Studio Visualizer. (CC0) via Commons Wikimedia
2. “Epinephrine-ampule” By Jfoldmei – Own work (CC BY 3.0) via Commons Wikimedia