The Endocrine System

The endocrine system is made of glands and organs that produce and secrete hormones. Hormones are chemical signals that act as messengers between …

The endocrine system is composed of glands, tissues, and organs distributed throughout the body. Endocrine glands are ductless glands that secrete …

A signaling cascade is a sequence of events that transfers information within or between cells, resulting in a response in the target cell. Hormones are …

Hormones can be classified into steroids, eicosanoids, amino acid-based derivatives, and peptide hormones based on their structures. Steroids and …

Water-soluble hormones cannot move across the plasma membrane, so they use protein receptors that span the membrane to trigger intracellular signaling …

Hormones bind to receptors on a target cell’s surface or interior and initiate various cellular …

Hormone secretion is regulated by different types of signals, including neural, humoral, and hormonal stimuli. Neural stimuli are triggered by the …

The pituitary gland is a small endocrine organ located in the sphenoid bone under the hypothalamus. Primarily, the pituitary in adults has two distinct …

The small, pea-sized pituitary gland is located at the base of the brain. It is crucial in regulating various bodily functions, from growth to …

The thyroid gland is a small, butterfly-shaped gland. It covers the anterior surface of the trachea in the neck region. It has two lateral lobes connected …

Low blood levels of the thyroid hormones — triiodothyronine (T3) and thyroxine (T4) — signal the hypothalamus to release the …

The thyroid hormone, or TH, is essential for the normal development and maturation of the skeletal, muscular, and nervous systems during fetal and …

Calcitonin is a polypeptide hormone that regulates calcium levels in body fluids. The parafollicular cells or C cells are present in the follicular …

The thyroid gland's posterior surface contains two embedded pairs of parathyroid glands. They are separated from the thyroid gland by a dense …

The adrenal or supra-renal glands are paired, pyramid-shaped glands located above the kidney and in line with the twelfth rib.  When the body …

The adrenal hormones are crucial for the body's electrolyte balance and stress response. The adrenal cortex produces over two dozen types of …

Adrenal gland disorders occur when the concentration of adrenal hormones produced is too high or too low. Adrenal insufficiency occurs when the adrenal …

The pineal gland is a small endocrine gland named for its pinecone shape. This gland is located on the roof of the third ventricle within the …

The gonads, the testes in males, and the ovaries in females produce gonadal hormones. Testosterone is the primary male gonadal androgen. It is responsible …

The pancreas is a glandular organ in the abdominal cavity that is part of the digestive and endocrine systems. It consists of exocrine and endocrine cells …

The pancreatic hormones glucagon and insulin regulate blood glucose levels. Between meals or during fasting, the blood glucose levels drop, triggering the …

Diabetes mellitus is a chronic metabolic disorder characterized by high blood glucose levels due to inadequate insulin production, insulin resistance, or …

In Type 2 or insulin-independent diabetes, the insulin receptors on the cells stop responding to insulin, developing resistance to insulin functions. This …