Endocrine System in Animals

Hypothalamus

Part of the diencephalon of the brain. Controls activities of the pituitary gland. Portal system of blood vessels links to anterior portion of pituitary gland

Pituitary Gland

Called the master endocrine gland. The two separate glands with different embryological origins, different structures, different functions are the anterior and posterior

Anterior Pituitary

The rostral portion that produces hormones when stimulated

Posterior Pituitary

The caudal portion that stores and releases hormones

Growth Hormone (GH)

Also known as somatotropin and somatotropic hormone. Promotes body growth in young animals and helps regulate metabolism of proteins, lipids, and carbohydrates in all body cells. Encourages anabolism of proteins. Causes release of lipids in storage and their catabolism. Discourages cells from using carbohydrates, esp. glucose

Anabolism

The chemical reactions that synthesize molecules of proteins

Catabolism

Degradative metabolism involving the release of energy and resulting in the breakdown of complex materials within the organism

Follicle-Stimulating Hormone

Named for effect on females. It stimulates oogenesis and the production and secretion of estrogen. In males, it stimulates spermatogenesis

Oogenesis

Spermatogenesis

Antidiuretic Hormone (ADH)

It helps regulates water pressure and water retention. It’s released when hypothalamus detects dehydration. Deficiency can cause diabetes insipidus

Oxytocin

Induces uterine contractions at breeding and parturition. Stimulation of teat by nursing or milking causes it to be released. It causes movement of milk down to lower parts of the mammary gland

Thyroid

Two lobes on either side of larynx. Lobes may be connected by isthmus. Two hormones produced in follicles: thyroid hormone and calcitonin

Uterine Contractions

Rhythmic tightening and relaxing of the uterine muscles

Milk Letdown

The process of milk being released from the breast into the milk ducts

Adrenal Glands

Located near cranial ends of kidneys. The hormonal secretions are adrenaline and cortisol. Consist of the cortex and medulla

Pancreas

Long, flat organ located in the abdomen near the duodenum. Has both exocrine and endocrine functions

Gonads

The reproductive organs: testes in the male and ovaries in the female. They produce reproductive cells and important hormones

Hyperthyroidism

More commonly seen in cats; signs are tachycardia and increased appetite.

Hypothyroidism

More commonly seen in dogs; lethargy, weight gain, obesity, haircoat changes