Introduction to Endocrinology of Animals

Comprehensive vocabulary flashcards covering basic endocrinology terminology, gland types, hormone classifications, and metabolic actions based on Arkansas State University lecture notes.

Endocrinology

A subdivision of the broader field of physiology concerned with the study of hormones.

Hormone

A chemical messenger produced by a gland, secreted into the blood, that controls the actions of a distant target tissue or cell.

Exocrine glands

Glands that contain ducts and secrete products such as sweat, tears, saliva, or milk into these ducts which lead to the lumen of organs or the body surface.

Endocrine glands

Ductless glands that secrete their products directly into the blood, such as the liver, gonads, or pituitary.

Pancreas

The only organ of the body containing both exocrine and endocrine functions.

Neural control

A "wire system" using nerves and neurons that results in fast and short-lived responses requiring no genetic translation or protein synthesis.

Hormonal control

A "wire-less system" using endocrine secretions that is more often slower and has a longer duration of control than neural methods.

Autocrine action

A type of hormone action where a cell produces a hormone that acts on itself.

Paracrine action

A type of hormone action where a cell produces a hormone that acts on neighboring cells or tissues.

Pheromones

Hormones produced by an individual that act on or are detected by another individual.

Von Mering and Minkowski (1889)

Researchers who demonstrated that diabetes mellitus could be produced in the dog after surgical removal of the pancreas.

Bayliss and Starling (1902)

Scientists recognized for coining the word "Hormone" and discovering Secretin.

Berthold (1845)

The researcher who published the first recorded endocrine experiment involving the transplantation of testes in roosters.

Amines

A class of hormones produced from amino acids, such as Tyrosine, Triiodothyronine ($T_3$), and Thyroxine ($T_4$).

Glycoproteins

Hormones composed of protein chains and carbohydrates, such as FSH, LH, and TSH.

Beta ($\beta$) subunit

The unique subunit of a glycoprotein hormone that confers biological activity and determines hormone specificity.

Steroid Hormones

Hormones with a four-ringed cyclopentanoperhydrophenanthrene nucleus synthesized from cholesterol.

Eicosanoids

A group of hormones (meaning "20" in Greek) produced from the 20-carbon arachidonic acid, including prostaglandins and leukotrienes.

Leptin

A hormone produced by adipose tissue that targets the hypothalamus to suppress appetite.

Erythropoietin

A hormone produced by the kidneys that stimulates red blood cell production in the bone marrow.

Somatomedins

Hormones produced by the liver that target cartilage to stimulate cell division and growth.

Basal metabolic rate (BMR)

The basal rate of cell respiration promoted by Thyroxine ($T_4$) and Triiodothyronine ($T_3$).

Cholesterol

The 27-carbon structure used as the precursor for steroid hormone synthesis.

Progesterone

A steroid hormone containing $21 \text{ carbons}$.

Testosterone

A steroid hormone containing $19 \text{ carbons}$.

Estradiol

A steroid hormone containing $18 \text{ carbons}$.

Prostaglandin $F_{2\text{α}}$ ($PGF_{2\text{α}}$)

An eicosanoid responsible for smooth muscle contraction, vasoconstriction, and luteal regression.

Second messenger systems

Intracellular systems, such as cAMP, activated after a water-soluble hormone binds to a membrane-bound receptor.

Intracellular/Nuclear receptors

Receptors utilized by lipid-soluble hormones (thyroid or steroid) that initiate a slow response (hours to days) by altering gene transcription.

Transcription factor

The complex formed by a steroid hormone and its nuclear receptor that initiates the transcription of DNA into mRNA.

Carrier proteins

Molecules (such as plasma proteins) that bind to lipophilic steroid hormones to transport them through the blood.