Endocrine System Lecture Notes

Vocabulary-style flashcards covering the key structures, hormones, and physiological processes of the endocrine system based on the lecture notes.

Endocrine Gland

A ductless gland that releases hormones directly into the bloodstream rather than through tubes or ducts.

Target cell

A specific cell containing receptors that allow a particular hormone to act upon it; without these receptors, the hormone has no effect.

Hypothalamus

Known as the "Master of the Master Gland," it controls the endocrine system by producing releasing and inhibiting hormones.

Pituitary Gland (Hypophysis)

Located in the sella turcica of the sphenoid bone, it is called the "Master Gland" because it controls many other endocrine glands.

Anterior pituitary

The larger lobe of the pituitary gland that produces 6 hormones: GH, Prolactin, TSH, ACTH, FSH, and LH.

Posterior pituitary

A lobe consisting of nerve fibers and neuroglia that stores and releases ADH and Oxytocin, which are produced by the hypothalamus.

TSH (Thyroid Stimulating Hormone)

An anterior pituitary hormone that stimulates the thyroid gland to produce $T_3$ and $T_4$.

GH (Growth Hormone)

A hormone that stimulates the growth of bones and muscles.

Prolactin (PRL)

A hormone produced by the anterior pituitary that stimulates breast milk production.

ACTH

A hormone that stimulates the adrenal cortex to produce cortisol.

FSH

A hormone that stimulates follicle (Graafian) growth and estrogen in women, and sperm production in men.

LH / ICSH

A hormone that triggers ovulation and progesterone in women, and stimulates Leydig cells to produce testosterone in men (ICSH is the male-specific term).

ADH (Antidiuretic Hormone / Vasopressin)

A hormone that increases water reabsorption in kidney tubules, thereby increasing blood volume and potentially blood pressure.

Oxytocin

A hormone that contracts the uterus after birth and causes milk ejection during breastfeeding.

Resorption

The process where calcium is released from the bone into the blood; mnemonic: "resorption is release."

Reabsorption

The process where the kidney recovers a substance (such as calcium or sodium) back into the blood instead of losing it in urine.

PTH (Parathyroid Hormone)

Produced when blood calcium is low, it increases blood calcium by stimulating bone resorption and kidney reabsorption.

Aldosterone

The main mineralocorticoid of the adrenal cortex that reabsorbs $Na^+$ and excretes $K^+$ in urine.

Glucocorticoids

Hormones such as Cortisol and Cortisone that increase blood glucose and act as anti-inflammatories.

Androgens

Sex hormones from the adrenal cortex with masculinizing effects; excess in women can cause body hair and a deeper voice.

Glucose

The body's immediate energy source.

Glycogen

The storage form of glucose located in the liver and muscles; it is not used directly for energy.

Pancreas

The only gland that is both exocrine (producing digestive juices via ducts) and endocrine (producing hormones via Islets of Langerhans).

Alpha cells

Cells in the Islets of Langerhans that produce Glucagon to increase blood glucose.

Beta cells

Cells in the Islets of Langerhans that produce Insulin to decrease blood glucose.

Glucagon

A hormone that makes the liver release stored glycogen as glucose when blood sugar is low.