Physiology Lecture 23 - Endocrinology I & Related Concepts

A comprehensive set of flashcards summarizing key endocrine terms and concepts from physiology lecture notes.

Pineal gland

Produces melatonin and regulates circadian rhythms.

Posterior pituitary gland

Stores and releases oxytocin (milk ejection, labor) and vasopressin (water reabsorption).

Anterior pituitary gland

Produces hormones like prolactin (milk production), growth hormone (GH), and tropic hormones affecting other glands.

Thyroid gland

Produces thyroid hormones (T3 and T4), involved in metabolism, growth, and development.

Parathyroid gland

Produces parathyroid hormone (PTH), which increases calcium ion levels in the blood.

Hydrophilic hormones

Hormones that exit cells via exocytosis and are transported dissolved in plasma.

Hydrophobic hormones

Hormones that use simple diffusion to exit cells and require carrier proteins for transport in blood.

Action potential

A rapid rise and fall in membrane potential that occurs when neurons are activated.

Myelin sheath

An insulating layer around axons, speeding up action potential conduction.

Absolute refractory period

The time after an action potential when a second action potential cannot occur, regardless of stimulus strength.

Saltatory conduction

The process where action potentials jump from one Node of Ranvier to another, increasing conduction speed.

Epinephrine

A neurohormone produced mainly by chromaffin cells in the adrenal medulla, involved in fight-or-flight responses.

Testes

Produce androgens like testosterone, involved in sperm production and sexual characteristics.

Ovaries

Produce estrogen and progesterone, involved in egg production and female secondary sexual characteristics.

Cortisol

A steroid hormone involved in stress response, affecting metabolism and immune functions.

Graded potential

A local change in membrane potential that can summate and potentially trigger an action potential.

Neurohormones

Hormones released by neurons into the blood, influencing various bodily functions.

Hypothalamus

A brain region that synthesizes neurohormones regulating the anterior pituitary and other endocrine functions.

Goiter

Thyroid gland enlargement that can occur in hyperthyroidism and hypothyroidism.

Somatostatin

Hormone that inhibits gastric acid secretion and plays a role in regulating insulin and glucagon.

Adrenal cortex

A part of the adrenal gland that produces steroid hormones like cortisol and aldosterone.

Adrenal medulla

The inner part of the adrenal gland that produces catecholamines, including epinephrine and norepinephrine.