Endocrine System Lecture Notes

This set of flashcards covers key concepts, definitions, mechanisms, and roles of the endocrine system based on the lecture notes.

Endocrine system

The body’s second great controlling system which influences metabolic activities of cells by means of hormones.

Hormone

A chemical substance released by a group of cells to control the function of other types of cells.

Endocrine glands

Glands that release hormones directly into the blood, including pituitary, thyroid, parathyroid, adrenal, pineal, and thymus.

Hyposecretion

Insufficient secretion of hormones, which can lead to conditions like diabetes insipidus and cretinism.

Hypersecretion

Excessive secretion of hormones, which can lead to conditions like gigantism and diabetes mellitus.

Negative feedback mechanism

A control system that reverses a change in a controlled condition, helping to maintain homeostasis.

Positive feedback mechanism

A control system that intensifies a change in a controlled condition, often seen during childbirth.

Prostaglandins (PGs)

A group of lipid compounds that have hormone-like effects on various systems in the body.

Steroid hormones

Hormones derived from cholesterol that can cross cell membranes and bind to intracellular receptors.

Nonsteroid hormones

Hormones that cannot cross cell membranes and typically act via cell surface receptors, requiring a second messenger.

Neurohormone

Chemicals secreted by specialized neurons into the blood instead of a synaptic cleft.

Target cells

Cells that contain specific receptors for a particular hormone, allowing them to respond to that hormone.

Adrenal cortex hormones

Hormones such as cortisol and aldosterone produced by the adrenal cortex.

The Hypothalamus

The brain region responsible for regulating the endocrine system through hormone release.

Blood glucose regulation

The process of maintaining glucose levels in the blood through insulin and glucagon secretion.

Hormonal receptors

Large proteins that are specific for a single hormone, found on cell membranes or within cells.