Chapter 13: The Endocrine System

These flashcards cover essential vocabulary related to the endocrine system, including definitions of hormones, glands, and key concepts from the lecture notes.

Endocrine glands

Ductless glands that secrete hormones directly into the bloodstream.

Hormones

Chemical messengers secreted by endocrine glands that act on target cells.

Exocrine glands

Glands that secrete substances into ducts or tubes leading to a body surface.

Paracrine secretions

Substances that affect nearby cells.

Autocrine secretions

Substances that affect the cells that secrete them.

Neurotransmitters

Chemicals released by the nervous system to relay messages.

Signal transduction

The process of converting a chemical signal into cellular response.

Upregulation

The increase in the number of receptors on target cells in response to decreased hormone levels.

Downregulation

The decrease in the number of receptors on target cells due to increased hormone levels.

Steroid hormones

Hormones derived from cholesterol, such as sex hormones and adrenal cortex hormones.

Non-steroid hormones

Hormones that cannot penetrate cellular membranes and typically use second messengers to induce effects.

Cyclic AMP (cAMP)

A common second messenger in non-steroid hormone signaling.

Tropic hormones

Hormones that regulate the functions of other glands.

Antidiuretic hormone (ADH)

Hormone that decreases urine production by reducing water excretion in the kidneys.

Prolactin

Hormone that promotes milk production in females.

Growth hormone (GH)

Stimulates growth and cell reproduction.

Thyroid-stimulating hormone (TSH)

Stimulates secretion of T3 and T4 from the thyroid gland.

Adrenocorticotropic hormone (ACTH)

Stimulates secretion of cortisol from the adrenal cortex.

Insulin

Hormone that decreases blood glucose levels by promoting glucose uptake by cells.

Glucagon

Hormone that increases blood glucose levels by stimulating liver to convert glycogen into glucose.

Melatonin

Hormone secreted by the pineal gland; regulates sleep-wake cycles.

Hypothalamus

Region of the brain that regulates hormones released from the pituitary gland.

Addison Disease

A disorder caused by insufficient hormone secretion from the adrenal cortex.

Cushing Syndrome

A disorder caused by excessive cortisol secretion, often leading to various metabolic issues.

Hyperthyroidism

Condition characterized by an overactive thyroid gland, resulting in excessive hormone production.

Hypothyroidism

Condition characterized by an underactive thyroid gland, resulting in insufficient hormone production.