Hormones and Their Actions

These flashcards cover key concepts and terms related to hormone functions, secretion, interactions, and the body's response to stress.

Hormone Secretion

The process by which hormones are released into the bloodstream, stimulated by neural, hormonal, or humoral factors.

Neural Stimuli

Nerve fibers that elicit the release of hormones from some endocrine glands, such as the sympathetic nervous system stimulating the adrenal medulla.

Hormonal Stimuli

Hormones from the hypothalamus that regulate the secretion of hormones from the anterior pituitary gland.

Humoral Stimuli

Blood-borne stimuli that trigger hormone release, such as rising blood glucose levels stimulating insulin secretion.

Up-regulation

The process of increasing the number of hormone receptors on target cells, enhancing sensitivity to that hormone.

Down-regulation

The process of reducing the number of hormone receptors on target cells, decreasing sensitivity to that hormone.

Synergistic Effect

When multiple hormones act together to produce a greater effect, such as FSH and testosterone on sperm production.

Permissive Effect

When one hormone enhances the target organ's response to a second hormone, for example, estrogen preparing the uterus for progesterone.

Antagonistic Effect

When one hormone opposes the action of another, such as insulin lowering blood glucose levels while glycogen raises it.

Alarm Reaction

Initial response to stress mediated by the sympathetic nervous system, preparing the body for fight or flight.

Stage of Resistance

The phase in response to stress where alternative fuels for metabolism are provided, dominated by cortisol.

Cortisol

A hormone that plays a role in the stress response; has glucose-sparing effects but can also suppress the immune function.

Eicosanoids

A family of paracrine secretions derived from arachidonic acid, involved in inflammatory responses.

Paracrine Signals

Chemical messengers that diffuse short distances to stimulate nearby cells, such as histamine and nitric oxide.

Autocrine Signals

Chemical messengers that stimulate the same cell that secreted them, like hepcidin regulating iron release.

Nonsteroidal Anti-inflammatory Drugs (NSAIDs)

Medications like aspirin and ibuprofen that inhibit prostaglandin and thromboxane synthesis to reduce inflammation.