Cell Signaling and Endocrine System Practice Flashcards

Vocabulary flashcards covering cell signaling mechanisms, feedback loops, endocrine glands, and major hormones from the Human Anatomy & Physiology lecture notes.

Ligand

A signaling molecule, such as a neurotransmitter, steroid, or amino-acid hormone, that binds to a specific receptor.

Target Cell

A cell that has specific receptors allowing it to recognize and respond to a particular ligand.

Gap Junctions

Protein-lined pores that allow direct cytoplasmic signaling and transport between adjacent cells.

Autocrine Signaling

A form of cell signaling in which a cell secretes a hormone or chemical messenger that binds to autocrine receptors on that same cell.

Paracrine Signaling

A type of local signaling where a cell produces a signal to induce changes in nearby cells.

Synaptic Paracrine Signaling

A specific type of paracrine signaling occurring in the nervous system where neurotransmitters diffuse across a synapse.

Endocrine Signaling

A signaling method where hormones are released into the bloodstream to affect target cells at a distance.

Negative Feedback

A control mechanism in which a stimulus causes a response that reverses or reduces the initial stimulus to maintain homeostasis.

Positive Feedback

A control mechanism in which the response to a stimulus reinforces or increases that stimulus.

Antagonistic Hormones

Hormones that have opposite effects on the body, such as insulin and glucagon.

Synergistic Hormones

Hormones that work together to produce an effect greater than the sum of their individual effects.

Tropic Hormones

Hormones that have other endocrine glands as their target.

Direct Hormones

Hormones that act directly on non-endocrine target tissues to produce a physiological response.

Hypothalamus

The link between the nervous and endocrine systems that can send nervous impulses and create hormones to control the pituitary.

Anterior Pituitary Gland

Known as the "master gland" because it produces and secretes hormones that regulate the activity of other endocrine glands.

Posterior Pituitary Gland

The gland that stores and releases direct hormones, specifically $OT$ and $ADH$, produced by the hypothalamus.

Epinephrine

Also known as adrenaline; a hormone released during the "fight or flight" response to influence heart rate and energy.

Insulin

A hormone produced by the pancreas that lowers blood glucose levels by facilitating glucose uptake in target cells.

Glucagon

A hormone produced by the pancreas that increases blood glucose levels by signaling the liver to release stored glucose.

Oxytocin (OT)

A direct hormone produced by the hypothalamus and stored in the posterior pituitary, involved in childbirth and social bonding.

Antidiuretic Hormone (ADH)

A direct hormone produced by the hypothalamus and stored in the posterior pituitary that helps regulate water balance in the body.

Cortisol

A hormone involved in the body's response to stress; long-term elevated levels from ongoing stress can lead to negative health effects.

Nervous System

A system characterized by fast response rates, short duration of response, and transmission via electrochemical impulses over short distances across synapses.

Endocrine System

A system characterized by slower response rates, longer length of response, and transmission via hormones in the blood over long distances.