Endocrine System and Neurotransmitters Overview

A collection of flashcards that cover key concepts related to the endocrine system and neurotransmitter functions as outlined in the lecture notes.

Endocrine System

The second major controlling system in the body, influencing cells via hormones.

Hormones

Long-distance chemical signals that travel in blood or lymph to affect target cells.

Endocrinology

The study of hormones and endocrine organs.

Reproductive Control

One of the functions of the endocrine system.

Electrolyte Balance

Maintenance of electrolyte, water, and nutrient balance of blood.

Hormone Effects

A hormone only affects target cells with specific receptors for that hormone.

Target Cells

Cells that have specific receptors for a specific hormone.

Permissiveness

A situation where one hormone cannot exert its effects without another hormone being present.

Synergism

When multiple hormones produce the same effects on the same target cell, causing amplification.

Antagonism

When one or more hormones oppose the action of another hormone.

Chemical Messengers

Substances like hormones that transmit signals in the body.

Exocrine Glands

Glands that have ducts and secrete their products onto a surface.

Endocrine Glands

Glands that lack ducts and secrete hormones into interstitial fluid.

Pineal Gland

An endocrine gland involved in regulating circadian rhythms.

Hypothalamus

A brain region that controls the endocrine system.

Pituitary Gland

Often referred to as the 'master gland' of the endocrine system.

Thyroid Gland

An endocrine gland that regulates metabolism.

Parathyroid Gland

Glands that help regulate calcium levels in the blood.

Thymus

An endocrine organ that plays a role in immune function.

Serial Processing

A pattern of neural processing where input travels along one pathway to a specific destination.

Parallel Processing

A pattern of neural processing where input travels along several pathways.

Reflexes

Rapid, automatic responses to stimuli, mostly demonstrating serial processing.

Reflex Arcs

Neural pathways that mediate reflex actions.

Neuronal Pool

Functional groups of neurons that integrate incoming information.

Discharge Zone

Region in a neuronal pool where neurons are more likely to fire impulses.

Facilitated Zone

Region in a neuronal pool that requires extra stimulation to fire impulses.

G-Protein Linked Receptors

Receptors that respond indirectly and slowly to neurotransmitters.

Messenger

A molecule that transmits signals between cells.

Neurotransmitters Functions

Can be grouped by their effects (excitatory or inhibitory) and their actions (direct or indirect).

Direct Action

Neurotransmitter binding directly to open ion channels.

Indirect Action

Neurotransmitter affects signaling through intracellular second messengers.

Neuromodulator

A chemical messenger that affects the strength of synaptic transmission without causing postsynaptic potentials.

Channel-Linked Receptors

Receptors that allow ions to cross the membrane and alter the membrane potential.

Action Potential (AP)

A rapid change in membrane potential that constitutes the signal of nerve cells.

Endocannabinoids

A type of neurotransmitter that acts at the same receptors as THC.

Gasotransmitters

Gaseous neurotransmitters such as nitric oxide that have signaling functions.

Purines

Monomers of nucleic acids that act as neurotransmitters.

Substance P

A neuropeptide that mediates pain signals.

Endorphins

Natural opiates produced by the body that reduce pain perception.

GABA

Gamma-aminobutyric acid; an inhibitory neurotransmitter.

Biogenic Amines

Neurotransmitters made from amino acids, including catecholamines and indolamines.

Acetylcholine (ACh)

A neurotransmitter crucial for muscle contraction at neuromuscular junctions.

Synaptic Potentiation

The increased ability of presynaptic cells to excite postsynaptic neurons following repeated use.

Temporal Summation

The process where multiple impulses rapidly follow one another to generate a stronger response.

Spatial Summation

The process where many terminals stimulate a postsynaptic neuron simultaneously.

EPSP (Excitatory Postsynaptic Potential)

An excitatory change in the postsynaptic cell's membrane potential that makes it more likely to fire.

IPSP (Inhibitory Postsynaptic Potential)

An inhibitory change that makes the postsynaptic cell less likely to fire an action potential.

Chemical Synapses

Junctions that allow neurotransmitters to be released from one neuron to stimulate another.

Membrane Potential

The electric potential difference across a cell's membrane.