Human Physiology - Exocytosis and Membrane Potential

This set of flashcards covers key concepts related to exocytosis, membrane potential, and action potentials from the human physiology lecture.

Exocytosis

The process of vesicles fusing with the plasma membrane to release their contents outside the cell.

Endocytosis

The process of internalizing substances into the cell by engulfing them with the plasma membrane.

Hormones

Large polar molecules released via exocytosis that act as signaling molecules in the body.

Membrane Potential

The electrical charge difference across the plasma membrane, representing a separation of opposite charges.

Resting Membrane Potential

The typical electrical charge of a cell at rest, usually around -70 mV.

Na-K Pump

A membrane protein that transports 3 sodium ions out of the cell and 2 potassium ions into the cell, contributing to resting membrane potential.

Depolarization

A decrease in the membrane potential, making the inside of the cell less negative compared to resting potential.

Hyperpolarization

An increase in the membrane potential, making the inside of the cell more negative compared to resting potential.

Action Potential

A brief electrical signal that travels along the axon of a neuron, caused by rapid changes in membrane permeability.

Ion Channels

Proteins that allow specific ions to pass through the membrane, crucial for changes in membrane potential.

Gated Channels

Ion channels that open or close in response to specific stimuli, such as voltage changes or ligand binding.

Graded Potentials

Local changes in membrane potential that vary in magnitude and occur in response to specific triggering events.