Physiology in Health and Medical Sciences: The Cell and Membrane Potentials

Flashcards covering key terms and concepts from the lecture on the physiology of cells and membrane potentials.

Organelle

A specialized subunit within a cell that has a specific function, such as the nucleus, mitochondria, or endoplasmic reticulum.

Membrane Potential

The difference in electric potential across a cell membrane due to the unequal distribution of ions.

Endocytosis

The process by which cells internalize substances from the outside environment by engulfing them in a vesicle.

Exocytosis

The process by which cells expel materials in vesicles to the exterior environment.

Diffusion

The movement of molecules from an area of higher concentration to an area of lower concentration.

Active Transport

The movement of ions or molecules across a cell membrane against their concentration gradient, requiring energy.

Homeostasis

The maintenance of a stable internal environment within an organism.

Negative Feedback Loop

A mechanism of homeostasis in which a change in a physiological variable triggers responses that counteract that change.

Positive Feedback Loop

A mechanism that enhances or accelerates a process, leading to an increased effect in the same direction as the initial stimulus.

Resting Membrane Potential

The electrical potential of a cell when it is not actively sending impulses, typically around -70mV for neurons.

Phospholipid Bilayer

A double layer of phospholipids that makes up the cell membrane, with hydrophilic heads pointing outwards and hydrophobic tails inward.

Golgi Apparatus

An organelle responsible for modifying, sorting, and packaging proteins and lipids for secretion or delivery to other organelles.

Mitochondria

Organelles that produce energy (ATP) through cellular respiration, often referred to as the 'powerhouse' of the cell.

Cytoplasm

The aqueous component of the cell in which organelles are suspended and cellular processes occur.

Rough Endoplasmic Reticulum (rER)

A type of endoplasmic reticulum that is studded with ribosomes and is involved in protein synthesis.

Smooth Endoplasmic Reticulum (sER)

A type of endoplasmic reticulum that lacks ribosomes and is involved in the synthesis of lipids and detoxification.

Neurotransmitter

Chemicals that transmit signals from one neuron to another across a synapse.

Calcium Ion

An important signaling molecule that plays a role in various cellular processes, including muscle contraction and neurotransmitter release.

Ion Channel

A protein structure that allows ions to pass through the cell membrane, facilitating processes like action potentials.