Cell Structure, Membrane Transport & Action Potential

Flashcards covering key concepts from the lecture on cell structure, membrane transport, and action potentials.

What is the basic structural and functional unit of life?

The cell.

What surrounds the cell and separates internal and external environments?

The plasma membrane.

What is the primary composition of the cell membrane?

A phospholipid bilayer.

What are the two types of membrane transport?

Passive transport and active transport.

Define passive transport.

Movement of substances down their concentration or electrochemical gradient without energy.

What is active transport?

Movement of substances against their gradient, requiring energy (ATP).

Give an example of passive transport.

Simple diffusion.

What structure allows facilitated diffusion?

Specific carrier or channel proteins in the cell membrane.

What is osmosis?

Movement of water molecules across a membrane.

What is the role of aquaporins?

Facilitate the transport of water through the membrane.

What happens in a hypertonic solution?

Cell shrinkage.

What does the sodium-potassium pump (Na⁺/K⁺-ATPase) do?

Pumps 3 sodium ions out and 2 potassium ions into the cell using ATP.

What is membrane potential?

The electrical difference in charge between the inside and outside of the cell membrane.

What is the resting membrane potential in neurons?

Approximately -70 mV.

What are the phases of an action potential?

Depolarization, repolarization, and hyperpolarization.

What does saltatory conduction refer to?

Impulses jumping between nodes of Ranvier in myelinated nerves.

What are common clinical implications of disrupted action potential conduction?

Neuropathies, electrolyte imbalances, and arrhythmias.

What is the relationship between ion gradients and cell excitability?

Ion gradients are critical for cell excitability and function.

Why is understanding these membrane processes important for nursing?

They are fundamental to managing fluids, electrolytes, and neurological assessments.