03 PT 1

Cytology

The study of the structure and function of cells.

Light Microscopy (LM)

Uses visible light to magnify cell structures, allowing observation of live or stained cells but with limited resolution.

Electron Microscopy (EM)

Uses electron beams for high-resolution imaging of cells.

Scanning Electron Microscopy (SEM)

Provides a 3D view of the cell’s surface.

Transmission Electron Microscopy (TEM)

Provides detailed images of internal cell structures.

Cell Theory

All living things are made of cells; cells are the basic units of life; all cells arise from pre-existing cells; cells are fundamental units of homeostasis.

Extracellular Fluid (Interstitial Fluid)

Fluid surrounding cells that provides nutrients and removes waste.

Cell Membrane (Plasma Membrane)

A lipid bilayer that separates the cell from the external environment.

Cytoplasm

The fluid inside the cell that contains cytosol and organelles.

Cytosol

The intracellular fluid containing ions, proteins, and dissolved nutrients.

Organelles

Specialized structures within the cytoplasm that perform specific functions.

Selective Permeability

The ability of the membrane to control which substances enter or exit the cell.

Passive Transport

Transport that does not require ATP, including diffusion, osmosis, and filtration.

Active Transport

Moves molecules against a concentration gradient using ATP, such as the Sodium-Potassium Pump.

Endocytosis

Bringing substances into the cell.

Exocytosis

Expelling materials from the cell.

Isotonic Solution

No net movement of water; cell remains stable.

Hypertonic Solution

Water moves out of the cell, causing it to shrink (crenation).

Hypotonic Solution

Water moves into the cell, causing it to swell and possibly burst (lysis).