Introduction to Cytology and the Microscope

Flashcards covering the history of cytology, microscope components and usage, types of human cells (neurons and red blood cells), and the postulates of classic and modern cell theory.

Microscope

An optical device used to see and observe things that cannot be seen by the naked eye.

Light Microscope

A tool that provide a magnified image of small structures and samples, typically for observing cell sizes ranging from $0.001\,mm$ to $0.1\,mm$.

Eyepiece

The part of the microscope that the user looks into to observe the specimen.

Revolving Nosepiece

The part of the microscope that holds the objective lenses and can be turned to switch between them.

Coarse Adjustment Wheel

A knob used to move the objective lens or stage significantly to bring the specimen into general focus.

Fine Adjustment Wheel

A knob used for small, precise movements to obtain a clearer and sharper image of the specimen.

Stage

The flat platform where the specimen slide is placed for examination.

Aperture

The hole in the stage that allows light to reach the specimen.

Cytology

The study of the cell.

Unicellular Organism

An organism consisting of a single cell, such as Euglena, Amoeba, or Bacteria.

Multicellular Organism

An organism composed of many cells, such as humans who have approximately $37.2\text{ trillion}$ cells.

Nerve Cells (Neurons)

The fundamental and functioning unit of the entire system in the brain, characterized by a star-like shape.

Dendrites

Short projections surrounding the cell body of a neuron that receive signals.

Axon

The long, single branch of a nerve cell that sends signals away from the cell body.

Myelin Sheath

An insulating layer around the axon that speeds up the nerve impulse.

Synapse

The junction or gap between two neurons where signals are transmitted.

Motor Neuron (Efferent)

A type of neuron that carries impulses from the brain or spinal cord to muscles or glands.

Sensory Neuron (Afferent)

A type of neuron that carries impulses from the sense organs to the brain or spinal cord.

Interneuron (Association Neuron)

A neuron that connects sensory and motor neurons inside the brain or spinal cord.

Red Blood Cells

Oval biconcave discs that lack a nucleus and are the most abundant cells in the human body.

Hemoglobin

A protein substance found in red blood cells that carries oxygen in the blood.

Robert Hooke

An English scientist who coined the term 'cellula' in 1665 while observing cork cell walls.

Anton Van Leeuwenhoek

A Dutch naturalist known as the Father of Microscopy and Microbiology who discovered 'animalcules'.

Robert Brown

A botanist who discovered the cell nucleus in 1831.

Felix Dujardin

A French biologist who discovered sarcode (protoplasm) in 1835.

Matthias Schleiden

A German botanist who concluded in 1838 that all plants are made of cells.

Theodor Schwann

A German zoologist who concluded in 1839 that all animals are made of cells.

Rudolf Virchow

A German physician who stated 'omnis cellula e cellula' in 1858, meaning cells arise from pre-existing cells.

Classic Cell Theory

The theory stating cells are the building blocks of life, all organisms contain one or more cells, and cells arise from pre-existing cells.

Modern Cell Theory

An extension of cell theory stating all cells have the same chemical composition and contain genetic material passed between generations.