General Histology - Cell Structure and Cell Cycle

Vocabulary practice flashcards covering cell membrane composition, cellular organelles, cytoskeleton components, mitosis phases, and embryonic development.

Cell

The basic building blocks of all life, encased within a cell membrane and containing specialized organelles suspended within the cytoplasm.

Cell Membrane

A semipermeable barrier consisting of a lipid bilayer (including cholesterol, phospholipids, and glycolipids) that exhibits a fluid mosaic model and contains membrane proteins.

Mitochondria

Rod-like or oval organelles bounded by a smooth outer membrane and an inner membrane folded into cristae that provide energy for the cell in the form of Adenosine Triphosphate (ATP).

Cristae

The internal folds of the inner membrane of a mitochondrion.

Endoplasmic Reticulum

An extensive cytoplasmic network of sacs, vesicles, and interconnected flat tubules called cisternae.

Cisternae

Interconnected flat tubules or flattened, stacked pouches found within the endoplasmic reticulum and Golgi apparatus.

Smooth Endoplasmic Reticulum (SER)

A morphologically distinct form of endoplasmic reticulum that is agranular and devoid of ribosomes.

Rough Endoplasmic Reticulum (RER)

A morphologically distinct form of endoplasmic reticulum that is granular and studded with dark staining granules called ribosomes.

Golgi Apparatus

A membrane-bound organelle made of flattened, stacked pouches called cisternae that functions in transporting, modifying, and packaging proteins and lipids into vesicles.

Free Ribosomes

Ribosomes suspended in the cytoplasm that synthesize proteins for use within the cell cytoplasm.

Attached Ribosomes

Ribosomes bound to the ER membrane that produce proteins stored in cell lysosomes or released as secretory products.

Lysosomes

Dense vesicles produced by the Golgi apparatus filled with digestive enzymes (acid hydrolases) that destroy pathogens and break down materials.

Acid Hydrolases

A variety of hydrolyzing or digestive enzymes contained within lysosomes.

Peroxisomes

Small, membrane-enclosed organelles that carry out oxidation reactions leading to the production of hydrogen peroxide.

Microtubules

Microscopic hollow tubes made of alpha and beta tubulin proteins that form part of the cytoskeleton in almost all cell types except red blood cells.

Microfilaments

Solid fibers made of polymerized actin protein (also called actin filaments) involved in cell movement, muscle contraction, and cell division.

Intermediate Filaments

Cytoskeletal elements thicker than microfilaments that provide mechanical support for the plasma membrane at cell contacts or extracellular matrix sites.

Centrosomes

Organelles located near the nucleus made of two barrel-shaped clusters of microtubules called centrioles and a protein complex, key to cell division and spindle fiber formation.

Centrioles

Two short rods or granules composed of nine sets of three fused microtubules located near the nucleus that function in chromosome movement during mitosis.

Cytoplasmic Inclusions

Diverse intracellular non-living substances not bound by membranes, such as glycogen granules in liver/muscle cells and lipid droplets in fat cells.

Nucleus

The largest cellular structure, consisting of a nuclear envelope containing chromatin and one or more specialized regions called nucleoli.

Chromatin

The mass of DNA and its associated proteins contained within the nucleus.

Nucleolus

A specialized region of chromatin forming a round mass of RNA within the nucleus.

Cell Cycle

The regulated process of cellular reproduction and division comprising Interphase (G1, S, G2 phases) and Mitosis (Prophase, Metaphase, Anaphase, Telophase).

G1 Phase

The Gap 1 phase of the cell cycle where metabolic changes prepare the cell for division until it reaches the restriction point.

S Phase

The Synthesis phase of the cell cycle where DNA replication occurs, resulting in chromosomes made of two sister chromatids.

G2 Phase

The Gap 2 phase of the cell cycle where metabolic changes assemble cytoplasmic materials required for mitosis and cytokinesis.

M Phase

The Mitosis phase of the cell cycle involving nuclear division (mitosis) followed by cell division (cytokinesis).

Prophase

The stage of mitosis in which chromatin condenses into visible, distinct chromosomes.

Prometaphase

The stage of mitosis where the nuclear envelope breaks down and spindles begin to interact with chromosomes.

Metaphase

The stage of mitosis where chromosomes align along the equatorial plane (metaphase plate) of the cell.

Anaphase

The stage of mitosis where sister chromatids separate and are pulled by spindle fibers toward opposite poles.

Telophase

The stage of mitosis where daughter chromosomes reach the poles and two new nuclear envelopes begin to form.

Germ Layers

The three primary cell layers—Ectoderm, Mesoderm, and Endoderm—that develop during Week 2 of embryonic development.