Anatomy and Physiology: Cell Biology and Tissues Flashcards

Vocabulary flashcards generated from lecture notes covering cell organelles, transport mechanisms, mitosis, and epithelial tissue classifications.

Cytoplasm

Everything located inside the cell, including the cellular fluid and all membranous and non-membranous organelles, excluding the nucleoplasm.

Cytosol

The fluid portion of the cytoplasm that is high in potassium, low in sodium, contains dissolved proteins, and maintains an overall negative charge.

Plasmalemma

The cell membrane or plasma membrane composed of a dynamic lipid bilayer with hydrophobic tails facing inward and hydrophilic heads facing outward.

Microvilli

Cellular membrane projections that function specifically to increase surface area for absorption, found in areas such as the duodenum, jejunum, and ileum.

Cilia

Surface organelles that function to move materials across the apical surface of a cell, commonly found along the respiratory tract.

Centrosome

The organelle containing a pair of centrioles at right angles that produces the cytoskeletal elements that attach to kinetochores during mitosis.

Ribosomes

Non-membranous organelles that serve as the primary sites for protein synthesis in eukaryotic cells.

Polysomes

Free-floating ribosomes in the cytosol that synthesize proteins used internally within the cell.

Rough Endoplasmic Reticulum (RER)

A membranous network continuous with the nuclear envelope that is studded with fixed ribosomes for protein synthesis and modification.

Smooth Endoplasmic Reticulum (SER)

A membranous network lacking ribosomes that is continuous with the RER and nuclear envelope, involved in lipid synthesis and detoxification.

Mitochondria

Organelles containing maternal DNA that produce the majority of cellular energy currency (ATP) via the tricarboxylic acid (Krebs) cycle.

Nuclear Pores

Openings in the nuclear envelope that regulate the passage of molecules entering and exiting the nucleus.

Chromatin

The uncoiled nuclear material composed of DNA bound to histone proteins, visible during interphase.

Golgi Apparatus

An organelle with a cis (receiving) face and trans (sending) face that modifies secretions and renews the lipid bilayer of the plasmalemma via vesicular transport.

Lysosomes

Digestive vesicles containing lysozyme enzymes that breakdown internalized materials, perform autolysis, and participate in apoptosis.

Autolysis

The self-digestion of a cell that occurs when lysosomal membranes rupture and release digestive enzymes into the cytosol.

Peroxisomes

Digestive organelles containing catalases and peroxidases that degrade free radicals into hydrogen peroxide ($H_2O_2$) and subsequently into water and oxygen.

Facilitated Diffusion

A passive transport process where large or insoluble molecules cross the plasmalemma down their concentration gradient using a protein carrier mechanism without extra cellular energy.

Sodium-Potassium ATPase Exchange Pump

An active transport carrier mechanism that pumps ions against their concentration gradients to maintain cellular membrane potential.

Pinocytosis

A non-specific form of endocytosis often referred to as cell drinking, where extracellular fluid and small molecules are internalized in pinosomes.

Phagocytosis

A form of endocytosis referred to as cell eating, where pseudopodia extend to engulf large structures, such as bacteria, to form a phagosome.

Receptor-Mediated Endocytosis

A highly specific form of endocytosis where specific extracellular molecules (ligands) bind to targeted cell-surface receptors before being internalized in clathrin-coated pits.

Microfilaments

Cytoskeletal elements that tighten like a belt around the cell equator during telophase to form the cleavage furrow.

Microtubules

Cytoskeletal components that attach to the kinetochores of paired sister chromatids to pull them apart toward opposite poles during anaphase.

Gap Junctions

Intercellular connections, such as intercalated discs in cardiomyocytes, that allow direct electrical, chemical, and physical communication between adjacent cells.

Cytokinesis

The physical process of cytoplasmic division and cellular movement, which occurs concurrently with late mitosis but is distinct from nuclear division phases.

Epithelial Tissue

An avascular but highly innervated tissue class that covers body surfaces, lines internal cavities, controls permeability, and produces secretions.

Pseudostratified Ciliated Columnar Epithelium

A specialized single-layer epithelium where all cells contact the basal lamina but vary in nuclear height, creating a false multi-layered appearance; found lining the trachea.

Stratified Squamous Epithelium

A multi-layered protective epithelial tissue characterized by flattened, scale-like cells at its apical surface, lining high-friction areas such as the esophagus and tongue.