Anatomy Lecture 2.docx

Extracellular Matrix

Protective layer surrounding eukaryotic cells, secreted by the cells themselves.

Collagen

Most abundant glycoprotein in the animal kingdom, providing structural support and protection.

Glycoprotein

Compound composed of sugars and proteins, with smaller sugars and larger proteins.

Fibroblasts

Cells responsible for creating connective tissue and elastin.

Elastin

Highly hydrophobic protein that forms elastic fibers designed to stretch.

Glycosaminoglycans (GAGs)

Polysaccharides composed of repeating disaccharides, attracting cations and water.

Proteoglycans

Small proteins with large sugar components, possessing a negative charge that attracts cations.

Adhesive Glycoproteins

Compounds in the extracellular matrix that help cells adhere to it.

Fibronectin

Type of adhesive glycoprotein found in connective tissues, aiding in tissue connection.

Laminin

Adhesive glycoprotein that binds to integrins in epithelial tissues.

Integrin

Integral protein that interacts with adhesive glycoproteins, affecting cellular behaviors.

Plasma Membrane

Semi-permeable membrane made of phospholipids, allowing selective passage of substances.

Phospholipids

Amphipathic molecules forming a bilayer in the plasma membrane, with hydrophobic tails and hydrophilic heads.

Fluid Mosaic Model

Describes the plasma membrane structure, composed of a phospholipid bilayer with embedded proteins.

Glycolipids

Similar to phospholipids but with sugar chains, serving as surface receptors.

Cholesterol

Strengthens the plasma membrane and maintains its stability.

Peripheral Proteins

Proteins embedded on one side of the plasma membrane, involved in structural integrity.

Integral Proteins

Proteins that span the plasma membrane, often functioning as channels or transporters.

Passive Transport

Movement of substances across the membrane without energy, following concentration gradients.

Active Transport

Movement of substances against their concentration gradient, requiring ATP.

Aquaporin

Channel proteins that facilitate water movement across the plasma membrane.

Endocytosis

Process by which cells take in substances via vesicle formation.

Exocytosis

Process by which cells expel substances, often involving the release of hormones.

G-Protein Complex

A signaling mechanism involving three subunits that activate or inhibit cellular activities.

Epithelial Tissue

Tissue that covers body surfaces and lines cavities, involved in protection, secretion, and absorption.

Basement Membrane

Thin layer of connective tissue supporting epithelial cells, composed of collagen and adhesive glycoproteins.

Simple Epithelium

Single layer of cells allowing for efficient nutrient and gas exchange.

Stratified Epithelium

Multiple layers of cells providing protection, with only the bottom layer accessing nutrients.

Simple Squamous Epithelium

Thin, flat cells facilitating diffusion, found in alveoli and blood vessels.

Stratified Squamous Epithelium

Multiple layers of cells, with keratinized and non-keratinized types, providing protection.

Transitional Epithelium

Specialized epithelium that stretches, found in the urinary bladder.

Exocrine Glands

Glands that secrete products into ducts leading to surfaces, including goblet cells.

Endocrine Glands

Glands that secrete hormones directly into the bloodstream.

Merocrine Glands

Glands that release secretions via exocytosis.

Holocrine Glands

Glands that release entire cells as secretions, such as sebaceous glands.