Unit Two

(remind grant to study visuals)

UNIT 2: TISSUES — EPITHELIAL TISSUE

  • Epithelial Tissue → Tissue that covers body surfaces, lines cavities, and forms glands

  • Simple Epithelium → Single layer of cells

  • Stratified Epithelium → Multiple layers of cells

  • Squamous → Flat, thin cells

  • Cuboidal → Cube-shaped cells

  • Columnar → Tall, rectangular cells

  • Basement Membrane → Thin layer that anchors epithelial tissue to connective tissue

Types of Epithelial Tissue

  • Simple Squamous Epithelium → Single layer of flat cells; allows diffusion and filtration; found in air sacs and capillaries

  • Simple Cuboidal Epithelium → Single layer of cube-shaped cells; secretion and absorption; found in kidney tubules and ducts

  • Simple Columnar Epithelium → Single layer of tall cells; secretion and absorption; found in digestive tract and uterus

  • Goblet Cells → Specialized cells that secrete mucus

  • Microvilli → Small projections that increase surface area for absorption

  • Stratified Squamous Epithelium → Multiple layers of flat cells; protection; found in skin and mouth

  • Pseudostratified Columnar Epithelium → Appears layered but is one layer; secretion and movement; found in air passages

  • Cilia → Hair-like projections that move substances along the surface

  • Transitional Epithelium → Stretchable tissue that blocks diffusion; found in the urinary bladder

  • Glandular Epithelium → Tissue specialized for secretion; makes up glands

  • Exocrine Glands → Glands that secrete through ducts (ex. sweat, salivary)

  • Endocrine Glands → Glands that secrete hormones directly into the bloodstream

CONNECTIVE TISSUE

  • Connective Tissue → Most abundant tissue; supports, protects, binds, and connects body parts

  • Matrix → Non-living material surrounding connective tissue cells

  • Ground Substance → Gel-like part of the matrix

  • Fibers → Protein strands that provide strength and support

Types of Connective Tissue

  • Areolar (Loose) Connective Tissue → Binds organs to skin and each other; forms thin membranes

  • Adipose Tissue → Fat tissue; insulation, protection, and energy storage

  • Fibrous Connective Tissue → Strong tissue that connects structures

  • Tendon → Connects muscle to bone

  • Ligament → Connects bone to bone

  • Cartilage → Dense connective tissue that provides support and flexibility

  • Chondrocytes → Cells that produce and maintain cartilage

  • Hyaline Cartilage → Smooth cartilage; padding at joints and respiratory passages

  • Elastic Cartilage → Flexible cartilage; found in ear and larynx

  • Fibrocartilage → Tough, shock-absorbing cartilage; found between vertebrae

CONNECTIVE TISSUE CELLS

  • Mast Cells → Release substances that prevent blood clotting

  • Macrophages → Cells that engulf and digest pathogens and debris

  • Fibroblasts → Cells that produce fibers in connective tissue