Lab 2- Histology I Power Point

Histology Overview

• Histology: Study of tissues.

• Cytology: Study of cells.

• Tissue: Group of cells that perform specific functions.

Building Materials of Tissues

• Cells are essential building materials for tissues.

• Materials needed for practical exercises:

  • Print Building Grid #1

  • Playdough or clay

  • Colored pencils/markers

  • Lab instructions for Lab 2.

Tissue Categories

• Epithelium: Covers body surfaces, lines cavities, forms glands.

• Connective Tissue: Connects and supports body parts, fills spaces.

• Muscle Tissue: Made of excitable, contractile elements.

• Nervous Tissue: Composed of excitable communication cells.

General Characteristics of Tissues

• Analyze characteristics of each tissue type:

  • Complete a table with descriptions, examples, and functions.

  • Sketch and construct models in clay.

  • Virtually examine tissues using A&P Revealed.

Epithelium Characteristics

• Small, closely packed cells.

• Contains an apical or luminal surface.

• Avascular: Lacks blood supply.

• Supported by a basement membrane.

Naming Epithelium

• Based on the number of cell layers:

  • Simple: Single cell layer.

  • Stratified: Multiple layers.

• Based on cell shape:

  • Squamous: Flat cells.

  • Cuboidal: Cube-shaped cells.

  • Columnar: Taller than wide cells.

Types of Epithelium

• Simple Squamous Epithelium:

  • Function: Absorption.

  • Location: Alveoli (lungs), kidney glomeruli.

• Simple Cuboidal Epithelium:

  • Function: Absorbs fluid, secretes molecules.

  • Location: Ducts, glands (ovary, kidney, endocrine glands).

• Simple Columnar Epithelium:

  • Features: Goblet cells for mucus production.

  • Non-ciliated: Lines digestive tract.

  • Ciliated: Lines bronchioles, uterine tubes.

• Stratified Squamous Epithelium:

  • Structure: Multiple layers; uppermost cells can be squamous.

  • Function: Protects against abrasion.

Muscle Tissue

• Characteristics:

  • Contractile elements that shorten and contract.

  • Excitable, producing electrical impulses.

  • Types: Skeletal, Cardiac, and Smooth.

Skeletal Muscle

• Structure:

  • Long, cylindrical fibers with striations.

  • Multinucleated with peripheral nuclei.

• Function: Voluntary movements.

Cardiac Muscle

• Structure:

  • Y-shaped cells with intercalated disks (gap junctions).

  • Weak striations, often with 1-2 nuclei.

• Function: Involuntary, forms heart walls.

Smooth Muscle

• Structure:

  • Large, central nuclei, no striations.

• Function: Involuntary; sustains contractions to move substances.

Nervous Tissue

• Two main cell types:

  • Axons: Long processes transmitting signals.

  • Dendrites: Short processes receiving signals.

• Characteristics: Excitable and capable of conducting electric potentials.