Tissues and Histology Quiz

Tissues

• A group of cells that work together to perform specific functions in the body.

Histology

• The study of the structure and composition of tissue and organs at the microscopic level.

Types of Tissues

• Epithelial
• Connective
• Muscle
• Nervous

Location of Tissues

• Epithelial: Found on the skin surface and lining of hollow organs.
• Connective: Found in bones, blood, and cartilage.
• Muscle: Found throughout the body, attached to bones via tendons.
• Nervous: Found in the brain, spinal cord, and nerves.

Functions of Tissues

• Epithelial: Provides a covering of the skin and lining of the various passages inside the body.
• Connective: Supports other tissues and binds them together.
• Muscle: Allows the body to move.
• Nervous: Made up of nerve cells, used to carry messages to form various parts of the body

Differences Between Tissues

• Epithelial: Acts as a covering, controlling the movement of material across the surface.
• Connective: Binds various parts of the body parts together.
• Muscle: Allows the body to move.
• Nervous: Functions in communication.

Matrix

• Noncellular, extracellular material that surrounds and supports cells within the tissue.

Epithelial Tissue

• Lightly packed cells that form sheets that line and cover the body's surface, cavities, and organs.

Functions of Epithelial Tissue

• Support
• Secretion
• Protection
• Sensory reception

Epithelial Shapes

• Squamous (flat like)
• Cuboidal (cube-like)
• Columnar (column-like)

Epithelia Classification Based on Cell Layers

• Simple epithelium: Single layer of cells.
• Stratified epithelium: Multiple layers of cells stacked on top of each other.

Keratinized vs. Non-Keratinized Stratified Squamous Epithelium

• Keratinized: Protects the body from stress and other damages and forms the skin's epidermis.
• Non-keratinized: Contains multiple layers, lacks keratin.

Specific Examples of Epithelial Tissue Types

• Simple Squamous Epithelium: Lines blood vessels and the heart (aka Endothelium).
• Stratified Squamous Epithelium: Found on the surface of the skin, tongue, and esophagus.
• Simple Cuboidal Epithelium: Gland, ducts, a single layer of cube-liked cells that line ducts and secretory glands of organs in the body.
• Stratified Cuboidal Epithelium: The lining of some ducts, occurs in the excretory ducts of sweat glands and salivary glands.
• Simple Columnar Epithelium: The lining of the stomach intestine, specialized for absorption and has picail cilia and microvilli.
• Stratified Columnar Epithelium: Small areas of the pharynx and mammary glands provide protection and facilitate the movement of milk through ducts.
• Pseudostratified Ciliated Columnar Epithelium: The lining of the nasal cavity, trachea, tissue lined the bronchi, and other parts of the respiratory tract.

Transitional Epithelium

• Stratified epithelium that can withstand repeated cycles of stretching and recoiling.

Why It's Called Transitional

• Changes appearance as stretching occurs, can look plump and cuboidal flat, found in areas like urinary bladder and ureter.

Endocrine and Exocrine Glands

• Endocrine: Organs that produce hormones that are released into the bloodstream and travel to tissue.
• Exocrine: Glands that secret substances onto the body surface through ducts.

Functions of Connective Tissue

• Support
• Protect
• Give structure to the other tissues and organs in the body.

Three Main Types of Connective Tissue

• Fibrous
• Fluid
• Supporting

Key Cell Types Within Connective Tissue

• Fibroblast: Secretes collagen proteins that help maintain a structural framework of tissues.
• Macrophages: Ingest and degrade dead cells, debris, tumor cells, and foreign materials.
• Adipocytes: Provide energy storage, insulation from extreme temperatures, and cushioning around soft organs.
• Mesenchymal: Supports and maintains other cells.
• Melanocytes: Produce and distribute melanin.
• Mast cells: Protect the body from foreign invaders and toxins.
• Lymphocytes: Help your body from the foreign immune system.
• Plasma cells: Produce antibodies and play a critical role in the body's immune response.

Adipose Tissue

• Loose connective tissue composed of adipocytes.
• Stores energy.
• Insulates the body.
• Cushions internal organs.

Examples of Loose Connective Tissue

• Areolar
• Adipose
• Reticular tissue

Reticular Tissue Location

• Located in the spleen, liver, lymph nodes.

Function of Reticular Tissue

• Provides a supporting framework.

Dense Connective Tissue

• Mostly made up of tough protein fibers called collagen.