HomeChapter 3 - Tissues 1. Introduction Main tissue types: Epithelial, Connective, Muscle, Nervous Functions: Protection, secretion, absorption, connection, movement, information processing Tissue membranes: Epithelial membranes: Mucous, Serous, Cutaneous Connective tissue membranes: Synovial membranes (joints) 2. Types of Tissues Four categories: Epithelial: Covers surfaces, lines cavities Connective: Supports, connects, transports Muscle: Enables movement Nervous: Sends and receives signals Embryonic origin: Derived from ectoderm, mesoderm, endoderm 3. Epithelial Tissue Characteristics: Closely packed cells, avascular, polarity (apical/basal surfaces), rapid regeneration Cell Junctions: Tight junctions: Barrier function (e.g., intestines) Anchoring junctions: Stability (e.g., skin) Gap junctions: Communication (e.g., heart) Types: Simple (one layer) vs Stratified (multiple layers) Shapes: Squamous (flat), Cuboidal (cube-shaped), Columnar (tall) Specialized types: Pseudostratified: Appears layered but isn’t Transitional: Stretchable (e.g., bladder) Glands: Endocrine (ductless, secretes hormones into bloodstream) Exocrine (ducts, secretes onto surfaces) Modes of secretion: Merocrine: Exocytosis (e.g., sweat glands) Apocrine: Pinched off portion of cell (e.g., mammary glands) Holocrine: Entire cell disintegrates (e.g., sebaceous glands) 4. Connective Tissue Structure: Cells dispersed in extracellular matrix (ground substance + protein fibers) Fiber types: Collagen (strong, flexible) Elastic (stretchy) Reticular (supportive framework) Categories: Proper: Loose (Areolar, Adipose, Reticular) Dense (Regular, Irregular, Elastic) Supportive: Cartilage (hyaline, elastic, fibrocartilage) Bone (osteocytes in lacunae, vascularized) Fluid: Blood (RBCs, WBCs, plasma) Lymph (immune function) Functions: Structural support, transport, immune defense, energy storage 5. Muscle Tissue Properties: Excitable, contractile Types: Skeletal: Striated, voluntary, attached to bones Cardiac: Striated, involuntary, heart muscle (intercalated discs) Smooth: Non-striated, involuntary (digestive, respiratory, reproductive systems) 6. Nervous Tissue Function: Conducts electrical impulses, processes information Cell types: Neurons: Transmit signals (axon, dendrites) Neuroglia: Support, protect, nourish neurons 7

Chapter 3 - Tissues 1. Introduction Main tissue types: Epithelial, Connective, Muscle, Nervous Functions: Protection, secretion, absorption, connection, movement, information processing Tissue membranes: Epithelial membranes: Mucous, Serous, Cutaneous Connective tissue membranes: Synovial membranes (joints) 2. Types of Tissues Four categories: Epithelial: Covers surfaces, lines cavities Connective: Supports, connects, transports Muscle: Enables movement Nervous: Sends and receives signals Embryonic origin: Derived from ectoderm, mesoderm, endoderm 3. Epithelial Tissue Characteristics: Closely packed cells, avascular, polarity (apical/basal surfaces), rapid regeneration Cell Junctions: Tight junctions: Barrier function (e.g., intestines) Anchoring junctions: Stability (e.g., skin) Gap junctions: Communication (e.g., heart) Types: Simple (one layer) vs Stratified (multiple layers) Shapes: Squamous (flat), Cuboidal (cube-shaped), Columnar (tall) Specialized types: Pseudostratified: Appears layered but isn’t Transitional: Stretchable (e.g., bladder) Glands: Endocrine (ductless, secretes hormones into bloodstream) Exocrine (ducts, secretes onto surfaces) Modes of secretion: Merocrine: Exocytosis (e.g., sweat glands) Apocrine: Pinched off portion of cell (e.g., mammary glands) Holocrine: Entire cell disintegrates (e.g., sebaceous glands) 4. Connective Tissue Structure: Cells dispersed in extracellular matrix (ground substance + protein fibers) Fiber types: Collagen (strong, flexible) Elastic (stretchy) Reticular (supportive framework) Categories: Proper: Loose (Areolar, Adipose, Reticular) Dense (Regular, Irregular, Elastic) Supportive: Cartilage (hyaline, elastic, fibrocartilage) Bone (osteocytes in lacunae, vascularized) Fluid: Blood (RBCs, WBCs, plasma) Lymph (immune function) Functions: Structural support, transport, immune defense, energy storage 5. Muscle Tissue Properties: Excitable, contractile Types: Skeletal: Striated, voluntary, attached to bones Cardiac: Striated, involuntary, heart muscle (intercalated discs) Smooth: Non-striated, involuntary (digestive, respiratory, reproductive systems) 6. Nervous Tissue Function: Conducts electrical impulses, processes information Cell types: Neurons: Transmit signals (axon, dendrites) Neuroglia: Support, protect, nourish neurons 7

The Silk Road

Overview

A vast network of trade routes
Established during the Han Dynasty of China
Connected the East to the West

Key Features

Named after the valuable commodity of silk
Involved the trade of various goods:
- Spices
- Tea
- Porcelain
- Precious metals

Economic Impact

Facilitated cultural exchange
Influenced trade dynamics between regions

Conclusion

The Silk Road played a crucial role in the development of international trade and cultural interactions.