Anatomy Chapter 4: The living fabric Tissue

Definition and Histology of tissue

• Groups of cells similar in structure that perform common or related function 

• Study of tissues 

• Tissue transplantations

Four types of primary tissue

• Epithelial tissue

• connective tissue

• muscle tissue

• nerve tissue

Epithelial Tissue

• Functions

  • Cover: protection, absorption, filtrations, diffusion, excretion, secretion, sensory reception 

• Locations

  • Line the cavities 

  • Covers the surfaces 

  • Lining of digestive tract organs and other hollow organs: capillaries, kidney, lung

  • Skin surface (epidermis) and organ surface (serosa) 

  • Interface tissue which results upon connective tissue 

• Characteristics

  • Polarity

    • Apical surface: microvilli or cilia

    • Basal surface: connective tissue

  • Abundant cell junctions 

    • Tight junction

    • Adgerens junction

    • Desmosome 

    • Gap junction 

    • Hemidesmosome 

  • Supported by connective tissues 

  • Avascular, but innervated 

    • No blood vessels in epithelial tissue

      • Must be nourished by diffusion from underlying connective tissue 

    • Is supplied by nerve fibers 

  • Can regenerate 

    • Contain stem cells

Types of Epithelial tissue

• simple squamous epithelium

• simple cuboidal epithelium

• simple columnar epithelial

• stratified squamous epithelium

• stratified cuboidal epithelial

• stratified columnar epithelial

Characteristics Simple Squamous Epithelium

• A single layer of thin, flattened cells (width >> height)

• Diffusion or filtration >> protection 

Characteristics of Simple Cuboidal Epithelium

• A single layer of cube shaped cells with centrally located nuclei (width = height)

• Absorption and secretion 

Characteristic of simple Columnar epithelium

• A single layer of tall cells (width < height); with microvili or cilia

• Absorption, secretion and protection 

• GI tract: stomach and intestine 

Characteristics of stratified squamous epithelium

• Layers of flattened cells (width > height) 

• Widely distributed 

• Strong protection 

• Function: protection in mouth, esophagus and vagina 

Characteristics of Stratified cuboidal epithelium 

• Layers of cuboidal cells (width = height); rare 

• 2-3 layer

Characteristics of stratified columnar epithelium 

• Top layer of columnar cells (width < height); limited 

• 2-3 layer 

• Function: protection in male ductus deferens and urethra; transitional areas 

Characteristics of pseudostratified columnar epithelium 

• Single layer with cell nuclei at different levels

• Appears stratified, but is not 

• Simple epithelium 

• Function: protection and secretion in upper respiratory tract (trachea) with cilia 

Characteristics of Stratified cuboidal epithelium 

• Layers of cuboidal cells (width = height); rare 

• 2-3 layer 

Characteristics of stratified columnar epithelium 

• Top layer of columnar cells (width < height); limited 

• 2-3 layer 

• Function: protection in male ductus deferens and urethra; transitional areas 

Keratinized stratified squamous epithelium 

• Protection in skin 

• Strongest protection physically

Transitional epithelium 

• Protection in urinary bladder

Four types of primary tissue

Epithelial tissue 

• Covers 

Connective Tissue

• Supports and connects 

Muscle tissue

• Moves 

Nerve tissue 

• Controls 

Major functions of connective tissue

• Binding and support

• Protecting

• Insulating 

• Storing reserve fuel 

• Transporting substances 

• Most abundant and widely distributed; most durable 

Three elements of connective tissue 

• Ground substance 

• Fibers 

• Cells 

• Matrix = Ground substance + Fibers 

• Ground Substance: gelatinous, liquid, solid 

• Fibers: collagen, elastic and regular fibers 

• Cells: blast, cyte, and other cells 

Characteristics of Connective tissue

• Origin: mesenchyme

•  good blood supplies 

  • Except cartilage, ligament and tendon 

• Have extracellular matrix 

• Under epithelium tissue 

Four Classes of connected tissue

• Connective tissue proper 

• Cartilage 

• Bone

• Blood

Connective tissue proper 

• Loose connective tissue:areolar, adipose, reticular

• Dense/fibrous connective tissue: regular, irregular, elastic 

Areolar connective tissue

• Fibroblast and fibrocytes 

• Under epithelium to form serous membrane

• Serosa, Not mucosa 

• Most common 

Reticular connective tissue 

• Reticular fibers form internal skeleton for liver, spleen and lymph nodes

Regular dense connective tissue 

• Fibers in a parallel fashion, which resist pulling forces in one direction 

• Ligament 

• Tendon

• Aponeurous: flattened tendon 

Irregular dense connective tissue 

• Fibers not in a parallel fashion, which resist pulling forces in multiple directions 

Elastic connective tissue 

• Full of elastic fibers (elastin)

• Aorta 

• Vocal cord

• Ligament flava 

• Lung 

cartilage

• Chondroblast and chondrocytes 

• Without nerve and without blood supply 

• Up to 80% water - can rebound after compression/reduce friction at joints 

Cartilage Types: three

• Hyaline cartilage 

• Elastic cartilage 

•  Fibrocartilage 

Hyaline cartilage 

• Most abundant 

• Costal cartilage

• Nose

• Ends of long bone 

• Trachea

Elastic Cartilage 

• Most springy and flexible 

• Ears; epiglottis 

Bone functions

• Supports and protects body structures 

• Synthesisizes blood cells in cavities 

• More collagen than cartilage; strongest 

• Has inorganic calcium salts 

• Osteoblast produce matrix 

• Osteocytes maintain the matrix 

• Osteons - structural units 

• Richly vascularized 

Blood

• Most atypical connective tissue - fluid 

• Red blood cells most common cell type

• Fibers are soluble proteins: fibrinogen from liver 

Muscle Tissue types: Three 

• Skeletal muscle tissue

• Cardiac muscle tissue 

• Smooth muscle tissue 

Nerve tissue types: two

• Central nerves: brain and spinal cord 

• Peripheral nerves: cranial nerves and spinal nerves; somatic and automatic nerve

Covering and Lining membranes types: three

• Cutaneous 

  • Epidermis: keratinized stratified squamous epithelium

  • Dermis: thick layer of connective tissue; innate immune 

•  Mucous membranes 

• Serous membranes