Four types of tissue

Epithelial Tissuecovers surfaceslines vessels, organs, ductsforms glands

Connective Tissuematerial between cellssupports and bindsstores energyprovides immunity to disease

Muscle Tissueproduces movement

Nerve Tissueconducts electrical signals detects changesresponds

Characteistics of Epithelium:Cellularity (little matrix)Specialized junctions (e.g., Tight, Desmosomes)Apical surfaceAvascular (Basement membrane - Basal lamina & reticular lamina)Thoroughly innervatedHighly regenerative

Tight junctions

Adherens junctions

Gap junctions

Desmosomes

Hemidesmosomes

Cell types:

squamous - flat, central nucleus

cuboidal - cube shape, central nucleus, microvilli

columnar - column, inferior nucleus, ciliated, microvilli, goblet

transitional - combination

Epithelial tissue types:

simple - 1 layer

stratified - 2 or more

psuedostratified - 1 but appears to be 2

Simple squamous: simplest, most delicate

Alveoli, blood vessels (endothelium), glomeruli

Diffusion, filtration

Simple cuboidal: microvilli

Kidney tubules, small glands, ovarian surface

Secretion, absorption

Non-ciliated simple columnar; microvilli, goblet

GI tract

Absorption, secretion,

Ciliated simple columnar: goblet

Small bronchi (airways), uterine tubes

Secretion, propulsion

Stratified squamous: many layers keratinized or non-keratinized, basal cells cuboidal and mitotic

Non-K version forms moist linings - esophagus, mouth, vagina

K version forms dry membrane - epidermis

Protection

Stratified Cuboidal: usually 2 layersDucts of large glands, mammary and salivary glandsProtection

Stratified Columnar Epithelium:Basal layer cuboidal,Goblet, ciliatedStomach/esophageal jct.Protection

Transitional Epithelium: resembles stratified squamous and cuboidalBasal cells cuboidal or columnarUreters, bladder, urethraDistension according to fluid volume

Pseudostratified Columnar: 1 layer some cells not reaching apical surfaceGoblet, ciliated and non-ciliatedNon-C in ducts of large glands, male urethraC lines trachea and upper airwaysSecretion, propulsion

Exocrine glands

Connective tissue

Connective tissue fibers:CollagenReticularElastic

Connective tissue cells:Fibroblasts - FibrocytesChondroblasts - ChondrocytesOsteoblasts - Osteocytes*MacrophagePlasma: secrete antibody proteinsMast: secrete histamine [vasodilator], heparin [anticoagulant]Adipocytes

Embryonic Connective Tissue:(Mesenchyme)Mesenchymal cellGives rise to all other CT

LOOSE CT Loosely woven fibers, cellularity, vascular, 3 types

1. Areolar CT:fibroblasts, plasma cells, macrophages, mast cells, white blood cellsAll 3 fibers typesWidely distributed beneath epitheliaWraps, cushions organs, phagocytic

2. Adipose: adipocyteReduces heat loss, energy storage, protection

3. Reticular: reticular cells (fibroblast)Internal skeleton of organs, lymph vessels

DENSE CT: More fibers, fewer cells, poorly vascularized, 3 types

1. Dense regularParallel rows of collagen fibers, many fibroblastsForms tendons, ligamentsUnidirectional stretch

2. Dense Irregular Connective Tissue:Irregular arrangement of collagen fibersJoint capsulesMulti-directional stress

3. Elastic: elastin fibers and fibroblastsvocal cords, ligament between vertebrae,walls of aortadurability with stretch

CARTILAGE : Network of fibers in firm matrix, nearly avascular, 3 types

1. Hyaline(articular)Firm but rubbery matrixChondrocytesAvascularEmbryonic skeletonEnds of long bonesResists wear and tear, compressive forces

2. Fibrocartilagechondrocytes collagen fibers intervertebral discsmenisci

3. Elastic:elastic fibersshape and durability

ear, nose, vocal cartilages

Four types of tissue

Epithelial Tissuecovers surfaceslines vessels, organs, ductsforms glands

Connective Tissuematerial between cellssupports and bindsstores energyprovides immunity to disease

Muscle Tissueproduces movement

Nerve Tissueconducts electrical signals detects changesresponds

Characteistics of Epithelium: Cellularity (little matrix) Specialized junctions (3 categories)

1. Tight2. Plaque bearing

AdherensCell-to-cellCell-to-extracellular

DesmosomeHemidesmosome

3. Gap Apical surface Avascular (Basement membrane - Basal lamina & reticular

lamina) Thoroughly innervated Highly regenerative

Connective tissue fibers:

Collagen

ReticularElastic

Connective tissue cells:

Fibroblasts - FibrocytesChondroblasts - ChondrocytesOsteoblasts - Osteocytes*MacrophagePlasma: secrete antibody proteinsMast: secrete histamine [vasodilator],

heparin [anticoagulant]Adipocytes

Cell types:

squamous - flat, central nucleus

cuboidal - cube shape, central nucleus, microvilli

columnar - column, inferior nucleus, ciliated, microvilli, goblet

transitional - combination

Epithelial tissue types:

simple - 1 layer

stratified - 2 or more

psuedostratified - 1 but appears to be 2