TISSUES,GLANDS AND MEMBRANES

TISSUES

• Epithelial

• Connective • Muscle

• Nerve

epithelial tissue

• Found throughout the body where it covers internal and external surfaces

epithelial tissue

Skin, lining of cavities (digestive tract, respiratory tract, blood vessels)

epithelial tissue

Consists of cells with very little extracellular matrix between them

free surface

composed of layer with one surface, which is not in contact with the other cells

basement membrane

attaches the epithelial cells to underlying tissues

basement membrane

made up of CHO and CHON that are secreted by epithelial cells and underlying tissues

epithelial tissues

Blood vessels do not extend from underlying tissues into epithelium gases, nutrients and waste products must diffuse across the basement membrane

simple

one cell layer

stratified

more than one layer of cells (which are named according to the shape of the cells in the apical layer)

squamous

wider than tall

cuboidal

as tall as wide

columnar

taller than wide

simple

single layer

stratified

Consists of more than one layer, with some cells sitting on top of other cells

squamous

Single layer of thin, flat cells

simple cuboidal

Single layer of cube-like cells

simple columnar

Single layer of tall, thin cells

squamous

where diffusion is important

cuboidal

where tissues are involved in secretion and absorption: larger cells because of the machinery of production, packaging, and energy requirements

Simple squamous epithelium

Single layer of flattened cells with disc-shaped central nuclei and sparse cytoplasm; the simplest of the epithelia.

simple cuboidal epithelium

Single layer of cubelike cells with large, spherical central nuclei.

single layer of tall cells with round to oval nuclei, some cells bear cillia; layer may contain mucus secreting unicellular glands

Pseudostratified columnar

• Special type of simple epithelium

• Consists of one layer of cells, with all the cells attached to the basement membrane

Stratified Squamous

• Forms a thick epithelium because it consists of many layers of cells

• Deepest cells are
  cuboidal/columnar, capable of producing new cells

Transitional

• Special type of stratified epithelium that can be greatly stretched

Pseudostratified columnar epithelium

Singlo layer of colls of differing heights, some not reaching the free surface; nuclei seen at different levels; may contain goblet cells and bear cilia.

Stratified squamous epithelium

Thick membrane composed of several cell layers; basal cells are cuboidal or columnar and metabolically active

stratified columnar epithelium

several cell layers basal cells usually cuboidal; superficial cells elongated and columnar

microvilli

• Fingerlike extensions of the plasma membrane of apical epithelial cells