Histology & Integument 

4 Basic Tissue Types

  • %%epithelial%%
  • ==connective==
  • nervousnervous
  • ^^muscular^^

%%Epithelial Tissues%%

-composed of sheets of cells packed close together

-%%classified by number of cell layers and cell shape%%

-one layer=simple

-more than one=stratified

-pseudo stratified: all cells touch basement membrane

-basement membrane: anchors epithelium to connective tissue and allows for exchange of nutrients and waste

  • %%Squamous: flat%%
  • %%Cuboidal: cube shaped%%
  • %%Columnar: column or rectangle shape%%

%%Locations and Functions%%

Simple Squamous Epithelium: single layer of flat cells

Location: %%Alveoli and capillaries%%

Function: %%Allows for rapid diffusion%%

Simple Cuboidal Epithelium: single layer of round cells

Location: %%Kidneys and glands%%

Function: %%Absorption and secretion%%

Simple Columnar Epithelium: Single layer of tall/narrow cells (may make goblet cells)

Location: %%Gi tract and uterus%%

Function: %%Absorption and secretion%%

Pseudo stratified Columnar Epithelium: single layer of tall and short cells

  • cell nuclei not arranged in rows (appear random and clustered) often ciliated may have goblet cells

  Location: %%Respiratory tract%%

  Function: %%Secrete and propel mucus%%

Stratified Squamous: many cell layers, basal cells appear round become increasingly flattened as they near apical surface, may be keritanized

Location: %%epidermis, mouth, anus, vagina%%

Function: %%resist abrasion, protection%%

==Connective Tissues==

Diverse set of tissues includes: fibrous, adipose, cartilage, bone, and blood

-Have lots of ECM and relatively fewer cells

2 main functions: bind other tissues together and protect organs

==Locations and Functions==

Fibrous includes dense and loose (areolar)

Dense: densely packed collagen fibers, wavy/shiny appearance, very little ground substance (not much open space)

Location: ==tendons, ligaments, dermis==

Function: ==resist stress==

Loose: all 3 fiber types randomly arranges, lots of ground substance

Location: dermis, underlying all epithelia

Function: ==binds epithelia ilia to deeper tissues, allows passage of nerves and vessels through tissues==

Adipose: lots of adipocytes (large, empty-looking cells)

Location: ==hypo-dermis, breast, surrounding organs==

Function: ==energy storage, insulation, cushion==

==Cartilage==

Hyaline cartilage: lacunae often appear in pairs; collagen fibers give shiny appearance

Location: ==nose, repiratory tract, articular cartilage (at sonovial joints), costal cartilage==

Function: ==Structural support==

Elastic cartilage: lacunae randomly arranged, stringy elastic fibers present

Location: ==ear, epiglotis==

Function: ==Flexible elastic support==

Fibro cartilage: Lacunae often in rows; collagen fibers give shiny appearance

Location: ==pubic symphysis; invertebrate discs; knee==

Function: ==Shock absorption==

==Bone==

-calcified matrix arranged in concentric lamellae (rings) lacunae appear as balck spots

Location: ==Skeleton==

Function: ==Structural support, protection, calcium storage==

==Blood==

-abundant red blood cells appear as pale pink discs white blood cells and platelets dispersed throughout; liquid matrix=blood plasma

Location: ==heart, blood vessels==

**Function: **==transport; immune defense==