Tissues Flashcards
group of cells with similar structure and function plus extracellular substance (matrix)
Tissues
study of tissues
Histology
Types of Tissues:
- Epithelial
- Connective
- Muscular
- Nervous
Epithelial Tissues
Location:
- cover body (internal and external)
- Ex. Skin, kidney, trachea, glands, etc.
Characteristics:
- cells close together (very little extracellular
matrix)
- form most glands
- have a free surface
Basal surface:
- attaches epithelial cells to underlying tissues
Functions of Epithelial Tissues:
- Protect
- Act as a barrier
- Diffusion and Filtration
- Secretion
- Absorption
Simple Epithelium
Structure: 1 layer of cells
Stratified Epithelium
Structure: many layers of cells
Simple Squamous
Structure: 1 layer of flat, tile-like cells
Function: diffusion and filtration
Location: blood vessels, lungs, heart, kidneys
Simple Cuboidal
Structure: 1 layer of square-shaped cells
Function: secretion
Location: glands, ovaries, kidneys
Simple Columnar
Structure: 1 layer of tall, narrow cells
Function: secrete mucus and absorption
Location: stomach, intestines, resp. tract
Pseudostratified Columnar
Structure: 1 layer of tall, narrow cells appears stratified but isn’t
Function: secrete mucus and propel debris out of resp. tract (cilia)
Location: nasal cavity and trachea
Stratified Squamous
Structure: many layers of flat, tile-like cells
Function: protect and acts as a barrier
Location: skin, mouth, throat, esophagus
Transitional
Structure: a special type of stratified epi. changes shape (stretched squamous, not stretched cuboidal)
Function: hold fluids
Location: urinary bladder
increase cell’s surface area
Microvilli
move materials across cell’s surface
Cilia
it produce mucus
Goblet cells
bind adjacent cells together
Tight junctions
mechanical links that bind cells
Desmosomes
bind cells to basement membrane
Hemidesmosomes
small channels that allow molecules to pass
between cells
Gap junctions
structures that secrete substances onto a surface, into a cavity, or into blood
Glands
glands with ducts
Exocrine glands
no ducts (directly into bloodstream)
Endocrine glands
Types of Exocrine Glands:
- Simple: no branches
- Compound: many branches
- Tubular: end of duct
- Alveolus: sac-like structure
Types of Protein Fibers:
- Collagen fibers
- Reticular fibers
- Elastic fibers
look like ropes and are flexible but resist stretching
Collagen fibers
supporting network that fills spaces between organs and tissues
Reticular fibers
recoil after being stretched
Elastic fibers
Loose
Location: between organs, muscles, glands, skin
Structure: collagen fibers far apart
Function: support and protect
Dense
Location: tendons, ligaments, skin
Structure: collagen fibers packed close together
Function: connect and can withstand pulling forces
Adipose
Location: under the skin and around organs
Structure: collagen and elastic fibers, cells filled with lipids
Function: storage, insulate, cushion
- Type of connective tissue
- Composed of chondrocytes
- Contains collagen
- Withstands compressions
- Provides support, flexibility, strength
Cartilage
Types of Cartilage:
- Hyaline cartilage
- Fibrocartilage
- Elastic cartilage
Hard connective tissue
Bone
Liquid connective tissue
Blood
Consist of neurons or nerve cells
Nervous Tissue
substitution of dead cells for viable cells
Tissue repair
cells of same type develop (no scar)
Regeneration
cells of a different type develop (scar)
Replacement
