Lecture 4 - Basic tissues Flashcards
What are the functions of epithelia?
Covers surfaces
Lines cavities and tubes
Forms glands
What are some characteristics of epithelia?
Attachment, cells adhere
Avascularity
Regeneration
Polarity
What is the basic structure of epithelia?
Closely packed cells supported by a basement membrane
What is the structure of simple squamous epithelia?
Flat cells
Oval shaped nuclei
One layer of cells
What is the function of simple squamous epithelia?
Exchange of nutrients and gases
What is the location of the simple squamous epithelia?
Blood vessels, alveoli
What is the structure of the non-keratinised stratified squamous?
Flat surface cells
Oval nuclei
Many layers
What is the function of the non keratinised stratified squamous?
Acts as protection and a barrier
What is the location of the non keratinised stratified squamous?
In the oral cavity and oesophagus
What is the structure of the keratinised stratified squamous?
Flat surface cells
Oval shaped nuclei
Many layers
Keratin
What is the function of keratinised stratified squamous?
Acts as protection and a water proof barrier
What is the location of the keratinised stratified squamous?
In the skin
What is the structure of the simple cuboidal epithelium?
Square cells
Round nuclei
One layer
What is the function of simple cuboidal epithelium?
Secretion and absorption
What is the location of the simple cuboidal epithelium?
In the glands and kidney tubes
What is the structure of the simple columnar epithelium?
Tall cells
Oval basally located nuclei
One layer
What is the function of the simple columnar epithelium?
Absorption and secretion
What is the location of the simple columnar epithelium?
The gastrointestinal tract
What is the structure of the pseudostratified ciliated columnar epithelium?
Tall cells
Cells touch basement membrane but not free surface
Has goblet cells
What is the function of the pseudostratified ciliated columnar epithelium?
Mucociliary escalator
What is the location of pseudostratified ciliated columnar epithelium?
Trachea and large respiratory airways
What are intercellular junctions?
Specialised areas of cell membrane that bind one cell to another
What are desmosomes?
Strong connections that join adjacent cells
Resist stretching and twisting
What are hemidesmosomes?
They attach cells to the basement membrane, this stabilises the position of the cell and anchors it to the underlying tissue
What are tight junctions?
Near the apical side of the cell
Adjacent cell membranes bound together by interlocking proteins
It stops the passage of water and solutes between cells
What are gap junctions?
Interlocking membrane proteins hold cells together
Connexons contain a central pore, allows movement of small molecules and ions between cells
In cardiac muscle
What is the function of connective tissue?
Forms structural framework around body
Supports other tissue types
Protects delicate organs
Transports fluids and dissolved materials
Defends body from microorganisms
What is the structure of the connective tissue?
Has cells within an extracellular matrix
What is loose/areolar connective tissue?
Lots of ground substance
Few fibres (collagen and elastic)
Variety of cells
Under epithelium
What is dense irregular connective tissue?
Little ground substance
Many collagen fibre bundles arranged haphazardly
Few cells
Resists excessive stretching and distension
Found in dermis
What is dense regular connective tissue?
Little round substance
Lots of densely packed bundles of collagen fibres in parallel rows
Few cells
In tendons and ligaments
