TISSUES

• TISSUES- Groups of cells that are similar in structure and function.
• The structure of each tissue type is related to its function, and the structure of the tissues in an organ is related to the organ's function.
• FOUR MAIN TYPES OF TISSUES:

  - Epithelial Tissue

  - Connective Tissue

  - Muscular Tissue

  - Nervous Tissue
• Epithelial Tissue- It cover external and internal surfaces throughout the body. It also forms most glands. Functions include protection, absorption, filtration, and secretion.
• The basal surface of epithelium rests on a basement membrane, a material secreted by both the epithelial cells and the connective cells deep to the epithelium.
• Epithelial tissue- Have no blood supply of their own (avascular) and depend on diffusion from the capillaries in the underlying connective tissue for food and oxygen.
• FUNCTIONS OF EPITHELIAL TISSUE: Except for glandular epithelium, epithelial cells fit closely together to form continuous sheets. It has free or apical surface is exposed to the body’s exterior or to the cavity of an internal organ. If well nourished, epithelial cells regenerate themselves easily.
• The basement membrane is composedof a mixture of proteins andcarbohydrates that function as a filterand as a barrier to the movement ofthe cells.
• Major functions of epithelia

  • Protecting underlying structures
  • Acting as a barrier
  • Permitting the passage of substances
  • Secreting substances
  • Absorbing substances
• Protecting underlying structures

  • Outer layer of the skin
  • Epithelium of the oral cavity
• Epithelium preventing substances from moving through it


  Prevents many substances from moving through it
• Epithelium acting as a barrier

  • Epithelium of the skin acts as a barrier to water and reduces water loss from the body
  • Epithelium of the skin prevents many toxic molecules and microorganisms from entering the body
• Epithelium permitting the passage of substances


  Allows many substances to move through it
• Epithelium permitting the passage of substances

  • Oxygen and carbon dioxide are exchanged between the air and blood by diffusion through the epithelium in the lungs
• Epithelium secreting substances

  • Sweat glands
  • Mucous glands
  • Enzyme-secreting portion of the pancreas
• Epithelial tissues absorbing substances

  Cell membranes contain carrier proteins that regulate the absorption of materials
• Epithelial tissues absorbing substances

  • Epithelial cells of the intestines absorb digested food molecules, vitamins, and ions
• name the following

  A) FREE SURFACE

  B) LUNG

  C) pleutera

  D) nucleus

  E) basement membrane

  F) connective tissue

  G) capillary

  
• classifications of epithelial tissue - The first indicates the number of cell layers it has.

  - The second describes the shape of its cells.

  • The terms describing the shape and arrangement are then combined to describe the epithelium fully.
• name the following & what type of layer epithelia is this

  A) Simple

  B) Basal Surface

  C) Apical Surface

  
• name this & what type of layer of epithelia is this

  A) stratified

  B) basal surface

  C) apical surface

  
• Simple epithelium- is a layer of epithelia that is composed of one layer of cells
• Stratified epithelium- is a layer of epithelia that has a combination of more than one cell layer
• The two types of layers of epithelia are stratified and simple epithelium
• The three shapes of epithelial tissue are squamous, cuboidal, and columnar
• Squamous cells are flattenedlike fish scales.
• Cuboidal cells are cube shapedlike dice.
• Columnar cells are shaped likecolumns.
• determine and name these shape of epithelium

  A) squamous

  B) cuboidal

  C) columnar

  
• Simple squamous epithelium


  This type of epithelium usually forms membranes where filtration or exchange of substances by rapid diffusion occurs
• Locations of simple squamous epithelium


  • Lining of blood vessels and the heart
  • Lymphatic vessels
  • Alveoli of the lungs
  • Portions of the kidney tubules
  • Lining of serous membranes of body cavities (pleural, pericardial, peritoneal)
• Simple squamous epithelium


  • It forms the walls of capillaries, where nutrients and gases pass between the blood in the capillaries and the interstitial fluid
  • It also forms serous membranes, the slick membranes that line the ventral body cavity and cover the organs in that cavity
• NAME THESE

  A) NUCLEUS

  B) BASEMENT MEMBRANE

  C) NUCLEI

  D) AIR SACS

  
• SIMPLE CUBOIDAL- LOCATION: Common in glands and their associated small tubes called ducts. Can also be found in kidney tubules, choroid plexuses of the brain, lining of terminal bronchioles of the lungs, and surfaces of the ovaries
• NAME THESE:

  A) NUCLEUS

  B) BASEMENT MEMBRANE

  C) SIMPLE CUBOIDAL EPITHELIAL CELLS

  D) BASEMENT MEMBRANE

  E) CONNECTIVE TISSUE

  
• SIMPLE COLUMNAR- LOCATION: the Goblet cells (produce ubricating mucus), the digestive tract from the stomach to the anus Epithelial membranes that line body cavities open to the body exterior are called mucous membranes.
• NAME THESE LABELS:

  A) NUCLEI/NUCLEUS

  B) BASEMENT MEMBRANE

  C) MUCUS

  D) SIMPLE COLUMNAR EPITHELIAL CELL

  E) BASEMENT MEMBRANE

  
• Pseudostratified Columnar- Single layer of cells; cells are tall and thin and reach the free surface while others do not. LOCATION: Lining of nasal cavity, nasals in uses, auditory canal, trachea, and bronchus. Often has cilia.
• NAME THESE LABELS:

  A) PSEUDO STRATIFIED

  B) BASEMENT MEMBRANE

  C) NUCLEI/NUCLEUS

  D) CILIA

  E) PSEUDOSTRATIFIED

  F) BASEMENT MEMBRANE

  G) CONNETIVE TISSUE

  
• STRATIFIED SQUAMOUS- Several layers of cells that are cuboidal Protects against abrasion, forms keratinized (dry)nonkeratinized (moist). Keratinized stratified epithelium, the cytoplasm of cells at the surface is replaced by a protein called keratin, and the cells are dead. LOCATION: Keratinized—outer layer of the skin; nonkeratinized—mouth, throat, larynx, esophagus, anus, vagina, inferior urethra, and corneas