Animal tissue

• Tissue specimens must be fixed (preserved) and sectioned (sliced) thinly enough to allow light transmission.
• Tissue sections must be stained with dyes that bind to different parts of the cell in slightly different ways so that anatomical structures are distinguished from one another.
• Tissues – Groups of cells that are similar in structure and perform a common or related function
• Functions of epithelial tissue: protection, absorption, filtration, excretion, secretion, and sensory reception.
• Special characteristics of epithelium: cellularity, specialized contacts, polarity, Supported by connective tissue, Avascular but innervated, and Regeneration.
• Cellularity – composed mainly of closely-packed cells
• Specialized contacts – cells are joined by tight junctions and desmosomes
• Apical surface – free surface exposed to the body exterior or cavity
• Basal surface – attached surface
• Avascular but innervated – epithelial tissue that no blood vessels but there are nerve fibers
• Regeneration – lost cells are rapidly replaced by cell division
• Classification of epithelial tissue: Number of cell layers present and shape of the cell.
• Simple – one layer of cells
• Stratified – more than one layer of cells
• Squamous – scalelike or disk like flat shape
• Cuboidal – cube-shaped
• Columnar – column-shaped
• Types of epithelial tissue: Simple epithelia, stratified epithelia, and glandular epithelia.
• Kinds of simple epithelia: Simple squamous, Simple cuboidal, Simple columnar, and Pseudostratified
• Pseudostratified - Single layer of cells of differing heights
• Tissue is a group of cells and it is microscopic.
• Epithelial Tissue – covering or lining tissue
• Epithelial tissue - It is for protection because it is located in the skin and it protects our internal organs.
• Squamous – tissue that can be found on the checks.
• Cuboidal – tissue that can be found on the kidney.
• Columnar – tissue that can be found on intestines, throat, fallopian tube.
• Simple tissue - tissue that is made up of 1 layer.
• Stratified tissue – tissue that is made up of 2 or more layer.
• Endothelial tissue – tube connecting tissue and is also thin layer. Fast growing cell.
• Congenital defect – can be developed during pregnancy that affects the DNA. (ex. conjoined twin)
• Progeria – a disorder where only women are affected. Wherein they only have 18 years to live.
• Capillary – small blood vessels
• Diffusion – can be found in the lungs and is thin. Where the substance will go to the empty space. Spreading the substance
• External respiration - breathing, involves both bringing air into the lungs (inhalation) and releasing air to the atmosphere (exhalation). 
• Internal respiration (cellular respiration) – cell used energy source like carbohydrate and it convert it to ATP.
• ATP - is used to run all the activity of a cell.
• pseudo means false.
• Pseudo Stratified Columnar Epithelium - Its tissue looks like layered but every individual cell is attached to the basement membrane. It only looks illusion layered because of the shape
• Simple squamous - Permits diffusion and filtration; secretes lubricating substances in serous membranes
• Simple cuboidal – secretion and absorption