Do Now!  What is the definition of a tissue? Give an example of where you can find tissues! When someone is sick or injured, they may need to replace an organ or tissue. What do scientists need in order to grow new tissues?

Ch. 5: Tissues!!

Let’s Create a Beating Heart https://www.youtube.com/watch?v=AjPu9esr1HQ

Do Now!  Where in the body can you find tissues? Think of the definition of tissues and where you can find them. What are some functions of these tissues?

Objectives To explain the difference between different kinds of tissues To identify the types of epithelial tissue To list the locations of each type of epithelial tissue

Important Terms Histology: The study of tissues Tissues: Groups of specialized cells which are similar in structure and perform common functions

4 Types of Tissues Epithelial Connective Muscle Nervous Make some observations! Epithelial Connective Muscle Nervous

Activity!! 

Do Now!!  What are the 4 types of tissues? There are many different types of epithelial tissue. Hypothesize how you think those types are characterized! (there are 2 ways)

4 Types of Tissues (cont.) Epithelial: Form protective coverings Function in secretion and absorption Connective: Provide support and protection Bind structures together Muscle: Produce body movements Nervous: Control and coordinate body activities * Most organs contain all 4 types

Epithelial Tissue: Location in Body Forms covering of body surfaces Covers organs Forms inner lining of body cavities Lines hollow organs Major tissue in glands

Epithelial Tissue (cont.) Functions: Protection from physical/chemical injury and invasion Secretion, excretion, filtration and reabsorption of materials Diffusion of certain gases Sensory reception

Epithelial Tissue: Facts to Know One free surface always exposed to the outside or open internal space: apical surface Attached to basement membrane on the other side Tightly packed Avascular: NO blood vessels!! Rely on diffusion from underlying connective tissue Divides rapidly Classified according to top layer of cells

Activity!! 

Classes of Epithelia (Layers) Simple: just one layer Stratified: multiple layers

Classes of Epithelia (Shape) Squamous: squashed (thin and flat, like an egg) Ex: lines blood vessels and pleural and pericardial cavities Columnar: columns Ex: Lining of gut tube; sometimes has cilia Cuboidal: cubed (square shaped) Ex: Walls of glands

Activity!! 

Do Now!!  Identify the tissues below! C A B D E

Squamous Simple Diffusion and filtration Ex: alveoli, capillary walls, lines blood and lymph vessels 2. Stratified Squamous Physical protection against abrasion Protection against pathogens Ex: Epidermis, oral cavity, esophagus, vagina and anal canal

Squamous (cont.) 3. Keratinized Stratified Squamous: Aging skin cells produce keratin, harden then die “keratinization”: produces dry, tough, protective covering Contains layers of dead squamous cells Prevents water/substance loss Barrier to organisms

Columnar 1. Simple Columnar provides some protection absorption/secretion usually contain “goblet” cells Ex: Uterus, most organs of digestive tract 2. Stratified Columnar - *rare secretion/absorption - Ex: small portion of male urethra

Columnar (cont.) *Contains cilia!! 3. Pseudostratified Ciliated Columnar Appears stratified - All cells touch basement membrane and have exposed end Ex: passageway of respiratory system *Contains cilia!!

Cuboidal Simple Cuboidal secretion/absorption secretes sweat line ducts Ex: ovaries, kidney tubules, ducts of glands (salivary, thyroid, pancreas and liver) 2. Stratified Cuboidal *rare usually only 2-3 layers Larger ducts of glands Ex: mammary glands, sweat glands, Salivary and pancreas

Transitional Stratified Tolerates repeated stretching Ex: bladder, ureters, and urethra

Can You Identify the Classes of Epithelium? Quiz!! E Can You Identify the Classes of Epithelium? D A B C

Activity!! Try and identify the type of epithelial tissue on the slide.

Slides Simple Squamous *Lung

Slides Simple Cuboidal *Kidney

Ciliated Pseudostratified Columnar Slides Ciliated Pseudostratified Columnar *Trachea

Slides Stratified Cuboidal *Sweat gland duct

Slides Simple Columnar *Small intestine

Slides Stratified Squamous *Skin

Slides Transitional *Bladder

1. Epithelial! 2. Connective!