EPITHELIAL TISSUES

Do Now: Write the following video questions on page 23

1. What is the medical dream for body parts?

2. What are the benefits of lab grown body parts?

3. How is an organ like a building?

CAN WE LIVE FOREVER? VIDEO

https://www.youtube.com/watch?v=VEi68CeE5eY (7:00-9:41)

Watch video and answer Do Now questions

Be ready to share

EPITHELIAL TISSUE (PAGE 24)

Function/Definition: Protection, Secretion, absorption, excretion

Location: Cover body surfaces, cover and line internal organs, compose glands

Distinguishing Characteristics: Lack blood vessels, readily divide; cells are tightly packed

SIMPLE SQUAMOUS EPITHELIUM

Function/Definition: Tissue with flattened or scale-like cells

Location: Air sacs of lungs (alveoli), capillaries, lines the insides of blood and lymph vessels

Distinguishing Characteristics: Thin and delicate, so easily damaged

SIMPLE CUBOIDAL EPITHELIUM

Function/Definition: Consists of a single layer of cube-shaped cells. Assist with secretion and absorption

Location: Covers the ovaries, lines kidney tubules, ducts of salivary glands, thyroid gland, pancreas and liver

Distinguishing Characteristics: Centrally located spherical nuclei

SIMPLE COLUMNAR EPITHELIUM

Function/Definition: Elongated, composed of a single layer of cells whose nuclei are elongated. Assist with secretion and absorption

Location: Basement membrane, uterus, most organs of the digestive tract

Distinguishing Characteristics: Thick tissue, enables to protect underlying tissues

PSEUDOSTRATIFIED COLUMNAR EPITHELIUM

Function/Definition: Appear stratified or layered, but they are not. Trap dust and microorganisms that enter through air in the respiratory system.

Location: Line the passages of the respiratory system

Distinguishing Characteristics: A layered effect occurs because the nuclei are at two or more levels in the row of aligned cells

STRATIFIED SQUAMOUS EPITHELIUM

Function/Definition: Forms the outer layer of the skin. Prevents water and other substances from escaping underlying tissues and blocks various chemicals and microorganisms from entering.

Location: Outer layer of skin, lines the oral cavity, esophagus, vagina, and anal canal

Distinguishing Characteristics: Cells divide in the deeper layers, and newer cells push older ones farther outward, where they flatten

STRATIFIED CUBOIDAL EPITHELIUM

Function/Definition: Consists of 2 or 3 layers of cuboidal cells that form the lining of a lumen.

Location: Lines the larger ducts of the mammary glands, sweat glands, salivary glands, and pancreas. Forms the lining of developing ovarian follicles and seminiferous tubules

Distinguishing Characteristics: Layers of cells provides more protection to the glands.

STRATIFIED COLUMNAR EPITHELIUM

Function/Definition: Several layers of cells. The superficial cells are columnar, whereas the basal layers consist of cuboidal cells.

Location: Male urethra and ductusdererens and in parts of the pharynx

Distinguishing Characteristics: N/A

TRANSITIONAL EPITHELIUM

Function/Definition: Specialized to change in response to increased tension. Provides an expandable lining, forms a barrier that helps prevent the contents of the urinary tract from diffusing back into the internal environment

Location: Forms inner lining of the urinary bladder and lines the ureter and the superior urethra

Distinguishing Characteristics: Specialized to change in response to increased tension

GLANDULAR EPITHELIUM

Function/Definition: Cells epithelium, and 1 or more are specialized to produce and secrete substances into ducts or into body fluids

Location: Found in glands

Distinguishing Characteristics: 1 or more of these cells constitute a gland

DRAWING TISSUES ACTIVITY

1 or 2 pictures at every lab table

Colored pencils

Label and draw each Tissue and write a 1 sentence description from notes

Must get all 10 examples drawn and colored This will be your exit ticket at the end of the class