Epithelial Tissue

liitle to no extracellular space outside of cell, it is a sheet of cells that cover a body surface or lines a body cavity

Epithelial Tissue

Line and Covery Body Surfaces/cavities

Renew Continously by mitosis

Lack a vascular supply

Anchored to a basal lamina

Almost no intercellular space

Located in areas of subjected to wear and tear

Surface cells constantly rubbed away, cells replaced by basal cells

Located on outer skin and mouth

Stratified Cubodial and Columnar

Rare

Located in ducts of larger glands-sweat glands, salivary glands

Steps in Tissue Repair

Inflammation

Organization

Regeneration and fibrosis

Good regeneration Capacity

Epidermis

Dermis

aka Superficial Fascia

Underlies the dermis

Mainly adipose tissue-fat storage, loose anchor, shock absorber, insulator

Thickens with weight gain

Layers of the epidermis

Stratum Basale

Stratum Spinosum

Stratum Granulosum

Stratum Lucidum

Stratum Corneum

Keratinocytes

Melanocytes

Langerhan's cells

Merkel Cells

Keratin-protective properties

Stratum Basale

Upward movement-living cells to keratin filled plasma membranes

Sloughs-new epidermis every 25-45 days, why?

Certain areas are rubbed more than others

Least malignant and most common

Stratium basale

Surgical excision

1 layer of active cells

Mitotically active cell (mainly keratinocytes)

desmosomes

Spiny Cells (mainly of keratinocytes)

Processing artifact

pre-keratin are attached to desmosomes

Seen in thick skin only

Clear, flat, dead keratinocytes

Stratum spinosum

surgical excrision

radiation therapy

Metasizes (can come from anywhere) and can grow rapidly

Skin Color

We all have the same amount of this substance, just depends on what color.

Found in the deepest part of the dermis

5% of all skin cancers

Most malignant

The raised mole is worse than the flat mole

The most resistant to radiation therapy

Very Deadly

A.B.C.D.E Rule

Epidermal dinotic cells

Antigent presenting cells

Arises from Bone Marrow

Epidermal-Dermal Junction

Assoicated with Nerve Ending

Touch Receptors

Flexible connective tissue

Rich nerve fibers, blood vessels

Fibroblasts, macrophages, and mast cells are common

Located in the Meisner's corpuscle

Finger prints/toe prints for grip

Superficial

Areolar connective tissue

80% of the Dense Irregular Connective Tissue

Matrix: interlacing collegen fibers

Collegen

Elastin

Flexure lines

Stretch marks (which don't go away with creams they are cracks in the epidermis)

Not caused by diabets, but about 60% of diabetics have this disease

Degenerative collegen disease

Excessive bleeding

Touch Receptors

Scalp hair

Filters

Physical Trauma

Heat Loss

Shaft

Root

Hair Conditioner

Split Ends

Comes from melain

Gray is due to the stopping of production of melain

sweat in palms, soles, forehead

true sweat-99% water with salts, vitamin C, anitbodies, and traces of metabolic wastes

true sweat+fatty substances+protein

Secretion is odorless, but bacteria decomposes=body odor

Specialized glands

Secrete milk in response to hormones

Chemical Barrier

Physical Barrier

Biological Barrier

Body Temperature Regulation

Cutaneous sensation

Metabolic Function

Blood Reservoir

Excretion

Gross Anatomy of the Typical Long Bone

-->Membranes

Periosteum

Endosteum

Fibrous layer-more outside

Osteogenic layer-closer to the bone

Perforating Sharpey's fibers

Red marrow

Spongy bone in hip bones and sternum are more active in adults

yellow marrow

repeating unit is the osteon

periosteal blood vessel-->volkmann's canal->central canal or Haversian's Canal->canaliculi

Trabeculae align precisely along lineso f stress and help the bone resist stress

No osteons

Nutrients diffuse through canaliculi from capillaries in the endosteum

Intramembraneous ossification

Endochrondal ossification

1.) dev. of ossification

mesenthyme tissue/mesenthymal stem cells

-it is a tissue to make anything, far there it forms ossification center that takes these stems to become osteoblasts

2.) Osteoid secretion

-make osteoblasts turn into osteocytes, calicy (going to get hard)

3.) Woven Bone & Periosteum:osteoblasts secretion will go around blood vessels, pattern of spongy bone (woven) and then the mesenthymal tissue will condense and make the periosteum

4.) Periosteum will rearrange to make the bony collar bring in the red blood vessels to make the red bone marrow

Forms all bones below the base fo the skull except the clavicles

Begins with a hyaline cartilage template

1.) Formation of the bony collar

-Hyaline cartilage begins as the template for the ossification

-Osteoblasts come together to form the compact bone on the outside of this cartilage

2.) Cavitation chondroblasts grow and die leaving behind holes for the osteoblasts to come in and secrete osteoid in the "holes" (make bone tissue)

3.)Periosteal bud invades, spongy bone forms

-periosteal bud invades bringing with blood vessels that make up spongy bone

4.) Medullary Cavity is formed in the diaphysis, secondary ossification centers are formed in the ephysis

5.) Ossification of epiphysis-only happens after puberty