Anatomy unit 5-6

Histology

Study of tissues

Epithelial tissue

lining tissue that forms the boundary between our body and the external environment

Epitheleal functions

protection, absorption, filteration, secretion

Free surface

apical surface

Bottom surface

basal surface

membrane underneath basal surface

basement surface

avascular

no blood vessels

How are epitheleal tissue classified?

number of layers and the shape of the cells

Simple epithelial tissue

one layer of cells

stratified epithelial tissue

more than one layer of cells

Simple squamouse epthelium

Single flat layer, rapid diffusion of materials, blood vessels and lung tissue

simple cuboidal epithelium

secreation and absorption of substances, tissue of the kidney

Simple columnar epithelium

tall closely packed cells, cilia and goblet cells, digestive tract

Goblet cells

secrete mucus

Stratified squamous epithelium

Found in the epidermal layer of the skin, epidermis

Stratified cuboidal epithelium

more than one layer of cuboidal epithelium,salivary and mammary glands

stratified columnar epithlelium

free surface lined with columnar cells, larynx and male urethra

pseudo stratified epithelium

cell nuclei found at different levels, upper respiratory tract, secretion and absorption

transitional epithelium

stretching of the tissue, urinary bladder

Gland

a group of cells that secrete a fluid substance

Two types of glands

exocrine and endocrine

Exocrine glands

secrete substances outward through a duct

Endocrine Gland

Ductless glands that secrete hormones through the bloodstream

What are the types of exocrine glands

merocrine, apocrine,holocrine

Merocrine

cells excrete the products via exocytosis

Apocrine Glands

Cell pinches off the secreted products

Holocrine gland

cell ruptures and spill products (cell sepukku)

What stem cell is responsible for connective tissue?

Mesenchyme

Ground substance

Gel-like substance secreted by cells in connective tissue

Fibers or threads

collagen, elastic or reticular

Loose connective tissue proper

Areolar, adipose, reticular

Dense connective tissue proper

regular, irregular, elastic

Areolar (loose connective tissue)

mostly open space that holds water and salts for surrounding tissues. found under epithelium and around organs

Adipose (loose connective tissue)

Fat cells

Reticular(loose connective tissue)

contains reticular fibers which create a stiff framework that supports other cells.

Regular (dense connective tissue)

Collagen fibers are arranged in one direction, found in tendons and ligaments

Irregular(dense connective tissue)

collagen fibers are arranged in many directions, found in capsules around organs

Elastic( dense connective tissue)

flexible cushioning, found between vertebrae and in arteries

Cartilage

Hyaline, fibro-cartilage,elastic

Hyaline

glassy looking, firm gound substance with lacuna, few collagen fibers, found in larynx, bridge of nose and ribs

Fibro-cartilage

contains lots of collagen, mostly running parallel

Elastic (cartilage)

highly flexible, found in outer ear and tip of nose

Osseous tissue

Spongy and compact

Mast cells

detect foreign substances, contain granules that secrete inflammatory chemicals

Macrophages

Blob-like cells that engulg invading substances or organisms

Epidermis

outer layer

Dermis

Inner layer

hypodermis

insulating layer beneath dermis

Stratum corneum

Layer of dead cells 20-30 thick. Portect the deeper layers. Regularly shed from the body

Stratum lucidem

A thin layer of translucent cells only found in palms and feet

Statum granulosum

Cells here begin to flatten and disintegrate, waterproofs the skin

Stratum spinosum

“Spiny layer” named for the irregular shape of the cells

Stratum Basale

constantly dividing and pushing cells to next layer.

Melanocytes

Produce melanin

Types of skin cancer

melanoma, basal cell carcinoma

Sebaceous glands

oil glands, typically located on the scalp , holocrine glands

What are hair and nails made of

Hard keratin

Eponychium

cuticle

Hyperthermia

abnormally high body temp

Hypothermia

too low body temp

Inflammation

normal response to injury or stress

Rule of nines

how doctors identify what percent of the body is burned in major burns