Key Concepts in Tissue Types, Embryonic Layers, and Connective Tissue Structure

Tissue Level

group of similar cells and the materials surrounding them

What are the 4 major types of tissues?

epithelial, connective, muscle, nervous

Extracellular matrix

the cells and non-cellular material that surrounds the cell/tissue

Biopsy

removal of live tissues for microscopic study

Autopsy

examination of a body after death

Stem cells

cells that have not been differentiated into a specific type, has not become anything yet just a cell

Embryonic tissues

are also called germ layers/germ tissues these form before your embryotic stage and give rise to ALL tissues in the body

Endoderm

"inner layer" forms the digestive track and related organs

Mesoderm

"middle layer" forms muscle,bone, and cardiovascular

Ectoderm

"outer layer" forms the skin and nervous system

Epithelial Tissue

very little to no space, cells are very close to each other or are touching

Basement (Basal) Membrane

the bottom group of cells that connect epthelial tissue to other tissues

Cilia

hair-like projections on the surface that constantly move

Microvilli

small folds that increase the surface area of the cell without taking up more space

Squamous

flat

Cuboidal

cubes

columnar

tall shaped like columns

simple

one layer

stratified

more than one layer

psuedostratified

one layer that looks like multiple

Transitional

stratified with more than one cell type

Connective tissue

cells do not touch each other, they are seperated with extracellular matrix

Matrix

empty space between adjacent cells that are filled with proteins,ground substance, and fluid

Collagen fibers

most common protein in the body; flexible but not elastic

Reticular fibers

filamentous;branches to connect to tissues

Elastic fibers

elastic; returns to original shape

Ground substance

hyaluronic acid; sugar; acts as a lubricant

Blasts

create/build the matrix

Clasts

specialized macrophages that break the matrix down

Cytes

maintain the composition of the matrix

proper

connects

support

supports

fluid

transports

Areolar

connects tissues with organs

Adipose

fat;nutrient storage and cushioning

Reticular

irregular arranged, creates space with organs

Regular fibers

run the same direction

irregular fibers

run in multiple directions

facia

covering around muscles and organs

tendons

Connect muscle to bone

ligaments

connect bone to bone

Cartilidge

avascular, matrix is flexible, and made up of hyaluronic acid

Bone

osteocytes, matrix is fully solid,

Contract

ability to shorten when a force or stimulus is applied

Fluid CT (blood)

fluid, matrix called "plasma" mostly water and carried different things

Neurons

primary cell that makes up a nerve

Cell Body/Soma

central hub of the cell with the nucleus and process information

Dendrites

processes that extend from the body and receive stimuli from other cells and neurons that carry AP to the soma

Axons

processes that extend from the cell body and carry AP away from the soma to another cell/neuron

Glial cells

cells that support the neuron

Epidermis

(skin) largest single organ and consists of squamous keratinocytes

Melanin

a pigment that gives skin its color, MSH and UV amounts can affect your melanin production

Vasodilation

increases blood flow to the skin and allows excess heat to be vented/radiated to the environment

Vasoconstriction

decreases blood flow to the skin, this is due to the lack of heat

Epithelial root shealth

how new hair grows, when hairs are pulled out the internal part comes out and is as visible as a white bulb