Histology + Integumentary System

Epidermis

composed of stratified squamous, epithelium arranges itself into 4 or 5 layers

Dermis

thicker middle layer made out of dense fibrous connective tissue, regulates body temperature

Hypodermis

deepest layer, well innervated

Smooth

nonstraited cells involuntary uninucleate

Cardiac

striated cells, involuntary uniucleated

Skeletal

striated cells, voluntary multinucleate

muscle tissue

contractile

Nervous tissue

specialized to carry electrical signals called action potentials, made up of neurons

Blood cells

suspended in fluid matrix

bones

vascular and heals rapidly, produce osteocytes

Elastic Cartilage

epiglottis in throat, so many fibers

Fibrocartilage

intervertebral discs, pubic symphysis, tiny fibers

Hyaline Cartilage

nose, trachea, ribers, no fibers

Cartilage

avascular and lacks nerve fibers

loose connective tissue

vascular with nerves: areolar, adipose

Dense Irregular

random arrangement of fibers: e.x. most dermis of skin, for strength

dense regular

primarily made up of collagen: e.x. tendons, ligaments, for attachment of muscles to bones

Dense Connective Tissue

avascular and no nervous input, fibroblasts: dense regular and irregular

Adipose

closely packed fat cells: e.x. under skin, around kidney, for cushioning and insulation

Areolar CT

has all 3 fiber types, for anchoring skin to underlying tissues and anchoring tissues tgt

Fluid Connective Tissue

has a liquid extracellular matrix: e.x. blood and lymph

Glycosaminoglygans

help to hold water

Hyaluronic Acid

large unbranched polysaccharides, makes certain connective tissues very slippery

Proteoglycans

aid in water retention by connective tissue makes CT able to withstand pressure

Ground Substance

gel-like material that fills the space between cells and fibers of connective tissues

Reticular Fibers

web between tissues, in lymphoid organs

Connective Tissue Proper

loose and dense connective tissue

Elastic Fibers

can be stretched and return to original shape: in lungs, large blood vessels

-elasts

destroy

3 major components of CT

1. Protein Fibers, 2. ground substance of nonfibourous proteins, 3. fluid

Collagen Fibers

strong but inflexible: in tendons, ligaments, and bones

-cytes

mature

-blasts

build

Connective Tissue

develop from embryonic tissue called mesenchyme

Transitional

Relaxed-cubodial, Stretch- squamous: e.x. bladder, urethra, allows stretching as it fills

Sqamous

flat, scale like cells, for diffusion

Characteristics of Epithelial Tissue

avascular but innervated, regeneration, location (surface)

Hemidemosomes

connect cells to basement membrane

Epithelial Tissue

Mose abundant, lines all body cavities:e.x. extracellular matrix, desmosome, tight junction, Polarity: free surface

Cuboidal

cube cells, to secret or absorbs substances

Columnar

tall, skinny, rectangular cells, for secretion or absorption

Stratified Columnar

layers of rectangular cells: e.x. large ducts of gland, kidney, for protection

Stratified Cubodial

cube-shaped cells in multiple layers: e.x. sweat glands, ovary follicle, mammary glands, for protection and secretion

Simple

1 layer thick, for diffusion, filtration, secretion, absorption

Supporting Connective Tissue

bone and cartilage

Tissues

composed of groups of specialized cells working together to perform specific functions

Basement Membrane

where cells are attached to at bottom

Tight Junctions

ties cells together

Simple Squamous

single cell layers: e.x. capillaries, endothelium, alveoli, for diffusion and filtration

Stratified

many layers, protection

Simple Columnar

single-layer column shaped: e.x. lines digestive tract, uterus tubes, for secretion of mucous (contains goblet cells)

Stratified Squamous

multiple layers of flat cells:e.x. esophagus, mouth, anus, epidermis, for protection against abrasion

Simple Cubodial

single layer cube shaped: e.x. ducts of kidneys, surface of ovaries, for absorption, active transport

Pseudostratified

all cells touch basement membrane, looks multilayers: e.x. respiratory tract, male urethra, for specialized goblet cells, release mucous that coat passage ways

Dendrites

receive electric signals and send them towards the cell body

Cell Body (soma)

site of general cell functions

Axon

conduct action potentials away from the cell body