Anatomy Histones Unit

4 main tissue types

Epithelial, Connective, Nervous, Muscular

What is the function of Epithelial tissue?

The lining that forms the boundary between our body and the environment (Protection)

What is simple vs. stratified tissue?

Simple (one layer of cells), Stratified (multiple layers of cells)

What are the parts to an epithelial tissue

Top surface (Free/apical surface), basal surface (Bottom surface), basement membrane

Simple squamous epithelium

Single, flat, thin, permeable

Simple cuboidal epithelium

Single layer of cube shaped cells

Simple columnar epithelium

Single, tall, closely packed

Stratified squamous epithelium

Thick layers providing protection to underlying layers

Stratified cuboidal epithelium

Many cuboidal cell layers, rare

Stratified columnar epithelium

Free surface lined with columnar cells, rare

Pseudo-stratified epithelium

Think “Fake”- Appears stratified but is simple

Transitional epithelium

Change shape with elasticity (Bladder lining)

Glandular epithelium

Made of a group of cells that secrete a fluid substance

Exocrine vs endocrine

Exocrine (secrete outward, one area of the body, & have ducts), endocrine (secrete hormones through bloodstream, systemic effect, & ductless)

Merocrine

Excrete the products via exocytosis (Sweat glands)

Apocrine

A portion of the cell pinches with secreted products (Mammary)

Holocrine

Cells rupture and spill products into the duct (Oil glands in skin)

What is the function of connective tissue?

Provide support and bind other tissues together

What are connective tissues made of?

Extracellular matrix (Fibers & grounds), loosely arranged

Areolar

Open space, holds water and salts, under epithelium

Adipose

Fat cells, insulate/warm body, provides nutrients to other cells

Reticular

Has reticular fibers, stiff framework

Regular

Fibers in one direction, provides strength like a rope

Irregular

Fibers in many directions, provides strength

Elastic

Flexible cushioning

What are the 3 main types of connective tissues

Cartilage, bone and blood

Hyaline

Glossy looking, firm ground substance, lacuna (space), few fibers

Fibrocartilage

Lots of collagen, running parallel

Elastic

Highly flexible, elastic fibers

What are osteocytes?

They secrete ground substances, fibers, collagen, and fluids (Types: spongy and compact)

Mast cells

Detect foreign substances, have granules

Macrophages

Engulf invading substances/organisms

Blood cells

Types: red (Carry oxygen) and white (Provide immune response) blood cells

How do the ground substances differ in the main connective tissue types?

Cartilage (Flexible), bone (Calcified), blood (Plasma/fluid)

What is the function of muscle tissue?

Movement

Smooth muscle tissue

Contracts involuntarily, non-striated (NO LINES)

Cardiac muscle tissue

Contracts involuntarily, striated (FIBOROUS)

Skeletal muscle tissue

Contracts voluntarily (I CHOOSE), striated, connected to bones

What is the function of nervous tissue?

Transport impulses around the body

Neurons

convert stimuli into nerve impulses, pass impulses to other neurons, unable to regenerate

Neuroglia

Support & protect neurons, don’t generate nerve impulses, regenerate after injury