Histology

simple epithelium

A single layer of cells

Stratified epithelium

several layers of cells

Epithelial Tissue

A body tissue that covers the surfaces of the body, inside and out

simple squamous (location)

air sacs of lungs, walls of capillaries, and inside blood and lumphatic

Simple squamous (functions)

filtration, diffusion, osmosis,

Stratified squamous (location)

oral cavity, anal cavity, vagina

Stratified squamous (function)

Protection

simple cuboidal (location)

ovaries, kidney tubules, and salivary glands

simple cuboidal (function)

Secretion and absorption

stratified cuboidal (location)

ducts of the mammary glands, sweat glands, and the pancreas

stratified cuboidal (function)

Protect, support, and secrete

Simple columnar (location)

lining of the uterus and tubes of the digestive tract

Simple columnar (function)

Absorption, secretion, and protection

stratified columnar (location)

vas deferens, epididymis, and pharnyx

stratified columnar (function)

protection and secretion

Pseudostratified (location)

passages of the respiratory system and various tubes of the reproductive system

Pseudostratified (function)

Secretion and protection

Transitional (location)

Urianary bladder

Transitional (function)

Distensibility and protection

Glandular (function)

Produce and secrete

Exocrine glands (location)

sweat, salivary, mammary, sebaceous, and mucous

Exocrine glands

Glands that secrete products into ducts leading to internal or external surface (have ducts)

Endocrine glands (location)

Pineal gland, pituitary gland, pancreas, ovaries, testes, thyroid gland, parathyroid gland, and adrenal gland.

Endocrine glands

Glands that secrete into tissue fluid or blood (no ducts)

Merocrine (function)

fluid is released without the loss of cellular tissue

What type of gland is a merocrine gland?

Can be a sweat gland

Do merocrine glands have hair follicles?

No, they do not have hair follicles

What type of secretion do serous cells produce?

Watery secretion with high enzyme percentage

What type of secretion do mucus cells produce?

Thicker secretion for the digestive tract and respiratory tubes

Apocrine

Fluid is released with cellular products and portions of the free ends of glandular cells

Apocrine (location)

Hair follicle, armpits, groin, odor, mammary glands (can be sweat glands)

Holocrine (function)

Fluid is released with entire cells that are laden with secretory products

Holocrine

Not a sweat gland

Sebum-oily, oily secretions, skin

Connective tissue

binds structures together, provides support, serves as a framework, fills spaces, stores fat, produces blood cells, provides protection against infections, and repairs tissue damage

Fibroblast

A star-shaped cell that produces fibers by secreting proteins into the matrix of connective tissue

Mast cells

Releases heparin and histamine

Adipocytes

Fat cells

Macrophages

Act as scavengers/clear foreign particles from tissue

lmyphocytes

Recognize antigens to produce antibodies

Microphages

wbc (neutrophils, eosinophils), phagocytic, increase when infection or injury

What type of cells produce collagen?

Fibroblasts

What is collagen?

Thick pieces of protein

How is collagen organized?

Grouped in long parallel bundles

What is a characteristic of collagen's flexibility?

Flexible but not very elastic

What is the primary function of collagen?

Holds structures together

What property of collagen allows it to resist pulling forces?

High tensile strength

What type of connective tissue is collagen commonly found in?

Tendons

What color does collagen appear?

White

What type of cells produce elastic fibers?

Fibroblasts

What is the main protein that makes up elastic fibers?

Elastin

What is a characteristic of elastic fibers in terms of strength and flexibility?

Not a lot of tensile strength, but very flexible

What color are elastic fibers typically?

Yellow

What type of connective tissue contains elastic fibers?

Ligaments

Where in the body can elastic fibers be found?

In the vocal cords and air passages of the respiratory system

What are reticular fibers composed of?

Collagen

How thick are reticular fibers?

Very thin

What is the structure of reticular fibers?

Highly branched to form supporting networks

What is the function of reticular fibers in lymph nodes and bone marrow?

Support for other cells

What is loose connective tissue?

A mesh-like tissue that supports the epithelium.

What is the function of loose connective tissue?

It binds skin to underlying organs and fills spaces between muscles.

What is the packing material of the body?

Loose connective tissue.

What does loose connective tissue contain to nourish nearby epithelial cells?

Numerous blood vessels.

What type of cells are mainly found in loose connective tissue?

Fibroblasts.

What is the most widely distributed connective tissue in the body?

Aerolar

What is the function of aerolar tissue?

It serves as packing material between other tissues.

What does aerolar tissue bind and wrap?

It binds and wraps around glands.

What type of tissue forms subcutaneous tissue?

Aerolar tissue

What does subcutaneous tissue attach?

It attaches skin to underlying structures.

What are reticular fibers?

Reticular fibers are a type of fiber that forms a supportive internal framework in various tissues.

What is the function of reticular fibers in lymph nodes, spleen, and bone marrow?

Reticular fibers form an internal framework that supports many free blood cells.

What is adipose tissue?

A type of loose connective tissue that stores fat in droplets.

What happens to adipose cells when they occur in large numbers?

They become enlarged and can crowd out other tissue.

What are the functions of adipose tissue?

Provides cushioning, insulation, lubrication in some areas, and energy storage.

Where is adipose tissue commonly found in the body?

Beneath the skin, around the kidneys, heart, and joints between muscles.

What type of fibers does dense connective tissue contain?

Thick collagenous fibers and a fine network of elastic fibers

What is the function of dense connective tissue?

Binds organs and bones together

Where is dense connective tissue found?

In ligaments and tendons, as well as in eyes and skin

Why do tendons and ligaments heal poorly?

They have a poor blood supply

What characteristic do ligaments and tendons have?

They have high tensile strength

What is the primary function of cartilage?

To provide support and protection.

What structural role does cartilage play in developing bones?

It forms a structural model for developing bones.

What is the composition of the intercellular material in cartilage?

It is largely composed of fibers embedded in a gel-like ground substance.

What is the covering of fibrous connective tissue that encloses cartilage called?

Perichondrium.

What are the cells in cartilage called?

Chondrocytes.

Where do chondrocytes occupy in cartilage?

Small chambers called lacunae.

How do nutrients enter cartilage?

By diffusion.

What happens to cartilage as humans age?

It tends to dry up or become dehydrated, leading to degeneration.

Why do cartilage cells have poor healing capabilities?

They do not divide very frequently.

Does cartilage have a direct blood supply?

No, it has no direct blood supply.

Hyaline cartilage

found in the ends of bones, the soft part of the nose, larynx, and the trachea

Elastic cartilage

found in the larynx and the ear

Fibrocartilage

found in intervertebral discs

skeletal muscle

Straiated

attach to bones

voluntary

contract from nerve stimulation

Cardiac muscle

Involuntary

Heart

striated