A&P Test 2

What type of tissue covers and lines body surfaces and cavities and can also secrete substances?

epithelial tissue

What is the free surface of epithelial tissue called?

Apical surface

What structure connects epithelial tissue to connective tissue?

Basement membrane

What are the two surfaces of epithelial tissue?

Apical surface and basement membrane

Does epithelial tissue contain blood vessels?

no

If epithelial tissue does not have blood vessels, how does it receive nutrients and oxygen?

They diffuse from connective tissue through the basement membrane

Why can epithelial tissue repair itself relatively quickly?

It grows rapidly

What two characteristics are used to classify and name epithelial tissue?

Shape and number of layers

If an epithelial tissue has only one layer of cells, what is it called?

Simple epithelium

If an epithelial tissue has multiple layers of cells, what is it called?

Stratified epithelium

If you were looking at an epithelial tissue under a microscope, what two things would you use to help identify its type?

Number of layers and cell shape

How many layers does simple squamous epithelium have?

One layer

What shape are the cells of simple squamous epithelium?

Thin and broad/flat

What does the nucleus of a simple squamous cell look like compared with cuboidal or columnar cells?

It is smaller

What type of epithelial tissue would you expect to find where rapid diffusion is important?

Simple squamous epithelium

Where is simple squamous epithelium found in the lungs?

In areas where diffusion occurs

Where is simple squamous epithelium found in the cardiovascular system?

Blood vessels

What is the name of the simple squamous epithelium that lines the heart and blood vessels?

Endothelium

What is the name of the simple squamous epithelium that lines the major body cavities?

Mesothelium

What three major body cavities are lined by mesothelium?

Pleural, pericardial, and peritoneal cavities

What are three functions of simple squamous epithelium?

Absorption, diffusion, and reduction of friction

A tissue needs to allow substances to rapidly diffuse across it. What type of epithelium would be most appropriate?

Simple squamous

A blood vessel needs a thin lining that allows substances to pass between the blood and surrounding tissues. What type of epithelium would you expect?

Simple squamous epithelium

If an epithelial tissue is only one cell layer thick and the cells appear thin and broad, what type is it most likely to be?

Simple squamous

How many layers does stratified squamous epithelium have?

Multiple layers

What layer determines the name of stratified squamous epithelium?

The outermost/apical layer

Why is stratified squamous epithelium useful in areas exposed to severe mechanical or chemical stress?

Its multiple layers provide protection

When looking at stratified squamous epithelium, what happens to the cells as they move toward the apical surface?

They become flattened

Where are new cells produced in stratified squamous epithelium?

Near the basement membrane

What happens to new cells as they are pushed away from the basement membrane?

They become flattened and move toward the apical surface

What happens to the cells toward the apical surface of keratinized stratified squamous epithelium?

They become dead and are filled with keratin

Where would you expect to find stratified squamous epithelium?

Areas exposed to severe mechanical or chemical stress

If an epithelial tissue has many layers and the cells at the apical surface are flat, what type of epithelium is it?

Stratified squamous

If cells at the basement membrane are more elongated but become progressively flatter toward the surface, what type of tissue could this be?

Stratified squamous epithelium

Why does stratified squamous epithelium have multiple layers instead of only one?

To provide greater protection from mechanical and chemical stress

What shape are the cells of simple cuboidal epithelium?

Cube-shaped

What is distinctive about the nucleus of a simple cuboidal cell?

It’s giant

What are the two main functions of simple cuboidal epithelium?

Secretion and absorption

How does simple cuboidal epithelium participate in secretion and absorption?

It releases some substances and takes other substances in from the blood

If you see one layer of cube-shaped cells with large nuclei, what type of epithelium is it?

Simple cuboidal

An epithelial tissue needs to both absorb substances and secrete substances. What type of epithelium could perform these functions?

Simple cuboidal

How many layers does stratified cuboidal epithelium have?

Multiple

What shape do the cells of stratified cuboidal epithelium have?

Cuboidal

What is distinctive about the nuclei of stratified cuboidal epithelium?

they’re giant

Where is stratified cuboidal epithelium found? (3)

Larger ducts of sweat glands, ovarian follicles, and tubes of the testes

What type of epithelium lines the larger ducts of sweat glands?

Stratified cuboidal

What type of epithelium is found in ovarian follicles?

Stratified cuboidal

What type of epithelium is found in the tubes of the testes?

Stratified cuboidal

If you see multiple layers of cuboidal cells surrounding a duct, what type of epithelium might it be?

Stratified cuboidal

What type of epithelium would you expect in an organ that must repeatedly expand and contract without being damaged?

Transitional epithelium

Where is transitional epithelium found?

bladder, ureters, urethra, renal pelvis

What type of epithelium can stretch and recoil without being damaged?

Transitional epithelium

What does transitional epithelium look like when it is relaxed compared with when it is stretched?

thicker or stratified cuboidal, thinner with flatter cells

What are the major functions of transitional epithelium? (4)

Prevents diffusion, allows distension and volume accumulation, protects from mechanical/chemical stress, allows regeneration and repair

If a tissue needs to protect an organ while also allowing the organ to expand significantly, what type of epithelium would you expect?

Transitional epithelium

What shape are the cells of simple columnar epithelium?

Elongated/column-shaped

Where are the nuclei of simple columnar cells generally located (near basement membrane or apical surface)?

Near the basement membrane

What structures may be present on simple columnar epithelium that help with movement or absorption?

Cilia or microvilli

What is the function of microvilli on simple columnar epithelium?

Increase absorption

Where is simple columnar epithelium commonly found?

Stomach, intestines, and parts of the female reproductive tract

What are the major functions of simple columnar epithelium?

Absorption and secretion

What type of cell is commonly found among simple columnar epithelial cells that secretes mucus?

Goblet cell

If an epithelial tissue contains tall cells, nuclei near the basement membrane, and goblet cells, what type is it likely to be?

Simple columnar epithelium

A tissue needs to absorb large amounts of nutrients. What type of epithelial tissue would you expect in the lining of the intestine?

Simple columnar epithelium

Why would simple columnar epithelium in the intestine have microvilli?

To increase surface area for absorption

What is the purpose of the thicker layer of simple columnar epithelium?

Greater protection

How many layers of cells does pseudostratified columnar epithelium actually have?

One

Why does pseudostratified columnar epithelium appear to have multiple layers?

The nuclei are located at different heights

What structures may be present in pseudostratified columnar epithelium?

Cilia or goblet cells

Where is pseudostratified columnar epithelium commonly found?

Respiratory tract and parts of the male reproductive system

A tissue looks stratified because its nuclei are at different heights, but every cell contacts the basement membrane. What type of epithelium is it?

Pseudostratified columnar

What is distinctive about the cell shapes in stratified columnar epithelium?

The basement layer is cuboidal while the apical layer is columnar

Where is stratified columnar epithelium found?

Conjunctiva, large exocrine ducts of certain glands, and certain parts of the male urethra

If the cells next to the basement membrane are cuboidal but the cells at the free surface are columnar, what type of epithelium is this?

Stratified columnar

What are glandular epithelia?

Collections of epithelial cells or derived structures that produce secretions

What is the main function of glandular epithelium?

Producing secretions

What is the difference between exocrine and endocrine glands?

Exocrine glands secrete through ducts

What type of gland secretes through ducts?

Exocrine gland

What is mucin?

a merocrine secretion that mixes with water to form mucous

How do merocrine glands release their secretions?

exocytosis

What type of secretion is thick and contains mucin?

Mucous secretion

What are examples of merocrine glands?

Salivary glands, pancreatic acinar glands, and eccrine sweat glands

A gland releases its secretion by exocytosis without losing part of the cell. What type of gland is it?

Merocrine

What are examples of apocrine glands?

Mammary glands, ciliary glands, and certain sweat glands

Where are some apocrine sweat glands found?

Armpits and pubic regions

A gland releases its secretion along with part of the cell's cytoplasm. What type of gland is it?

Apocrine

Which gland type secretes entire cells?

Holocrine

What are examples of holocrine glands?

Sebaceous glands and meibomian glands

What is the defining characteristic of a simple gland?

It has a single, unbranched duct

What are the five types of simple glands in your notes? (5)

Simple tubular, simple coiled tubular, simple branched tubular, simple alveolar/acinar, simple branched alveolar

What is an example of a simple tubular gland?

Intestinal glands

What is an example of a simple coiled tubular gland?

Merocrine sweat glands

What are examples of simple branched tubular glands?

Gastric glands and mucous glands of the esophagus, tongue, and duodenum

What is the simple alveolar/acinar gland found in?

A stage in embryonic development of simple branched glands

What is an example of a simple branched alveolar gland?

Sebaceous glands

What is the defining characteristic of a compound gland?

It has a branched duct system

What are the three types of compound glands in your notes?

Compound tubular, compound alveolar/acinar, compound tubuloalveolar

What are examples of compound tubular glands?

Mucous glands in the mouth and bulbo-urethral glands

What is an example of a compound alveolar/acinar gland?

Mammary glands

What are examples of compound tubuloalveolar glands?

Salivary glands, glands of the respiratory passages, pancreas