Epithelial tissue

Question 1

Epithelial tissue

Answer 1

Consists of cells arranged in continuous sheets with little extracellular matrix
Either single or multilayered
Avascular

Question 2

What does epithelial tissue form?

Answer 2

Epithelia and glands

Question 3

Three surfaces

Answer 3

Apical
Lateral
Basal

Question 4

Apical surface

Answer 4

Faces the body surface, body cavity, or lumen of a hollow organ or duct

Question 5

Lateral surfaces

Answer 5

Face the lateral surface of adjacent cells

Question 6

Basal surfaces

Answer 6

Located opposite the apical surface

Adheres to extracellular materials

Question 7

Basement membrane

Answer 7

Thin layer of extracellular material underlying the epithelial cells
Provides a point of attachment and support for the overlying epithelial tissue

Question 8

Components of basement membrane

Answer 8

Basal lamina

Lamina densa

Question 9

Basal lamina

Answer 9

Secreted by epithelial cells and is found closes to them

Question 10

Lamina densa

Answer 10

Found below the basal lamina and is composed of fibrous proteins produced by the underlying connective tissues

Question 11

Functions of epithelia tissue

Answer 11

Protecting underlying structures
Secretion of substances
Absorption 
Filtration
Sensation

Question 12

Example of protecting underlying structures

Answer 12

The outer layer of skin and epithelium of the oral cavity protect underlying structures from abrasion

Question 13

Example of secretion of substances

Answer 13

Mucous glands, sweat glands, enzyme-secreting portions of pancreas all composed of epithelial cells

Question 14

Example of Absorption

Answer 14

Absorption of nutrients across epithelium of small intestines

Question 15

Example of filtration

Answer 15

Kidney epithelia in glomeruli filer out wastes from blood capillaries

Question 16

Example of sensation

Answer 16

Epithelial structures with sensory nerve endings are found in the skin, nose, ear and eyes

Question 17

Major divisions of epithelia

Answer 17

Covering and lining epithelia

Glandular epithelia

Question 18

Types of covering and lining epithelial tissue

Answer 18

Simple
Stratified
Pseudo-stratified
Transitional

Question 19

Simple epithlia

Answer 19

Composed of one layer of cells which may be squamous cuboidal or columnar

Question 20

Simple Squamous epithelium

Answer 20

One layer of flat cells
Permeable by meany substances allowing movement (absorption, secretion and gas exchange)
Involved in diffusion

Question 21

Simple squamous epithelium locations

Answer 21

Alveoli (lungs), Glomeruli (kidneys), Endothelium (blood vessels) and serosa (gut)
Heart, blood and lymphatic vessels, air cells, body cavities and glomeruli

Question 22

Simple cuboidal epithelium

Answer 22

One cell layer of cube shaped cells

Involved in secretion such as mucous production and absorption

Question 23

Simple cuboidal epithelium locations

Answer 23

Found in many glands and ducts e.g thyroid, mammary and salivary glands
Also found in the liver, bronchioles (lungs) and kidney tubules

Question 24

Simple columnar epithelium

Answer 24

Single layer of tall column shaped cells
Involved in absorption and secretion
Can be modified for function

Question 25

Modifications of simple columnar epithelium

Answer 25

Goblet cells (secretion) Cilia (movement) Microvilli (Absorption)

Question 26

Locations of simple columnar epithelium

Answer 26

Often lines hollow visceral structures e.g GI tract, uterus, kidney and uterine tubes

Question 27

Stratified epithelia

Answer 27

Refers to several layers of cells also variable in shape

Question 28

Types of stratified epithelia

Answer 28

Keratinised stratified squamous epithelium Non-keratinised stratified squamous epithelium Stratified cuboidal epithelium Stratified columnar epithelium

Question 29

Keratinised stratified squamous epithelium

Answer 29

Multiple layers of flat, squamous cells covered with dead cells filled with keratin (tough protein) Slows down water loss and provides a barrier to microorganisms

Question 30

Keratinised stratified squamous epithelium locations

Answer 30

Covers outer skin on body surface

Question 31

Non-Keratinised stratified squamous epithelium

Answer 31

Multilayered surface epithelium forming moist, slippery layer without surface layer of dead cells Primary function is protection

Question 32

Non-keratinised stratified squamous epithelium locations

Answer 32

Lines mouth, tongue, esophagus, vagina and anal canal

Question 33

Stratified cuboidal epithelium

Answer 33

Two or more cell layers; surface cells square | Secretions

Question 34

Location of stratified cuboidal epithelium and role in that location

Answer 34

Sweat gland ducts - Secret sweat | ovarian follicles and semiiniferous tubules - Produce sperm and hormones

Question 35

Stratified columnar epithelium

Answer 35

Multiple layers of columnar cells | Rare

Question 36

Stratified columnar epithelium locations

Answer 36

Located in segments of male urthra and near anus

Question 37

Pseudostratified

Answer 37

Tissues that appear to be more than one layer but are in fact just one

Question 38

Pseudostratified columnar epithelium

Answer 38

Columnar cells of differing heights but still a single layer | All cells rest on basement membrane but may not reach the free surface above

Question 39

Pseudostratified columnar epithelium locations

Answer 39

Line the trachea (respiratory tract) and segments of the male reproductive system

Question 40

Pseudostratified columnar epithelium modifications

Answer 40

Motile cilla and muscus secretion

Question 41

Cilia function

Answer 41

Cilia move surface material by undulating power strokes and alternating rest strokes

Question 42

Transitional epithelium

Answer 42

Flexible cells that change the tissue shape as they stretch and relax Cells change from round to flat when stretched Protect organ walls from tearing Stratified; often 10 or more layers thick

Question 43

Transitional epithelium locations

Answer 43

Lining of hollow viscera subjected to stress e.g urinary bladder

Question 44

Types of glandular epithelia

Answer 44

Endocrine glands | Exocrine glands

Question 45

Glandular epithelia

Answer 45

Function is secretion | Helps form glands in the body

Question 46

Gland

Answer 46

May be single or group of glandular epithelial cells that secrete substances into ducts, onto surface, or into the blood stream

Question 47

Endocrine glands

Answer 47

Secrete substances (hormones) into the blood stream

Question 48

Exocrine glands

Answer 48

Secretes substances into a duct that empties onto the surface of a covering and lining epithelium e.g skin surface, GI tract