Epithelial tissue Flashcards Preview

BMS 191 > Epithelial tissue > Flashcards

Flashcards in Epithelial tissue Deck (48)
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1
Q

Epithelial tissue

A

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

2
Q

What does epithelial tissue form?

A

Epithelia and glands

3
Q

Three surfaces

A

Apical
Lateral
Basal

4
Q

Apical surface

A

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

5
Q

Lateral surfaces

A

Face the lateral surface of adjacent cells

6
Q

Basal surfaces

A

Located opposite the apical surface

Adheres to extracellular materials

7
Q

Basement membrane

A

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

8
Q

Components of basement membrane

A

Basal lamina

Lamina densa

9
Q

Basal lamina

A

Secreted by epithelial cells and is found closes to them

10
Q

Lamina densa

A

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

11
Q

Functions of epithelia tissue

A
Protecting underlying structures
Secretion of substances
Absorption 
Filtration
Sensation
12
Q

Example of protecting underlying structures

A

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

13
Q

Example of secretion of substances

A

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

14
Q

Example of Absorption

A

Absorption of nutrients across epithelium of small intestines

15
Q

Example of filtration

A

Kidney epithelia in glomeruli filer out wastes from blood capillaries

16
Q

Example of sensation

A

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

17
Q

Major divisions of epithelia

A

Covering and lining epithelia

Glandular epithelia

18
Q

Types of covering and lining epithelial tissue

A

Simple
Stratified
Pseudo-stratified
Transitional

19
Q

Simple epithlia

A

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

20
Q

Simple Squamous epithelium

A

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

21
Q

Simple squamous epithelium locations

A

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

22
Q

Simple cuboidal epithelium

A

One cell layer of cube shaped cells

Involved in secretion such as mucous production and absorption

23
Q

Simple cuboidal epithelium locations

A

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

24
Q

Simple columnar epithelium

A

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

25
Q

Modifications of simple columnar epithelium

A

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

26
Q

Locations of simple columnar epithelium

A

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

27
Q

Stratified epithelia

A

Refers to several layers of cells also variable in shape

28
Q

Types of stratified epithelia

A

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

29
Q

Keratinised stratified squamous epithelium

A

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

30
Q

Keratinised stratified squamous epithelium locations

A

Covers outer skin on body surface

31
Q

Non-Keratinised stratified squamous epithelium

A

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

32
Q

Non-keratinised stratified squamous epithelium locations

A

Lines mouth, tongue, esophagus, vagina and anal canal

33
Q

Stratified cuboidal epithelium

A

Two or more cell layers; surface cells square

Secretions

34
Q

Location of stratified cuboidal epithelium and role in that location

A

Sweat gland ducts - Secret sweat

ovarian follicles and semiiniferous tubules - Produce sperm and hormones

35
Q

Stratified columnar epithelium

A

Multiple layers of columnar cells

Rare

36
Q

Stratified columnar epithelium locations

A

Located in segments of male urthra and near anus

37
Q

Pseudostratified

A

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

38
Q

Pseudostratified columnar epithelium

A

Columnar cells of differing heights but still a single layer

All cells rest on basement membrane but may not reach the free surface above

39
Q

Pseudostratified columnar epithelium locations

A

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

40
Q

Pseudostratified columnar epithelium modifications

A

Motile cilla and muscus secretion

41
Q

Cilia function

A

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

42
Q

Transitional epithelium

A

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

43
Q

Transitional epithelium locations

A

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

44
Q

Types of glandular epithelia

A

Endocrine glands

Exocrine glands

45
Q

Glandular epithelia

A

Function is secretion

Helps form glands in the body

46
Q

Gland

A

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

47
Q

Endocrine glands

A

Secrete substances (hormones) into the blood stream

48
Q

Exocrine glands

A

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