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Tissues (Chpter 4) > Epithelial Tissues > Flashcards

Flashcards in Epithelial Tissues Deck (23)
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1

Tissue covers exposed surfaces, lines internal passageways & chambers, forms glands

Epithelial tissues 

2

Functions of Epithelial tissues may include:

1.Protection (cover surfaces & line cavities)

2.Absorption & Secretion (ex. kindney tubles, digestive tract)

Glands: the secretory part of a gland. (Ex. sweat gland)

3.Permeability

3

General characteristics of epithelial tissues include :

1.Tightly packed cells

2.avascular

3.free surface:eposed to the outside of the body/to an internal organ.

4.Basement membrane: Made of collagen & glycoproteins/attaches the epithelium to connective tissue underneath

5. Regeneration

6.Nerve supply

7.Keratinized/non-kertinized,cillia, goblet cells:mucus filled cell(unicellular)

 

4

Functions of the Basement Membrane:

A. attaches epithelium to connective tissues located under the basement membrane

B.Filters(permeability)

C.Provides a surface for cells to expand along when they undergo mitosis

5

Where do epethilial cells get their nutrients if the tissue is avascular?

From the connective tissues under the basement membrane.

6

How do you classify epithelial tissues?

1. Layers

2.Shape

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Epithelial tissue Shapes:

   A. Squamous 

B. Cuboidal

 C.Columnar 

8

Layers of Epithelial Tissues:

A. Simple (one layer)

B.Stratified (Multiple layers of cells)

9

Simple squamous tissue

 

  • One layer of flat cells
  • lines blood vessels,body cavities air sacs; found in kidney tubles
  • provides a thin layer of cells for diffusion across the cells

10

Specific types of simple squamous tissues:

  • Endothelium (lines the inner surface of the heart and all the blood vessels)
  • Mesothelium (lines the abdominal & thoracic cavity). The pleura, pericardium, and peritoneum contain a superficial layer of mesothelium.

11

Simple Cuboidal Tissue

  • One layer of cuboidal cells 
  • Found in the ducts, glands, kidney tubles, thyroid glands
  • often involved in secretion and absorption

12

Simple Columnar Tissue 

  • one layer of cells
  • involved in secretion and absorption
  • found in cilliated tissues found in the bronchi,uterine tubes. Smooth tissues found in digestive tract & gall bladder
  • some may be goblet cells that produce mucus 
  • may have microvilli on the free surface 

13

Why would goblet cells be necessary in the digestive tract?

to protect tissues from highly acidc enviroment. 

14

Why would a columnar epithelium in the digestive tract need microvilli?

Increase surface area, increase absorption. 

15

Stratified Sqaumous Tissue

  • Several layers of cells. Cells at the free surface are flat
  • found in the skin,lining of the mouth, esophagus,vagina & rectum 
  • found where protection is needed.

16

Why does mitosis occur near the basement membrane & not the free surface?

Cells at the basement membrane are alive and recieve nutrients. Cells at the free surface are dead.

17

What is Keratinized stratified squamous tissue?

  • Tissue that is tough & water resistant
  • produces the protein Keratin
  • protects againt abraison, mechanical stress, and dehydration

18

Stratified cuboidal tissue & Stratified columnar tissue

  • Stratified cuboidal tissue is found in swaet gland ducts, stratified columnar tissue is found in salivary gland ducts
  • tissue function primarily as protection

19

Transitional tissues

  • Combination of differently shaped cells that can change their shape (for stretch & recoil)
  • lines the utuerus & bladderf
  • when the cells change shape from cuboidal to squamous the organ expands

20

Pseudostratified Tissues

  • appears to have more than one layer, but every cell touches the basement membrane
  • Found lining the respiratory tract & part of the male reproductive tract 
  • often ciliated, tissue typically has goblet cells to produce mucin. 

21

Glandular tissues

  • exocrine gland (into a duct)
  • endocrine gland (hormone secretes into bloodstream)

22

Unicellular gland that makes mucin?

mucus gland (goblet cells)

23

Examples of Exocrine glands:

  • Holocrine glands : Ex. sebaceous gland-Whole cell fills with secretion & detaches, cells is then replaced
  • Merocrine glands: Ex. sweat gland-secretes by exocytosis, then vessicle transpo
  • Apocrine gland: Ex. mammary glands-secretion builds up & then pinches off a portion of a cell. Leaves via duct.