Tissues of the body (epithelial)

Question 1

What are the 4 tissue types of the body

Answer 1

Epithelial, connective, muscle, nervous

Question 2

What are tissues made up of?

Answer 2

Cells that are related in structure and function and an extracellular matrix (ECM)- the surrounding material made up of different substances

Question 3

What is the ECM made up of?

Answer 3

Made up of substances in liquid, thick gel, or solid form that surrounds cells of a tissue.

Question 4

What are the 3 functions of ECM

Answer 4

1. provides tissue strength to resist tensile (stretching) and compressive forces
2. Direct cells to proper positions within tissues, holds cell in place.
3. Supports proper function and survival of cells

Question 5

What are the 2 main components of ECM

Answer 5

Ground substances and protein fibres

Question 6

What are the two main parts of Ground Substances

Answer 6

1. Glycosaminoglycans
2. Proteoglycans

Question 7

What are Cell- adhesion molecules

Answer 7

type of glycoprotein that adhere the cell to other cells and the ECM

Question 8

What are protein fibres. What do they look like and what do they provide

Answer 8

Large polypeptides that are embedded within the ground substance. They are a rope like structure and provide tensile strength

Question 9

What are the 3 types of protein fibres?

Answer 9

1. Collagen fibers
2. Elastin fibers
3. Reticular fibers

Question 10

What do collagen fibers do?

Answer 10

resist tension and pressure

Question 11

what do elastin fibers do?

Answer 11

allow stretch and elastic recoil

Question 12

what do reticular fibers do?

Answer 12

small collagen fibers that form a scaffold to structurally support cells and ground substances

Question 13

When cells attatch, what are the 3 ways they can?

Answer 13

1. Tight junctions
2. Desmosomes
3. Gap junctions

Question 14

How do tight junctions work

Answer 14

” sewing” 2 cells together. Things cannot pass through

Question 15

How do Desmosomes work

Answer 15

“Linkers” they help promote integrity of tissue. They are loosely connected and small molecules can diffuse through cells.

Question 16

How do gap junctions work?

Answer 16

“tunnel” they make a tunnel between 2 cells. They share intercellular fluid. Fluid and ions can pass through

Question 17

What is epithelial tissue made of

Answer 17

mainly made up of cells with little ECM.

Question 18

What is the ECM called?

Answer 18

Called the basement membrane as it is a thin layer beneath the layer of cells.

Question 19

What are the 2 components of the basement membrane and what do they consist of?

Answer 19

Basal Lamina- collagen fibers and ground substances
Reticular lamina- reticular fibers and ground substances

Question 20

are epithelial cells linked together by tight junctions, desmosomes, or gap junctions. Pick 2

Answer 20

Tight junctions and desmosomes

Question 21

What are the roles of epithelial tissues in the body

Answer 21

Protection- physcial barrier to shield tissues from thermal, mechanical injury
Immune defence- physical barrier prevents invasion by microorganisms
Secretion- some ephithelial tissues form glands
Transport of substances between tissues
sensation- nerves embedded within the tissue.

Question 22

what are the two classifications of number of cell layers

Answer 22

Simple- single cell layer
Stratified- more than 1 cell layer

Question 23

The shape of the epithelial cell can be divided into 3 classifications. What are those?

Answer 23

Squamous- flattened cells
Cuboidal- short
columnar- tall and elongated

Question 24

what are the 2 different types of ephithelial tissue

Answer 24

1. Covering and lining epithelial
2. Glandular ephithelial

Question 25

What does covering and lining epithelial do?

Answer 25

Covers every internal and external body surface, line organ and fluid filled cavities

Question 26

what does glandular ephithelial do?

Answer 26

tissues that produce and secrete product.

Question 27

what are the 2 types of glanular ephithelial glands?

Answer 27

Exocrine glands- secrete substances into a duct that is lined with ephithelial cells. (local effects)
Endocrine- made up of specialized epithelial cells that secret hormones into the bloodstream. (distant effects)

Question 28

what are the four types of simple epithelia

Answer 28

1. simple squamous epithelium
2. simple cuboidal ephitheliam
3. simple columnar epithelium
4. pseudostatified columnar epithelium

Question 29

What is simple squamous epithelium

Answer 29

very thin layer of cells (fried egg appearance). They allow rapid diffusion of substances (oxygen, carbon dioxide, fluids, and ions)

Question 30

what is simple cuboidal ephitheliam

Answer 30

Single layer of cube shaped cells with large central nucelus. Thin enough for rapid substance diffusion

Question 31

what is simple columnar epithelium

Answer 31

single layer of rectangular shaped cells with nuclei in basal portion of cell. Often microvilli or cilia on apical plasma membrane

Question 32

what is pseudostatified columnar epithelium

Answer 32

appears layered because nuclei are at various heights. Only one cell layer thick with basal plasma membranes firmly in contact with basement membrane. In segments of respitory tract and nasal cavity.

Question 33

what are the 2 routes of transport across epithelia

Answer 33

1. paracellular transport
2. Transcellular transport

Question 34

what is paracellular transport

Answer 34

substance passes through the narrow space between cells

Question 35

what is Transcellular transport

Answer 35

substances enters the cell via active or passive means. Substance diffuses through the cytosol, substances exits the other surface of the cell via active or passive means.

Question 36

what are the four types of stratified epithelia?

Answer 36

1. stratified squamous
2. stratified cuboidal
3. stratified columnar
   4.transitional

Question 37

what is stratified squamous

Answer 37

Kertainized stratified squamous- no nuclei. Filled with protein keratin which is tough
Nonkertatinized stratified squamous- outer layer has nuclei. protection from mechanical stresses. Found in mouth, throat, esophagus.

Question 38

what is stratified cuboidal

Answer 38

lines the ducts of sweat glands

Question 39

what is stratified columnar

Answer 39

apicial layer columnar- basal layer more cuboidal. Function: protection, some absorption, secretion. Found in male uretha, cornea of eye, ducts of certain glands

Question 40

what is transitional epitheliam

Answer 40

cuboidsal basal cell layers and dome shaped apical cell layers when tissue is relaxed. Cell on the apical end can flatten to allow tissue to stretch. Found only in urinary system