Epithelia

Question 1

What are the features common to all eukaryotic cells?

Answer 1

Outer membrane, inner cytosol, cytoskeleton, membrane bound organelles and inclusions

Question 2

What is the cytosol?

Answer 2

Solution of proteins, electrolytes and carbohydrates. Has both fluid and gel like properties

Question 3

What is the cytoskeleton made from?

Answer 3

Thin intermediate filaments and microtubules

Question 4

What is the function of the cytoskeleton?

Answer 4

Determines the shape and fluidity of the cell

Question 5

Where are the membrane bound organelles?

Answer 5

In the cytosol

Question 6

What are inclusions?

Answer 6

Other structures within the cytoplasm which may or may not be bound by a membrane

Question 7

What has to happen to cell metabolism and degradative post mortem processes?

Answer 7

Has to be haited

Question 8

What is fixation?

Answer 8

Cells being exposed to a chemical that prevents cell metabolism and degradative post mortem processes.

Question 9

What is the most common fixation?

Answer 9

Formalin

Question 10

What does formalin react with?

Answer 10

The amino groups on proteins

Question 11

What is embedding?

Answer 11

Process where the tissue is embedded in support medium

Question 12

What does embedding allow?

Answer 12

The tissue to be thinly sliced allowing light or electrons to penetrate the tissue

Question 13

What is the impregnated material used to cut the tissue?

Answer 13

Paraffin wax

Question 14

Stains are…

Answer 14

Aqueous

Question 15

Common stains used?

Answer 15

Haematoxyoin and Eosin

Question 16

What colour does Haematoxylin stain the nucleus?

Answer 16

Blue / purple

Question 17

The acidic molecules in haematoxylin are said to be?

Answer 17

Basophilic

Question 18

What kind of dye is Eosin?

Answer 18

Acidic

Question 19

What colour does Eosin stain?

Answer 19

Pinkish red

Question 20

Structures stain in Eosin are said to be?

Answer 20

Eosinophilic

Question 21

What are the 4 tissue types?

Answer 21

Epithelium, connective tissue, muscle and nervous tissue

Question 22

What does the epithelia form?

Answer 22

The secretory part of some solid organs and glands

Question 23

What a the function of the surface epithelium?

Answer 23

Cover and lines surfaces, cavities and tubes

Question 24

What is epithelia composed of?

Answer 24

Closely aggregated, polyhedral epithelial cells with a minimum of intercellular substance

Question 25

Adhesion between cells is?

Answer 25

Strong

Question 26

What happens when cellular sheets are formed?

Answer 26

Able to cover exposed external surfaces and line internal cavities

Question 27

Functions of epithelia?

Answer 27

Mechanical barrier, Chemical barrier, Absorption, Secretion, Containment and Locomotion

Question 28

Example of mechanical barrier?

Answer 28

Skin

Question 29

Example of chemical barrier?

Answer 29

Lining of the stomach

Question 30

Example of absorption?

Answer 30

Lining of intestines

Question 31

Example of secretion?

Answer 31

Salivary gland

Question 32

Example of containment?

Answer 32

Lining of urinary bladder

Question 33

Example of Locomotion?

Answer 33

Oviduct

Question 34

Minor functions of epithelium include?

Answer 34

Sensation (taste buds) and contractility (myoepithelial cells)

Question 35

What are the characteristics of epithelium?

Answer 35

Typically polarised, basal surface attached to basal lamina, non vascularised, adhere together in sheets so cells are closely apposed to each other

Question 36

What are the three main classes of filaments?

Answer 36

Microfilaments, intermediate filaments and microtubules

Question 37

Filaments are classified by?

Answer 37

Size

Question 38

Size of microfilament?

Answer 38

5nm in diameter

Question 39

Size of intermediate filament?

Answer 39

10nm in diameter

Question 40

Size of microtubules?

Answer 40

25nm in diameter

Question 41

What do the filamentous proteins become attached to?

Answer 41

Cell membranes and to each other

Question 42

What is the function of intercellular junctions?

Answer 42

Link individual cells together into a functional unit

Question 43

What are the 3 types of junctions?

Answer 43

Occluding junctions, Anchoring junctions / Adherent junctions and communicating junctions

Question 44

What are occluding junctions?

Answer 44

Junctions that form a diffusion barrier

Question 45

What are anchoring / adherent junctions?

Answer 45

Junctions that provide mechanical strength

Question 46

What are communicating junctions?

Answer 46

Junctions that allow movement of molecules between cells

Question 47

What is a junctions complex?

Answer 47

Close association of several types of junctions found in certain epithelium and other tissues

Question 48

What are epithelia classified by?

Answer 48

Cell shape, number of layers, cell/tissue surface and presence of specialised cells

Question 49

What are the cell shapes?

Answer 49

Squamous (flattened), cuboidal (cube shaped) and columnar (like a column)

Question 50

What are the number of layers called?

Answer 50

Simple (one layer), stratified (two or more layers) and pseudostratified (tissue appears to have multiple layers, but all cells are in contact with basal lamina)

Question 51

What are microvilli?

Answer 51

Finger like projections of the cell membrane

Question 52

What are the size of microvilli?

Answer 52

0.5-1um in length

Question 53

What are the function of microvilli?

Answer 53

Increase the surface area of the cell membrane

Question 54

What are cilia?

Answer 54

Mobile cell processes

Question 55

What is the size of cilia?

Answer 55

10um long

Question 56

What is the function of cilia?

Answer 56

Serve to propel mucous or fluid over the cell surface

Question 57

What is keratin?

Answer 57

A group of tough structural proteins.

Question 58

Examples that are made of keratin?

Answer 58

Hair, fingernails and horns

Question 59

What epithelium lines the trachea?

Answer 59

Pseudostratified columnar epithelium, ciliated with goblet cells

Question 60

Where is secretion in the exocrine glands?

Answer 60

The apical end of the cell, into the lumen of an internal space, into a duct or onto body surface

Question 61

The exocrine glands are termed?

Answer 61

Ducted glands

Question 62

The endocrine glands are secreted?

Answer 62

Toward the basal end of the cell and then distributed by vascular systems throughout the body.

Question 63

What is the endocrine gland termed?

Answer 63

Ductless glands

Question 64

Examples of exocrine glands?

Answer 64

Lacrimal glands, salivary glands, mammary glands, liver, pancreas, brunners glands, sweat glands and sebaceous glands

Question 65

What are examples of endocrine glands?

Answer 65

Pituitary glands, thyroid gland, thymus gland, pancreas, adrenal glands and ovaries/testis