HISTOLOGY - Overview

Question 1

What is the main type of staining used for histological samples?

Answer 1

Hematoxylin and eosin (H&E)

Question 2

List the four layers of tissue that are identified in histological samples

Answer 2

Epithelial tissue
Connective tissue
Muscular tissue
Nervous tissue

Question 3

What are the functions of epithelium?

Answer 3

Forms a barrier between the internal and external environments
Mechanical protection
Absorption and secretion

Question 4

What is the function of junctional complexes between adjacent epithelial cells?

Answer 4

To determine what can or can’t pass through the adjacent epithelial cells

Question 5

Describe the function of occluding (tight) junctions

Answer 5

Prevent the diffusion of molecules between the adjacent epithelial cells

Question 6

Describe the function of anchoring (adhering) junctions

Answer 6

Adhere adjacent epithelial cells together to provide mechanical strength

Question 7

Give two examples of anchoring (adhering) junctions

Answer 7

Demosomes
Hemi-demosomes

Question 8

Describe the function of communicating (gap) junctions

Answer 8

Allow direct movement of molecules between adjacent cells

Question 9

List and describe the different types of epithelial cell layers

Answer 9

Simple: one epithelial cell layer
Stratified: more than one epithelial cell layer

Question 10

List the different shapes of epithelial cells

Answer 10

Squamous
Cuboidal
Columnar

Question 11

Which surfaces are squamous epithelial cells functionally suited to?

Answer 11

Squamous epithelial cells are functionally suited to surfaces where mechanical protection isn’t required

Question 12

Why is simple squamous epithelium functionally suited to lining blood vessels?

Answer 12

Simple squamous epithelium is smooth and thus creates low resistance to blood flow

Question 13

Which surfaces are cuboidal epithelial cells functionally suited to?

Answer 13

Cuboidal epithelial cells are functionally suited to surfaces with an absorptive/secretory role

Question 14

Which surfaces are columnar epithelial cells functionally suited to?

Answer 14

Columnar epithelial cells are functionally suited to surfaces with an absorptive role

Question 15

List the different epithelial surface specialisations

Answer 15

Keratin
Cilia
Microvilli

Question 16

Which surfaces are stratified squamous and keratinised squamous epithelial cells functionally suited to?

Answer 16

Stratified squamous and keratinised squamous epithelial cells are functionally suited to surfaces that require a high degree of mechanical protection

Question 17

Which surfaces are stratified cuboidal/columnar epithelial cells functionally suited to?

Answer 17

Stratified cuboidal/columnar epithelial cells are functionally associated with the ducts of exocrine glandular epithelium

Question 18

Where in the body is transitional epithelium/urothelium located?

Answer 18

The urinary system

Question 19

Which surfaces are transitional epithelium/urothelium cells functionally suited to?

Answer 19

Transitional epithelium/urothelium cells are functionally suites to surfaces that are required to stretch

Question 20

Describe pseudostratified epithelium

Answer 20

Stratified epithelial cells with no distinct layer as the cells are still in contact with the epithelial membrane

Question 21

Give an example of singular secretory cells associated with the surface epithelium

Answer 21

Goblet cells

Question 22

What are the two types of secretory cell groups embedded in the underlying connective tissue of the epithelium?

Answer 22

Exocrine glands
Endocrine glands

Question 23

What are the main functional differences between the exocrine and endocrine glands?

Answer 23

• Exocrine glands secrete mucus or serous secretions onto the surface of the epithelium via ducts
• Endocrine glands secrete hormones directly into the bloodstream

Question 24

What are the histological differences between the exocrine serous and mucus secretions?

Answer 24

Mucus: stains pale
Serous: stains dark

Question 25

List the three different types of connective tissue

Answer 25

Loose connective tissue Dense connective tissue (regular or irregular) Adipose tissue

Question 26

List the main components of connective tissue

Answer 26

Ground substance Protein fibres Resident cells Transient cells

Question 27

List the different protein fibres that can be found in connective tissue

Answer 27

Elastin fibres Collagen fibres Reticular fibres

Question 28

List the different resident cell types that can be found in connective tissue

Answer 28

Fibroblasts Firbocytes Adipocytes Macrophages Mesenchymal stem cells

Question 29

What is the function of fibroblast cells found in the connective tissue?

Answer 29

The production of protein fibres and ground substance

Question 30

List the different transient cells types that can be found in the connective tissue

Answer 30

Plasma B-lymphocytes Eosinophils Neutrophils Lymphocytes

Question 31

What is the main structural difference between loose and dense connective tissue?

Answer 31

- Loose connective tissue has more cells than protein fibres - Dense connective tissue has more fibres than cells

Question 32

What is the main structural difference between regular and irregular dense connective tissue?

Answer 32

- The protein fibres of regular dense connective tissue are arranged in an alignment - The protein fibres of irregular dense connective tissue are arranged randomly

Question 33

What is the main cell type found in adipose tissue?

Answer 33

Adipocytes

Question 34

What are the different functions of white fat and brown fat?

Answer 34

White fat: energy storage Brown fat: heat production

Question 35

List the different muscle types

Answer 35

Skeletal muscle Smooth muscle Cardiac muscle

Question 36

Describe the appearance of skeletal muscle on a longitudinal histological sample

Answer 36

Striated Peripheral nuclei Multinucleated fibres Long fibres Very little connective tissue between the fibres

Question 37

Describe the appearance of skeletal muscle on a transverse histological sample

Answer 37

Peripheral nuclei Multinucleated fibres Very little connective tissue between the fibres Myofibrils present in the cytoplasm

Question 38

Describe the appearance of cardiac muscle on a longitudinal histological sample

Answer 38

Striated Central nucleus Short, branched fibres Lots of connective tissue between the fibres Intercalated discs

Question 39

Describe the appearance of cardiac muscle on a transverse histological sample

Answer 39

Central nucleus Lots of connective tissue between the fibres

Question 40

Describe the appearance of smooth muscle on a longitudinal histological sample

Answer 40

Non-striated Central nucleus Short spindle shaped fibres Limited connective tissue between the fibres

Question 41

Describe the appearance of smooth muscle on a transverse histological sample

Answer 41

Only a few fibres with a central nucleus due to the spindle shape of the fibres