Lecture 8 Introduction to Microscopic Anatomy

Question 1

What is the basement membrane?

Answer 1

A collagen layer to anchor epithelial cells onto

Question 2

What are glands?

Answer 2

Specialized epithelial structures (made of cuboidal or columnar cells) to make secretions

Question 3

What are cytokeratins?

Answer 3

Scaffolding proteins typical for epithelial cells and also produce keratinocytes

Question 4

Explain the process of taking a tissue sample from a patient and turning it into a viewable microscopy slide

Answer 4

1) Macroscopic assessment is made and sample is removed
2) Tissue is fixated with formalin (10% formaldehyde in water). Fixation prevents autolysis and ensures preservation of the proteins as well as hardening of tissue.
3) Resection marks are inked and string attached at 12 o clock area
4) Sample is transported to pathology lab in plastic casettes and form filled out with patient details
5) Sample is cut into sections
6) Sample is processed by first washing water out with alcohol, then washing alcohol out with xylene, then washing xylene out with paraffin.
7) Microtone is used to extract singular was piece and placed in warm water to flatten the wax slice.
8) Sample is placed on microscope slide then stained with Haemotoxylin and Eosin (H&E)

Question 5

What does the Haemotoxylin identify?

Answer 5

Nucleus

Question 6

What does Eosin identify?

Answer 6

Cytoplasm and Cell Membrane

Question 7

What are desmosomes?

Answer 7

Desmosomes are intercellular junctions that provide strong adhesions between cells

Question 8

What do Eosnophilic Granulocytes look like?

Answer 8

Tomatoes with sunglasses

Question 9

Can you describe immunohistochemistry

Answer 9

Immunochemistry is a means of detecting proteins by staining antibodies for a particular protein. When the antibody binds to the protein, it stains the protein identifying it out.

Question 10

Which protein is a granular cell tumour associated with?

Answer 10

S100 Protein Positive

Question 11

What are the six main types of tissues?

Answer 11

1) Epithelium
2) Connective Tissue
3) Muscle
4) Neural Tissue
5) Germ Line Cells
6) Blood

Question 12

What are the main epithelium cells and what are their functions

Answer 12

Squamous Epithelium - Protective
Glandular Epithelium - Glandular Secretions
Urothelium - Waterproof and Stretchable
Mesothelium - Lines large body cavities (eg pluera, serosa)
Endothelium - Lines blood vessels and lympathic systems

Question 13

What is simple epithelia?

Answer 13

One cell layer and a basement membrane

Question 14

What does cytokeratin do?

Answer 14

Cytokeratin intermediate filaments within provide support to the epithelium

Question 15

What are the cytokeratins associated with each epithelium cell?

Answer 15

Squamous: CK5/6 and CK14

Glandular/Columnar: CK7 and CK20

Urothelium: CK7

Urothelial Umbrella Cells: CK20

Question 16

What is the difference between exocrine glands and endocrine glands?

Answer 16

Exocrine glands have ducts and secrete to outside the body whereas endocrine glands do not have ducts and secrete to inside the body