Histology Basics Flashcards
Light microscope ?
Is the most common
Phase contrast
Deals with living things without stains
Fluorescent microscopes?
Depends on ultraviolet rays
Electron microscope
High magnification and resolution power
Hematoxylin
Basic stain , turns blue if basophilic
Eosin
Acidic stain , turns red if acidophillic
Nb
Basophilic structures are acidic in nature
Acidophilic structures are basic in nature
Ex: nucleic acid is basophilic
Cella are formed of ?
Cytoplasms and karyoplasms
Cytoplasm contains
Hyaloplasm organelles cell inclusions
Cytoplasm is essentially
Hyaloplasm , organelles, and cell inclusions
The karyoplasm is?
The nucleus
What is the hyaloplasm?
A viscid colloidal mass formed of CHO , lipids , proteins , and enzymes
What’s embedded on the hyaloplasm ?
Nucleus , organelles, and cellular inclusions
What are the two different types of organelles ?
Membranous and non membranous organelles
What are cell inclusions
Non living , inert that contain stored food , pigments , and secretions
Stored food (aka cell inclusion) examples?
CHO ( stored as glycogen)
How do we stain CHO
Under LM they can be stained by
PAS and appear purple
Best’s carmine and appear red .
Other methods of staining glycogen include ?
Under EM, they appear into two forms :
Alpha granules : found at liver and are rosette in shape
Beta granules : found at muscle , are irregular dense granules .
Other examples of stored food ?
Lipids and pigments .
How do lipids appear under different microscopes?
Under LN:
By HX &E have a signet ring appearance due to fat dissolving in the stain
How do lipids appear under special stains ?
1- sudan black and it appears black in color
2 -Sudan III and it appears orange in color
3- Osmic acid .
What are the two different types of pigments ?
Endogenous and exogenous pigments
What are the 3 different types of endogenous pigments ?
Melanin, hemoglobin, lipofusin
What are the functions of said endogenous pigments ?
Melanain : protects against UV rays
Hemoglobin: found in RBCs , broken into hemosiderin & bilirubin
Lipofusin : found in nerve cells and heart muscles, increases with age , represents waste product
Examples of exogenous pigments
1-Dust and carbon
2-tattoo
3 - Carotene in carrots
Nb
Carotenoma gives off a yellowish skin color as due to excessive consumption of carrots
Secretion granules ?
Mucoud and serous
Crystals?
Curate crystals which cause gout
Membranous organelles properties
Have permanent structures , contain enzymes , fuel metabolism .
Non membranous organelles
Antis of membranous organelles .
Exs of membranous organelles?
Cell membrane
Mitochondria
Golgi apparatus
Lysosome
Peroxisomes
Coated vesicles
Endosomes
Other examples of membranous organelles ?
Endoplasmic reticulum
Annulate lamellae
Nonmembranous organelles
Centrioles ( ex : cillia and flagella )
Cytoskeleton ( filaments and microtubules )
Ribosomes
Cell membrane alternative name?
Plasmalemma
What does the cell membrane consist of ?
Lipids: phospholipid :hydrophilic head charged , directed outwards , appears dark by EM ( ofosmium decay )
Non polar tail : hydrophobic , non charged , directed inwards , responsible for permeability of cell membrane
2- cholestrol: responsible for rigidity
What else does the cell membrane consist of ?
Protein content : extrinsic and intrinsic
Cell coat : glycocalyx
Extrinsic ( peripheral ) protein is ?
Loosely attached
Can be easily removed
Found on both surfaces
Integral ( intrinsic ) protein
Embedded in lipid bilayer ( firmly attached )
Presents itself as a lipid bilayer formed of polar and non polar area
(2 hydrophillic heads and a hydrophobic center )
Minimally a barrier
Largely responsible for transport
Cell coat (glycocalyx)
