Histology exam 1 Flashcards
Resolution of Human eye, Light microscope, and Electron microscope
0.2 mm, 0.2 um (200 nm), and 0.2 nm (2 A angstroms)
Size of Red blood cell
7.8 um (micro-meters)
Most common fixative
Formalin (Formaldehyde)
Hematoxylin stains…….
Nucleic acids
Eosin stains…….
Proteins
Toluidine Blue
(+) charged basic dye, that stains acidic (-) charged molecules.
Also metachromasic (it can change color) to Purple for glycogen and other things.
H&E
Hematoxylin is a basic dye, that stains acidic molecules (dark blue color). Eosin is a acidic dye, that stains basic molecules (red-pink color).
- Does not detect sugars
Acidophilia or Acidophilic
Things that “love acid” and therefore are basic. They would be stained by Eosin.
Ex. Cytoplasmic or Secretory proteins (Proteins are basic)
Basophilia or Basophilic
Things that “love base” and therefore are acidic. They would be stained by Hematoxylin.
Ex. rER, heterochromatin, nucleoli (Nucleic acids are acidic)
Na+
K+
Cl-
Ca 2+
(Cytoplasmic [], Extracellular [] )
5-15 mM, 145 mM (Na+)
140 mM, 5 mM (K+)
5-15 mM, 110 mM (Cl-)
0.2 uM
mM = milli-Molar uM = micro-Molar
Micro-filaments
Made up of: Actin
Microtubules
Made up of: Tubules
Intermediate Filaments
Made up of: Inter Fil. proteins such as Keratin or Vimentin
Cytoskeleton
Made up of: Microfilaments, Microtubules, and Intermediate Filaments.
Cannot be seen on normal H&E stain with LM as it is smaller than 200 nm.
1 ) Allows for movement of stuff within cell
2) Separation of chromosomes during mitosis
3) Changes the cell shape during specific functions (phagocytosis, cytokineses)
Heterochromatin
Dark staining chromatin that is transcripionally inactive
Euchromatin
Light staining chromatin that is transcriptionally active
Nucleolus (Nucleoli)
Dark staining area within the Nucleus that is transcritionally active and synthesizes rRNA and assembly of ribosomal subunits.
Mitochondria
Makes heat
Double stranded CIRCULAR dna
Makes its own tRNA, rRNA, and mRNA
Residual Bodies / Lipofuscin
Lysosomes with undegraded substances. Are created to protect the cell from adverse effects of partially degraded molecules.
sER
Responsible for lipid synthesis, steps in hormone production (P450), and detoxification.
Site of Ca 2+ storage.
Secretory pathway (simple)
rER»_space; Golgi»_space; Vesicle»_space; Plasma membrane
N-linked Glycosylation
Added to the side chain of Asparagine. Occurs in the rER and is modified in the Golgi.
O-linked Glycosylation
Sugars are added to the oxygen atom in the side chains of serine, threonine, hydroxiproline, and hydroxylysine. Occurs in the Golgi and are not modified.
Endocytosis pathways
1) Recycling (Absorbed to be Excreted)
2) Transcytosis (Passing right through)
3) Degradation (Absorbed to be broken down)
Difference between recycling and transcytosis is where the vesicles end up. Recycling is on the same side (apical-apical). Transcytosis is on different sides (apical-basal).
Familia Hypercholesterolemia
Characterized by high serum cholesterol due to low LDL clearance by liver. Caused by mutations that impair normal receptor mediated endocytosis of LDL.
Epidermolysis Bullosa Simplex
EB Simplex is the most common form of EB and results in fragile skin due to absence of keratin 14 that keeps the intraepidermal layer together. Due to mutation of KRT14 gene.
Lipids stained with Toludine Blue are what color
black (appears as small black dots can be bigger)
4 types of tissue
Epithelial
Connective, (CT proper, Specialized CT [ adipose, blood, bone, cartilage, lymphatic, hemopoietic]
Nerve
Muscle
Name the junctions of an Epithelial cell from apical to basal**
1) Tight Junctions (Seals gap between cells)
2) Adherens Junctions (Connect actin filament bundle in one cell to another)
3) Gap Junctions ( Allow passage of stuff from one cell to another)
4) Desmosomes ( Connects intermediate filaments in one cell to another)
5) Hemidesmosomes (Connect epithelial cells to basal lamina)
What is/makes up the basal lamina
Basal Lamina is the ECM layer at the basal surface of all epithelial.
Made up of: Collagen 4 (forms a network rather than fibril) Laminin Nidogen Perlecan
Different classifications of epithelial
Simple squamous, Simple columnar, Simple cuboidal
Stratified squamous, Stratified columnar,
Stratified cubodial
What kind of epithelial is in the trachea
Psuedostratified columnar cells
Simple squamous epithelial that lines blood vessels
Endothelium
Simple squamous epithelial that lines body cavities
Mesothelium
Thin skin, Thick skin, Specific tissues (ex. Oral epithelium)
Keratinized (but thin layer), Keratinized (but thick layer)
Not Keratinized
Microvilla vs Cillia
Microvilla are made up of actin, non force generating
Cilia are made up of microtubules, force generating
Two kinds of glands
Exocrine and Endocrine
Exocrine glands
1) Secrete products into ducts
2) Have a secretory and duct portion
3) Secretory epithelium is called glandular epithelium
Exs: Acinus (have granules focused around the lumen at the center, mushroom shaped)
Endocrine glands
1) Do not have ducts
2) Secrete product into blood
3) Highly vascularized
Secretory Mechanisms**
Merocrine: “regular” normal exocytosis (endocrine glands only option)
Aporine: Whats being transported takes some of the membrane (Mammary)
Holocrine: Cell ruptures releasing its contents (Sebaceous)