Cytology Flashcards
Centrioles
Short, cylindrical, 9 groups of peripherally arranged 3 microtubules each
Source of basal bodies
What is 2 centrioles at a right angle called?
Centrisome
Nucleus
Largest organelle, visible with LM
Has chromatin and nucleoli
F: controls/ regulates cell’s activities
Stains with hematoxylin
What is the nuclear material inside the nucleus?
Nucleoplasm
Cell cycle
G1, S, G2 and M
G1
Pre-duplication
Cells performs its specific functions
S
Synthesis Stage
Where the centrioles and DNA duplicate
G2
Post duplication stage
Cell finishes replicating and synthesizes enzymes that control cell division
M
Mitotic Stage
Cell forms 2 daughter cells
G1, G2 and S make up ________
Interphase
Nuclear Degenerative Changes
Pyknosis
Karyorrhexis
Karyolysis
Pyknosis
Clumping Chromatin
Karyorrhexis
Breaking down chromatin
Karyolysis
Dissolution of chromatin
Phospholipid
Molecules arranged in a bilayer with hydrophilic heads facing out and hydrophobic ends facing the CM
Barrier for things to go in and out the cells
Microtubules
Cylindrical, 25 nm
Provide support and moving organelles
Part of the cytoskeleton, centriole, basal body, cilium, flagellum
Lumen surrounded with B protofilaments of globular proteins called tubulin
Active Transport
Carrier- mediated transport of solute through a membrane up its concentration gradient
Requires ATP
EX: calcium pump, sodium-potassium pump
Osmosis
Diffusion of water down its concentration gradient
Renewing cells
Body cells continuously replaces @ a fixed interval
When are blood cells replaced?
120 days
When are leukocytes and GI epithelial cells replaced?
2-3 days
When are skin cells replaced?
2-3 weeks
Ribosomes
Composed of ribosomal proteins and RNA
F: protein factory
3 types of RNA: tRNA, mRNA, rRNA
tRNA
Carries amino acids to ribosomes
mRNA
Carries code for amino acid sequence
rRNA
Produces ribosomes with the ribosomal proteins that are responsible for mRNA translations
Proteins in the cell membrane
2% CM 50% of the CM weight
2 types: transmembrane and peripheral
Function: receptors, enzymes, cell identity markers, second-messenger system, channel proteins, carriers, cell adhesion molecules
Transmembrane Proteins
Have hydrophilic regions facing the cytoplasm and ECF, and hydrophobic regions passing back and forth through the lipid of the membrane
EX: glycoproteins
Peripheral Proteins
Don’t protrude through the phospholipids but adhere to the one face of the membrane
Cell
The smallest unit of life capable of independent existence
Cytoplasmic Inlcusions
Metabolic byproducts
Endogenous: Pigments, glycogen, lipids, secretory granules
Exogenous: dust, bacteria, viruses
Cell Membrane
Semi-permeable with 3 laminae (each 2-3 nm thick)
Made of 98% lipids and 2% proteins
Diffusion
Passive transport
Movement of particles from high concentration to low
EX: transport of oxygen into the blood stream
What is diffusion directly affected by
Temperature, molecule weight, concentration gradient and surface area
Peroxisomes
Spherical bodies, 0.5-1.2 nm diameter
Uses O2 to oxidize organic molecules –> produces H2O2–> broken into wtaer and O2 by catalyze enzyme
Where are peroxisomes abundant q
Liver and kidney cells
they neutralize free radicals and detoxify drugs, alcohol and blood-borne toxins
Lysosomes
- Primary: homogenous
- Secondary: heterogenous
- Tertiary: contain undigested material (lipofuscin pigment/ residual body)
Autophagy
Cells using lysosomes to digest old organelles
Lysosomes in neutrophils and macrophages
Digest/ dispose foreign material
Lysosomes in the liver
Break down glycogen
Autolysis
Uses lysosomes to shrink its size after pregnancy
Golgi Complex
A stack of flat cisternae with inner face (cis, forming) and outer face (trans, maturing)
Supranuclear
Stained paraffin sections wit silver stain
F: receives proteins from RER, processes them, then sorts them to their cytoplasmic destinations
Rough ER
Cisternae covered with ribosomes
F: Synthesizes proteins destined for other organelles
Smooth ER
Cisternae that lacks ribosomes
F: Liver- synthesizes steroids, detoxifies alcohol and drugs, stores and releases calcium
Endoplasmic Reticulum
Network of interconnected channels called cisternae enclosed by a membrane
Mitochondria
Double membrane, cristae
Circular DNA, ribosomes and calcium ion in matrix
F: powerhouse of the cell
Involved in ATP synthesis and the Kreb’s cycle
The mitochondria synthesizes ____ mitochondrial proteins
13
Stable Cells
Body cells
Normally don’t divide but can divide in response to disease/ injury
EX: liver cells
Static Cells
Body cell
Never divide, stem cells aren’t present
EX: neurons, cardiac cells
G0 phase for life
Apoptosis
Process of programed cell death that occurs continuously in all organs throughout life
Filtration
Passive transport
Driven by hydrostatic pressure
EX: transport of water, salts, nutrients
Vesicular Transport
Moves large particles, droplets of fluid or numerous molecules at once
Contained in vesicles or vacuoles
Actin
Microfilament
6 nm thick and form part of cytoplasmic skeleton in all cells
Associated with pinocytosis, endocytosis and exocytosis and migratory activities of the cell
Intemediate
Microfilament
Resists stress placed on cell and forms part of junction
Tonofilaments
Types of intermediate filaments in the epithelium
Keratin
Types of intermediate filaments in the mesenchymal
Vimentin
Types of intermediate filaments in the muscle
Desmin
Types of intermediate filaments in the Glial cells
Flial fibrillary acidic protein
Types of intermediate filaments in the neurons
Neurofilaments
Pinocytosis
Cell drinking
Bulk transport of small molecules, nonspecific
Example: pinocytic vesicles in epithelial cells in kidney
Endocytosis
Brings matter into the cell
Exocytosis
Removes matter from the cell
Phagocytosis
Absorption of large particles by means of pseudopods
Occurs only on specialized cells (macrophages and neutrophils)
Passive Transport
Requires ATP
Ex: filtration and diffusion
Active Transport
Requires ATP
EX:carrier-mediated and vesicular transport
Facilitated Diffusion
the carrier-mediated transport through a membrane down its concentration gradient, but it does not consume ATP,