Cytology

Cytology is the study of cells

The Cell Theory:
All organisms are composed of cells
Cells are smallest physiological unit
Organism activity is based on cellular activity
Cells come only from preexisting cells
All cells have similar molecular characteristics

Cell Shapes and Sizes:
Squamous - fried egg shape
Cuboidal
Columnar
Polygonal
Stellate - star shaped
Spheroid/ovoid
Discoid
Fusiform
Fibrous

Basal - bottom, 'basement'
Apical - top, surface

Cells measured in micrometers - RBC's are 7-8 micrometers

The Outer-Cellular Components:
ICF - intracellular fluid
ECF - extracellular fluid

The Plasma Membrane:
Holds material in and out of cell
Many physiological functions
Fluid mosaic model - varied, nothing is solid
Phospholipid bilayer - fat w/ a phosphate attached
   Hydrophilic heads
   Hydrophilic tails
Cholesterol - makes hormones
Glycolipids - combination of sugar and fat

Membrane Proteins:
Integral proteins - pass all the way through membrane
Peripheral proteins - only found on either side
Functions:
   Receptors - allows chemicals in/out
   Enzymes - proteins, speed up cells
   Channels - passageway from ICF to ECF
   Cell identity markers - peripheral in ECF
   CAMS - cell adhesion molecules, keeps things in place
   Carriers - integral proteins (specific channels)
Membrane transport - how material gets back and forth through membrane

Outside the Cell Membrane:
The Glycocalyx - slim layer, ID's cell, keeps in place
   Glycolipids and glycolipids
   Functions - enables movement
Cellular Extensions:
Microvilli - smallest
Cilia
Flagellum - largest
Intercellular junctions:
keeps cells together
   Tight junctions - share a membrane (fence)
   Desmosomes - peripheral, snap connection/velcro
   Gap junctions - integral, direct communication

Cytoplasm:

Cytoskeleton - structure of cell, allows movement in cell
Micro filaments
Intermediate filaments
Microtubules

Organelles
The Nucleus - boss
   Nuclear envelope and pores, chromatin, nucleoplasm,
Endoplasmic Reticulum - production facilities
   Rough - produces proteins
   Smooth - produces lipids and carbohydrates
Ribosomes - make protein out of amino acids
   Free - mobile in ICF
   Fixed - attached
Golgi Complex - packaging, addresses proteins
Lysosomes - gets rid of waste, 'stomach of the cell'
Peroxisomes - gets rid of H2O2 and alcohol specifically
Mitochondria - powerplant, convert to ATP
   Crista (folds) - double membrane, inner, large surface area
   Matrix - fluid in mitochondria
Centrioles - expansion devices, makes new cells (divides)
Inclusions - storage sheds after product is made

Cytosol - ICF (potassium)
Fluid different in chemical composition than ECF (sodium)