cytology: the study of cells (need microscopes)

microscopy:

• using a microscope to view small-scale structures

• staining techniques provide contrast

  • different cells pick up different stains

  • use hematoxylin and eosin (h + e) mainly

types of stains

• hematoxylin: + charged dye, purple or dark blue, basic

• eosin: - charged dye, stains +, red or pink, acidic

• PAS: stains complex carbs (glycogen), dark red or magenta

• masson trichome: stains supporting tissue (collagen)

  • blue - connective tissue

  • dark red/purple - nuclei

  • red/pink - cytoplasm, muscles, keratin, erythrocyte

• alcian blue: stains acidic polysaccharides blue

• van gieson: stains blood vessels and skin

• giemsa stain: stains for blood and bone marrow smears

• sudan black and osmium: stains lipid containing structures brown/black

cell features and function

• plasma membrane

  • forms outer barrier, selectively permeable

• nucleus

  • largest structure in cell, enclosed by a nuclear envelope

  • contains genetic material, dna, and a nucleolus

• cytoplasm

  • cellular contents between plasma membrane and nucleus

  • includes cytosol, organelles and inclusions

cytoplasmic contents

• cytosol (intracellular fluid)

  • viscous fluid of cytoplasm

  • increases water content

  • contains dissolved macromolecules and ions

• organelles (little organs)

  • complex, organized structures within cells

  • membrane or non-membrane bound

• inclusions

  • cytosol stores temporarily, not considered organelles

  • molecules added to and removed from continuously

    • ex pigments, glycogen, triglycerides

lipid components

• plasma membrane

• phospholipids and phospholipid bilayer

• cholesterol

• glycolipids

membrane proteins

• integral

• peripheral

• transport

• cell surface receptors

• identity parkers

• glycoproteins

• enzymes

• anchoring

• cell adhesion

membrane transport - active and passive

resting membrane potential (rmp): potential when cell is at rest

membrane potential: potential energy of charge difference