Lecture 3 - HMB202
Last week we talked about the differences between gram negative and gram
Question 1) What is the gram stain? What does gram positive mean?
During de-colourizing the outer membrane in the gram negative cell is soluble
Basic dyes have a net positive charge, this allows it to remain inside the bacteria
cell, meaning the bacteria cell must have a negative charge, that comes from it's
DNA which is negatively charged, it has no nucleus.
95% ethanol, fast, dissolve quickly and it dehydrates quickly (removes water from
the system quickly) but we don't use 100% alcohol because it de hydrates too
cilia - a specialized cell that moves back and forth and removes junk in out
Eyes - tears with lysozyme - antibacterial.
Mouth - Saliva - Lymphoid tissue/nodes.
Salty skin secretion + acidic environment make it un-hospitable to bacteria.
Hair follicles and sebum (oils).
antigens - foreign invaders.
primary organ is for the education of t and b cells, t cells in thymus b cells in bone
lymphatic system - drain capillary beds.
lymph node - filter your lymph.
tonsil - mass of diffuse lymphoid tissues with many lymph nodes.
macrophages filter out your lymph - these openings in lymph nodes allow
macrophages to filter out the lymph.
thymus - focus as time progresses the thymus gets infiltrates with fat and the function decreases
significantly. If they are educated their then what has happened to the t- and b-
formation of lobules within the thymus, compartmentalization, we are segregating
the different parts from each other, it's like having many tiny organs within a
parenchyma - the cells that map up the organ for the thymus - t cells +
macrophages + dendritic cells + reticular cells.
Stroma - Holds it together - lots of collagen and lots of fat.
they form tight - gap junctions so nothing gets through the compartments of the
thymus. What happens if something does get through and the t cells can't handle
it because the t-cells can't handle it yet. If this happens the body shuts down the
compartment, the compartment then shuts down and dies. The t cells in the
compartment are un-educated and not able to act or respond to antigens yet.
cortex region - dendritic cells immature t cells and reticular cells that line along
the barriers of the cells/regions
once compartmentalization happens, education begins. The t cells that recognize
self antigens are eliminated so they don't attack our bodies own cells.
erc's - barrier formation. forms a thymus blood barrier. they don't want anything
except oxygen dn food coming form the blood. forms occluding junction, and
creates no entry point for anything to come in.
1- outer 2 - mid cortex 3- deep cortex
around puberty age most of the changes occurs.
What are the steps when we place a bacteria directly in our lung tissue.
adaptive t/c cells are specific, innate is generic.
mast cells degranulate upon stimulation - the granules affect the vasculature
greatly, they are the initiators of acute inflammation. Neutrophils are the first
troops that respond to acute inflammation, 74% of the wbc count are neutrophils,
shock troops first on the scene all or none trying to destroy the antigen
completely, they also destroy the local tissue within that area. mast cells place close to blood vessels. histamine are responsible for
degranulation and allergy systems. histamine causes local vasculatures to link
and become dilated, then plasma