Notesale: Turn your study into money

Document Preview

Extracts from the notes are below, to see the PDF you'll receive please use the links above

---

• Resistance

Host Defense Mechanisms
(specific and non-specific)

Host Defenses

– Ability to ward off disease
– Varies among organisms and individuals within the
same species

• Immunity - mechanisms used by the body as
protection against microbes and other foreign
agents; self vs
...
, Candida albicans)

First line of defense – physical &
chemical barriers

• Microbial antagonism

– Normal flora vs
...
g
...
It contain two dyes:
•
•

Eosin dye stains basic cell components  reddish
Methylene blue dye stain acidic cell components  blue-ish

Formed Elements In Blood

Wandering or Fixed

4

Can you identify these leukocytes?

Granulocytes

Neutrophils (aka polymorphonuclear cells or PMN)
• Most common leukocytes in the blood
...


Eosinophils

platelet

erythrocyte

• the granules of cytoplasm are stainable with
eosin (red)
• its role in allergy, asthma and parasitic
(helminth) infection; some phagocytosis
...
g
...
g
...
g
...
g
...
g
...


Inflammation

• Four cardinal signs
–
–
–
–

Redness
Heat
Swelling
Pain

• Primary functions

– Localize infection
– Neutralize toxins at
injury site
– Repair damage tissue

Second Line of Defense

Inflammation

• Major events

– Vasodilation
– Increase permeability
of capillaries
– Mobilization of
leukocytes to site of
injury (chemotaxis &
emigration)
– Phagocytosis

Inflammation – cont
...
Many white blood cells engulf invasive
microorganisms by the process of phagocytosis
...
Chemotaxis is the process by which phagocytes
are attracted to microorganisms
...
Attachment: The phagocyte then adheres to the
microbial cell
...

– 3
...

– 4
...
The microbe is killed and
digested
...
8a

Specific defense (3rd line)

• Four major features
– Specificity (recognize particular antigens)
– diversity (responds to millions of different
invaders)
– self/nonself recognition– memory - acquired immunity so the
second time body is infected the response
will be quick enough to avoid serious
infection
...


Cell surface markers

• Blood cells A, B, and Rh Factor proteins
• Major histocompatibility complex (MHC) are
glycoproteins marking cell as self
• MHC class I are on all nucleated cells
• MHC class II are only on specific immune cells
• Huge amount of variety, so each individual is
unique in their MHC proteins
...
(B and T cells)
• B- cells fully develop in the bone marrow
before being released
• T - cells then travel to the the thymus for
further development before leaving
...


2nd exposure

• 2nd time the antigen stimulates Memory B
cells and memory T cells to activate both
humoral and cell-mediated responses
...

• Supressor T cells are thought to help turn
off the immune response when antigens
are gone
...

• Five types of immunoglobulins are divided by their
constant regions IgM, IgG, IgA, IgD, and IgE
...
Plentiful in mucus
...


Helper T-cells
• Helper T cells are stimulated by interleukin
1 of macrophages after engulfing antigens
and presenting them
...


10



---