Chapter 15/16- Immunity Flashcards
In order for a pathogen to successfully cause disease in humans, the pathogen must come to the surface of our body, they successfully attach to the surface of our body because they overcome our body’s first line of defense against infection. These pathogens then invade our epithelial surface and penetrate into deeper tissues. The next thing these pathogens must be able to do in order to successfully cause disease in humans is to _____ our second line of defense against infection.
evade
Most immunologists describe three lines of defenses that humans have against infection:
___ line of defense- nonspecific surface barriers (____)
___ line of defense- nonspecific immune response (___)
___ line of defense- specific immune response (____)
1st line of defense- nonspecific surface barriers (innate)
2nd line of defense- nonspecific immune response (innate)
3rd line of defense- specific immune response (adaptive/acquired)
Innate immunity
- Present and functional at birth
- Nonspecific
- No memory
Adaptive immunity
- Present and nonfunctional at birth
- Specific
- Memory
The environmental factors that can influence the growth of microorganisms are the nutrients, temperature, pH, and oxygen supply. In addition to these environmental factors, since our normal microbiota only live on the surface of our body, our body surface can present _____ to the growth of microorganisms.
These barriers are known as our ___ ___ of ____ against microorganisms or (to be more specific) against infection. These barriers are also known as our ____ _____ defense, they are nonspecific because basically they act against almost all microorganisms.
The environmental factors that can influence the growth of microorganisms are the nutrients, temperature, pH, and oxygen supply. In addition to these environmental factors, since our normal microbiota only live on the surface of our body, our body surface can present barriers to the growth of microorganisms.
These barriers are known as our first line of defense against microorganisms or (to be more specific) against infection. These barriers are also known as our nonspecific surface defense, they are nonspecific because basically they act against almost all microorganisms.
4 barriers:
structural, mechanical, chemical, and genetic barriers.
Structural barrier-
Microorganisms that form our normal microbiota only live on the surface of our body (it can be either external or internal surface), this body surface is made up of _____ ____. There are two main types of epithelial surfaces: the ____ and the ____ ____
Structural barrier-
Microorganisms that form our normal microbiota only live on the surface of our body (it can be either external or internal surface), this body surface is made up of epithelial cells. There are two main types of epithelial surfaces: the skin and the mucous membrane.
Structural barrier-
Because the epithelial cells of the epithelium are constantly growing and being sloughed off the surface and replaced by new ones from below the microorganisms that attach to the epithelium also tend to be soughed off ____
- Also have _____ ____ between epithelial cells
Because the epithelial cells of the epithelium are constantly growing and being sloughed off the surface and replaced by new ones from below the microorganisms that attach to the epithelium also tend to be soughed off rapidly.
- Also have tight junctions between epithelial cells
Mechanical barrier involves _____- _____ _____ the _____
Mechanical barrier involves movement- physically removing the microbe
(1) The first kind of mechanical barrier is due to the ______ ______ of the epithelial cells lining the surfaces of ____ and ____. These epithelial cells can produce mucus that entraps microorganisms. Cilia on epithelial cells constantly move this mucus toward the mouth, where the mucus along with the trapped microorganisms is _____ and eliminated
(1) The first kind of mechanical barrier is due to the mucociliary movement of the epithelial cells lining the surfaces of nose and throat. These epithelial cells can produce mucus that entraps microorganisms. Cilia on epithelial cells constantly move this mucus toward the mouth, where the mucus along with the trapped microorganisms is swallowed and eliminated
The second kind of mechanical barrier is due to
fluid movement- flushes microbes from the surface
(2) The second kind of mechanical barrier is due to the movement of our body fluids (such as blood, urine, tears, semen…..etc). For example, in the ____, the rapid flow of urine washes away most microorganisms that happened to establish residence on the lining of urethra. Another example would be our ___ washing microorganisms off the conjunctiva
(2) The second kind of mechanical barrier is due to the movement of our body fluids (such as blood, urine, tears, semen…..etc). For example, in the urethra, the rapid flow of urine washes away most microorganisms that happened to establish residence on the lining of urethra. Another example would be our tears washing microorganisms off the conjunctiva
Biochemical barrier (or chemical barrier)-
Biochemical barriers are..
chemicals produced by cells on the surface of the human body against microorganisms
Examples of biochemical barriers
- Keratin
- Perspiration
- Lysozymes
- Sebum
- Acids (HCl)
Keratin
Keeps skin dry, waterproofs the skin
Perspiration
- Secreted by eccrine (sweat) glands
- Salt inhibits growth of pathogens
Lysozymes
- Made by saliva and tears, antibacterial
Genetic barrier-
Some hosts are..
genetically immune to the diseases of other hosts
Genetic barrier, Species Specific Exs
- HIV (humand) vs FIV (felines
- Ebola virus
- Heartworms
For genetic barriers, perhaps the microbe doesn’t have the appropriate ____ to attack the host cells (_______). This is often referred to as ____ ______
For genetic barriers, perhaps the microbe doesn’t have the appropriate receptors to attack the host cells (glycoproteins). This is often referred to as species specificity
Our body’s second line of defense against microbial invasion or infection has to do with our body’s natural, nonspecific immune responses. These immune responses include four components:
inflammation, phagocytosis, interferon, and complement
Inflammation is a
nonspecific response to tissue damage
Inflammation can be identified by four classic symptoms: _______________. A fifth symptom, the loss of ____, is often added to these classic symptoms but can be attributed to the swelling and pain.
Inflammation can be identified by four classic symptoms: redness, heat, swelling, and pain. A fifth symptom, the loss of function, is often added to these classic symptoms but can be attributed to the swelling and pain.
Goals of inflammation:
- Remove the agent causing inflammation
- Keep damage localized
- Allow it to heal
- Alert adaptive immunity
3 sequential stages of inflammation (and local or systemic):
Vascular Changes (local)
Edema/Swelling (local)
Fever Development (systemic)
During the “vascular changes” stage of inflammation, chemicals like ______ and ______ are released, triggering ________
During the “vascular changes” stage of inflammation, chemicals like Prostaglandin and Histamine are released, triggering vasodilation
Vasodilation during Vascular Changes increases the ___ ____ into the injured area, hence speeding up the influx of immune components to the injured area to repair the damaged tissue. This increase in blood flow is also responsible for the _____ and ____ symptoms of inflammation.
Vasodilation during Vascular Changes increases the blood flow into the injured area, hence speeding up the influx of immune components to the injured area to repair the damaged tissue. This increase in blood flow is also responsible for the redness and heat symptoms of inflammation.
Edema-
The formation of edema is due to the influx of ____ from blood vessels into damaged tissues. Accumulation of this fluid in the tissues gives rise to local _____ and _____
Edema-
The formation of edema is due to the influx of fluid from blood vessels into damaged tissues. Accumulation of this fluid in the tissues gives rise to local swelling and hardness.
Edema- some of the same chemicals (prostaglandin and histamine) from vascular changes lead to _______ ______
increased permeability
Edema-
The swelling not only _____ ____, but also applies..
The swelling not only dilutes toxins but also applies pressure to nearby nerves
Pain can be attributed to which stage of inflammation
Edema/Swelling
Fever Development- Fever is initiated when a circulating substance called _____ , _____ the ______ ______ to a _____ ______
Fever is initiated when a circulating substance called pyrogen, resets the hypothalamic thermostat to a higher setting.
Pyrogens can be any _____ substance coming from outside the body (_____ pyrogen) or originating internally (______ pyrogen).
Pyrogens can be any chemical substance coming from outside the body (exogenous pyrogen) or originating internally (endogenous pyrogen).
Example of exogenous pyrogen
Bacterial toxins
Example of endogenous pyrogen
Any chemical released by phagocytes
Phagocytosis is a process of engulfment and destruction of the foreign matter including microorganisms. The cells that perform phagocytosis are known as _____
phagocytes
5 sequential stages of phagocytosis:
- Chemotaxis
- Ingestion
- Fusion
- Killing
- Elimination
Chemotaxis
recognition of invader due to signal molecules on the microbe surface
Ingestion- membrane extensions surround microbe forming a ____
membrane extensions surround microbe forming a phagosome
Fusion-______ fuses with phagosome creating a _______
lysosome fuses with phagosome creating a phagolysosome
