Immune system Flashcards
What does the Immune system does
works to defend body against
internal and external threats
What 2 systems work together in immunity
Immune and lymphatic systems
What does the immune system consists of
1) Contains no organs or tissues
2) Instead consists of cells and proteins in blood and tissues of other systems
3) including lymphatic system
What formed elements does the immune system has
1) leukocytes, or white blood cells (WBCs)
2) immune proteins located in plasma
What is immunity?
is the ability to ward off damage or disease through our defenses
What is susceptibility
lack of resistance
What are the two general types of immunity
Innate (nonspecific)
Adaptive (specific)
What is innate (nonspecific) immunity
1) nonspecific defense mechanisms that come into play immediately or
within hours of an antigen’s appearance in the body.
2) Physical barriers such as skin, chemicals in the blood, and immune system cells that attack foreign cells in the body
What is adaptive (specific) immunity
1) antigen-specific immune response
2) More complex than nonspecific
3) The antigen first must be processed and recognized. Once an antigen has been recognized, the adaptive immune system creates an army of immune cells specifically designed to attack that antigen.
4) Adaptive immunity also includes a “memory” that makes future responses against a specific antigen more efficient.
(long memory, when you do not have to put more than 1 vaccine)
What is the Lymphatic system
group of organs and tissues that not only works with immune system but also participates in number of functions such as fluid
homeostasis
What are the two main components of the lymphatic system
1) lymphatic vessels
2) lymphatic tissue and organs
What are the Lymphatic vessels
system of blind-ended tubes
What are some components of the Lymphatic tissue and organs
includes clusters of lymphoid follicles such as
1) Tonsils
2) Lymph nodes
3) Spleen
4) Thymus
What are the major functions of the lymphatic system
1) Regulation of interstitial fluid volume
- interstitial fluid and lymph are similar in composition
- returns fluid and any leaked plasma proteins to the blood
2) Absorption of dietary fats
3) Immune functions
- lymphoid organs filter pathogens from lymph and blood antigens provoke responses by B cells, plasma cells (which produce antibodies),
memory B cells, and several types of T cells including helper T cells, cytotoxic T cells, regulatory T cells and memory T cells
Where is the lymph collected
In vessels called lymph-collecting vessels
lymph-collecting vessels merge to form what
lymph trucks
How many lymph trunks drain lymph from specific body
regions
9 1) lumbar trunks 2) Intestinal trunk 3) Jugular trunk 4) Bronchomediastinal trunks 5) Subclavian trunks 6)
Where does the lumbar trunks receive lymph from
receive lymph from lower limbs and pelvic area
Where does the Intestinal trunk receives lymph from
receives fat-containing lymph from small lymphatic vessels—in small intestine
Where does Broncho mediastinal trunks receive lymph from
Receive lymph from thoracic cavity
Where does the Subclavian trunks receive lymph from
receive lymph from upper limbs
Where does the Jugular trunks receive lymph from
receive lymph from head and neck
Where does the Intestinal trunk and lumbar trunks
all drain into
a large, swollen vessel called cisterna chyli
Cisterna chyli and trunks from left side of
body drain into which duct?
thoracic duct
Where does the Thoracic duct, largest lymphatic duct, drains
into
into the junction of the left internal jugular and left
subclavian veins
Who makes up low-pressure circuit to drive lymph through vessels
Lymphatic vessels
What prevents lymph from flowing backward
Valves
Lymph flow through vessels is driven in part by
contractions of smooth muscle found in walls of lymph- collecting vessels
Why do the Cells of lymphatic capillary walls are not
tightly joined but able to flap open and close
To allow macrophages and other immune cells to
enter lymph
What are the Lymph nodes
clusters of lymphoid organs along pathway of lymphatic vessels
What do the Lymph nodes limit
spread of pathogens through the body by acting as filters
trap pathogens and prevent them from traveling elsewhere
What has an easier time entering lymphatic
capillaries than blood capillaries
Pathogens such as bacteria and cancer cells in interstitial fluid
What is the predominant tissue type of the lymphatic system
lymphoid tissue
loose connective reticular tissue
Lymphoid organs house
Leukocytes
What are the Macrophages
mature monoctes
What are B and T lymphocytes
agranulocytes with diverse immune functions
What are Dendritic cells
immune cells with spiny processes resembling dendrites of neurons
derived from bone marrow while others originate from connective tissue
What are Reticular cells
particularly abundant in organs such as spleen and
lymph nodes
produce reticular fibers composed of specialized, thin collagen protein
What is the Mucosa-associated lymphatic tissue (MALT)
loosely organized clusters of lymphoid tissue
What does MALT protect
1) protects mucous membranes, which are exposed to large number of pathogens
2) oral and nasal cavities scattered throughout gastrointestinal tract, respiratory passages, and, to
limited extent, genitourinary tract
Much of MALT in body consists of
loosely organized clusters of B and T cells that lack connective tissue capsule
Peyer’s patches defends against of
any bacteria that have escaped from large intestine
Appendix defends against of
- defends body from bacteria in large
intestine
What does Epithelium lining tonsils form
tonsillar crypts that trap bacteria and debris
1) Pharyngeal tonsils (2)
2) Palatine tonsils (2)
3) Lingual tonsil (1)
what are Lymph nodes
small, vaguely bean-shaped clusters of
lymphatic tissue located along lymphatic vessels
throughout body
Specific clusters of lymph nodes include
1) axillary lymph nodes
2) cervical lymph nodes
3) inguinal lymph nodes
4) mesenteric lymph nodes
What does Lymph nodes have
1) external connective tissue capsule
2) surrounds network of reticular fibers filled with
3) macrophages, lymphocytes, and dendritic cells
What are the Interior of node divided into… (2)
outer cortex and inner medulla
What traps approximately 90% of
pathogens in lymph
Lymph nodes and it prevents pathogens from being delivered to blood, where
they could easily spread to other tissues and organs
Lymph that has been “cleaned” of pathogens
drains out… where?
through efferent lymphatic vessels on other side of node
at hilum
What is the Spleen and where is located
largest lymphoid organ in body
located on lateral side of left upper quadrant of
abdominopelvic cavity
the internal structure of the spleen consists of
network of reticular fibers
Two distinct histological regions in reticular network
1) Red pulp—contains macrophages that destroy old erythrocytes
2) White pulp—filters pathogens from blood and contains
leukocytes and dendritic cells
Adult thymus
Consists of subunits called thymic lobules (thymic corpuscles
Each lobule contains two regions: outer cortex and inner medulla
-Cortex contains densely packed T cells
-Medulla contains fewer T cells
- Site of destruction of certain populations of T cells that could react to body’s own cells
Edema
(swelling)—accumulation of excess
interstitial fluid
Lymphadenopathy
Occurs when the lymph
nodes swell due to infections.
Filariasis
An infection of the lymphatic channels by a
worm or parasite.
