Chapter 21 Flashcards
define the immune system
not an organ system, but a cell population that inhabits all organs and defends the body from agents of disease
what is the true organ system
lymphatic system
what organs consist of the lymphatic system
thymus, red bone barrow, lymph nodes, spleen, tonsils
what are the three main functions of the lymphatic system
fluid recovery, immunity, lipid absorption
in fluid recovery fluid continually filters from __ into the __
blood capillaries, tissue spaces
during fluid recovery blood capillaries reabsorb __%
85
during the function of immunity in the lymphatic system, excess filtered fluid pills up foreign cells and chemicals from the tissues which passes through the
lymph nodes
in lipid absorption, __ in the small intestine absorb dietary lipids
lacteals
what are the components of the lymphatic system
lymph, lymphatic vessels, lymphatic tissues, lymphatic organs
what is lymph
the recovered fluid
what is the role of lymphatic vessels
transport the lymph
lymphatic tissues are composed of
lymphocytes and macrophages
where are defense cells especially concentrated
in the lymphatic organs
lymphatic organs are separated from surrounding organs by
connective tissue capsules
lymph is clear, colorless fluid, similar to plasma, but much less
protein
lymph Originates as __ drawn into lymphatic capillaries
extracellular fluid
lymph has __when draining from small intestines
High lipid content
lymph has __when leaving lymph nodes
Large number of lymphocytes
__ merge to form larger lymphatic vessels
Lymphatic capillaries
lymphatic vessels are absent from
cartilage, cornea, bone, and bone marrow
Capillary wall is __ cells
endothelial
lymphatic vessel cells are tethered to surrounding tissue by
protein filaments
Endothelium creates valve-like flaps that open when interstitial fluid pressure is __, and close when it is__
high, low
what are the three layers of larger lymphatic vessels
tunica interna. tunica media, tunica externa
what Is the tunica intern composed of
endothelium and valves
what is the tunica media composed of
elastic fibers and Smoot muscle
what is the tunica external consist of
a thin outer layer
what iOS the flow of lymphatic vessels
lymphatic capillaries, collecting vessels, six lymphatic trunks, two collecting ducts
what do the six lymphatic trunk do
drain the major portions of the body
what are the six lymphatic trunks
Jugular, subclavian, bronchomediastinal, intercostal, intestinal (unpaired), and lumbar trunks
what are the two collecting ducts
the rich lymphatic and thoracic duct
what is the role of the right lymphatic duct
receives lymph from right arm, right side of head and thorax; empties into right subclavian vein
what is the role of the thoracic duct
receives lymph from below diaphragm, left arm, left side of head, neck, and thorax; empties into left subclavian vein
which duct Isi larger and longer
thoracic duct
where does the thoracic duct begin
as a prominent sac in the abdomen called the cisterns chyli
how is the flow of lymph moved along
by rhythmic contractions of lymphatic vessels
the stretching vessels stimulates
contraction
the flow of lymphatic vessels is aided by
the skeletal muscle pump
__ significantly increases lymphatic return
exercise
Rapidly flowing blood in __, draws lymph into it
subclavian veins
what are the six lymphatic cells
Natural killer cells, T lymphocytes, B lymphocytes, Macrophages, dendritic cells, reticular cells
what do Natural killer cells do
destroy bacteria, transplanted tissue, host cells infected with viruses or that have turned cancerous
what does the T in T lymphocytes stand for
Thymus-dependent
where do T lymphocytes mature
in the thymus
what is special about B lymphocytes
they are Antigen-presenting cells
what does APC stand for
antigen-presenting cells
what happens when B lymphocytes are activated
activated causes proliferation and differentiation into plasma cells that produce antibodies
where are B lymphocytes mature
in the bone marrow
what type of tissue are macrophages
connective tissue
from what do macrophages develop from
monocytes
what do macrophages phagocytize
tissue debris, dead neutrophils, bacteria, and other foreign matter
what are dendritic cells
Branched, mobile APCs found in epidermis, mucous membranes, and lymphatic organs
what do dendritic cells do
Engulf foreign matter by receptor-mediated endocytosis and Alert immune system to pathogens that have breached the body surface
what are reticular cells
Branched stationary APCs that contribute to the framework (stroma) of a lymphatic organ
what are lymphatic tissues also known as
Mucosa-associated lymphatic tissue
what does MALT stand for
Mucosa-associated lymphatic tissue
what are lymphatic nodule
Dense masses of lymphocytes and macrophages that congregate in response to pathogens
what is a constant feature of the lymph nodes, tonsils, and appendix
lymphatic nodules
where are Aggregated lymphoid nodules found
dense clusters in the ileum, the distal portion of the small intestine
what are the primary lymphatic organs
the thymus and red bone marrow
where are T and B cells able to recognize and respond to antigens
primary lymphatic organs
what are the secondary lymphatic organs
Lymph nodes, tonsils, and spleen
___ cells populate the secondary lymphatic organs
immunocompetent
red bone marrow is involved in __ and immunity
hemopoiesis
the thymus is a member of what systems
endocrine, lymphatic, an dimming systems
what are the functions of the thymus
houses developing lymphocytes, secretes hormones regulating their activity, degeneration with age
__ divide the thymus into several lobes
trabeculae
Epithelial cells seal off cortex from medulla of the thymus forming the
blood–thymus barrier
the blood–thymus barrier produces
Produce signaling molecules thymosin, thymopoietin, thymulin, interleukins, and interferon
what are the most numerous lymphatic organs
lymph nodes
the lymph nodes have what two functions
cleanse the lymph and acts s aside of T and B cell activation
the __ are where B cells multiply and differentiate into plasma cells
germinal centers
Lymph leaves the node through one to three __ that leave the hilum
efferent lymphatic vessels
what are the main lymph nodes locations
cervical, axillary, thoracic, abdominal, intestinal and mesenteric, inguinal, and popliteal
what is lymphadentitis
swollen, painful node responding to foreign antigen
what is lymphadenopathy
collective term for all lymph node diseases
what is metastasis
cancerous cells break free from original tumor, travel to other sites in the body, and establish new tumors
Treatment of breast cancer is __, along with removal of nearby axillary nodes
lumpectomy, mastectomy
with are tonsils
patches of lymphatic tissue located at the entrance to the pharynx
what are the tonsils function
Guard against ingested or inhaled pathogens
what are the three main sets of tonsils
palatine, lingual, and pharyngeal
what is the body’s largest lymphatic organ
the spleen
what two types of tissue does the spleen exhibit
red pulp and white pulp
what is red pulp
sinuses filled with erythrocytes
what is white pulp
lymphocytes, macrophages (monocytes) surrounding small branches of splenic artery
what are the functions of the spleen
- Healthy red blood cells (RBCs) come and go
- For old, fragile RBCs, spleen is “erythrocyte graveyard”
- Blood cell production in fetus (and very anemic adults
- White pulp monitors blood for foreign antigens and keeps an army of monocytes for release when needed
- Stabilizes blood volume through plasma transfers to lymphatic system
what are pathogens
agents capable of producing disease
what are some living pathogens
bacteria and fungi
what are some non-living pathogens
viruses, poisons, and allergens
what are the three lines of defense that compose the immune system
- skin and mucous membranes
- several innate defense mechanisms
- adaptive immunity
what is innate immunity
defenses we are born with; first and second lines
is innate immunity local or widespread
local
is innate immunity have memory
no
what line of defense is adaptive immunity
third
what does the adaptive immunity do
Adapts the body to the presence of an environmental pathogen so the body becomes less vulnerable to the illness it might cause.; Defeats a pathogen, and leaves the body with a “memory” of it so it can defeat it faster in the future
what are some external barriers of innate immunity
skin, mucous membranes, and subepithelial areolar tissue
what is/does the acid mantel do
thin film of lactic and fatty acids from sweat and sebum that inhibits bacterial growth
what are the role of peptides and some examples
in the skin that kill microbes: dermicidin, defensins, and cathelicidins.
what are some mucous membrane examples
Lysozymes from mucus, tears, saliva kill microbes
what does hyaluronic acid do
creates a viscous ground substance that traps microbes
what are phagocytes
cells that engulf foreign matter
what are some examples of leukocytes
Neutrophils Eosinophils Basophils Monocytes --> Macrophages Lymphocytes
Macrophages and leukocytes have important roles in__ and __ immunity
innate, adaptive
neutrophils do what
Wander in connective tissue killing bacteria
how can neutrophils kill bacteria
using phagocytosis and digestion, by producing a cloud of bactericidal chemicals
where are eosinophils found
especially in mucous membranes
what do eosinophils do
- Guard against parasites, allergens, and other pathogens
- Kill tapeworms and roundworms by producing superoxide, hydrogen peroxide, and toxic proteins
- Promote action of basophils and mast cells
- Phagocytize antigen–antibody complexes
- Limit action of histamine and other inflammatory chemicals
what do basophils do
Secrete chemicals that aid mobility and action of other leukocytes
what chemicals do basophils release
leukotrienes, histamines nd heparin
what do leukotrienes do
activate and attract neutrophils and eosinophils
what do histamines do
vasodilator, Speeds delivery of leukocytes to the area
what does heparin do
inhibits clot formation
what else secretes the same substances as basophils
mast cells
what are the three basic categories of lymphocytes
T,B, and NK cells
Circulating blood contains
__% T cells
__% B cells
__% NK cells
80, 15, 5
NK cells are part of __, all others are part of__; helper T cells function in both
innate immunity, adaptive immunity
what do monocytes do
emigrate from the blood into connective tissues and transform into macrophages
what do wandering macrophages do
actively seek pathogens
what do fixed macrophages do
phagocytize only pathogens that come to them
where are microglia
in central nervous system
where are alveolar macrophages
in the lungs
where are hepatic macrophages
in the liver
what are antimicrobial proteins
Proteins that inhibit microbial reproduction and provide short-term, Innate Immunity to pathogenic bacteria and viruses
what are the two families of antimicrobial proteins
interferons and the complement system
Interferons are secreted by __
certain cells infected by viruses
what do interferons do
Alert neighboring cells and protect them from becoming infected
what is the complement system
A group of 30 or more globular proteins that make powerful contributions to both innate immunity and adaptive immunity
what is the complement system synthesized by
the liver
what is the complement system activated by
the presence of a pathogen
what do NKC attack and destroy
bacteria, transplanted cells, cells infected with viruses, and cancer cells.
what is fever
an abnormal elevation of body temperature
what are some synonyms for fever
pyrexia; febrile
what causes fever
trauma, infections, drug reactions, brain tumors, and other causes
what are some results of fever
- Promotes interferon activity
- Elevates metabolic rate and accelerates tissue repair
- Inhibits reproduction of bacteria and viruses
Fever usually triggered by __ such as Glycolipids on bacterial and viral surfaces
exogenous pyrogens
what are some examples of endogenous pyrogens
attacking neutrophils and macrophages
what are the stages of fever
onset, stadium, defervescence
what is inflammation
local defensive response to tissue injury, including trauma and infection
what are the four cardinal signs of inflammation
redness, swelling, heat, and pain
what suffix denotes inflammation
-itis
what are cytokines
small proteins that regulate inflammation and immunity
cytokines are secreted by
leukocytes
what alters the physiology of a receiving cell
cytokines
what do cytokines include
interferon, interleukins, tumor necrosis factor, chemotactic factors, and others
what are the major processes of inflammation
- mobilization of body defenses
- containment and destruction of pathogens
- tissue cleanup and repair
what is chemotaxis
attraction to chemicals such as bradykinin and leukotrienes that guide leukocytes to the injury site
what are the four cardinal signs of inflammation
heat, redness, swelling and pain
heat results from
hyperemia
rednesses during inflammation is due to
hyperemia and extravasated RBCs in the tissue
swelling during inflammation is due to
increased fluid filtration from the capillaries
pain during inflammation is due to
from direct injury to the nerves, pressure on the nerves from edema, stimulation of pain receptors by prostaglandins, bacterial toxins, and bradykinin
with is the priority of inflammation
to prevent pathogens from spreading throughout body.
what does fibrinogen do
filters into tissue fluid clots, Forms a sticky mesh adjacent to injury that walls off microbes
what does heparin do
prevents clotting at site of injury
what do neutrophils do
quickly respond to and kill bacteria by phagocytosis, respiratory burst, and Secrete cytokines for recruitment of macrophages and additional neutrophils
Macrophages and T cells secrete__ to stimulate leukopoiesis thereby raising WBC counts in blood
colony-stimulating factor
what is eosinophilia
elevated eosinophil count in allergy or parasitic infection
what are monocytes
the primary agents of tissue cleanup and repair
how soon do monocytes arrive
8 to 12 hours and become macrophages
what do monocytes do
Engulf and destroy bacteria, damaged host cells, and dead and dying neutrophils
__ contributes to tissue cleanup
edema
what is pus
yellow accumulation of dead neutrophils, bacteria, cellular debris, and tissue fluid
platelet derived growth factor is secreted by
blood platelets and endothelial cells in the injured area
what does platelet derived growth factor do
Stimulates fibroblasts to multiply, Synthesizes collagen
what does hyperemia do
Delivers oxygen, amino acids, and other necessities for protein synthesis
Increased heat increases metabolic rate, speeds mitosis, and tissue repair
what are three characteristics that distinguish adaptive from innate immunity
- systemic effect (throughout the body)
- specificity (immunity directed against a particular pathogen)
- memory (when reexposed to the same pathogen, the body reacts so quickly that there is no noticeable illness)
what re the two forms of adaptive immunity
cellular and humoral