Chapter 10 Flashcards
components of lymphatic system
- lymph: the fluid
- lymphatics: the vessels
- spleen and thymus
functions of lymphatic system
- return fluid to the bloodstream
- transports fats from digestive tract to the bloodstream
- surveillance and defense
- originate as lymph capillaries
- capillaries unite to form larger vessels
- resemble veins in structure
- connect to lymph nodes at various intervals
lymphatics
lymphatics ultimately deliver lymph into 2 main channels
right lymphatic duct and thoracic duct
- drains right side of head & neck, right arm, right thorax
- empties into the right subclavian vein
right lymphatic duct
- drains the rest of the body
- empties into the left subclavian vein
thoracic duct
who’s in charge with the flow of lymph fluid
muscle movement and contraction
the fluid the lymphatic system collects comes from…
cells and tissues throughout the body
the lymphatic system is part of the immune system. It produces and releases [ ] (white blood cells) and other immune cells that monitor and then destroy the
foreign invaders
lymphocytes
job of the spleen
- fight invading germs in blood
- controls levels of blood cells
- filters blood
composition of diffuse lymphatic tissue
lymphocytes and macrophages associated with a reticular fiber network
location of diffuse lymphatic tissue
lamina propria (middle layer) of the mucus membranes (mucosae) that line the respiratory and gastrointestinal
tracts.
- no capsule present
- oval-shaped masses
- found singly or in clusters
lymphatic nodules
- capsule present
- lymph nodes, spleen, thymus gland
lymphatic organs
lymph nodules has [ ] that separate them from neighboring cells
clear boundaries
lymph cells are also referred as…
mucosa-associated lymphoid tissue (MALT)
lymphatic nodules contain
lymphocytes and macrophages
major clusters of nodules
- peyer’s patches: small intestine
- tonsils: throat
- appendix: large intestine
nodule vs. node
- nodule is smaller and does not have a well-defined connective-tissue capsule as a boundary.
- does not function as a filter, because it is not located along a lymphatic vessel.
composition of lymph organs
encapsulated organs contain lymphatic nodules and diffuse lymphatic cells surrounded by a capsule of dense connective tissue.
- oval structures located along lymphatics
- enclosed by a fibrous capsule
lymph nodes
located at the cortex and produces lymphocytes
germinal centers
the inner portion medulla contains [ ]
medullary cords
lymph enters nodes through [ ] lymphatics, flows through sinuses, exits through [ ] lymphatic
afferent; efferent
multiple groups of large lymphatic nodules located at the mucous membrane of the oral and pharyngeal cavities
tonsils
posterior-lateral walls of the oropharynx
palatine tonsils
posterior wall of nasopharynx
pharyngeal tonsils
base of tongue
lingual tonsils
largest lymphatic organ located between stomach and diaphragm
spleen
structure of spleen
- capsule present
- no afferent vessels/sinuses
histology of spleen
- red pulp contains components of circulating blood
- white pulp is similar to lymphatic nodules
location of thymus gland
behind the sternum in the mediastinum
how many lobes does thymus gland have
the capsule divides it into two lobes
infant thymus size
inconspicuous
thymus size in puberty
maximum
thymus size in maturity
decreases in size
function of thymus gland
differentiation and maturation of T cells
2 types of defenses by lymphatic system
non-specific and specific
two types of adaptive immunity
humoral and cell-mediated
involves B cells that become plasma cells which produce antibodies that bind with specific antigens.
humoral immunity
involves T cells that directly destroy foreign cells
cell-mediated immunity
the ability to resist infection and disease
immunity
- Can involve the epithelium on the body surface (integument) or occur in connective tissue, in the GI system and/or may involve a cellular response
- Respond immediately to many different harmful agents
- Do not require a previous exposure to a foreign substance
Innate (non-specific) defenses
- Lymphocytes (B, T,): Are major players in the immune response but other cells and participants in the innate system work cooperatively
- Identifies, attacks, and reinforces immunity to a specific pathogen
Adaptive (specific) defenses
main purpose of innate immune response
to immediately prevent the spread and movement of foreign pathogens throughout the body.
1st line of defense in innate immune response
physical barriers: skin and mucosal barriers
engulf pathogens and cell debris; release toxic chemicals, and present antigens
phagocytes: neutrophils and macrophages
natural killer cells (NK cells) destroy abnormal cells.
immunological surveillance
- Chemical messengers that coordinate the defenses against viral infections.
- Antiviral proteins do not kill viruses but block replication in cell
interferons
complement action of antibodies to destroy pathogens
complement
triggers a complex inflammatory response limiting the spread of infection
inflammation
a high body temperature which increases body metabolism, accelerates defenses and accelerates body defenses
fever
give instructions to other cells by producing signals. each of them only looks out for one type of pathogen. many are needed to watch for many different diseases or invaders.
t helper cells
they punch holes in the walls of the pathogen cell so that the contents ooze out.
cytotoxic (killer) t cells
phagocytic cells
neutrophil, eosinophil, macrophage
these cells are like the spies. they notice if there is an invader and then present evidence of the invader to T cells in the lymph nodes.
dendritic cells
produce antibodies, which lock onto the antigen of invading bacteria and immobilise them until the macrophage consumes them.
b cells
when the infection is gone, the immune system needs to be calmed down (or the killer cells may keep killing). the [ ] slow down or turn off the immune system to prevent damage to good cells.
suppressor t cells
open up vessels & increase blood flow
basophils
proinflammatory chemical-secreting cells
basophil and mast cell
