Chapter 22: Lymphatic System Flashcards
2 types of immunity
- innate immunity
- adaptive immunity
What does the lymphoid system consist of
several structures and organs that contain lymphatic tissue, bone marrow, and fluid called lymph plasma that flows within lymphatic vessels
Lymph nodes attach to
lymph vessels
Functions of lymphatic system
- drain excess interstitial fluid
- transport dietary fats
- carries out immune responses
Lymphatic vessels begin as
lymphatic capillaries which are closed on one end
Lymph vessels are like veins because
they have valves and the fluid travels only one way
Where does lymph travel to after lymph vessels
lymph plasma passes through lymph nodes and then into lymph trunks
What do lymph trunks include
lumbar trunks, intestinal trunks. bronchomediastinal trunks, subclavian trunks, and the jugular trunks
What do lymph trunks do?
returns lymph plasma to the venous system independently or via merged structures called lymphatic ducts
Lymph plasma enters the venous flow at the
subclavian veins
Formation and flow of lymph
interstitial fluid –> lymph capillaries –> lymph vessels –> lymph trunks –> lymph ducts –> subclavian veins
What are primary lymphatic organs and examples
primary lymphatic organs are organs where immune cells become immunocompetent
- red bone marrow (in long bones)
- thymus
Medulla, cortex, and capsule
- medulla: center
- cortex: outer layer
- capsule surrounds whole
Secondary lymphatic organs and tissues
lymph nodes, spleen, lymphatic nodules
eg: tonsils, aggregated lymphoid follicles, mucosa-associated lymphatic tissue (MALT)
Where do immunocompetent lymphocytes live while they wait for foreign antigens
secondary lymphatic organs and tissues
Where do adaptive immune cels form and become competent
primary lymphatic organs
Structure of a lymph node
contains many different types of white blood cells which are used for specific antigens
Spleen function
- filters bacteria that enters the blood
- removes dead or damaged rbcs
- where wbcs reside
What are lymph nodules
are masses of lymphatic tissue that are not surrounded by a capsule
Where are lymphatic nodules found
scattered throughout lamina propria of mucous membranes lining the gastrointestinal, urinary, and reproductive tracts and the respiratory airways
- also referred to as MALT
Innate immunity
refers to a wide variety of body responses that serve to protect us against invasion by a wide variety of pathogens and their toxins
- provides non-specific protection
- born with it
- acts immediately
Which two lines of defense does innate immunity include
- skin and mucous membranes
- internal defenses
Skin and mucous membrane defense types
- mechanical defenses and chemical defenses
Mechanical defenses of skin and mucous membranes (innate immunity)`
- skin
- mucous membranes
- tears
- saliva
- cilia
- epiglottis
- urine flow
- defecating
- vomiting
What do tears and saliva contain
tears and saliva contain an enzyme called lysozyme which helps kills bacteria
- tears wash away the bacteria
Chemical defenses of skin and mucous membranes (innate immunity)
sebum, lysozyme, gastric juice
Internal defenses of innate immunity
- anti-microbial proteins
- phagocytes
- natural killer cells
- inflammation
- fever
Anti-microbial proteins (internal defenses of innate immunity)
have broad-spectrum antimicrobial activities and attract dendritic cells and mast cells
Phagocytosis (internal defenses innate immunity)
- chemotaxis (movement of particle)
- adherence; binds to microbes
- ingestion: forms vesicle phagosome
- digestion
5, killing
