lymphatic and immune Flashcards
what are the functions of the lymphatic system?
- fluid recovery: filters blood capillaries into the tissue spaces (back to venous circulation)
- Immunity: excess filtered fluid picks up foreign cells and chemicals from tissues
- lipid absorption: lacteals in small intestine absorb dietary lipid that aren’t absorbed by blood capillaries
what is lymph?
the recovered fluid
what is lymphatic tissue?
composed of aggregates of lymphocytes and macrophages that populate many organs in the body
what is lymphatic vessels?
transport the lymph
what do lymphatic organs do?
defense cells especially concentrated in these organs
what is lymph?
- clear, colorless fluid, similar to plasma, much less protein
- originally ecf
what are the layer of the lymphatic vessels?
-tunica interna: endothelium and valves
-tunica media: elastic fibers, smooth muscle
-tunica externa: thin outer layer
what are lymphatic capillaries?
- they penetrate tissues
- contain a one-way valve
- made of endothelial cells
what are the 2 collecting ducts that make up lymphatic vessels?
- right lymphatic duct: lymph from right arm to right subclavian
- thoracic duct: lymph from diaphragm to left subclavian
what is the flow of lymph?
- moved along by rhythmic contractions of lymphatic vessels
- flow aided by skeletal muscle pump
- arterial pulsation rhythmically squeezes lymphatic vessels
- thoracic pump aids flow from abdominal to thoracic cavity
what are the different types of lymphatic cells? what do they do?
- natural killer: attack and destroy bacteria
- T cells: mature in thymus
- B cells: proliferation and differentiation into plasma produce antibodies
- dendritic: into APCs, alert immune system
- reticular cells: contribute to stroma
- macrophages: phagocytic, into monocytes
what are the types of lymphatic tissue?
- diffuse lymphatic tissue: scattered, in body passages, open to exterior, MALT
- lymphatic nodules: dense masses of lymphocytes and macrophages
what are aggregated lymphoid nodules?
dense clusters in the ileum, the distal portion of the small intestine
what are the 2 types of lymphatic organs?
- primary lymphatic organs: where T and B cells became immunocompetent (RBM and thymus)
- secondary lymphatic organs: immunocompetent, (lymph nodes, tonsils and spleen)
what do lymph nodes do?
- cleanse the lymph
- act as a site of T and B cell activation
- enclosed with fibrous capsule
- lymph leaves node through one of 3 efferent lymphatic vessels
What does the Thymus do?
it houses developing T-lymphocytes
what is lymphadenitis?
swollen, painful, node responding to foreign antigen
what is lymphadenopathy?
a collective term for all lymph nodes disease
what is metastasis?
cancerous cells break free from original tumor, travel to other sites in the body, and establish new tumors
what are tonsils:
patches of lymphatic tissue located at the enterence to the pharyns
what are the different sets of tonsils?
- pharyngeal
- palatine
- lingual
what ate the function of the spleen?
- Healthy RBCs come and go
- erythrocyte graveyard
- highly vascular and vulnerable to trauma and infection
- white monitors blood
what is MALT?
mucosa-associated lymphatic tissue
What are the types of Internal Defenses?
- immune cells
- antimicrobial proteins
- inflammation
- fever
what is a pathogen?
agents capable of producing disease
What is an innate defense?
- guard equally against a broad range of pathogens
- they lack capacity to remember pathogens
- local, nonspecific, lacks memory
What are the three kinds of innate defenses?
- protective proteins
- protective cells
- protective processes
What is adaptive immunity?
- body must develop separate immunity to each pathogen
what are antimicrobial proteins? and what are the 2 types?
- attack microbes or hinder their ability to reproduce
- interferons
- complement proteins
what are interferons?
Viral infected cells secrete interferons
- induce other cells to secrete Anti-viral proteins
- activate macrophages and mobilize NK cells
what is immunity?
resistance to disease
What is the first line of defense?
skin and mucosa
what is the function of the mucous membranes?
mucus traps, lysozyme