Intro to Immuno Flashcards
primary sites for immune system
these are regenerative or central and contain developing lymphocytes
Example of bone marrow and thymus
secondary sites for immune system
peripheral sites that contain more mature cells for fighting infection
Examples are spleen, lymph nodes and MALT (mucosal associated lymphoid tissue
hematopoeisis
growth and maturation of blood cells in the bone marrow
is in all bones when developing but as adult it shifts to being in flat bones like ribs and sternum
some antibiotics decrease activity of the bone marrow
thymus
bi lobed organ in upper anterior thorax, involutes early in infancy
brings cells in through blood and out through lymphatic or blood vessels
site of maturation and selection of T cells
sail sign on chest Xray
sign of the thymus on the right hand portion of thorax in an infant
spleen
in upper left quadrant of abdomen under the diaphragm
divided into white pulp and red pulp sections
trauma, cancer, sickle cell all lead to risk of spleen loss and immuno compromised individual
White pulp of spleen
has the lymphocytes, T cells near arterioles and B cells are more peripheral
red pulp of the spleen
involved in breakdown of RBCs
odd numbered organ
The spleen is 1 inch x 3 inches x 5 inches in dimensions
The spleen is usually about 7 ounces in weight
The spleen is found under ribs 9 and 11 (i.e. its surface anatomy)
lymph nodes
tons of them in human body
have an outer capsule with many afferent (coming in) vessels and one efferent (going out) vessel
usually the first organ center to encounter a pathogen
grow in size due to pathogen stimulating large production/recruitment of immune cells
regions of lymph nodes
cortex- cell aggregates called follicals that are germinal centers
paracortex
medulla
palpable lymph nodes
cervical, axillary, occipital, epitrochlear, inguinal, femoral, popliteal
good to palpate because can direct you to site of infection…if popliteal swollen then prob somewhere in lower leg
cervical lymph nodes
located in head and neck
drain from scalp, face, nasal cavity, and pharynx
Axillary lymph nodes
location is axilla
drain from arm, chest wall and breast
Mediastinal lymph nodes
in or near the mediastinum or central posterior thorax
drains mid chest, upper abdomen and lungs
Hilar lymph nodes
located near hilum of lungs, central near mediastinum
Drains the lungs
Look for TB malignancy or fungal infection if inflamed
Celiac lymph nodes
located near celiac artery
drains liver, stomach, spleen, pancreas, upper duodenum
mesenteric superior/inferior lymph nodes
located in lower abdomen near intestines
drains small and large intestine to splenic fixture (superior) and then splenic fixture to the rectum (inferior)
para-aortic lymph nodes
near aorta
drains testes ovaries kidneys and uterus
iliac, external and internal lymph nodes
near illiac artery
drains cervix, upper bladder, body of uterus, lower rectum and vagina, cervix and prostate
superficial inguinal lymph nodes
located in groin
drains genitalia, buttock/anus, abdominal wall, legs
popliteal lymph nodes
located in posterior leg near knee
drains lower leg and foot
MALT
mucosal associated lymphatic tissue…can be GIm respiratory, and urogenital
make a ton of the antibody producing cell population
GALT
gut associated lymphatic tissue
includes tonsils, adenoids, appendix, Peyers patches
peyer patches
patches of mucosal lymphatic tissue in the GI tract where M cells help secrete into lumen
BALT
bronchial/tracheal associated lymphatic tissue
NALT
nose associated lymphoid tissue
VALT
vulvovaginal associated lymphoid tissue
lymphatic system
separate from circulatory system
has white blood cells and plasma and lymph
not a circular system…no pump
functions of lymphatic system
collect/drain excess fluid from surrounding tissues and return to vascular
absorb fat from villi of small intestine
conduit for immune cells
lymphatic drainage
initiated by uptake of interstitial fluid in lymphatic capillaries
flow through nodes and finally into blood circulation
two quadrants of the lymphatic system
upper right quadrant that drains into the right subclavian vein
upper left and lower body quadrant that drains into the thoracic duct and into left subclavian vein
virchow’s node
the left supraclavular node, is often first palpable site from abdominal malignancies and infections
lymphedema
interstitial collection of lymph due to disruption of lymphatic flow, usually not symmetric
usually progressive, can lead to hypertrophy or fibrosis
swelling, skin changes, restricted range of motion
primary lymphadema
genetic/inheritance
presents at any age
secondary lymphadema
due to underlying disease or prior treatment
most often due to malignancy or cancer treatment in USA, like masectomy messing up the axillary region nodes
Etiology is obstruction of lymphatic vessels or nodes, can be compression by a tumor
Filariasis
worldwide is most common secondary lymphadema cause…
due to a helminth…nematode Wuchereria bancrofti
transmitted by mosquitoes, adult worms mainly reside in lymphatic vessels in legs or male scrotum
diagnosis of Filariasis
identify the microfilariae on thick smear of blood taken between 10PM and 2AM
treatment of filariasis
goal is to kill the adult nematode..done with diethylcarbamazine citrate
lymphangitis
inflammation or infection of the lymph vessels
site of infection usually distal to affected vessel
strep pyogenes is common…use antibiotics
chylothorax
accumulation of lymph in thorax…usually after cardiac surgery where surgeon clips the thoracic duct and it leaks
lose a lot of immune cells, anitbody supplements sometimes needed
lymphadenopathy
enlargement of 1 or more lymph nodes…localized is one and generalized is 2 or more
can be associated with malignancy, infection, inflammatory disorders (autoimmune)
lymphadenitis
lymphadenopathy with pain or signs of inflammation (red/tender)
means active infection
lymphoma
type of cancer with immune cells
neutrophil
innate, live 2 days
WBC granulocyte
engulf bacteria and fungi with phagolysosome..oxidative burst
monocyte/macrophage
innate
WBC mononuclear, live in blood for day or so as monocyte then grow to macrophage in connective tissue
engulf bacteria, fungi and cellular debris, make cytokines, antigen processing/presenting
eosinophil
innate
WBC granulocyte
associated with allergic response and parasitic infection
basophil
innate
WBC granulocyte
associated with hypersensitivity and releases histamine
mast cell
innate
bone marrow
granules contain vasoactive amines like histamine, proteases can kill bacteria
natural killer cell
innate
WBC lymphocyte
recognize stressed or infected cells and kills them by secreting macrophage activating cytokine
B cells
adaptive
WBC lymphocyte
plasma and memory cells, specific recognition of antigens as mediator of humoral immunity
T cells
adaptive
WBC lymphocyte
helper, cytotoxic, regulatory, and memory
recognize antigens as medator of cell-mediated immunity
B lymphocytes
neutralize a microbe, phagocytosis, and complement activation
Helper T lymphocytes
activate macrophages, inflammation response, activate and differentiate B and T cells
cytotoxic T cells
kills infected cells
regulatory T cells
suppresses the immune response
natural killer cells
kills infected cells..innate
dendritic cells
are antigen presenting to initiate T cell response
phagocytic
derived from bone marrow
follicular dendritic cells
mesenchymal derived
antigen presenting to B cells in humoral response
cytokines
proteins made and secreted by immune and non immune cells that act as intercellular mediators important for biological responses
Bind to signal receptors on target cells that make cascade and have an effect on the cell
can be autocrine, paracrine and endocrine
autocrine cytokine example
T cells make IL-2 which stimulates proliferation of same cells
paracrine cytokine example
t cell activates a macrophage by interferon gamma
endocrine cytokine example
GM-CSF made by T cells in enough amount and will go to granulocytes to increase production from bone marrow
JAK-STAT pathway
major signaling pathway in immune system
stands for Janus Kinase Signal Transducer and Activator of Transcription
JAK activated at membrane then in turn activates other molecules including STAT
STAT is then a TF that helps transcribe mRNA for proteins that make cell function in specific way
important pro inflammatory Cytokines!!!
TNF-alpha
IL-1
IL-6
all innate
Important Innate cytokines
TNF-alphs, IL-1, IL-6, IL-12, IFN-alpha and beta, IFN-gamma
important adaptive cytokines
Th-1 cells: IL-2, IL-3, IFN-gamma
Th-2 cells: IL-4, IL-5, IL06, IL-10, TGF-beta
hematopoesis cytokines
IL-3, IL-7, M-CSF, G-CSF, GM-CSF
chemokines
small chemo attractant molecules that cause cells to migrate towards a concentration gradient of the chemokine
notably have cysteine AA residues
groups are CC, CXC, C, and CXXXC where X is any other amino acid
CXCL8 recruitment
chemokine that recruits neutrophils
CXCL2 recruitment
chemokine that recruits naive T cells
CCL2
chemokine that recruits and activates macrophages
