ARS 4 Flashcards
(24 cards)
epo
stimulates all RBC development, made by renal cells
gm-csf
stimulates granulocyte and macrophage development, made by lymphocytes, endothelium, fibroblasts
g-csf
stimulates granulocyte development, made by macrophages, endothelium and fibroblasts
il-3
stimulates all myeloid cells, made by t-lymphocytes
thrombopoetin
stimulates production of platelets, made by liver and kidney
erythropoesis
7 days (5 as blasts, 3 as reticulocyte), 120d lifespan. early: large with large nucleus and royal blue cytoplasm, nucleoli stains lighter blue - nucleolus disappears, cytoplasm becomes gray or blue/red - eosinophilic, more heterogeneous - lose granules, nucleus condenses and cell shrinks.
site of erythropoiesis
prenatal: yolk sac, liver, spleen; then bone marrow rises until birth - 100% cellularity. postnatal: by 50yo vertebrae and pelvis, sternum and ribs, tibia and femur in young adult.
megakaryopoiesis
7d, microtubule- and dynein-filled megakaryocytes extend processes out, bud off platelets into sinuses, last 7d in circulation; can have some rER
bone marrow architecture
stroma: reticular fibers and adventitial cells close to endothelium of sinuses, fat. Red=active, less fat, more cell production. Yellow: inactive, relatively more fat. aplasia-fat but also amorphous material/CT replacing cell-making cells
marrow lines
neutrophils 60%, erythrocytes 20%, lymphocytes 15%, eosinophils 3%
stratum basale
deepest layer, single cell cuboidal or low columnar, basophilic due to abundant ribosomes. mitotic activity for all other layers (keratinocyte SCs), cells synthesize keratin to form filaments. melanocytes produce melanin that gets packaged into melanosome caps for keratinocytes.
stratum spinosum
cells attached via desmosomes results in spiny appearance, cuboidal or flattened cuboidal, mostly squamous at top, thickest layer (3-4 cells). cytoplsmic tonofibril keratin bundles attach to desmosomes attachment plaques
stratum granulosum
1-3 layers of flattened, nucleated cells: cytoplasm has keratinohyaline granules w/ filaggrin proteins to adhere keratin in tonofibrils together, lamellar bodies secrete lipid via exocytosis into interface with stratum corneum for waterproofing
stratum corneum
superficial layer of dead anucleate keratin-filled cells; deepest have desmosomes to protect/resist abrasion/act as barrier from lipid coating.
stratum lucidum
extra layer between stratum granulosum and stratum corneum with solid, light-appearing cells in thick skin
melanocytes
originate from neural crest, produce melanin which causes dark skin (not more melanocytes)
langerhans cells
originate from bone marrow, antigen-presenting cells in all living layers; initiate cutaneous hypersensitivity reaction/contact allergen dermatitis; pale staining, dendritic processes and birkbeck granules.
merkel’s cells
modified keratinocytes in basal layer, part of merkel’s disk (mechanosensory receptor in dermis)
dermis
papillary layer: thin loose Ct, abundant collagen, dermal papillae
reticular layer: dense irregular CT, less cellular, more fibers, type I collagen, elastic and reticular.
subcutis/hypodermis
contains glands and adipose tissue, divided into lobules, lots of vessels/nerves
sweat glands
merocrine secretions from simple coiled tubular
eccrine: regular sweat, evaporative cooling, simple cuboidal epith. and stratified cuboidal duct
apocrine: associated with hair follicles in axillae, anogential, skin, middle ear, eyelid and breast.
sebaceous gland
simple branched acinar, holocrine secretions of sebocytes
mammary glands
modified sweat gland in superficial fascia (subcutis) with merocrine secretion for protein and antibody, apocrine for lipid.
stomach
glands: parietal cells (eosinophilic, hcl and intrinsic factors), chielf cells:
