Histo recap ++

• HS testis


  -Endocrine + exocrine -> secrete sperm and testosterone

  -Tunica vaginalis: mesothelium + CT layerblend w CT of scrotum + testis

  -Tunica albuginea; dense collageous tissue, has many bv and testicular arteries and a network of anastomosing veins.

  -Vaginal cavitie = separate parietal and visceral layer
• Intratesticular ducts


  -Straight tubules + rete testis (labyrinth like): carry spermatozoa from semineferous tubules to duct of epididymis

  -Tubuli recti: short straight that carry sperm from semineferous tubules to rete testis

  -Ep= Sertoli cells near semineferous and cuboidal cells near rete testis

  -Absorption + ciliary activity = fluid flow that bring sperm to the epididymis
• Extratesticular ducts

  -Efferent duct: rete testis open in 7-8 efd, short and coiled w pseudostrat col ep, ep cells lining duct are ciliated

  -Epididymis: end of efd receive sperm from efferent duct, pseudo start col ep w large microvilli, princip cells secrete glycolipids/glycoprot, absrobs water and debris thx stereocilia, overall diametre enlarge in time.

  -Ductus defferens: extraepididimal continuation, brind sperm from epididymis to ejaculatory duct, surrounding by CT, sm m cells are served by axons, lumen has a sim col ep on a CT layer.
• Spermatic cord 


  -carry prin (testi) artery to blood organ and veins

  -arteries and veins side to side, blood flow in opposite directions=optimized

  -sperm t>corp t

  -arterie divid in apex to vascularized tunica albuginea
• Vesicular gland or seminal vesicles 


  -2 of them, very coiled tubes (15cm), enclosed by CT capsule

  -Mucosa has thin folds, glandular ep pseudo strat col cells and basal cells, lamina propria contain elastic fibers

  -produce a yellow fructose-rich liquid that up to 70% of ejaculation
• vesicle gland: protaste

  -Are arranged in 3 zones:

  transition zone: periurethral mucosal galnd

  central zone: 25% of gland's tissue + periurethral submucosal glands

  peripheral zone: 70% of organ's tissue, prostate main glands
• vesicular gland (bulbourethral gland)


  -gland tubular (boars, cats), tubuloalveolar (stallions, rams), abs (dogs

  -secretory portion have simp col epit + basals cells dep of testosterone

  -gland is sheated by fibroelastic caps containing str m fib.

  -release clear mucus to lubrificate during erection
• HS penis

  -3 cylindrical masses of erectile tissued, contain cavernous spaced filled with endoth

  -penile uretra is lined pseudostrat col ep, in glans become strat sq ep

  -glans covered by the prepuce, retractable fold w sebaceous glandson internal surface

  -os found in carni, triangular, internal space filled with marrow

  -surface skin: start sq keratinized ep
• HS renal cortex & renal medulla

  Cortex:

  -darker red, large nb of renal corpuscules w round structure contain bv

  -renal corpuscules= blood filtration+iitial stage of urine, bulk has various types of tubules

  -structure contain straight and convoluted tubule seg

  Medulla:

  -inner lighter, no reanl corpuscules, striated + segmt to radiate the medulla containing cortical collecting ducts

  -cortical labyrinth contains irregular profile sof convoluted tubues

  -contains bv, pro+straight tubules, collecting ducts, loop of Henle

  -tip of each pyramid = renal papillae
• HS ureter, urinary bladder and urethra

  -Ureter: ep on basal laminae , has a support of CT, muscular wall of 2 layers of sm m cells, folding ep from tonus m, lumen dilates under pressure for urine

  -Urinary bladder: storage organ for urine, wall similar to ureter but 3 layers, elastic CT in wall for elasticity, urinary ep is folded

  -Urethra: carry urine from bladder to exterior, lined w transitionnal ep, then by st sq ep. In men 2 ductsfor sperm transport, consist of 3 segmet:

  *protastic urethra

  *membranous urethra

  *spongy urethra
• Blood supply of the kidney

  -role to filter the blood, flow thx to urine formation, interrupt° of blood flow =renal faillure, each kidney has a single renal arterie

  -arcuate arteries=interlobar arteries from variable vessel, supply glomeruli, one afferent correspond to one glomerulus.

  -blood leaving glomerulus does not do so in a vein, but in an artery
• HS liver=largest organ+largest gland, excretion/secretion/storage, synthetisis/phagocytosis


  -hepatocytes: cells of synthesis, storage and secretion, spherical nucleus, 25% are binucl, numerous lysosomes, developed rer and ser

  -bile canaliculi and bile duct: bile secreted in caniculi, function of emulsifing lipids in duo, caniuli lined by cub ep cells = cholangiocytes, small ducts lined w simp cub to col ep, larger duct is stratified

  -blood supply: blood from portal vein/hepatic artery, venous input is larger of 2 vessels, anastomosing sinusoids have thin linings of fenestrated endo cells
• HS pancreas

  -exocrine + endocrine organ

  -each lobule has secretory units, apical rgion contains zygomen granules

  -pancreatic islets are islets of Langherans=spherical masses of endocrine cells, surrounding by tthin capsule of CT, 4 major islets: alpha cells, beta cells, delta cells and PP cells

  -into lumen of acinus there are flattened cells= centro-acinar cells
• HS gallbladder


  -store bile produced in liver, tubular organ, folded mucosa

  -ep of tunica mucosae is tall simp col convered w microvili, goblet cells + endocrine cells

  -there is o muscularis mucosae that's a landmark of this organ
• HS bone marrow (=myeloid tissue)

  -red or yellow (blood or fat)

  red: form blood cells excepted lymphocytes, reach the maturation in lymphoid organs destruct° of old RBC

  yellow: storehouse for fat, may be converted to red marrow, only found in vetebrae, hips, ribs, ect in adults

  -space btw trabeculae r continuous w main marrow cavity in diaphysis and contain marrow marrow cavity + spaces among traberculae r lined w thin layer of mixed cells = endosteum
• HS thymus

  -covered by a thin CT capsule, thymic lobule in dark staining, cortex + lighter medulla

  -it's not a site of of antibody production so germinal center, thymic lobules well demarcated by CT , lobulat° is incomplete

  -BV enter thymus through capsule+travel along septa, then enter parenchyma.
• HS bursa of Fabricius

  -peculiar to birds, blind sac'like structure on side of cloaca, wall is made of 3 layer: mucosa, muscularis externa and serosa

  -central lymphoid organ that seeds B lymphocytes to germinal centers of peripheral lymphoid tissue+spleen

  -aggregation of lymphocytes=follicles, densely populated outer cortex+inner sparsely. Free surface on avian bursacovered w col ep.
• HS lymph nodes

  -lymph nodes: organized, shape like beans, w hilus where bv enter and leave, nodes, in cortex is organized lymphatic tissues, in medulla is loosely spaced lymphocytes, medulla contain T+B lymphocytes

  -lymph flow: at leats 1 afferent vessel, medullary sinuses r continuous w cortical sinuses, valves permit onlyone-way flow

  -blood flow: enters via arterioles, suplly blood to medullary cords + cortex, which have capillary plexuses
• HS spleen

  -large pop of lymphocytes, filled w reticular tissues, contain blood cells, macrophage and ACP, is a dispensible organ, function as a reservoir of erythrocytes, splenic pulpe has 2 components: white pulp (20%, small masses) and red pulp

  -blood flow: splenic artery, ramifie in capsule and send branches deeper, central arterioles = arteries surrounding by PALS, junction of terminal capillaries has 3 theories: open, close, compromise
• Blood flow theories

  -> open theory: no direction, cords as filters, capillaries en dby oppening in into splenic cords

  ->closed theory: arteries end in capillaries bed so loop is closed, cells in splenic cords get blood from sinusoids

  ->compromised theory: both ends, when need erythrocyte, connect° btw arteries and veins takes over
• Peyer's patches


  -aggregated lymphatic nodules in small intestine

  -in young R,P,C = a single in distal jejunum/ileum.

  -is a large cluster of lymphoid nodulesin wall of ileum, has a role of diversification of preimmune antigen recpetors repertoire + expansion of early B-cell pop
• HS heart + layers

  -heart: m organ, cardiac m in 4 chambers, wall chambers=3 major layer: internal endo, middle myo, ext epi

  -endocardium: thin layer of endo cells rest on a layer of collagen fibers, thicker layer deeper of CT (elastic and sm m fibers), also find modified cardiac m fib

  -myocardium: thickest layer, mainly cardiac m w fibers arranged spirrally around each chamberm bundles r oriented for most efficiency use of force of contraction, each cell have a single nucleus

  -epicardium: thin serous mb, inner portion of Ct+allow heart to move, simp sq mesoth w cells secrete lubrificant.
• HS capillaries


  -small vessels, 90% of body vascularization, optimize change btw vein and tissues, associated w perivascular contractile

  -diff types:

  ->closed: move material in/out using a process of endocytosis+exocytosis

  ->continuous: well-dvp occluding junct° btw overlappg endothelial cells

  ->fenestrated: more extensive molecular exchange accross e,dothelium, found in endocrine organs, rapid mvmt

  -> discontinuous: sinusoids, max exchangeof macromol, easier mvt btw tissue and blood
• Epiphysis (pineal gland)


  -cone shape structure in brain, parechyma = pinealocytes+astrocytelike

  -blood brain barrier isnt functionl, pinealocytes secretions easy access to capillaries

  -95%=pinealocytes, large highly stained, round nucleus, pinealocytes share a gap junction + extend axon, have secretory vesicles, produce melatonin in dark phase