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Kidney: The tubular part of the nephron: -proximal convoluted tubule -loop of Henle -distal convuluted tubule with macula densa Urinary bladder Female Reproductive System. Review renal corpuscle The proximal convoluted tubule: -simple cuboidal epi.
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Kidney: The tubular part of the nephron: -proximal convoluted tubule -loop of Henle -distal convuluted tubule with macula densa Urinary bladder Female Reproductive System
Review renal corpuscle • The proximal convoluted tubule: -simple cuboidal epi. • -tortuousdescending thick limb of Henle’s loop • (can descend into medullary ray) • PCT: -brush (striated) border ragged in paraffin • -occluded lumen in paraffin • interwoven lateral mbs, no distinct lateral mb by lm • Low cuboidal high almost columnar
What happens in the PCT? • Na is actively pumped to the serosal surface • chloride follows to preserve electrical neutrality • Water follows to maintain osmotic equilibrium Thin loop of Henle -simple squamous epit -length is long in juxtamedullary nephrons -descending is permeable to water, urea, Na, Cl etc. -ascending is not permeable to water Counter current if too much water is in blood
Ascending loop of Henle, thin segment and thick segment Thick segment is not permeable to water…let water stay DCT – short, lumen wide open, low cuboidal, granular cytoplasm -impermeable to water, urea Lots of hormonaly regulated (aldosterone) ATPase to re-absorb more Na to blood if req’d More ionic regulation here
Juxtaglomerular appartus: • -macula densa of DCT (tall cells) • -juxtaglomerular cells adjacent to afferent arteriole (sm mus) • -Extraglomerular mesangial cells (glomerulus) • No basal lamina between macula densa and juxtagl. cells • 2. Juxtaglomerular cells (round nuclei) • are modified smooth muscle cells in the afferent arteriole t. media • Contain granules with renin, angiotensin converting enzyme (ACE), • Angiotensin I and angiotensin II used for stimulating aldosterone • Secretion, vascular sm muscle contraction, thirst. • The extraglomerular mesangial cells are continuous with the • glomerular mesangial cells
Juxtaglomerular apparatus: communication within the kidney • -teenie things • Can regulate the amt of water being filtered, slow or fast • Open afferent arteriole lots of blood comes in • Close afferent arteriole little blood enters • Macula densa monitors filtrate volume & Na conc. • If Na is low in DCT • stimulate macula densa • Dilation of afferent arteriole (sm muscle relaxation) • More blood flow to glomerulus Also: instruct JG cells to release renin into circulation
Macula densa instructs juxtaglomerular cells to release • Renin into the circulation. • constriction of efferent glomerular arterioles • Both effects, of dilation of afferent arteriole and constriction Of efferent arteriole blood stays longer in the glomerulus More filtration
Collecting ducts: radial, simple cuboidal • Urinary Bladder: • -dome shaped cells when empty • -transitional epithelium • Lots of tight junctions • Plaques folded when the bladder is empty • Fold out, impermeable during filling
Female Reproductive system: Ovary Uterus Mammary glands
Ovary - hormonal regulation - - follicular development - Graafian follicle - corpus luteum
Ovary - covered by low cuboidal epithelium (germinal epi.) - cortex - stroma with fibroblasts - ovarian follicles--> development and atresia
Ovarian follicles - primordial follicle - primary follicle - secondary follicle - Graafian follicle - corpus luteum
Primordial follicle - primary oocyte (prophase or meiosis I) and simple squamous follicular cells
Primary follicle - enlarged oocyte (nucleus up to 150 mm) - simple cuboidal follicular cells --> stratified cuboidal --> granulosa cells / bl Zona pellucida During follicular dev., gap junctions between follicular cell filopodia and oocyte microvilli. Stroma cells --> theca interna -vascularized, secrete androstenedione --> theca externa (fibrous)
Secondary follicle - FSH stimulates granulosa cell proliferation --> liquor folliculi between granulosa cells --> antrum is space with coalesced liquor folliculi --> corona radiata around oocyte - FSH stimulates expression of LH receptors on granulosa cells
Graafian follicle: - can see on slide with unaided eye - cumulus oophorus: oocyte +corona radiata + attached follicular cells LH surge --> increased blood flow to ovaries --> edema (leaking plasma) in theca externa also: completion of meiosis I and then meiosis II --> ovulation of secondary oocyte and few follicle cells
Corpus luteum: Continued high LH Collapse of remaining Graafian follicle --> granulosa lutein cells produce progesterone & convert androgens to estrogen --> theca interna---> theca lutein cells produce progesterone, androgens & estrogen produce progesterone & convert androgens to estrogen
High levels of progesterone & estrogen --> LH and FSH secretion inhibited --> lower FSH prevents follicular dev. If pregnancy occurs, placenta secretes human choriogonic hormone (HCG), which maintains the corpus luteum.
Atretic follicles: - most follicles degenerate before maturing -