SUGER Flashcards by Katie Newton

KIDNEY

pale cortex / dark medulla / 10-15 meduallary pyramids
cortex contains glomeruli and coils of proximal/distal tubules
medulla contains pyramids with straight parts proximaal/distal tubule, loop of Henle, collecting duct

Blood

5/6 branches renal artery
arcuate arteries at medullary/cortical border (give off vasa recta - deep to medulla)
then interlobular arteries penetrate cortex at regular intervals
affertent to glomerulus
efferent from glomerulus (filtered blood) - thin walled and between tubules
acquire fluid and ions -> drain to arcuate veins -> systemic

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GLOMERULUS

blood to glomerulus for filtration
passes primary filtrate to nephron for selected reabsorption
parallel array of fenestrated capillaries ensheathed by podocytes
between loops = mesangiel cells (matrix forming)
afferent arteriole wall produces renin
next to glomerulus = segment of distal tubule with macula densa

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GLOMERULAR TUFT (PAS)

arise from vascular pole of glomerulus = entrance afferent and exit efferent
in this angle lies a distal loop of nephron with palisade of macula densa
capillary loop surrounded by podocyte
surrounded by urinary space - separates glomerulus from bowman’s capsule
arrow to distal tubule
MACULA DENSA - around blood vessels regulate blood flow, provides framework for glomerulus.

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FILTRATION BARRIER

basement membrane
synthesised and maintaiend by endothelial capillary cells and epithelial cells (podocytes) that ensheath them
endothelial = fenestrated
podocytes stand off membrane with foot processes
creates physical pores
pores guarded by filtration membrane
membrane is charged and resists passage of some molecules
water and solutes may pass to urinary space = primary filtrate

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PROXIMAL TUBULES (PAS)

highly coiled (sometimes with straight projection to medulla)
prominent brush border and complex invaginations @ basolateral membrane dark pink
extensive reabsorption here
Na+ active transport with glucose (cotransporter - GLUT)
take up protein and polypeptide by endocytosis
cells contain lyzosomes which break down proteins before returning to circulation
any small negatively charged protein can enter primary filtrate

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PROXIMAL TUBULES 2 (PAS)

this slide - straight portion of proximal tubule
leads to loop of Henle
if glomeruli present = cortex
some project to medulla

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LOOP OF HENLE (PAS)

mostly @ medulla
thick/straight descending, thin loop, thick ascending
thick descend = similar to proximal tubule
thick ascend = similar to distal tubule
longest thin loop penetrate deepest to medulla when glomerulus = cortico-medulla junction
thin descending portion = low permeability to ions and urea, high permeability to water
thin ascending portion retains water, reabsorption Na+ and Cl-
this produces dilute/hypotonic filtrate but a hypertonic interstitium
vasa recta (straight capillaries) run alongside tubules

this slide - thick and thin limbs and vasa recta

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DISTAL TUBULE (PAS)

from medulla to cortex then to vascular pole of glomerulus
macula densa here monitors sodium levels to influence intitial filtration of glomerulus
paler than proximal
deep invaginations of basal plasma membrane with numerous mitochondria
mitochondria indicative of control acid/base balance and concentration of urine (ATP)
with aldosterone sodium reabsorbed, potassium excreted
bicarbonate ions reabsorbed, hydrogen excreted - acidic urine

@ cortex both proximal and distal tubules present

proximal more tightly coiled therefore appear to be more numerous

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COLLECTING DUCTS (PAS)

pale cuboidal cells
wide lumen
starts at cortex, filtrate to collecting tubules than larger ducts
collecting tubules from many nephrons coalesce to larger ducts and form visible streaks - medullary rays
few organelles
collecting tubules - dark intercalated cells with high mitochondria
surrounded by hypertonic medium interstitial from loop of Henle
ADH increases permeability to water (concentrates urine)

prone to kidney stones and infection

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JUXTAGLOMERULAR APPARATUS (PAS)

afferent/efferent arterioles, macula densa, lacis cells
afferent - cells produce renin - granules in cytoplasm
renin catalyses angiotensin 1 (liver) -> angiotensin 2 (conversion at lungs) -> aldosterone release by suprarenal cortex -> reabsorption of sodium and water @ distal tubules and collecting ducts
lacis cells and macula densa regulate renin secretion by monitoring sodium levels

this slide - obvious macula densa

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UROTHELIUM

ureters, bladder and most urethra
pseudo-stratified epithelium
surface cells adapted to withstand prolonged urine exposure
3-8 layers (distension dependent)
basal cells = cuboidal
above = columnar (relaxed)
surface = large, binucleate umbrella cells

umbrella cells:

thickened membrane plates joined by thin membrane bands
lipid composition (unique)
relaxed plated = perpendicular to membrane
stretched = drawn to surface of cell

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URETER

epithelial tube with 2 helical layers of smooth muscle
star shaped lumen
towards bladder = longitudinal smooth muscle
3 constrictions (kidney stones will lodge here)
1. origin (pelvis of kidney)
2. at sacro-iliac joint (passes to true pelvis)
3. as enters postero-inferior bladder surface
reflux prevented by compression of ureter by muscular wall bladder
contains blood vessels and adipose
smooth muscle for peristaltic contraction

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URINARY BLADDER

wall = thick bundles of smooth muscle with no preferred direction except neck = 3 distinct layers
1. innermost = longitudinal projects inferiorly and turns transversely to form a sphincter around prostatic urethre (male) and external meatus (female)

thrown into folds w/ umbrella cells

walls of bladder contains small nerves (autonomic)

sympathetic NS = mainly blood vessels at bladder

inset = nerves

micturition

when external sphincter relaxes (sympathetic) and muscle wall (detrusor) contracts (para)

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PROSTATIC URETHRA

urethra longer in males

prostatic
membranous
bulbous
pendulous

urothelium (pseudo-stratified columnar) except at distal end
mucus glands along length
distal urethra = stratified squamous (male and female)
both sexes = striated (voluntary) muscle sphincter from muscles of pelvic diaphragm around membranous part
under prostatic urothelium = dense fibrous connective tissue to prevent distension

inset = U-shaped prostatic urethra

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TESTES

within collagenous capsule = tunica albuginea
within fibrous septa to 250 lobules (each lobule with up to 4 germ cell producing semniferous (tubules)
semniferous tubule = 50cm loop (open both ends)
drain to rete testes (channels)
Leydig cells between semniferous tubules

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SEMNIFEROUS TUBULE

stratified epithelium with support (sertoli) and germ line (developing spermatazoa)
at periphery = germinal epithelial
GE produces large cells with speckled chromatin = spermatagonis
spermatogonia develop to spermatocytes
spermatocytes pass blood testis barrier created by Sertoli
Sertoli = blood testis barrier and nurture sperm
production = 64 days
maturation wave passes slowly down each tubule

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SEMNIFEROUS TUBULES

thin fibrous capsule
closest to membrane = germinal epithelium with spermatogonia (speckled)
between cells are smaller primary spermatocytes and Sertoli cells (pale irregular nuclei)
towards centre depends on stage in cycle
sometimes primary/secondary spermatocytes (small dense nuclei)
otherms more mature (narrow and elongated heads)
between tubules = leydig clumps

arrow to spermatid

reduction division (2n-1n -> first meiotic) takes place when primary to secondary @ luminal side of blood testis barrier i.e. not in contact with blood stream

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EPIDIDYMIS

rete testis = cuboidal ep
rete testis to efferent ductules (similar)
epididymis = single 5m coiled tube
thick fibrous capsule attached to mediastinum of testes posteriorly - storage and maturation site for sperm aggregated within lumen
tall pseudo-stratified columnar ep
small rounded basal cells support tall columnar with microvilli (stereocilia)
stereocilia (non-motile) reabsorb seminal fluid, phagocytose damaged sperm and cell debris. also nutrients for sperm
thin layer of smooth muscle thicker as approaches vas

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VAS DEFERENS

spirally arranged smooth muscle
similar to epididymis but shorter cells and microvilli
sometimes has longitudinal folds - lamina propria
sudden and rhythmical contraction expels sperm

thick muscular wall makes vas feel cord like

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SEMINAL VESICLE

highly coiled glands at postero inferior bladder
double layered capsule of smooth muscle
long narrow folds
stimulated by testosterone - enlarge and secrete creamy opalescent fluid with acid pH. rich in globulin, vitamin C, amino acids and sugars
contraction of smoooth muscle mixes with spermatozoa
simple columnar epithelium

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PROSTATE

50 branched tubular glands
smooth muscle matrix
smooth muscle capsule around all
3 layers (concentric) of glands - mucosal - submucosal - main
@ ejaculation, contract and mix secretions @ ejaculatory duct

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PROSTATIC EPITHELIUM

glands varied - straight, coiled, branched
epithelium thrown into broad, branching folds
with testosterone, cells increase in height and secrete digestive enzymes - acid phosphatase (major component of seminal fluid) - (PSA) prostate specific antigen
lumen often with sec product / calcified glycoprotein

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PROSTATE 2

this slide L - skeletal muscle at underside of prostate - pelvic diaphragm with levator ani
this slide R - spiral tubular gland at submucosal level

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PENILE URETHRA

prostatic, membranous, penile
membranous and penile = non-secreting pseudostratified columnar
at distal end = stratified squamous epithelium (within glans)
bulbo-urethral glands within membranous urethra produce watery galactose rich secretion, precedes main ejaculate - can sometimes be a problem with catheterisation

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PENIS * erectile compartments = large endothelium lined blood vessels supported by connective tissue * each surrounded by compact collagen layer = **tunica albuginea** * helicine branches of pudendal artery * when flaccid arteries transmit very little blood due to **artero-venous shunts** * para. stimulus shut shunts (point and shoot) * most skin = hairy, loosely attached to columns - except prepuce and glans (non-kerat)

VAGINA * stratified squamous thinly keratinised at vulval end * thin pre-puberty and post menopause * beneath epithelium = lamina propria with small blood vessels (moisture by diffusion) * surrounding epithelium = fibro muschular tube with collagen/elastic and smooth muscle * sphincter of skeletal muscle at lower end * **bartholin glands** - mucus posterolaterally at lower end of vagina * with age = weaker fibro-muscular tube

EPITHELIAL SQUAMES * in menstrual cycle surface cells accumulate glycogen and flake off * desquamated cells rupture and bacteria generate lactic acid * low pH at vagina **pale green cells** - outermost layer, predominate at first half of menstrual cycle **pink cells** - deeper layer

CERVIS * protrudes to anterior wall vagina * surrounded by gulley - lateral, anterior, posterior ornices * **outer surface** - SSNKE (identical to vagina) * **cervical canal** (between internal and external os) = tall columnar epithelium thrown into deep gland-like folds * stroma = fibrous connective and smooth muscle * **this slide - external os**

CERVICAL LINING * secretes mucus - consitency of which varies throughout menstrual cycle * **first half** - thin and watery * **second half** - viscous after ovulation as plug to prevent microorganism entry * **transitional zone** - between sensitive cervical lining and other stratified squamous epithelium prone to infection and lesion * **this slide - mucus glands visible**

UTERINE BODY * 3 poorly defined layers **myometrium** smooth muscle * lined by epithelial **endometrium** * myometrium hormonally sensitive **hyperplasia and hypertrophy @ pregnancy** large arteries and veins between inner and middle layers, also supply endometrium and give rise to **spiral arteries** (**significant @ menstruation**)

ENDOMETRIUM * uterus = **simple columnar with tubular glands** **PROLIFERATIVE PHASE** - first half, stroma tickens and length glands increase **SECRETORY PHASE** - second half of menstrual cycle - glands secrete and stroma differentitates to environment for ovum **MENSTRUATION** - most endometrium shef leadving only **bases of glands - MENSES = 4 days**

PROLIFERATIVE ENDOMETRIUM * post menses * 10 days, regrow glands stroma and blood vessels * at end of proliferation = ovulation, then secretory * **TUBULAR GLANDS APPEAR STRAIGHT** and cells do not secrete endometrial mucus * stroma compact * uncoiled arteries and veins * **mitotically dividing cells within glands and stroma** * simple glands (often circular) * loose connective tissue

SECRETORY ENDOMETRIUM * ovulation @ day 14-16 * cells have large **vacuole of glycogen below nuclei** * from these stores syntehsise mucins * glands = irregular / sacculated with secretions @ lumen * stroma oedematous * arteries lengthen and become spiral * @ end (late phase) **spiral arteries close down and blood leaks to stroma** = anoxia therfoer decidua detaches and menses begins

UTERINE TUBES * 10 cm within broad ligament * 4 regions: 1. intramural 2. short narrow isthmus 3. long ampulla 4. wide infundibulum (with fimbria) * lumen varies in appearance * UTERINE = star-shaped * INFUNDIBULUM = complex folds and wide * ciliated - **cilia become longer and beat more strongly soon after ovulation**

UTERINE TUBE EPITHELIUM * two helical layers of smooth muscle (inner circular) and outer (longitudinal) * **simple columnar epithelium - ciliated and mucous secreting** * epithelium is hormonally-sensitive - cels taller and cilia beat more strongly around ovulation * also secretions are thinner and more copioius at this time 1. fertilised at ampulla 2. ectopic pregnancy at uterine tube 3. surrounded by broad ligament and mesovarium connecting ovary and broad ligament

OVARY * surface = germinal epithelium (thick BM) * attached by mesovarium mesentery to upper posterior surface of broad ligament (continuous with ovary) * 3 parts 1. hilum - blood vessels, lymphatics and nerves leave here 2. medulla - stromal cells with testosterone secreting cells (similar to Leydig) 3. cortex - **primordial germ cells and follicles from primary, secondary, atritic** GERM CELL PRODUCTION - to ovary @ w10 of devlopment - immediately start meiosis and reach prophase 1 of meiosis (primary oocutes @ birth) reawakened with each menstrual cycle - up to 20 cells begin to differentiate but only 1 acheives maturation -remainder resorbed ****

FOLLICULAR DEVELOPMENT * @ cortex, many germ cells many = dormant primordial follicles with germ cell in **theca** from stromal cells * **theca** - simple squamous (primordial), later to cuboidal or columnar * then differentiates into **granulosa cells** = theca interna that begin to secrete oestrogen and theca externa (flattened) and follicle becomes secondary * further growth and development -\> mature **Graafian follicle with fluid-filled antrum** * follices perish as atritic * once oocyte released from Graafian follicle theca persists and releases oestrogen and progesterone as **corpus luteum** **this slide - primordial follicles**

FOLLICULAR DEVELOPMENT 2 * TL - secondary follicle * TR - primary follicle * BL - mature graafian follicle * BR - primordial follicle

CORPUS LUTEUM * when Graafian follicle ruptures - antrum collapses = central blood clot * remaining **thecal cells** persist as corpus luteum * with **lutinising hormone** cells continue to secrete oestrogen and progesterone for 10 days - support secretory endometrium * if fertilisation occurs, corpus luteum **persists for 4 weeks till placenta** * most thecal cells produce **progesterone** but some at centre synthesise **oestrogen - thecal lutein cells** * final involution forms pale fibrous mass - **corpus albican** **this slide - theca interna and blood vessels**

CORPUS LUTEUM 2 * centre contains pale staining amorphous material and blood clot * surround is wide band of cells from theca interna invaded by blood vessels * theca externa also contains many blood vessels **theca externa** - stellate shape, small, pale **theca interna** - large, globular, intense pink

PITUITARY GLAND * anterior / posterior **POSTERIOR -** neuronal origin, down growth of brain, pituitary stalk to median eminence of mid-brain @ floor of V3 **supra optic and para-ventricular nuclei** 1. oxytocin 2. vasopressin **ANTERIOR (TROPHIC)** - epithelial origin. roof of primitive gut. adheres @ anterior border of posterior pituitary and surrounds stalk (**pars tuberalis)** 1. growth hormone 2. thyroid stimulating hormone 3. follicle stimulating hormone

PITUITARY PORTAL SYSTEM @ ANTERIOR * release trophic @ anterior pituitary regulated by factors @ neurons of hypothalamus * project to medial eminence * here they release secretions which are taken up by capillaries of pituitary portal and carried to anterior lobe * then act on hormone secreting cells "portal system" = one that starts and ends @ capillaries

ANTERIOR PITUITARY * 3 cell types 1. stain heavily with acid dyes - **alpha cells / acidophils /eosinophilic (dark red)** growth hormone 2. stain heavily with basic dyes - **beta cells / basophils (dark blue)** thyrotrophs/gonadotrophs/cotricotrophs 3. stain weakly **chromophobes**, undifferentiated and no hormone * cells with no stain may be immature of any type **anterior pituitary is darker staining than posterior**

ANTERIOR PITUITARY 2 * peptide based hormones in GRANULES * acidophils/basophils = small dark hormone containing granules * chromophobes = few or none

POSTERIOR PITUITARY * PALE STAIN H&E * axonal tracts and nerve endings of cell bodies @ hypothalamus (supraoptic or paraventricular nuclei) @ walls of V3 * swollen nerve terminals (**Herring bodies**) contain dark neuro-secreting granules - **brown** * granules contain: * **1) OXYTOCIN; 2) VASOPRESSIN** * hormones bound to carrier protein that is also secreted * much tissue (blue staining) is nerve axon/connective tissue OXYTOCIN - contraction of uterus, dilation of birth canal, contraction of myoepithelial cells around milk ducts + erect nipple for lactation

PINEAL GLAND * small gland * backward projection of V3 between corpus callosum * covered by meninges * calcium may accumulate making it visible on brain X-Ray * irregular clumps of neurone-like pinealocytes linked by **glial cells** * innervation = autonomic * secretes melatonin - diurnal rhythms * UNIFORM **this slide - loose layers of meninges @ bottom, small blood vessels @ pia**

THYROID FOLLICLES * lies between neck of thyroid cartilage and 4th tracheal ring * midling **thyroglossal ligamnet** links gland to foramen caecum of tongue * **THYROXINE AND CALCITONIN** * thyroxine producing cells arranged in follicles (hollow spheres) * **simple cuboidal epithelium** * centre of each follicle filled with **colloid rich thyroglobulin** * height of cells varies with metabolic activity * flattened when dormant * emptying when active/ if full when dormant * thyroid gland contains lymphocytes * parathyroid gland is posterior

FOLLICULAR PHASES * cyclical * synthesise thyroglobulin and store within follicle * after dormant period re-sorb and break down colloid and release active hormone (T4) into bloodstream

C CELLS * calcitonin producing cells * clumps between follicles * parafollicular * sometimes between BM and follicular cells **calcitonin is antagonistic to parathormone** calcitonin @ high blood calcium levels lowers serum calcium by promoting uptake of calcium in blood to bones (and muscles) inhibits absorption of calcium from blood

PARATHYROID * 4 @ dorsal surface of thyroid * mixture of fat cells and other secretory cells in clusters or short cords * **CHIEF CELL** - small an palely stained - very small granules = **parathormone (calcium from bone to serum)** * larger pink staining **OXYPHIL** cells fewer in number

PANCREATIC ISLETS * 5% of pancreatic mass, 4 types: 1. BETA - INSULIN - 70% 2. ALPHA - GLUCAGON - 20% 3. DELTA - SOMATOTSTATIN - 8% 4. PANCREATIC POLYPEPTIDE SECRETING CELLS - 2% beta cells at periphery of islets form cords to centre. other cell types lie between cords, plexus of capillaries/veins transport hormones to **hepatic portal system**

ADRENAL GLANDS * OUTER CORTEX = STEROID HORMONES * INNER MEDULLA = ADRENALINE AND NORADRENALINE * centripetal blood supply * arterioles from capsular arteries to cortical sinusoids and direct links to medulla * both systems drain to central vein -\> to renal vein or direct to IVC

ADRENAL CORTEX * 3 zones 1. OUTER **GLOMERULAR** (narrow) - **ALDOSTERONE AND MINERALOCORTICOIDS** 2. INTERMEDIATE THICK **FASCICULAR** long parallel cords responsible for **CORTISOL and GLUCOCORTICOIDS** 3. INNER **RETICULAR ZONE** anastomosing cords of cells that produce testosterone and other androgenics (DARKER STAINING) do not store the steroid hormones they synthesise - discharged to sinusoids accumulate droplets of **fat and cholesterol** from which hormones are synthesised = pale-staining of many cells

ADRENAL MEDULLA * irregular clumps interspersed with blood vessels * 2 types of secretory cells 1. ADRENALINE 2. NORADRENALINE stored in small neurosecretory granules in cytoplasm of cell until required **bathed in blood draining from adrenal cortex, thus influenced by steroid hormones** sympathetic stimulation

TESTICLE * ovaries/testes/placenta are also hormone secreting **this slide - Leydig cells clumped between semniferous tubules**

EPIDERMIS * 4 layers 1. GERMINATIVE - single layer 2. SPINOUS - thickest 3. GRANULAR - narrow with **keratohyaline** 4. DEAD LAYER - dead keratinised squames, thickness varies depending on location and abrasion DERMIS: * 2 layers 1. rich in collagen (close to epidermis) 2. deeper fatty layers

KERATINISED EPITHELIUM * thickest @ soles of feet and on hands (hairless) - subject to compression * thin on parts of abdomen/thorax and lips * epidermis **compact** and boundary with dermis **wavy** creating **dermal piapillae** * at upper boundary = thin, darkly-staining granular layer, synthesises **keratin** that surrounds dead squames - prominent **keratohyaline**

GERMINAL EPITHELIUM AND MELANOCYTES * majority = **keratinocytes** (from stem cells at germinal layer) * also within germinal layer = **melanocytes**, from neural crest of embryo * produce melanin - transferred to keratinocytes of **basal** and **prickle** cell layers * amount of melanin proportional to skin colour

SPINOUS (PRICKLE) CELL LAYER * thickest layer - joined by desmosomes - prevent skin splitting when stretched * if shrink - desmosomes become obvious and cells appear spiny * within = **LANGERHAN'S CELLS** = pale cytoplasm and irregularly shaped nucleus * @ basal layer of epidermis = **MERKEL CELLS** - difficult to resolve, synapse with nerve fibres @ dermis and transmit fine touch

HAIRY SKIN * roots of hair project from dermis, but are of epidermal origin * arise from geminative epithelium within hair bulb that contains melanocytes - hair colour * hair lengthens when a root sheath of epidermis with same layers as rest of skin but **thicker BM = glassy membrane** * surrounded by **collagenous follicle sheath** with **erector pili (smooth muscle)** (& autonomic nerve) * sympathetic stimulation = stand on end * to shaft = **sebaceous glands (lubrication)** * some parts of body with hairless sebaceous glands - face and groin

FINGERNAILS * compacted keratin * arise from nail matrix cell under a fold of skin (**eopnychium/cuticle**) at proximal end of nail * nail lengthens across epidermal nail bed, remains firmly attached at distal end where underlain by a skin fold - **hyponychium**

SWEAT GLANDS * dermis = 2 layers - outer with collagen and elastic fibres (**fibrous layer**) deeper = adipose (**fatty tissue**) * @ dermis = **roots of hairs, glands, plexi of blood vessels, sensory transducers and nerve endings** * most common = **ECCRINE SWEAT GLANDS - lined by glycogen rich cells** * tighly coiled knot of fluid secreting cells and straight duct with simple cuboidal epithelium * duct to surface of skin * coiled section surrounded by **MYOEPITHELIAL CELLS** * @ armpits and anus = apocrine sweat glands - earwax

SENSORY NERVE ENDINGS (OSMIUM TETROXIDE) * many are too fine to be resolved except: 1. **PACINIAN CORPUSCLE** - **pressure** @ dermis/pancreas - large structure with nerve ending at core - resembles an onion 2. **MEISSNER'S CORPUSCLE** - numerous with spiral appearance @ dermal papillae

EYELID * outside = thin hairy skin with row of prominent lashes * sweat glands discharge to outer surface of eyelid * inside = **conjunctiva** = stratified columnar with 2 cell layers * @ substance = single row of hairs, striated muscle (orbicularis oris) and glands to keep inside surface moist * **largest gland = MEIBOMIAN GLAND modified sweat = lipid rich secretion - reduces evaporation** * smaller sweat and sebaceous * **this slide - meibomian gland**

BREAST * start as mainly adipose tissue, into which grow solid cords from the nipple * branch out/hollow to form **lactiferous ducts** but no milk producing alveolar cells * **15-20 segments formed by fibrous strands from nipple** * **suspensory ligaments of Cooper** * ducts open to nipple via lactiferous sinuses * blind ended before pregnancy * adult inactive breasts are responsive to fluctuating hormones * @ 2nd half of each mesntrual cycle **PROGESTERON PROMOTED OEDEMA** - distension of segments

NIPPLE * area of skin with raised fibro-muscular core * 12-20 small openings of lactiferous ducts * surrounded by areola with raised sebaceous glands = **MONTGOMERY'S TUBERCLES** * undergo pigmentation at pregnancy lacteriferous duct = stratified cuboidal epithelium - **if nucleus roughly circular = cuboidal** contains muscle which many change protuberance of nipple

LACTATING BREAST * @ first trimester, enter proliferative phase stimulated by **OESTROGEN, GROWTH HORMONE + CORTISOL** * ducts divide and secretory alveoli develop at ends - columnar surrounded by flattened myoepithelial cells * alveolar cells mature and secretory material builds up within them and lumena, at the same time the **stroma becomes depleted of adipose tissue** * **@ latter stages = lymphocytes** **lactation suppressed by high levels of oestrogen and progesterone**

BREAST TISSUE - LACTATING * alveoli displace much of fat * contain secretory cells that produce milk proteins and fats and ion rich watery solution * milk protein and fat synthesis by same cells within alveoli but discharged differently * **milk fats - apocrine secretion** * **milk protein - merocrine process** **this slide = fibrous connective tissue - stroma**

LACTIFEROUS DUCT gynecomastia = proliferation of lactiferous ducts lobar carcinomas = dysplasia in small ducts

SUGER Flashcards

(69 cards)