Anatomy of the Skeletal System

In the name of God

Moradian MD, MPH, PhD Candidate Tehran University of Medical Sciences

[email protected] Pearson, Inc., Pearson Benjamin 2013 Cummings 2009 Dr. Budgie Hussain عملکردهای اصلی دستگاه ادراری کلیٍَاخًنرافیلترمیکىىذتامًادزیرراازآنتسدایىذ: سمًم،محصًالتديرریختىیسًختيساز،آبزیادی تذنيیًوُایزیادیتذن مًاردديرریختىیحايیویتريشنمثل:ايرٌ،اسیذايریکي کراتیىیه تعادلآب،الکتريلیتَایتذنيسطحاسیذ-تازتذنراحفظ میکىذ)رویه( اریتريپًئتیهراکٍمحرکخًنسازیدرمغساستخًاناست راترشحمیکىىذ.

2 Main Functions of Urinary System Kidneys filter blood to keep it pure Toxins Metabolic wastes Excess water Excess ions Dispose of nitrogenous wastes from blood Urea Uric acid Creatinine Regulate the balance of water and electrolytes, acids and bases (Renin) Secrete Erythtopoetine that stimulate BM RBC production 3 The Urinary System

کلیٍَاPaired kidneys

A Ureter for each kidney میسوای-حالة Urinary bladder مثاوٍ پیشاتراٌ Urethra

4 خلف صفاق Kidneys are retroperitoneal organs superior lumbar region of posterior abdominal wall واف Hilus is cleft: vessels, ureters and nerves enter and leave غدد فوق کلیً Adrenal glands lie superior to each kidney 11 cm , 130-150 gr

* *

5 6 Kidneys layers

منطقه مرکزی کلیه ها renal medulla منطقه قشری کلیه ها renal cortex کپسول لیفی renal capsule کپسول چربی perinephric (perirenal) fat نیام کلیه renal fascia چربی پارارنال paranephric (pararenal) fat peritoneum (anteriorly), and transversalis fascia (posteriorly)

7 8 Note layers of adipose (fat), capsule, fascia

Transverse sections show retroperitoneal position of kidneys

Note also: liver, aorta muscles on CT

9 Kidney regions Cortex: outer Columns of cortex divide medulla into “pyramids” Medulla: inner Darker, cone-shaped medullary or renal pyramids Parallel bundles of urine-collecting tubules

10 Kidney Structure The human kidney has lobes Pyramid and cortical tissue surrounding it 5-11 per kidney Renal pelvis (=basin) Expanded, funnel shaped, superior part of ureters Branches to form two or three major calices Each of these divides again, minor calices: collect urine from papillae of pyramids

11 12 Kidney Structure واحد ساختماوی کلیً: وفرون Nephron

جسمک کلیً (Renal corpuscle (in cortex گلومرول (Glomerulus (tuft of capillaries کپسول بومه Glomerular (Bowman’s) capsule Tubular section لولً پیچیدي وسدیک Proximal convoluted tubule قوش ٌىلً Loop of Henle لولً پیچیدي دور Distal convoluted tubule

مجرای جمع کىىدي Collecting duct

13 Nephron

14 The Kidney and the Nephron A. Renal Vein B. Renal Artery C. Ureter D. Medulla E. Renal Pelvis F. Cortex 1. Ascending loop of Henle 2. Descending loop of Henle 3. Peritubular capillaries 4. Proximal tubule 5. Glomerulus 6. Distal tubule More than a million of these tubules act together to form the urine

Three main mechanisms a. Glomerular filtration b. Tubular reabsorption c. Tubular secretion

Two major parts 1. A urine-forming nephron 2. A collecting duct which concentrates urine by removing water from it

16 Scanning EM of podocytes clinging to capillaries (left) and filtration membrane diagram (right) The capillary pores (fenestrations) restrict the passage of the largest elements such as blood cells The basement membrane and slit diaphragm hold back all but the smallest proteins while letting through small molecules such as water, ions, glucose, amino acids, and urea

17 Classes of nephrons

• Cortical nephrons – 85% of all nephrons – Almost entirely within cortex • Juxtamedullary nephrons – Renal corpuscles near cortex- medulla junction 22 The collecting ducts

• The most important role is to conserve body fluids • When the body must conserve water, the posterior pituitary gland secretes ADH (antidiuretic hormone) • ADH increases the permeability of the collecting tubules and distal tubules to water so more is reabsorbed • This decreases the total volume of urine • Alcohol inhibits the release of ADH, so less water is reabsorbed producing copious amounts of dilute urine (can cause dehydration) 24 Vessels • Afferent and efferent arterioles associated with glomerular capillaries – Allows high pressure for forcing filtrate out of blood – About 20% of renal plasma flow is filtered each minute (125 ml/min): this is the glomerular filtration rate (GFR), an important clinical measure of renal function • This is about one liter every 8 minutes (only 1% ends up as urine) • Peritubular capillaries arise from efferent arterioles – Absorb solutes and water from tubule cells

25 Histology

26 27 For studying

Parts of the kidney: 1. Renal pyramid 2. Efferent vessel 3. Renal artery 4. Renal vein 5. Renal hilum 6. Renal pelvis 7. Ureter 8. Minor calyx 9. Renal capsule 10. Inferior renal capsule 11. Superior renal capsule 12. Afferent vessel 13. Nephron 14. Minor calyx 15. Major calyx 16. Renal papilla 17. Renal column 28 Slender tubes about 25 The Ureters cm (10 “) long leaving each renal pelvis One for each kidney carrying urine to the bladder Descend retroperitonealy خلف صفاقی Enter posterolateral corners of bladder Run medially within posterior bladder wall before opening into interior This oblique entry helps prevent backflow of urine 29 محل های تنگی حالب: پس از لگنچه، روی عروق ایلیاک، انتهای حالب و ورود به مثانه layers of Ureters Ureters play an active role in transporting urine Transitional epithelium (it’s not just by gravity) (مخاطی) of mucosa (ماهیچه ای) Muscularis – Inner longitudinal, outer circular layers – Inferior 3rd with extra longitudinal layer) – Stimulated to contract when urine in ureter: peristaltic waves to propel urine to bladder (همبند) Adventitia

31 Urinary Bladder Collapsible muscular sac Stores and expels urine: 250-300 cm3 Lies on pelvic floor posterior to pubic symphysis Males: anterior to rectum Females: just anterior to the vagina and uterus See also brief atlas 32 If full: bladder is spherical and extends into abdominal cavity (holds about 500 ml or 1 pt) If empty: bladder lies entirely within pelvis with shape like upside-down pyramid Urine exits via the urethra Trigone is inside area between ureters and urethra: prone to infection (see slide 38)

33 Bladder wall layers Mucosa with distensible transitional epithelium (can مخاط قابل جمع شدن (stretch زیر مخاط Submucosa ماهیچه صافThick muscularis called the detrusor muscle 3 layers of highly intermingled smooth muscle سروز در سطح فوقانی Fibrous adventitia Urethra Smooth muscle with inner mucosa Drains urine out of the bladder and body پروستاتیک، پرده ای، اسفنجی Male: about 20 cm (8”) long Female: 3-4 cm (1.5”) long

Urethra____

35 Urethral sphincters Internal: involuntary sphincter of smooth muscle External: skeletal muscle inhibits urination voluntarily until proper time (levator anni muscle also helps voluntary constriction) Males: urethra has three regions (see right) ______trigone

1. Prostatic urethra______2. Membranous urethra____

3. Spongy or penile urethra_____ female

36 Micturition (Voiding ) – Urinating – Emptying the bladder

KNOW: Micturition center of brain: pons (but heavily influenced by higher centers) Parasympathetic: to void Sympathetic: inhibits micturition

37 Male Reproductive system دستگاه تولید مثل مردانه بیضه اپیدیدم مجرای منی بر کیسه ی بیضی آلت تناسلی خارجی کیسه منی غده پروستات غده کوپفر 38 Gonads – testes (testosterone) = sex characteristics • muscle development and maturity – ovaries (estrogen) = sex characteristics • maturity and coordination

39 Testis Spermatogenesis Oval organ, 4-5 cm x 2.5 cm in diameter احشایی و جداری Tunica vaginalis پردي سفید Tunica albuginea لولً مىی سازSeminiferous tubules بیىابیىی: ٌورمون Leydig cells Sertoli cells (supportive) Rete testis

40 (لولً وابران) Efferent ductules Histology of the Testis

41 Heat Exchange of Pampiniform Plexus

42 Spermatic Ducts

Efferent ductules 12 small ciliated ducts collecting sperm from the rete testes and transporting it to the epididymis Epididymis (head, body & tail) 6 m long coiled duct adhering to the posterior of testis site of sperm maturation & storage (fertile for 40 to 60 days) مجرای منی بر Ductus (vas) deferens muscular tube 45 cm long passing up from scrotum through inguinal canal to posterior surface of bladder مجرای انزالی Ejaculatory duct 2 cm duct formed from ductus deferens & seminal vesicle & passing through prostate to empty into urethra

43 Male Duct System

44 Accessory Glands کیسً ی مىی Seminal vesicles posterior to bladder empty into ejaculatory duct Prostate gland below bladder, surrounds urethra and ejaculatory duct empty through pores in urethral wall Bulbourethral (Cowper) glands near bulb of penis empty into penile urethra lubricating fluid 45 46 Anatomy of the Penis

47 Spermatozoon

48 Semen (Seminal Fluid)

2-5 ml of fluid expelled during orgasm 60% seminal vesicle fluid, 30% prostatic & 10% sperm and trace of bulbourethral fluid normal sperm count is 50-120 million/ml (< 25 million/ml is associated with infertility) sperm serve to digest path through cervical mucus and to fertilize egg Other components of semen fructose provide energy for sperm motility fibrinogen clotting enzymes convert fibrinogen to fibrin causing semen to clot fibrinolysin liquefies semen within 30 minutes prostaglandins stimulate female peristaltic contractions spermine is a base stabilizing sperm pH at 7.2 to 7.6

49 50 Female External Genitalia

Vulva: everything that is externally visible (mons pubis, labia majora, labia minora, clitoris, urethral orifice, vaginal vestibule, perineal body) mons pubis: mound of fatty tissue above the pubic bone labia majora: large, outer fatty folds of skin tissue labia minora: inner folds of skin and erectile tissue clitoris: small, highly sensitive organ glans: tip of the clitoris prepuce (clitoral hood): loose-fitting fold of skin covering the clitoral glans

51 Female External Genitalia vaginal vestibule: the cleft containing the vaginal and urethral openings Skene’s glands: group of small mucous glands that open into vaginal vestibule (near urethra) Bartholin’s glands: two glands that open into vaginal vestibule (on either side of the vaginal opening) - thought to provide some lubrication, may emit a pheromone hymen: thin mucous membrane partially covering the vaginal opening perineum: tissue between the genital and anus.

52 External Female Genitalia

53 Female Internal Genitalia

Vagina: tubular organ connecting external genitals with uterus Grafenberg spot (g-spot): mass of erectile and glandular tissue surrounding the urethra just below the bladder some women report that simulation to g-spot produces sexual arousal and orgasm uterus: hollow muscular organ - purpose to nurture developing fetus cervix: small lower portion of the uterus that projects into the vagina پوشش صفاقی :Perimetrium myometrium: layers of smooth muscle comprising the uterus endometrium: inner lining of the uterus that builds a rich blood supply and sloughs off the lining each month

54 Female Internal Genitalia ovaries: female gonads - containing the immature female reproductive cells ovum: female reproduce cell fallopian tubes: thin flexible muscular structures connecting the ovaries with the uterus - passageway for the ovum to travel to the uterus cilia: tiny hairlike projections that line the fallopian tubes and propel the ovum towards the uterus fimbriae: fringelike projections that reach out to the ovary to draw a released ovum into the fallopian tube.

55 56 Uterine tube

57 58 Ovaries The female gonads or sex glands They develop and expel an ovum each month A woman is born with approximately 400,000 immature eggs called follicles During a lifetime a woman release 400 to 500 fully matured eggs for fertilization The follicles in the ovaries produce the female sex hormones, progesterone and estrogen These hormones prepare the uterus for implantation of the fertilized egg