Pelvis Anatomy PDF - Touro College

Touro College Anatomy LAB PELVIS § § Houses urinary, reproductive and digestive structures The reproductive and urinary systems develop together in the fetus sharing some organ and are referred to as the urogenital system o Male and female gonads begin developing in the abdomen next to the kidneys t...

Touro College Anatomy LAB PELVIS § § Houses urinary, reproductive and digestive structures The reproductive and urinary systems develop together in the fetus sharing some organ and are referred to as the urogenital system o Male and female gonads begin developing in the abdomen next to the kidneys then descend into the pelvis later in embryonic development § § § In both sexes, holes exist in the lower quadrant of the anterior abdominal where either the spermatic cord or the round ligament of the uterus pass. They are known as the inguinal canals because they pass through ALL layers of the abdominal wall forming short canals The inguinal canal passes through the lower abdominal wall from the deep ring in the transversalis fascia to the superficial ring in the aponeurosis of the external oblique In the male each layer of the anterior abdominal wall contributes a concentric layer of spermatic cord surrounding the ductus deferens and testicular vessels as these structures traverse the inguinal canal L gonadal vein usually empties into L renal vein ( ^ incident varicocele) Varicocele Results from incompetent valves between the internal spermatic and renal veins resulting in dilitation of pampiniform plexis Almost always occurs on the left side where spermatic vein empties into the renal vein Right spermatic vein empties into inferior vena cava → varicocele on right should raise suspicion of malignancy or abdominal / pelvic mass Retrograde blood flow causes peritesticular veins to dilate. – Hyperthermia impairs spermatogenesis Varicocele Develops slowly, often no symptoms Most common 15-25 year olds 15-20% occurrence all males – 40% infertile males – associated with testicular growth arrest in adolescents Feels like “bag of worms” Gravity dependent therefore visible when standing § Diagnose with PE and ultrasound Surgical correction with infertility or pain Urethra joins urinary and reproductive systems in male Testes can produce viable sperm until 60-70yrs of age Ovaries produce eggs viable until usually 40-50…. § Generic Pelvic cavity / Pelvic Diaphragm o Pelvic cavity begins on plane running transverse to the iliac crests and inferiorly to the pelvic diaphragm which is § Composed of levator ani and coccygeus muscles + fascia…like a hammock Levator ani = actual floor pelvis…forms sling running from pubi and ilium with R and L halves meeting posterior to rectum Form structural basis of perineum o False Pelvis § Extend from crest of iliac to pelvic inlet or pelvic brim…. surrounded by bone § Houses lower portion GI organs o True Pelvis (lesser pelvis) § Houses mainly the organs of the reproductive system § Completely surrounded by bone § Pelvic inlet(promontory of sacrum) to pelvic outlet (pubic symphysis, ischiopubic rami and sacrotuberous ligaments)… pelvic diaphragm § Lateral wall formed by obturator internus § Posterior wall formed by coccygeus and piriformis muscles o Pelvic inlet…superior boundary true pelvis….plane from sacral promontory to superior aspect symphysis pubis o Pelvic outlet…plane from inferior tip of coccyx to inferior symphysis pubis § Lies between 2 ischial tuberosities § Closed by pelvic diaphragm and urogenital diaphragm Important in childbirth o Primary muscle functions is to support pelvic viscera and maintain continence o Nervous innervations § Sensory: pudendal § Motor: sacral branches ventral rami § Autonomic: Sympathetic from lumbar and sacral splanchnics Parasympathetic from pelvic splanchnics o Primary Blood Supply § Branches Internal Iliac to pelvic wall and pelvic viscera § Branches of internal pudendal to perineum § Female Pelvic cavity / peritoneum o Ant to post …. Urinary bladder, uterus and rectum o Laterally ….uterine tubes and ovaries o Superiorly…iliac form a HORSESHOE around these organs § 4 main components of female reproductive organs o Ovaries, uterine tubes, uterus, vagina § In fetus, ovary is attached to abdominal wall by ligament….gubernaculum…later attaches to ovary and becomes ovarian ligament and round ligament which passes through inguinal canal to labia majora § § Ovaries are surrounded by peritoneum but do NOT directly attaches to uterine tubes o Mature Ova…… ruptures peritoneal covering of ovary…..near fimbriae of uterine tube opening…… enters osteum of uterine tube….. into tube o If not….. Chance of ECTOPIC pregnancy Uterus o Most powerful muscle in male and female o Pear-shaped, hollow….inferior neck forms cervix § Vagina……acts as birth canal and female organ of copulation § Perineum o Diamond shaped extends from pubic symphysis to ischial tuberosity to the anus o Subdivided into TWO TRIANGLES § Anterior triangle is traversed by the urethra and diaphragm § Posterior triangle is traversed by the anus § Rectum…continuous from sigmoid colon…. pierces pelvic diaphragm for excretion § Organs of pelvic cavity are considered retro-peritoneal and are only partially covered by peritoneum o Folds of peritoneum connecting organ to organ or organ to abdominal wall are called ligaments § Double layer of peritoneum hanging from uterine tubes = broad ligaments…….Uterine tubes (fallopian tube), ovaries, ovarian blood vessels, ovarian ligament and round ligament found here § Broad ligament continues to the lateral body wall as the suspensory ligament that contains ovarian vessels and ureter 1. Round ligament 2. Uterus 3. Uterine cavity 4. Intestinal surface of Uterus 5. Versical surface(toward bladder) 6. Fundus of uterus 7. Body of uterus 8. Palmate folds of cervical canal 9. Cervical canal 10. Posterior lip 11. Cervical os (external) 12. Isthmus of uterus 13. Supravaginal portion of cervix 14. Vaginal portion of cervix 15. Anterior lip 16. Cervix § External Female Genitalia o Labia majora and minora o Urethra and vagina § Male Pelvic Cavity Contents / Testes and Spermatic Cord o Pelvic cavity contains urinary bladder and rectum o Urinary and reproductive systems MERGE § § Bladder contents Ductus deferens and seminal vesicles…..ejaculatory duct § Prostatic urethra….. to penile urethra o Testes : primary male sex gland Empty into prostatic urethra Embryologic Development of Testis At 12th week gestation gubernaculum develops in inguinal fold…tracts through abdomen toward scrotum = ultimate inguinal canal Processus vaginalis forms in peritoneum and follows course of gabernaculum Failure of closure can lead to hydrocele or inguinal hernia At 7 mos gestation processes vaginalis reaches ext oblique and thus begins testicular descent into inguinal canal and finally into scrotum by birth DIRECT AND INDIRECT INGUINAL HERNIAS Differentiation: inferior epigastric artery: direct hernias lie medial to this structure and indirect hernias lie lateral to it. Embryologic Development of Testis — Testosterone is responsible for the descent — Descent usually complete by the 7 – 8th month — Descent is complete in 97% of boys — 3% male infants have imperfect descent resulting in cryptorchidism = undescended testicle — About 30% 0f premature infants still have at least one undescended testicle Most undescended testes will descend during the first year of life o Through the descent, testicles also bring testicular artery, vein, nerve and ductus deferens (carries sperm) § This mixure of vessels, nerves, glandular duct, lymph and layers of the abdominal wall pushed ahead of the descending testicles constitutes the spermatic cord found within the inguinal canal o Vas (or ductus) deferens from the epididymis passes thru inguinal canal and joins ducts of seminal vesicles to form the ejaculatory duct which empties into prostatic urethra o Seminal vescicles and prostate both contribute to the formation of seminal fluid § Seminal fluid + sperm cells = semen Anatomy W ithin the scrotum each vas deferens travels in close association w ith blood vessels, nerves and muscle fibers mak ing up the spermatic cord Ly mphatics from the penile and scrotal surfaces drain into the inguinal lymph nodes Ly mphatics from the testis drain into the abdominal lymph nodes and cannot be palpated § Male External Genitalia o Penis primarily …..scrotum and testes § Penis contains three columns erectile tissue Corpora cavernosa = outer two columns Corpus spongiosum = single center column … houses the urethra § Erection All three columns become engorged