Lecture 22 - Anatomy (The Pelvic Viscera) PDF

THE PELVIC VISCERA Thomas Wilson Graphics from Grant’s Method of Anatomy, Netters Atlas of Human Embryology, Larsen’s Anatomy, Human Embryology and Developmental Biology, Moore’s Before We Are Born, Analysis of Vertebrate Structure, McMinn’s & Abrahams Clinical Atlas of Anatomy, Human Anatomy Colou...

THE PELVIC VISCERA Thomas Wilson Graphics from Grant’s Method of Anatomy, Netters Atlas of Human Embryology, Larsen’s Anatomy, Human Embryology and Developmental Biology, Moore’s Before We Are Born, Analysis of Vertebrate Structure, McMinn’s & Abrahams Clinical Atlas of Anatomy, Human Anatomy Colour Atlas & Textbook [email protected] Goal: What ‘fills the bowl’? Outline: Outcomes: Pelvic organ orientation Describe and contrast the orientation of the pelvic viscera of male & females, in relation to pelvic orientation. Peritoneum meets pelvic cavity Describe the nature of peritoneal pouches & mesenteries found in the male & female pelvises. Rectum & anus Identify the pelvic viscera, describing the sexually dimorphic, analogous/homologous features. Reproductive tracts Identify and describe the vasculature and lymphatic drainage of the pelvic organs (i.e. the internal iliac arteries), and their autonomic Blood / nerve / lymphatics nerve supply Recall the origins of the placenta, identify and describe the anatomy Fetal-maternal interface of the placenta and how it relates to its functions.  Orientating a pelvis Pelvic inlet: ~60-80° to the horizontal (dimorphic) AS IS ☆ Superior surface of pubic symphysis level with tip of coccyx Pubic symphysis ~parallel to upper sacrum ~Vertically level with the ASIS - Anterior superior iliac spine ☆ Rectum curves with sacrum Tight angle at junction of anal and urogenital triangles What causes this? Pub◦ rectalis muscle Organ orientation: Cloacal septation Anterior: Urinary tract Middle: Reproductive tract Posterior: Digestive tract } all same run parallel with the orientation as the pelvic inlet a- Male: peritoneal coverings & pouches 1- Parietal peritoneum is continuous: From somatopleure from the body wall - Covers the bladder (the “vesicle”) fluid-filled - sac Separates abo-organs from pelvic organs Recedes between bladder & rectum Rectovesical pouch (of Douglas) Fluid can accumulate here… Covers the upper 2/3 of rectum From pleure Join in the prostate [ Reproductive tract is joined to the urinary tract Related to retention of mesonephric duct Female: peritoneal coverings & pouches Peritoneum covers: Bladder  Uterus  Recedes on both sides of reproductive tract: upper 2/3 v. creates 2 pouches Bladder & uterus = Uterovesical pouch Uterus & Rectum = Rectouterine pouch (of Douglas) Accumulation of fluid, menstrual bleeding, infectious ↳ uterine tube not in direct contact debris with the ovary , so can leak out Pain, swelling, nausea, vomiting Can impact on lungs and other abdominal organs Rectum Rectum differs to colon: lacks taenia coli Continuous longitudinal SM coating instead 8 Can see this in the lab \ , 0 =⇐ _- Rectum broken into thirds Peritoneal coverings create: Upper 3rd: Pararectal fossae (cont. peritoneal cavity) Contents: Intestine, uterine tubes & ovaries, appendix, ischial spines 8 ↳ can palpate Middle 3rd: Rectovesical / Rectouterine pouch Male: seminal vesicles, vas deferens, ureters Female: Uterus, cervix, ureters ↑mosHy Lower 3rd: Direct contact with prostate / vagina ⑥ Why do these spaces/pouches/fossae matter?? I , tes µ ftp.rostatecanbeaccessedthroughanalcanal ' Fluid accumulation, surgical access, anatomical relations BIRTH - posterior tear through the vaginal canal cantearthe rectum  continuous \//// " "" muscle REVISION: The bladder Smooth muscle sac lined by transitional epithelium Lining is mostly derived from hindgut (Cloaca): Endoderm of pleure Detrusor muscle within the wall (meaning “thrust down”) Trigone: Internal area for ureter input & urethral output From I.M. mesoderm ( ) of urogenital sinus - from mesonephric ducts… Septum forms & divides cloaca in 6th week (note when the definitive kidney ascends) Urethra, anal canal, vagina present at 12th week (mesonephric kidney now gone) REVISION: Triangular pyramid 4 surfaces: 4 points: 2 lateral: Against the pubic bones 2 lateral: Originally receive ureters Superior: covered in peritoneum Ureters move down posterior wall Posterior: Receives ureters (trigone internally) Inferior: ‘Neck’ region, exit of urethra Anterior: ‘Apex’, urachus (within median umbilical lig.)  " %f " """ " The pelvic ‘Mesonephric’ tract metanephricduclmesonephricd.at - Ductus/Vas deferens: Cross over top of ureters Metanephric ducts extended dorsolaterally I - mesonephricductstracktheirwaymediallyqsuperioi.ly tothe ureters ( its moving down inthebladdertomakethetrigonearea.sc connection lower ) Forms ejaculatory ducts when seminal vesicle join seminal vesicle Ductus Deferens ampullae lie between them § Coiled tubular glands y Lie behind & below the bladder deep pouch/ urogenital External Prostate: urethra sphincter Receives three ducts ☒ It’s a modified urethral wall in neck of bladder bulbovrethral Wraps around neck of bladder glands ua+ mesonephric } duct metanephric ( duct seminal. ↓ " side #.rs / duct " "" aryduct urethra forming ?⃝ Penis - Corpora cavernosa Deep arteries ⑧ - high pressure blood flow during erection makes itmore rigid - Blood sinuses - fibrous tissue with blood filling in trabeculae - like structures Corpus spongiosum * Urethra protected patency - so sperm can pass through during erection Tunica albuginea - white Subtunic venous plexus  deep veins Semissary veins) ↳ around very thick fibrous tissue corpus cavernosa Deep (Buck’s) Fascia Dorsal vessels of the penis ↳ nerves, veins, arteries from pudendal &> Loose connective tissue Superficial veins Superficial (Dartos) fascia Skin Female reproductive tract Cervix: Protrudes slightly into vagina Creates ant./post. Forneces Uterus: Orientation is very important! External ‘Os’ (aka foramen) Cervix is anteverted on vagina: Orientated forwards Consequence of a retroverted cervix in pregnancy? Uterus is anteflexed on cervix: Curves to lie over the bladder Pouches allow expansion into abdomen Vagina: Urethra & vagina ~parallel to pelvic brim Strongly adhered to posterior wall of urethra & trigone of bladder Muscular passage Probably developed from ← ☒ ⑧  Paramesonephric tubes & peritoneal ligaments / Posterior superior view - protrudes anteriorly [ - coming from a posterior angle going anteriorly coming from a posterior angle - going anteriorly  Paramesonephric tubes & peritoneal ligaments Things that expand a lot tend to have mesenteries Uterine tubes curve posteriorly Peritoneum drapes over the uterine tubes as 1 Infundibullae & fimbriae very close to ovaries continuous sheet called… Ovary is visible from a posterior view The Broad Ligament: allows uterus to expand & the uterine tubes to - move Ovary is suspended slightly above the uterus Mesosalpinx (salpinx = trumpet opening) Suspensory ligament of the ovary: A peritoneal reflection Mesovarium over the ovary Mesometrium 4. ¥ ⇐ The uterus and its ligaments are amazing! Uterosacral and transverse cervical (cardinal) ligaments Question: How do you walk upright with a heavy uterus and child growing in the abdominal space? Anterior cardinal ligaments ↳ holds cervix central Round ligament ↳ travels through CERVIX ☆ inguinalcanal & into the labia majora as utero sacral ligaments sortoft-ofthereminantsho.no/dsuterustosacrumofthegvbernacu/ um - posterior "¥¥ " I. "' Blood supply: General ‘pattern’ of the internal/visceral iliac branches Anterior components 1. Umbilical Abdominal aorta 2. Obturator B 3. Superior vesicular 4. Uterine 1ˢᵗ 5. Inferior vesicular /mostofitisfibroticlig vaginal -. 3ʳᵈ canbranchoffinternalilio.ca _. 6. Middle rectal umbilical or a. 5th commonilia-a.tn/--ernaIiIiaca inmates Internal pudendal artery - 7. 8. Inferior rectal. 4ᵗʰ supplies uterus &part- the uterine tube Piriformism ✓ _ External ;/iaca.. 5th - in females 6ᵗʰ Greater sciatic foramen is A 2nd - travels through obturator canal sacrospinouslig. g travels out GSFÉ, 7th / back in LSF ° sacrotuberouslig RE-C-t-fkfffhfffk-branchesofpudendo.la. 8ᵗʰ. ☐ Lesser sciatic foramen inguinal 'hg. 9 Obturator canal Internal obturator m.  Blood supply of uterus Macro: the ovary tube Micro: supplies * uterine 1. Ovarian (gonadal) contribution Arcuate (arched)  Radial (radius of arch)  Spiral Travels in which mesenteric ligament??* suspensory ligament 2 communicates placenta with 2. Uterine contribution I lost is with menstural anastamosis shedding Lee M t Ovarian a. via suspensorylig. A - - ↓ Uterine a S- suspensory lig. e anastamosis ~ - Fetal-maternal interface Chorionic plate: Fetal villi covered in syncytiotrophoblast epithelia Fetal-maternal blood barrier Fetal and maternal blood does not ‘mix’ Basal plate: Spiral arteries open into intervillous space Chorionic villi carrier fetal vessels Major gas, waste, hormonal exchange site Cycle with menstruation in absence of conception G-Égi w &¥¥ w foetal maternal Autonomic nerve supply: Male Sympathetic: “Hypogastric nerve” Spinal level: T10 – L2 Ganglia levels: T10 – S5 Via superior & inferior hypogastric plexuses Parasympathetic pelvic sp Ian ch hic n. µ. communicates with → parasympathetics & pudendal n. Parasympathetic: “Pelvic nerve?” Pelvic splanchnic nerves: S2 – S4 Pudendal n. = sensory & skeletal motor Pelvic splanchnic n. = parasympathetic only Pain fibres carried with sympathetics ***The above info is all you need from this*** → I C- ¥  Autonomic nerve supply: Female Same as male BUT!! Important question… only Is the myometrium innervated by the ANS? No, it has the same receptors,its more responsive to the endocrine system Many function are endocrine driven Lymphatic system Bunches of nodes found at strategic locations ~ Develop in mesenchyme follows venous drainage Proximal limb areas: Axillary and inguinal nodes Interface of external and internal environments: Cervical, iliac, mesenteric, ‘pulmonary’ nodes Pelvic viscera: Internal iliac nodes  lateral and pre-aortic lumbar nodes Can flow into external iliacs, which join the same pathway Perineum: A) Deep pouch structures: internal pudendal lymph  Internal iliac nodes B) Superficial pouch structures: inguinal nodes  external iliac  internal iliac nodes ** X Gonads: circumvents - follow gonadal v. Follow the gonadal vessels!  Disease of gonad does not present in iliac lymph nodes Female: Ovarian nodes drain part of uterine tube, possibly part of uterus as well Male: testicular nodes only drain testicle