HSS2011 Human Anatomy PDF

HSS2011 Human Anatomy Module II series: 1. Regional anatomy of the Abdomen & Pelvis 2. Organs of the Digestive System 3. Organs of the Urogenital System Dr. Fiona Chen, HTI Updated: 30 September 2024 1 ...

HSS2011 Human Anatomy Module II series: 1. Regional anatomy of the Abdomen & Pelvis 2. Organs of the Digestive System 3. Organs of the Urogenital System Dr. Fiona Chen, HTI Updated: 30 September 2024 1  An overview of the urogenital system Urinary system Reproductive system Upper & Lower Renal Tract: Genital tracts: URT Kidneys Gonads (male, female) Ureters Ducts Urinary bladder Accessory glands LRT Urethra (male, female) The bony pelvis Function: Urine production & Homeostasis Function: Sex & Reproduction  Learning outcome At the end of the lecture, students should be able to: 1) Describe the gross anatomy of the kidney, ureter and urinary bladder. 2) Describe the microanatomy and functions of the renal tubules. 3) Appreciate two different sets of reproductive organs in the male and female pelvis. 4) Differentiate the structural differences between the male pelvic organs and the female pelvic organs. 5) Establish an understanding of the arterial blood supply, venous drainage and nerve innervations of the pelvis. 3  Outline 1. Anatomy of the Urinary System 2. Bony Pelvis & Pelvic Cavity 3. Anatomy of the Male Reproductive System 4. Anatomy of the Female Reproductive System 4  HSS2011 Human Anatomy Organs of the Urogenital system 1. Anatomy of the Urinary System 5  Surface anatomy of the kidneys Diaphragm Adrenal gland Left kidney Right kidney 12th rib Lumbar Right Renal artery Vertebra and Right renal vein Left ureter Inferior vena cava Abdominal aorta Iliac crest Urinary bladder Gluteal region Posterior view of the kidneys (T12 – L3)  Functions of the kidney 1. Filter blood 2. Reabsorb majority of filtrate (H2O, salts, glucose, nutrients) to the blood stream 3. Excrete remaining 1% as urine 4. Regulates blood pressure by controlling H2O and salt 5. Regulates pH by secreting H+ or reabsorbing HCO3- 6. Endocrine function (renin-angiotensin-aldosterone system, RAAS; erythropoietin) 7. Produces active Vitamin D 1) Retroperitoneal organs 2) ~9 – 13 cm in length 3) At the vertebral level: T12 – L3.  Microanatomy of the kidney Coronal section of the Left kidney Renal cortex Renal capsule Renal medulla Renal pyramid Adipose tissue in renal sinus Renal papilla Hilum Collecting system: Minor calyx Major calyx Renal pelvis Ureter Collecting system of the kidney: 4-5 minor calyces merge to form a major calyx, then 2-3 major calyces combine to form the renal pelvis. The renal pelvis leads to the ureter at the lower pole of the kidney.  Renal cortex vs. Renal medulla Renal cortex Renal medulla Outer portion of kidney Inner portion of kidney Contains renal corpuscles, proximal and 8-12 pyramids in each kidney distal tubules and peritubular capillaries Collecting ducts for all nephrons Receives 95% blood supply Receives 5% blood supply  Pictorial presentation of a renal lobe Renal capsule Glomerulus a network of capillaries Cortical nephron Arcuate artery Arcuate vein Renal pyramid Juxtamedullary nephron Interlobar artery Renal papilla Interlobar vein Minor calyx  The structural organization of a nephron 5. DCT 2. Bowman’s Renal cortex capsule Efferent arteriole 1. Glomerulus Afferent arteriole 3. PCT 4b. Ascending limb 4a. Descending limb Nephron- the functional unit Renal medulla Renal corpuscle (1+2) 1. Glomerulus & 2. Bowman’s capsule Renal tubule 3. Proximal convoluted tubule (PCT) 4. Loop of Henle (two limbs: 4a, 4b)) 5. Distal convoluted tubule (DCT)  Brief summary of functions Structure Function Renal corpuscle Filtration of plasma to produce filtrate Proximal convoluted tubule Reabsorption of water, ions, and all organic nutrients Descending limb of Henles’ loop Further reabsorption of water Ascending limb of Henles’ loop Reabsorption of sodium and chloride ions Distal convoluted tubule Secretion of ions, acids, drugs, toxins Variable reabsorption of water, sodium ions, and calcium ions (under hormonal control) Additional note: When sodium ion is reabsorbed from the filtrate back to blood, water reabsorption follows. Hilum Sympathetic innervation Entry/Exit site on the medial T10-12 spinal cord (lateral horn) regions of each kidney Vasoconstriction intra-renal arteries  Blood supply of the kidney A renal artery – segmental arteries – interlobar arteries – arcuate arteries – cortical radiate arteries  Anatomy of the ureter The ureter Transport urine to urinary bladder Retroperitoneal ~25cm long with 3mm diameter The urinary bladder  Anatomy of the urinary bladder Vesicouterine pouch Rectouterine pouch Vesicorectal pouch  Urinary bladder & urethra Lateral Views Female Male The urinary bladder collects urine from both ureters, which is partially retroperitoneal with its peritoneal-covered “dome”. 17  Microanatomy of the ureter & urinary bladder Microanatomy of Ureter LM ×65 Mucosa (Transitional epithelium) Smooth muscle Outer connective tissue layer Detrusor muscle Left ureter The urinary bladder is a highly distensible organ comprised of irregular crisscrossing bands of smooth muscle collectively called the detrusor muscle. Ureteral openings Rugae The urethra begins inferior and central to the two ureteral openings forming the three points of a trigone triangular-shaped area at the base of the bladder Internal urethral called the trigone. sphincter & orifice Male Prostate & Prostatic urethra Urogenital diaphragm  Anatomy of the urethra Female Male 3–5 cm 18–20 cm Coronal sections Function: Transports urine from the bladder to the outside world *males… passageway for urination & ejaculation 19  HSS2011 Human Anatomy Regional Anatomy of the Pelvis 2. Pelvic Cavity & Bony Pelvis 20  Hip bone (x2) The bony pelvis + The plane of Pelvic inlet: Sacrum & Coccyx The sacral promontory The pelvic brim The superior margin of pubic symphysis Right hip bone Pubic symphysis Lateral view Superior view Inferior view The plane of Pelvic outlet: The tip of coccyx False pelvis = area within entire pelvic girdle The inferior margin of pubic symphysis True pelvis = area below pelvic brim 21 Sex differences in the bony pelvis Narrower, rougher, more robust General Appearance Broader, smoother, less robust More vertical; extends farther Ilium Less vertical; less extension superior to sacroiliac joint superior to sacral articulation Long, narrow triangle Sacrum Broad, short with pronounced triangle with less sacral curvature sacral curvature Deeper Iliac fossa Shallower Narrower, Pelvic inlet Open, heart circular shaped shaped Narrow Pelvic outlet Enlarged Points Coccyx Points anteriorly inferiorly Directed Acetabulum Faces slightly laterally anteriorly Oval Obturator foramen Triangular Under 90 º Pubic angle 100º or more 22 The female: False pelvis vs. True pelvis The female bony pelvis is divided into: False pelvis: above the pelvic brim and has no obstetric importance. True pelvis: below the pelvic brim and related to the child -birth.  Pelvic diaphragm. Superior view showing the bony pelvis and skeletal muscles Pelvic brim S1 Tip of coccyx Coccygeus Obturator internus Levator ani Rectum The levator ani and the coccygeus (muscle) comprise the pelvic Pubic symphysis diaphragm (the pelvic floor). 24  The pelvic cavity & perineum Coronal section +Coccygeus The perineal body is a fibromuscular node that represents the insertion of the levator ani muscle at the floor of the pelvis. It attaches superficially onto the skin surface. 25  HSS2011 Human Anatomy Regional Anatomy of the Pelvis 3. Anatomy of the Male Reproductive System 26 The male pelvic organs Lateral Views 1) Testis 2) Epididymis 3) Ductus/Vas deferens 4) Seminal vesicles 5) Urethra 6) Prostate gland 7) Bulbourethral glands 27 8) Penis  Anatomy of the testis Spermatogenesis in Seminiferous tubules Head of Epididymis Spermatic cord Ductus deferens Seminiferous tubule Body of epididymis Testis Tunica albuginea Tail of epididymis Sperm development at 35 -36 degree Celsius. Gonadal arteries/veins  Vascular supply of the testis Lt/Rt testicular artery/ vein Spermatic cord  Anatomy of the epididymis Maturation of sperms occurs in the epididymis (head, body, tail). Spermatic cord: 1. Ductus (vas) deferens 2. Blood vessels 3. Nerves 4. Other connective tissue Ductus deferens Epididymis Testis Sagittal view Anterior view 30  Anatomy of the vas deferens and the seminal vesical Ductus (vas) deferens serves to transport sperms. The vas deferens unites with the seminal vesicle at the posterior aspect of the urinary bladder. Superior surface Median section of male pelvis Ureter Urinary Position of empty & Ductus (vas) Deferens bladder full urinary bladder & ampulla Seminal vesicle Ejaculatory duct Prostate gland Prostatic urethra Membranous urethra Bulbourethral glands Left lateral view Spongy urethra Posterior view of urinary bladder Clinical note: Benign prostatic hypertrophy & Prostatic cancer 31 Anatomy of the prostate gland Clinical note: Benign prostatic hypertrophy & Prostatic cancer  Anatomy of the penis Lateral view Transverse view The penis is composted of three column-like chambers of erectile tissue including the larger lateral chambers called corpora cavernosa and the corpus spongiosum which is a smaller chamber surrounding the urethra. 33  Sperms transportation & semen production Semen is the secretion released mainly from the prostate and seminal vesicles. Sperms production: Testis Maturation: Epididymis Spermatic cord Transportation: Vas deferens Prostate gland Testis & Epididymis Seminal vesicles Bulbourethral glands Scrotum A skin-covered, highly pigmented, muscular sack containing testes Male Reproductive System The structures of the male reproductive system include the testes, the epididymides, the penis, and the ducts and glands that produce and carry semen. The testes are located in a skin-covered, highly pigmented, muscular sack called the scrotum that extends from the body behind the penis. From the lumen of the seminiferous tubules, the immotile sperm are surrounded by testicular fluid and moved to the epididymis, a highly coiled tube (around 6m in lengthen) attached to the testis where newly formed sperm continue to mature. Sperm exit the scrotum through the ductus deferens, which is bundled in the spermatic cord. The seminal vesicles and prostate gland add fluids to the sperm to create semen. 35  HSS2011 Human Anatomy Organs of the Urogenital system 4. Anatomy of the Female Reproductive System 36  The female pelvic organs Median (mid-sagittal) section UT Uterine tube Ureter UB Urinary Bladder PS Pubic Symphysis Ovarian vessels O Ovary Vesicouterine pouch Rectouterine pouch Peritoneum O Uterus UB Internal urethral orifice PS External urethral orifice Levator ani Vaginal orifice & canal External anal sphincter Labium minus Labium majus Internal anal sphincter Trace the visceral peritoneum from the urinary bladder to reach the uterus and then the rectum. Identify two pouches. 37  Anatomy of the ovary & uterine tube Ovaries: Ovarian artery and vein Located in the pelvic cavity Uterine tube/ Oviduct/ Fallopian tube along the lateral wall within Ovary ligament the broad ligament Infundibulum Primary sex organ: produce Fundus female gametes Fimbriae (oocytes/ovum), estrogen and Ovarian follicle progesterone Uterus Broad ligament Body Ureter Uterine tube Uterine cervix The ovary, uterine tube and uterus are intraperitoneal structures supported by peritoneal folds e.g the board ligament. Vascular supply of the ovaries  Anatomy of uterine cavity & cervix Uterus: Hollow organ in pelvic cavity between bladder and rectum Organ of gestation: Receives and nourishes fertilized oocyte until birth. Uterine cavity Peritoneal cavity Fundus Body Endometrium Isthmus Myometrium Cervix Posterior vaginal fornix Cervical canal Female urethra Vascular supply of the uterus  Normal position of the Uterus The body of the uterus rests on the superior surface of the urinary bladder. Anteversion of uterus Anteflexion of uterus The axis of the cervix is tilted The body of the uterus is bended anteriorly (anteverted) relative to anteriorly (anteflexed) relative to the the long-axis of the vagina. long-axis of the uterine cervix. Mid-sagittal section of the female pelvis. With obstetric importance! 42  Anatomy of the uterine cervix & vagina Vagina: A muscular canal (approximately 10 cm long) Uterine cervix that serves as the entrance to the Lateral fornix: narrow space reproductive tract. around cervix Vaginal artery Rugae: circular folds of mucosa Vaginal canal The uterine cervix protrudes into the upper part of the vaginal canal. In human reproduction, semen is first ejaculated into the vagina (vaginal canal) in close proximity to the uterine cervix.  Fertilization of the ovum Luminal v i e w of t h e Ut erine t u b e and Ut erus Ampulla Perimetrium Isthmus Infundibulum Fundus of uterus Endometrium Fimbriae Mature follicle Myometrium Ovulation normally takes place on Uterine artery Uterine day 14 of the menstrual cycle, a and vein cavity mature follicle is released into the peritoneal cavity and immediately Internal os picked up by the fimbriae of the uterine tube. Vaginal artery External os Fertilization of the ovum normally takes place at the ampulla of the uterine tube. Implantation of the blastocyst (if any) heads towards the endometrium of the uterus. Ectopic pregnancy Implantation of the fertilized ovum This takes place at the endometrium of the uterus. New plate Growth & Development of the Embryo & Placenta Umbilical cord Amnion covering foetal surface of placenta Umbilical arteries (blue) Umbilical vein (red) Embryo: First 8 weeks of gestation. Fetus: 9th week of gestation to term at 40th week. Fetal Growth & Development in the uterus Small intestine is intraperitoneal. Position of organs of a full-term pregnancy  “Natural” childbirth Delivery at full term pregnancy (40th week of gestation). The fully dilated uterine cervix (~ 10 cm) & the vaginal canal serve as the birth canal.  Falciform Ligament vs. Round Ligament of the liver Fetal Circulation Posterior aspect of abdominal wall Anterior view of abdomen Falciform ligament Round Umbilicus ligament at the front Placenta Falciform ligament is a thickening of 2 folds of visceral Round ligament of the liver (Ligamentum peritoneum that anchors the liver to the anterior abdominal wall. teres) is a fibrous remnant of the umbilical vein that carries blood from the umbilical cord to the fetal liver. 49  Sex differences at the pelvis Mid-sagittal section of a female pelvis and a male pelvis Female Uterus Male Fallopian tube Uterine cervix Ureter Body Coccyx Urinary bladder Vas deferens Coccyx Urogenital diaphragm Prostate Urogenital diaphragm 50  Nerve intervention of the pelvis Sympathetic nerve: pelvic sympathetic chain Parasympathetic nerve: pelvic splanchnic nerves  Anatomy of the Female Perineum For students’ revision The external female reproductive structures are referred to collectively as the vulva. The mons pubis is a pad of fat that is located at the anterior, over the pubic bone. The labia majora are folds of hair-covered skin that begin just posterior to the mons pubis. The thinner and more pigmented labia minora extend medial to the labia majora. The clitoris (or glans clitoris) lies in the superior, anterior portions of the labia minora, an organ that originates from the same cells as the glans penis and has abundant nerves. 52  Anatomy of the female perineum Pubic symphysis External urethral orifice Patient lies in Lithotomy position Vaginal orifice Anus 53  Reference list Core Textbooks:  Saladin (2024) Human Anatomy, 5th edition. New York, N.Y: McGraw-Hill  Openstax Anatomy and Physiology Reference Textbooks:  Martini, Nath & Bartholomew (2017) Fundamentals of Anatomy & Physiology, 11th edition. Boston: Pearson  Drake, Vogl & Mitchell (2015) Gray’s Anatomy for Students, 3rd edition. Philadelphia: Churchill Livingstone Elsevier  Gosling et al (2017) Human Anatomy: Color Atlas & Textbook, 6th edition. Edinburgh: Elsevier  Moore, Agur & Dalley (2015) Essential Clinical Anatomy, 5th edition. Philadelphia :Wolters Kluwer Health 54