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Questions and Answers
What is the function of seminal vesicles?
What can cause benign hypertrophy of the prostate?
Aging in elderly men
Prostate cancer is primarily found in the peripheral region of the prostate.
True
What type of secretion do bulbourethral glands produce?
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The urethra opens at the ______ penis.
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Match the kidney structures with their functions:
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What are the constrictions of the ureters that can pose a problem for kidney stones?
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The female urethra is longer than the male urethra.
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What is the primary function of the urinary bladder?
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What is the function of the portal vein?
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What are the two triangles formed by the pelvic diaphragm?
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What muscles support the perineum during childbirth?
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Where does fertilization typically occur?
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The inner medulla of the ovary is where follicular genesis occurs.
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What is the main function of the epididymis?
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What happens to sperm stored in the epididymis after a month?
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The uterine artery supplies the _____, coming from the internal iliac artery.
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What is cryptorchidism?
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The glans clitoris is covered by skin.
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What does the Portal Vein drain blood from?
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What forms the pelvic diaphragm?
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The urogenital triangle is the posterior triangle of the pelvic diaphragm.
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What are the two regions of the ovary?
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Which part of the fallopian tubes is responsible for capturing the oocyte?
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What happens during ectopic pregnancy?
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The _____ is the site where fertilization occurs in the female reproductive system.
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What is the main function of the testes?
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The epididymis is where sperm are produced.
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What does vasectomy involve?
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What glands contribute to the volume of semen?
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Where are the seminal vesicles located?
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What is one of the functions of the prostate gland?
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Benign Hypertrophy of the Prostate does not occur in elderly men.
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Prostate cancer affects _____% of cases in the peripheral region.
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What is the primary function of the bulbourethral glands?
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Which condition is characterized by urethra opening along the shaft of the penis?
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What are the erectile tissues in the penis?
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Erection is mediated by the sympathetic nervous system.
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Match the parts of the male urethra with their characteristics:
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What anatomical position is the left kidney compared to the right?
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What is the principle blood supply to each kidney?
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What shape is the urinary bladder?
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The female urethra is longer than the male urethra.
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What is the primary function of the portal vein?
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What shapes the pelvic diaphragm?
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What are the two triangles that form the pelvic diaphragm?
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The muscle that contracts to elevate the anus is the ______.
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Which structure contains skeletal muscles that form voluntary sphincters around the urethra?
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Where does fertilization typically occur in the female reproductive system?
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The uterus is primarily supported at the cervix.
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What is ectopic pregnancy?
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What do the labioscrotal swellings develop into in males?
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What is the main function of the testes?
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What is a procedure to prevent sperm from reaching the penis?
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The part of the epididymis that is referred to as the ______ where sperm are initially stored.
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Which of the following glands contributes to the volume of semen?
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What fluid do the seminal vesicles secrete?
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The prostate gland is located inferior to the bladder.
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Benign hypertrophy of the prostate occurs in most elderly _____.
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What is the size of the prostate?
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What condition is a common malignancy in men?
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What do Bulbourethral glands secrete?
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Hypospadias is a congenital disorder where the urethra opens somewhere along the shaft of the penis.
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What are the parts of the male urethra?
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What do the kidneys primarily function to do?
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The renal hilum faces anteromedially and holds the renal _____, renal _____, and renal _____ along with nerves and lymphatics.
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Ureters begin at the renal hilum.
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What shape is the urinary bladder?
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What are some of the constriction points in the ureters?
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Study Notes
Portal Vein
- Drains blood from the abdominal GI tract, spleen, and pancreas
- Delivers venous blood to the liver for metabolism
- Metabolized blood exits the liver through hepatic veins, which drain into the inferior vena cava (IVC)
Pelvic Diaphragm
- Separates the pelvis from the perineum, the area superficial to the pelvic diaphragm
- Attachment point for external genitalia
- Diamond-shaped with two triangles:
- Urogenital triangle: Anterior, contains the urogenital hiatus (opening for urogenital system)
- Anal triangle: Posterior, contains the anal aperture (opening for GI tract)
- Formed by the levator ani muscle:
- Puborectalis: Attaches to the pubis bone and encircles the rectum, forming a sling that maintains fecal continence
- Pubococcygeus: Lateral to the puborectalis, attaches to the pubis and coccyx bones
- Iliococcygeus: Lateral to the pubococcygeus, attaches to the ilium and coccyx bones
Perineal Membrane
- Covers the urogenital triangle, a portion of the pelvic diaphragm
- Superficial to the pelvic diaphragm
- Contains openings for the urethra (male and female) and vagina (female)
Deep Perineal Pouch
- Located between the perineal membrane and levator ani
- Contains skeletal muscles that form voluntary sphincters around the urethra (external urethral sphincter) and vagina
Childbirth
- Muscles of the perineum, levator ani (especially puborectalis and pubococcygeus), perineal membrane, and deep perineal pouch are frequently injured during childbirth
- In females, these muscles support the urethra, vagina, uterus, and rectum
- Injuries can lead to urinary stress incontinence, uterine prolapse, and fecal incontinence
Ovary
- Paired, intraperitoneal organs
- Located posterior to the broad ligament and adjacent to the lateral wall of the pelvis
- Primary blood supply is the ovarian artery, a branch of the abdominal aorta
- The ligament of the ovary attaches the ovary to the uterus
- Irregularly shaped ball with two regions:
- Medulla: Inner region containing vessels, nerves, and lymphatics
- Cortex: Outer region where follicular genesis occurs
- Defined surface epithelium containing oocytes surrounded by supporting cells that prepare the oocyte for ovulation
- Oocytes are released into the fallopian tube during ovulation
Fallopian/Uterine Tubes
- Project laterally from the uterus and open adjacent to the ovaries
- Divided into three areas:
- Infundibulum: Funnel-shaped, facilitates oocyte collection, has fimbriae (finger-like projections) that attach to and capture oocytes
- Ampulla: Large, labyrinthine lumen, site of fertilization
- Isthmus: Narrow, connects to the uterus
Uterus
- Thick-walled, muscular organ
- Facilitates embryonic and fetal development
- Supplied by the uterine artery, a branch of the internal iliac artery
- Divided into three parts:
- Fundus: Top portion above the fallopian tubes
- Body: Largest portion, below fallopian tubes
- Cervix: Opening into the vagina
- Two linings:
- Myometrium: Middle layer composed of smooth muscle, undergoes hypertrophy and hyperplasia during pregnancy
- Endometrium: Inner lining, supports pregnancy (zygote implantation), sheds during menstruation
- Uterine position when the bladder is empty:
- Anteverted (AV) relative to the vagina
- Anteflexed (AF) over the bladder
- When the bladder is full, the uterus is displaced upwards
- Retroverted and retroflexed: Uterus displaced backwards, increasing risk of prolapse
- Uterine prolapse: Uterus pushed through the vagina due to high pressure in the pelvis
Cervix
- Opens inferiorly into the anterior wall of the vagina
- Divided into two parts:
- Supravaginal: Above the vagina
- Vaginal: Within the vagina
- The cervix is the primary support point for the uterus
Vagina
- Muscular passage connecting the uterus to the exterior
- Located between the urethra anteriorly and the rectum posteriorly
- The fornix refers to spaces created anterior, posterior, and lateral to the cervix within the vagina
- Supplied by the vaginal arteries, a branch of the internal iliac artery
Ectopic Pregnancy
- Fertilization typically occurs in the ampulla of the fallopian tube
- Implantation normally occurs within the endometrial lining of the uterine body
- Ectopic/extrauterine pregnancy: Implantation occurs outside the uterine lining
- Embryos implanted in areas with a large blood supply can continue to grow, leading to bleeding into the abdominal cavity
- Ruptured uterine tubes due to ectopic pregnancy are often misdiagnosed as appendicitis
Peritoneal Folds
- Peritoneum: Serous membrane covering the top of the pelvic viscera
- Provides support and protection for the pelvis
- Peritoneal folds form over pelvic viscera
- Broad ligament: Peritoneal folds coming together over the uterine tube
- Ovaries are surrounded by peritoneum (intraperitoneal) with an opening for oocyte passage
- Ligament of ovary: Peritoneal folds over the ovarian vessels
Peritoneal Pouches
- Created by peritoneal folds:
- Recto-uterine pouch: Between the rectum and uterus, deepest part of the abdominal cavity, fluid collects here, especially when lying on the back, fluid can be aspirated with a syringe through the fornix
- Vesico-uterine pouch: Between the bladder and uterus
Development of External Genitalia
- Identical in males and females during early development
- Genital tubercle: Develops into the glans penis (male) or glans clitoris (female)
- Testosterone promotes more rapid growth of the genital tubercle in males, resulting in larger size
- Urethral folds: Develop into the urethra (male and female) and labia minora (female)
- Labioscrotal swellings: Develop into the scrotum (male) and labia majora (female)
Anatomy of External Genitalia
- Vulva/pudendum: Erectile tissue and overlying skin comprising the external genitalia
- Labia minora: Two thin skin folds next to the midline, fat-free, hair-free with internal connective tissue
- Vestibule: Area between each labia minora containing the urethra and vagina
- Labia majora: Larger skin folds lateral to the labia minora
- Glans clitoris: Exposed erectile tissue located where the labia minora meet anteriorly
- Perineal membrane and pubic arch: Attachment point for the roots of external genitalia
Erectile Tissue
- Formed by:
- Corpora cavernosa: Located anterior to the glans clitoris, attach to the pubic arch
- Bulbs of vestibule: Located deep to labia minora
- Glans clitoris
- Body of the clitoris: Composed of the corpora cavernosa and bulbs of vestibule
- Erectile tissues are anterior to the urethra
- Greater vestibular glands: Posterior to bulbs, open into the vestibule and secrete lubricating mucus during arousal
Muscles
- Ischiocavernosus muscle: Covers the crus of the clitoris (part of the corpora cavernosa attaching to the pubic arch) and maintains clitoral erection
- Bulbospongiosus muscle: Encloses the bulbs and greater vestibular glands, supports the pelvic floor, assists in clitoral erection, and compresses the greater vestibular glands
Pelvic Diaphragm (Male)
- Same as the female pelvic diaphragm
- Only one opening in the perineal membrane for the urethra
- The deep perineal pouch also contains sphincters around glands
Perineal Membrane (Male)
- Superficial to the pelvic diaphragm
- Covers the urogenital triangle
- Contains an opening for the urethra (male and female) and vagina (female)
Deep Perineal Pouch (Male)
- Located above the perineal membrane
- Contains skeletal muscle that forms sphincters around the urethra, glands, and neurovascular structures supplying the penis
Testes
- Function in sperm production
- Septa (connective tissue) divide the testes into approximately 250 lobules
- Lobules contain 3-10 seminiferous tubules (site of spermatogenesis)
- Each tubule is a highly convoluted loop within the lobule
- Sperm differentiate closer to the lumen, but remain non-motile
- Tubules terminate as the tubulus rectus (straight tube) in the mediastinum, connecting to the rete testis
- Rete testis: Anastomosing channel system that collects sperm from all seminiferous tubules
- Outer capsules surrounding the lobules:
- Tunica albugenia: Surrounds lobules
- Tunica vaginalis: Covers the testes during descent, an extension of the abdominal peritoneum, surrounding the tunica albugenia
Testicular Descent
- Gonadal development occurs along the posterior abdominal wall
- Testes descend towards the inguinal canal by 7 months of gestation
- Pass through the inguinal canal into the scrotum just before birth
- Drags blood vessels, nerves, the duct system (vas deferens), and layers of the abdominal wall to the scrotum
Cryptorchidism (Undescended Testes)
- Results in histological changes that cause infertility
- Increases the risk of testicular cancer
- Requires surgical correction preferably before 18 months to 2 years of age
Epididymis
- Coiled tube approximately 5 cm long
- Sperm from the mediastinum of the testes travel through efferent tubules to the epididymis
- Composed of three sections:
- Caput: Head
- Corpus: Body
- Caudal: Tail
- Surrounded by smooth muscle that assists with sperm movement
- Functions to store and mature sperm
- Site where sperm acquire motility
- Sperm are stored for approximately one month in the epididymis before they die and are reabsorbed by epithelial cells
Vas Deferens
- Sperm travels from the epididymis to the vas deferens
- Long duct with a length and complex course due to testicular descent
- Penetrates the abdominal wall through the inguinal canal
- Descends along the lateral wall of the pelvic cavity
- Wolffian ducts: Develop into the vas deferens
- Smooth muscular duct with inner circular and outer longitudinal muscles
- Function: Transmits spermazoa to the ejaculatory duct
- Ejaculation mediated by the sympathetic nervous system causes smooth muscle contraction to pump sperm through
- Ejaculatory duct: Formed by the union of the vas deferens and the duct of the seminal vesicle
- Function: Transports sperm to the ejaculatory duct
- Part of the spermatic cord
Vasectomy
- Involves ligating the vas deferens to prevent sperm from reaching the penis
- The vas is superficial on the posterior side of the scrotum, allowing for a relatively non-invasive procedure
- White blood cells assist the epididymis in breaking down sperm after a vasectomy
Accessory Glands (Male Reproductive System)
- Contribute to the volume of ejaculate.
Male Accessory Sex Glands
-
Seminal Vesicles:
- Located at the back of the bladder.
- Their ducts merge with the vas deferens to form the ejaculatory duct, which empties into the prostatic urethra.
- Contribute significantly to semen volume.
- Secrete an alkaline, viscous fluid that neutralizes the acidic environment of the female reproductive tract.
- Support sperm motility and viability.
-
Prostate:
- Situated below the bladder, in front of the rectum, and above the perineal membrane.
- Surrounds the urethra.
- About the size of a walnut.
- Contains three zones: peripheral, transitional, and central.
- Secretes a watery fluid containing zinc, citric acid, prostaglandins, and proteolytic enzymes.
- Contributes to sperm viability and maturation.
- Numerous openings from the prostate lead into the prostatic urethra.
-
Benign Prostatic Hypertrophy (BPH):
- Common in older men.
- Results from enlargement of the central prostate.
- Can compress or block the urethra, leading to an interrupted urine flow.
- A digital rectal examination (DRE) reveals a large and soft prostate, as the central region is affected.
-
Prostate Cancer:
- A common malignancy in males.
- Approximately 70% of cases occur in the peripheral region.
- Affects the entire prostate.
- Diagnosed via DRE (prostate feels hard) or a blood test.
- Treated with radiotherapy, chemotherapy, surgical removal, or androgen deprivation therapy.
- Androgen deprivation therapy may shrink or eliminate the tumor if it is androgen-dependent.
- If the tumor recurs, it is often androgen-independent and more aggressive.
-
Bulbourethral Glands (Cowper’s Glands):
- Paired, pea-shaped glands.
- Located in the deep perineal pouch.
- Ducts open into the spongy urethra.
- Secrete mucus-like fluid that lubricates the urethra.
- Forms pre-ejaculate.
External Male Genitalia
-
Hypospadias:
- A congenital disorder of the penis where the urethra opens somewhere along the shaft of the penis.
- Affects approximately 1 in 250 boys.
-
Erectile Tissues:
- Covered by skin.
- The body of the penis is pendulous and completely covered by skin.
-
Scrotum:
- Homologous to the labia majora in females.
- Skin fuses in the midline at the raphe.
- Testes descend into the scrotum.
-
Prepuce:
- Skin covering the glans penis.
- Opens anteriorly and attaches to the glans penis at the frenulum.
-
Perineal Membrane and Pubic Arch:
- Provide attachment points for the roots of the penis.
-
Penis:
- Covered by skin.
- Rooted at the perineal membrane and pubic arch.
- Composed of erectile tissues:
- Two corpora cavernosa.
- One corpus spongiosum, which expands distally to form the glans penis.
- Urethra pierces the perineal membrane through the urogenital hiatus, enters the corpus spongiosum, and opens at the glans penis.
- Erection is mediated by the parasympathetic nervous system, causing relaxation of arteries in the penis and allowing blood to fill the erectile tissues.
-
Erectile Tissues:
- Contain three cylinders of erectile tissues:
- Two corpora cavernosa.
- One corpus spongiosum, which encloses the penile urethra.
- Each cylinder has a network of veins surrounded by collagen, elastic fibers, and smooth muscle cells.
- Contain three cylinders of erectile tissues:
-
Erectile Dysfunction in Males and Females:
- Both males and females have two corpora cavernosa.
- Males have a single corpus spongiosum, while females have two bulbs of the vestibule.
-
Penis Erection:
- Mediated by the parasympathetic nervous system, which relaxes arteries in the penis, permitting blood to fill the erectile tissues.
-
Muscles (Ischiocavernosus and Bulbospongiosus):
- Move blood from the root of the penis to the body of the penis.
- Constricts venous drainage.
Kidneys and the Urinary System
-
Kidneys:
- Adrenal glands sit superior and medial to each kidney.
- Produce urine.
- Paired, solid organs.
- Retroperitoneal (behind the parietal peritoneum).
- Bean-shaped (10 cm x 2 cm x 2.5 cm).
- Healthy kidneys are red-brown in color.
- Extend longitudinally from T12 to L3.
- Associated with the diaphragm, so their position changes with diaphragm contraction.
- The left kidney sits higher than the right due to the liver pushing it lower.
- Two surfaces: anterior and posterior (sits against the quadratus lumborum muscle).
- Surgical approaches to the kidneys are typically lateral or posterior due to their location.
-
Perinephric Fat and Renal Fascia:
- Perinephric fat surrounds the kidneys.
- Renal fascia lines the perinephric fat and kidneys, and sits behind the parietal peritoneum.
-
Kidney Structure:
- Renal capsule lines the kidney surface.
- Renal sinuses are spaces within the kidney filled with perinephric fat.
- Inner medulla:
- Renal pyramids are pyramid-shaped structures with their base against the surface and their apex towards the hilum.
- Composed of secretory cells that produce urine.
- Separated from each other by the cortex.
- Outer cortex:
- Continuous.
- Separates the renal pyramids.
-
Renal Collecting System:
- Urine is secreted from the medulla.
- Travels from the apex of the medulla towards the hilum.
- Collected into the minor calyx.
- Two to three minor calices combine to form a major calyx.
- Two to three major calices merge into the renal pelvis (upper portion of the ureter that passes through the renal hilum).
-
Renal Hilum:
- Located anteromedially.
- Contains the renal vein (front), renal artery (middle), and renal pelvis (back), along with nerves and lymphatics.
-
Renal Artery:
- Primary blood supply to each kidney.
- Arises from the paired branches of the abdominal aorta.
- Divides into five segmental arteries upon entering the hilum.
- Each segmental artery supplies a renal segment (a single surgically resectable functional unit, typically five).
-
Accessory Renal Artery:
- An additional blood supply.
- Develops as the kidneys form lower in the posterior abdominal wall.
- Often persists as the kidneys ascend due to differing growth rates.
- May enter the kidney through the hilum or the surface.
- Not present in everyone or on both sides.
-
Renal Vein:
- Drains venous blood from the kidneys directly into the inferior vena cava (IVC).
- The IVC lies to the right of the abdominal aorta in the midline.
- The left renal vein crosses the midline before draining into the IVC and has a longer course than the right renal vein.
-
Ureters:
- Carry urine from the kidneys to the bladder.
- Paired, hollow organs.
- Extend from the kidneys to the pelvis.
- Begin at the renal hilum as the renal pelvis, pass inferiorly in front of the psoas major muscle and lumbar transverse processes, cross the pelvic brim, and enter the bladder.
- Narrowing points (constrictions) exist at:
- Uretropelvic junction, where the renal pelvis meets the ureter.
- Where the ureter crosses the pelvic brim.
- Where the ureter obliquely traverses through the muscular bladder wall (functional sphincter that prevents urine reflux).
- These constrictions can pose a problem for kidney stones.
-
Urinary Bladder:
- A hollow organ with strong muscular walls and ridges.
- Stores urine.
- Pyramid-shaped:
- Base posteriorly, against the uterus in females and the rectum in males.
- Apex anteriorly, against the pubis bone in both sexes.
- The most anterior pelvic organ.
-
Bladder Neck:
- Inferiormost part of the bladder.
- Anchors the bladder, held by ligaments.
- Expands as the bladder fills, while the neck remains fixed.
-
Base:
- Forms an inverted triangle (trigone) with three openings:
- Two ureteric orifices, where the ureters enter the bladder.
- Urethral orifice, the internal opening of the urethra.
- The trigone lacks muscular ridges and is smooth.
- Forms an inverted triangle (trigone) with three openings:
-
Urethra:
- Conducts urine from the bladder to the exterior.
-
Female Urethra:
- Short and straight.
- Exits the bladder, passes through the pelvic floor and perineal membrane.
- Due to its shortness, females are prone to urinary tract infections (UTIs).
- Easy to insert a catheter.
-
Male Urethra:
- Long and curved.
- Divided into four parts:
- Preprostatic part, immediately after the bladder and before the prostate.
- Prostatic part, traverses the prostate.
- Membranous part, traverses the pelvic floor and perineal membrane.
- Spongy part, runs inside the penis (both bends are in the spongy part).
- Length makes males less susceptible to UTIs.
- Difficult to insert a catheter.
Portal Vein
- Drains blood from the gastrointestinal tract, spleen, and pancreas.
- Transports venous blood to the liver for metabolism.
- Metabolized blood exits the liver via hepatic veins, which then drain into the inferior vena cava (IVC).
Pelvic Diaphragm
- Separates the pelvic cavity from the perineum, the area superficial to the pelvic diaphragm.
- Provides an attachment point for the external genitalia.
- Shaped like a diamond with two triangles:
- Urogenital triangle (anterior) contains the urogenital hiatus, an opening for the urogenital system.
- Anal triangle (posterior) contains the anal aperture, an opening for the gastrointestinal tract.
- Composed of the levator ani muscle, which contracts to elevate the anus, composed of:
-
Puborectalis:
- Attaches to the pubis bone and wraps around the rectum.
- Forms a sling around the rectum, creating a kink.
- Contributes to fecal continence alongside the internal and external anal sphincters.
- Pubococcygeus (lateral to puborectalis): Attaches to the pubis and coccyx bones.
- Iliococcygeus (lateral to pubococcygeus): Attaches to the ilium and coccyx bones.
-
Puborectalis:
Perineal Membrane
- Covers half of the pelvic diaphragm (urogenital triangle).
- Lies superficial to the pelvic diaphragm.
- Contains openings for the urethra (male and female) and vagina (female).
Deep Perineal Pouch
- Located between the perineal membrane and levator ani muscle.
- Contains skeletal muscles that form voluntary sphincters around the urethra (external urethral sphincter) and the vagina.
Childbirth
- The perineum, levator ani (mainly puborectalis and pubococcygeus), perineal membrane, and deep perineal pouch muscles are frequently torn or injured during childbirth.
- These muscles are crucial for supporting the urethra, vagina, uterus, and rectum in females.
- Injury can lead to urinary stress incontinence, uterine prolapse, and fecal incontinence.
Ovary
- Paired organs located in the pelvic cavity.
- Intraperitoneal, meaning they are surrounded by the peritoneum.
- Situated posterior to the broad ligament and adjacent to the lateral wall of the pelvis.
- Receives its primary blood supply from the ovarian artery, a branch of the abdominal aorta.
- Secured to the uterus via the ligament of the ovary.
- Irregularly shaped with two distinct regions:
- Inner medulla: Contains vessels, nerves, and lymphatics.
- Outer cortex: Site of follicular genesis (development of egg cells).
- Possesses a defined surface epithelium.
- Oocytes are surrounded by supporting cells that prepare them for ovulation.
- During ovulation, the oocyte is released from the ovary and enters the fallopian tube.
Fallopian Tubes
- Extend laterally from the uterus and open near the ovaries.
- Divided into three distinct regions:
-
Infundibulum:
- Funnel-shaped.
- Plays a role in oocyte collection.
- Fimbriae, finger-like projections, attach to the anterior and lateral aspects of the ovary, helping to capture the oocyte.
-
Ampulla:
- Large and characterized by a labyrinthine lumen.
- Site of fertilization.
-
Isthmus:
- Narrow.
- Connects the fallopian tube to the uterus.
-
Infundibulum:
Uterus
- A thick-walled, muscular organ.
- Responsible for supporting the development of the embryo and fetus.
- Supplied by the uterine artery, a branch of the internal iliac artery.
- Consists of three parts:
- Fundus: The top portion, superior to the fallopian tubes.
- Body: The largest portion, located below the fallopian tubes.
- Cervix: The opening into the vagina.
- Two distinct linings:
- Myometrium: The middle layer composed of smooth muscle, which undergoes hypertrophy and hyperplasia during pregnancy.
- Endometrium: The inner lining that supports pregnancy (zygote implants in the endometrium) and sheds during menstruation.
- Uterine position (when the bladder is empty):
- Anteverted (AV): Tilted forward relative to the vagina.
- Anteflexed (AF): Bent forward over the bladder.
- When the bladder is full, the uterus is displaced upwards.
- Retroverted and retroflexed: Uterus tilted backward, increasing the risk of prolapse.
- Uterine prolapse: Uterus descends through the vagina due to elevated pressure in the pelvic cavity.
Cervix
- Opens inferiorly into the anterior wall of the vagina.
- Two parts:
- Supravaginal: Above the vagina.
- Vaginal: Within the vagina.
- The cervix provides strong support for the uterus.
Vagina
- A muscular passage connecting the uterus to the external environment.
- Situated between the urethra anteriorly and the rectum posteriorly.
- Fornix: Spaces formed anterior, posterior, and lateral to the point where the cervix enters the vagina.
- Supplied by the vaginal arteries, branches of the internal iliac artery.
Ectopic Pregnancy
- Fertilization typically occurs in the ampulla of the fallopian tube.
- Implantation usually takes place in the uterine body.
- Ectopic/extrauterine pregnancy: Implantation occurs outside of the endometrial lining.
- If an ectopic pregnancy occurs in an area with a robust blood supply, the embryo will grow.
- This can lead to bleeding into the abdominal cavity.
- A ruptured fallopian tube due to ectopic pregnancy is often misdiagnosed as appendicitis.
Peritoneal Folds
- The peritoneum is a serous membrane covering the top of the pelvic viscera.
- Provides support and protection for the pelvis.
- Peritoneal folds form over the pelvic viscera.
- Broad ligament: Peritoneal folds converging over the uterine tube.
- Ovaries are surrounded by the peritoneum, making them intraperitoneal. There is an opening for the oocyte to pass through.
- Ligament of ovary: Peritoneal folds overlying the ovarian vessels.
Peritoneal Pouches
- Formed by peritoneal folds.
-
Recto-uterine pouch:
- Located between the rectum and uterus.
- The deepest portion of the abdominal cavity.
- Fluid accumulates here, particularly when the patient is lying on their back.
- Fluid can be aspirated using a syringe through the fornix.
-
Vesico-uterine pouch:
- Located between the bladder and uterus.
Development of External Genitalia
- Similar in males and females.
- Genital tubercle: Develops into the glans penis (male) or glans clitoris (female).
- Testosterone promotes faster growth of the genital tubercle, resulting in a larger structure in males.
- Urethral folds: Form the urethra (male and female) and labia minora (female).
- Labioscrotal swellings: Develop into the scrotum (male) and labia majora (female).
External Genitalia Anatomy
- Vulva/pudendum: Erectile tissue and overlying skin comprising the external genitalia.
- Labia minora: Two thin, fat-free, and hairless skin folds near the midline, containing connective tissue.
- Vestibule: The area between the labia minora, containing the urethra and vagina.
- Labia majora: Larger skin folds located lateral to the labia minora.
- Glans clitoris: Erectile tissue, exposed (not covered by skin), located where the labia minora meet anteriorly.
- Perineal membrane and pubic arch: Provide attachment points for the roots of the external genitalia.
Erectile Tissue
- Formed by:
- Two corpora cavernosa: Located anterior to the glans clitoris, attached to the pubic arch.
- Two bulbs of vestibule: Located deep to the labia minora.
- Glans clitoris.
- Body of clitoris: Includes the corpora cavernosa and bulbs of vestibule.
- Erectile tissue resides anterior to the urethra.
- Greater vestibular glands: Located posterior to the bulbs, with openings into the vestibule, secreting lubricating mucus during arousal.
Muscles
- Ischiocavernosus muscle: Covers the crus of the clitoris (portion of the corpora cavernosa attaching to the pubic arch) and contributes to clitoral erection.
- Bulbospongiosus muscle: Encloses the bulbs and greater vestibular glands, supports the pelvic floor, assists with clitoral erection, and compresses the greater vestibular glands.
Pelvic Diaphragm in Males
- Identical to the female pelvic diaphragm.
- Contains only one opening in the perineal membrane for the urethra.
- The deep perineal pouch also contains sphincters around glands.
Perineal Membrane in Males
- Superficial to the pelvic diaphragm.
- Covers the urogenital triangle.
- Contains openings for the urethra (male and female) and vagina (female).
Deep Perineal Pouch in Males
- The space above the perineal membrane.
- Contains skeletal muscles forming sphincters around the urethra, glands, and neurovascular structures supplying the penis.
Testes
- Responsible for sperm production.
- Septa (connective tissue) divide the testes into approximately 250 lobules.
- Each lobule contains 3-10 seminiferous tubules, the sites of spermatogenesis.
- Seminiferous tubules form highly convoluted loops within the lobules.
- As sperm cells move closer to the lumen, they differentiate (but remain non-motile).
- Tubules terminate as tubulus rectus (straight tube) in the mediastinum, connecting to the rete testis.
- Rete testis: Interconnected channels that collect sperm from all seminiferous tubules.
-
Outer capsules:
- Tunica albugenia: Surrounds the lobules.
- Tunica vaginalis: Covers the testes during descent; an extension of the abdominal peritoneum, surrounding the tunica albugenia.
Testicular Descent
- Gonadal development occurs along the posterior abdominal wall.
- Testes descend towards the inguinal canal by 7 months of gestation.
- They travel through the inguinal canal into the scrotum just before birth.
- This descent brings blood vessels, nerves, the duct system (vas deferens), and layers of the abdominal wall into the scrotum.
Cryptorchidism (Undescended Testes)
- Can lead to histological changes, resulting in infertility.
- Increases the risk of testicular cancer.
- Requires surgical correction, ideally before 18 months to 2 years of age.
Epididymis
- A coiled tube approximately 5 cm long.
- Sperm from the mediastinum of the testes travel through efferent tubules to the epididymis.
- Consists of three distinct parts:
- Caput: Head.
- Corpus: Body.
- Cauda: Tail.
- Surrounded by smooth muscle to facilitate sperm movement.
- Its function is to store and mature sperm.
- Sperm acquire motility within the epididymis.
- Sperm are stored for approximately 1 month in the epididymis before dying and being reabsorbed by epithelial cells.
Vas Deferens
- After the epididymis, sperm travel through the vas deferens.
- A long duct with a complex course due to testicular descent.
- Penetrates the abdominal wall through the inguinal canal.
- Descends along the lateral wall of the pelvic cavity.
- Develops from the Wolffian ducts.
- Contains smooth muscle (inner circular and outer longitudinal layers).
- A muscular duct (smooth muscle wall) that transports sperm to the ejaculatory duct.
- Ejaculation is triggered by the sympathetic nervous system, causing smooth muscle contraction and propelling sperm through the duct.
- Ejaculatory duct: Formed by the fusion of the vas deferens and duct of the seminal vesicle.
- Function is to transport sperm to the ejaculatory duct.
- Part of the spermatic cord.
Vasectomy
- Involves ligating the vas deferens to prevent sperm from reaching the penis.
- The vas is located superficially on the posterior side of the scrotum, allowing for a minimally invasive procedure.
- White blood cells assist the epididymis in breaking down sperm after vasectomy.
Accessory Glands
- Contribute to the volume of the ejaculate.
Male Reproductive System - Accessory Glands
-
Seminal Vesicles:
- Located at the back of the bladder.
- Their ducts join with the vas deferens to form the ejaculatory duct, which opens into the prostatic urethra.
- Contribute to semen volume.
- Secrete an alkaline, viscous fluid that neutralizes the acidity of the female reproductive tract.
- Help with sperm motility and viability.
-
Prostate:
- Situated below the bladder, in front of the rectum, and above the perineal membrane.
- Surrounds the urethra.
- About the size of a walnut.
- Has three zones: peripheral, transitional, and central.
- Secretes a watery fluid containing zinc, citric acid, prostaglandins, and proteolytic enzymes.
- Assists with sperm viability and maturation.
- Has multiple openings into the prostatic urethra.
-
Benign Prostatic Hyperplasia (BPH):
- Affects most elderly men.
- Enlargement of the central prostate.
- Compresses or blocks the urethra, leading to an interrupted urinary stream.
- A digital rectal examination (DRE) reveals a large and soft prostate.
-
Prostate Cancer:
- Frequent malignancy in men.
- 70% occur in the peripheral region.
- Affects the entire prostate.
- Diagnosed through DRE (prostate feels hard) or blood tests.
- Treated with radiotherapy, chemotherapy, removal, or androgen deprivation therapy.
- If androgen-dependent, androgen deprivation therapy shrinks or eliminates the tumor.
- If the tumor recurs, it is not androgen-dependent and becomes more aggressive.
-
Bulbourethral Glands:
- Paired, pea-shaped glands.
- Located in the deep perineal pouch.
- Their ducts open into the spongy urethra.
- Secrete a mucous-like fluid that lubricates the urethra.
- Forms pre-ejaculate.
External Male Genitalia
-
Hypospadias:
- A congenital disorder of the penis.
- The urethra opens along the shaft of the penis.
- Affects 1 in 250 boys.
-
Penis:
- Covered by skin.
- Attached to the perineal membrane and the pubic arch.
- Erectile tissues include:
- Two corpora cavernosa.
- One corpus spongiosum.
- The corpus spongiosum expands distally to form the glans penis.
- The urethra pierces the perineal membrane through the urogenital hiatus and runs through the corpus spongiosum to open at the glans penis.
- Erections are mediated by the parasympathetic nervous system, causing relaxation of arteries in the penis and allowing blood to fill the erectile tissues.
- Three cylinders of erectile tissues:
- Two corpora cavernosa.
- One corpus spongiosum, surrounding the penile urethra.
- Each cylinder has a network of veins surrounded by collagen, elastic fibers, and smooth muscle cells.
-
Erectile Dysfunction (Male & Female):
- Two corpora cavernosa (male and female).
- Single corpus spongiosum in males; two bulbs of vestibule in females.
-
Muscles:
- Ischiocavernosus and bulbospongiosus muscles move blood from the base of the penis to the body and constrict venous drainage.
### Kidneys and the Urinary System
-
Kidneys:
- Adrenal glands sit superior and medial to each kidney.
- Produce urine.
- Paired, solid organs located behind the peritoneum (retroperitoneal).
- Bean-shaped (10x2x2.5 cm).
- Healthy kidneys are reddish-brown.
- Extend vertically from T12 to L3 vertebrae.
- Position shifts with diaphragm contraction.
- The left kidney is higher than the right due to the liver pushing the right kidney lower.
- Two surfaces: anterior and posterior (rests against quadratus lumborum).
- Approached for surgery laterally or posteriorly due to position.
-
Perinephric Fat and Renal Fascia:
- Perinephric fat surrounds the kidneys.
- Renal fascia encloses the perinephric fat and kidneys.
- These structures lie behind the parietal peritoneum.
-
Kidney Structure:
- Renal capsule covers the kidney surface.
- Renal sinuses are spaces within the kidney filled with perinephric fat.
- Inner medulla:
- Renal pyramids are pyramid-shaped structures (base at the surface, apex towards the hilum).
- Contain secretory cells that produce urine.
- Separated by the cortex.
- Outer cortex:
- Continuous.
- Surrounds the renal pyramids.
-
Renal Collecting System:
- Urine is secreted from the medulla.
- It flows from the apex of the medulla into the hilum.
- Minor calyx: collects urine.
- Major calyx: two to three minor calices merge into one major calyx.
- Renal pelvis: two to three major calices join to form the renal pelvis (upper part of the ureter, which passes through the renal hilum).
-
Renal Hilum:
- Faces anteromedially.
- Contains the renal vein, renal artery, and renal pelvis, as well as nerves and lymphatics.
-
Renal Artery:
- Main blood supply to each kidney.
- Branches from the abdominal aorta.
- Divides into five segmental arteries upon entering the hilum.
- Each segmental artery supplies a renal segment (a functional unit; typically five, surgically resectable).
-
Accessory Renal Artery:
- An additional blood supply.
- Forms during kidney development in the posterior abdominal wall.
- Difference in growth rates of the kidneys and the abdominal wall cause kidneys to ascend.
- Sometimes, both the initial blood supply and the new one remain (including the renal artery).
- Not present in everyone or on both sides.
- Can enter the kidney through the hilum or its surface.
-
Renal Vein:
- Drains blood from the kidneys directly into the inferior vena cava (IVC).
- The IVC is located to the right of the abdominal aorta.
- The left renal vein crosses the midline before entering the IVC, and its path is longer than the right renal vein.
-
Ureters:
- Transport urine from the kidneys.
- Paired, hollow tubes.
- Extends from the kidneys to the pelvis.
- Begins at the renal hilum as the renal pelvis and runs inferiorly in front of psoas major and the lumbar vertebral transverse processes, crosses the pelvic brim and enters the bladder.
- Constrictions:
- Uretropelvic Junction: narrowing where the renal pelvis meets the ureter.
- Where the ureter crosses the pelvic brim.
- Where the ureter obliquely passes through the bladder wall (functional sphincter preventing urine reflux).
- Constrictions are relevant to kidney stone passage.
-
Urinary Bladder:
- Hollow organ.
- Strong muscular walls with large muscular ridges.
- Stores urine.
- Pyramid-shaped:
- Base is posterior, against the uterus in females and rectum in males.
- Apex is anterior, against the pubic bone in males and females.
- Most anterior pelvic organ.
-
Bladder Neck:
- Inferiormost part of the bladder.
- Anchored by ligaments.
- Expands upward as the bladder fills, while the neck remains fixed.
-
Base:
- Three openings forming an inverted triangle (trigone).
- Two ureteric orifices where the ureters enter the bladder.
- Urethral orifice: internal opening of the urethra.
- The surface of the trigone lacks muscular ridges and is smooth.
-
Urethra:
- Carries urine from the bladder to the exterior.
-
Female Urethra:
- Short.
- Exits the bladder, traverses quickly through the pelvic floor and perineal membrane.
- Women are more susceptible to urinary tract infections (UTIs) due to its length.
- Easy to insert a catheter.
-
Male Urethra:
- Long, with two bends.
- Four parts:
- Preprostatic Part: immediately after the bladder, before the prostate.
- Prostatic Part: through the prostate.
- Membranous Part: through the pelvic floor and perineal membrane.
- Spongy Part: within the penis (both bends are in the spongy part).
- Men are less prone to UTIs due to the length.
- Difficult to insert a catheter.
Portal Vein
- Drains blood from the abdominal gastrointestinal tract, spleen, and pancreas.
- Carries venous blood to the liver for metabolism.
- Metabolized blood drains into the hepatic veins, which drain into the inferior vena cava.
Pelvic Diaphragm
- Separates the pelvis from the perineum.
- Attachment point for the external genitalia.
- Diamond-shaped, with two triangles:
- Urogenital Triangle: Anterior, contains the urogenital hiatus (opening for the urogenital system).
- Anal Triangle: Posterior, contains the anal aperture (opening for the gastrointestinal tract).
- Formed by the levator ani muscle (contributes to elevating the anus):
- Puborectalis: Attaches to the pubis bone and encircles the rectum, creating a sling that maintains fecal continence.
- Pubococcygeus: Located laterally to the puborectalis, attaches to the pubis and coccyx bones.
- Iliococcygeus: Located laterally to the pubococcygeus, attaches to the ilium and coccyx bones.
Perineal Membrane
- Covers half of the pelvic diaphragm (urogenital triangle).
- Superficial to the pelvic diaphragm.
- Contains openings for the urethra (male and female) and vagina (female).
Deep Perineal Pouch
- Space between the perineal membrane and the levator ani.
- Contains skeletal muscles forming voluntary sphincters around the urethra (external urethral sphincter) and vagina.
Child Birth
- Perineum, levator ani, perineal membrane, and deep perineal pouch muscles are prone to tearing or injury during childbirth.
- These muscles in females support the urethra, vagina, uterus, and rectum.
- Injuries can result in urinary stress incontinence, uterine prolapse, and fecal incontinence.
Ovary
- Paired, intraperitoneal organs.
- Located posterior to the broad ligament and adjacent to the lateral wall of the pelvis.
- Supplied by the ovarian artery, a branch of the abdominal aorta.
- The ligament of the ovary attaches the ovary to the uterus.
- Irregularly shaped ball with two regions:
- Medulla: Inner region containing vessels, nerves, and lymphatics.
- Cortex: Outer region where follicular genesis occurs.
- Has a defined surface epithelium.
- Oocytes are surrounded by supporting cells that prepare them for ovulation.
- Oocytes ovulate in the ovary and are expelled into the fallopian tube.
Fallopian/Uterine Tubes
- Project laterally from the uterus and open adjacent to the ovaries.
- Composed of three areas:
- Infundibulum: Funnel-shaped structure that facilitates oocyte collection, featuring fimbriae (finger-like projections) that help catch the oocyte.
- Ampulla: Large, labyrinthine lumen where fertilization occurs.
- Isthmus: Narrow region connecting to the uterus.
Uterus
- Thick-walled, muscular organ that facilitates embryonic and fetal development.
- Supplied by the uterine artery, a branch of the internal iliac artery.
- Composed of three parts:
- Fundus: Top part above the fallopian tubes.
- Body: Largest part below the fallopian tubes.
- Cervix: Opening into the vagina.
- Has two linings:
- Myometrium: Middle layer of smooth muscle that undergoes hypertrophy and hyperplasia during pregnancy.
- Endometrium: Inner lining that supports pregnancy (zygote implants in the endometrium) and sheds during menstruation.
-
Uterine Position (when bladder is empty):
- Anteverted (AV): Tilted forward relative to the vagina.
- Anteflexed (AF): Bent forward over the bladder.
- When the bladder is full, the uterus is displaced upwards.
- Retroverted and Retroflexed: Uterus displaced to the back (more prone to prolapse).
- Uterine Prolapse: Uterus pushed through the vagina due to high pressure in the pelvis.
Cervix
- Opens inferiorly into the anterior wall of the vagina.
- Composed of two parts:
- Supravaginal: Above the vagina.
- Vaginal: Within the vagina.
- The uterus is best supported at the cervix.
Vagina
- Muscular passage connecting the uterus to the exterior.
- Located between the urethra anteriorly and the rectum posteriorly.
- Fornix: Spaces created anterior, posterior, and lateral to where the cervix enters the vagina.
- Supplied by vaginal arteries, branches of the internal iliac artery.
Ectopic Pregnancy
- Fertilization typically occurs in the ampulla.
- Implantation usually occurs in the uterine body.
- Ectopic/Extrauterine Pregnancy: Implantation occurs anywhere but the endometrial lining.
- If an ectopic pregnancy occurs in an area with a large blood supply, the embryo will grow, causing bleeding into the abdominal cavity.
- A burst uterine tube from an ectopic pregnancy can be misdiagnosed as a burst appendix.
Peritoneal Folds
- Peritoneum: Serous membrane covering the top of the pelvic viscera that supports and protects the pelvis.
- Peritoneal folds form over the pelvic viscera.
- Broad Ligament: Peritoneal folds coming together over the uterine tube.
- Ovaries are surrounded by peritoneum and therefore are intraperitoneal (there is an opening for the oocyte to pass through).
- Ligament of the Ovary: Folds of peritoneum over the ovarian vessels.
Peritoneal Pouches
- Created by peritoneal folds.
- Recto-uterine pouch: Between the rectum and uterus, the deepest part of the abdominal cavity where fluid collects (especially when lying on the back).
- Vesico-uterine pouch: Between the bladder and uterus.
Development of External Genitalia
- Same in males and females.
- Genital Tubercle: Develops into the glans penis (male) or glans clitoris (female).
- Testosterone promotes faster growth of the genital tubercle, resulting in a larger size in males.
- Urethral Folds: Develop into the urethra (male and female) and labia minora (female).
- Labioscrotal Swellings: Develop into the scrotum (male) and labia majora (female).
Anatomy of the Vulva
- Vulva/Pudendum: Erectile tissue and overlying skin comprising the external genitalia.
- Labia Minora: Two thin skin folds next to the midline, devoid of fat and hair, with connective tissue inside.
- Vestibule: Area between each labia minora (contains the urethra and vagina).
- Labia Majora: Larger skin folds located lateral to the labia minora.
- Glans Clitoris: Erectile tissue, exposed (not covered by skin), located where the labia minora meet anteriorly.
- Perineal Membrane and Pubic Arch: Provide attachment points for the roots of the external genitalia..
Erectile Tissue
- Composed of:
- Corpora Cavernosa: Two structures located anterior to the glans clitoris that attach to the pubic arch.
- Bulbs of Vestibule: Two structures located deep to the labia minora.
- Glans Clitoris
- Body of the Clitoris: Comprised of the corpora cavernosa and bulbs of vestibule.
- Erectile tissues are located anterior to the urethra.
- Greater Vestibular Glands: Located posterior to the bulbs, with openings into the vestibule, secreting lubricating mucous during arousal.
Muscles
- Ischiocavernosus Muscle: Covers the crus of the clitoris (part of the corpora cavernosa that attaches to the pubic arch) and maintains clitoral erection.
- Bulbospongiosus Muscle: Encloses the bulbs and greater vestibular glands, supporting the pelvic floor and assisting in clitoral erection and compression of the greater vestibular glands.
Pelvic Diaphragm (Male)
- Same as the female pelvic diaphragm.
- Only one opening in the perineal membrane for the urethra.
- The deep perineal pouch also contains sphincters around glands.
Perineal Membrane (Male)
- Superficial to the pelvic diaphragm.
- Covers the urogenital triangle.
- Contains an opening for the urethra (male and female) and vagina (female).
Deep Perineal Pouch (Male)
- Space above the perineal membrane.
- Contains skeletal muscles forming sphincters around the urethra, glands, and neurovascular structures that supply the penis.
Testes
- Responsible for sperm production.
- Septa (connective tissue) divides the testes into approximately 250 lobules.
- Each lobule contains 3-10 seminiferous tubules where spermatogenesis occurs.
- Each tubule is a highly convoluted loop within the lobule.
- Closer to the lumen, sperm differentiate (still non-motile).
- Tubules end as tubulus erectus (straight tube), which connects to the rete testis in the mediastinum.
- Rete Testis: Network of anastomosing channels that collect sperm from all the seminiferous tubules.
-
Outer Capsules:
- Tunica Albugenia: Surrounds lobules.
- Tunica Vaginalis: Covers the testes during descent, an extension of the abdominal peritoneum surrounding the tunica albugenia.
Testicular Descent
- Gonadal development occurs along the posterior abdominal wall.
- Testes descend towards the inguinal canal by 7 months of gestation.
- They pass through the inguinal canal into the scrotum just before birth.
- This descent brings blood vessels, nerves, the duct system (vas deferens), and layers of the abdominal wall to the scrotum.
Cryptorchidism (Undescended Testes)
- Histological changes leading to infertility.
- Increased risk of testicular cancer.
- Requires surgical correction ideally before 18 months or 2 years of age.
Epididymis
- Coiled tube approximately 5 cm long.
- Sperm from the mediastinum of the testes travel through efferent tubules to the epididymis.
- Caput (head), Corpus (body), and Caudal (tail).
- Surrounded by smooth muscle that assists in sperm movement.
- Function is to store and mature sperm.
- Where sperm acquire motility.
- Sperm are stored for ~1 month in the epididymis before they die and are reabsorbed by epithelial cells.
Vas Deferens
- Sperm travels from the epididymis to the vas deferens.
- Long duct.
- Length and complex course result from testicular descent.
- Penetrates the abdominal wall through the inguinal canal.
- Descends along the lateral wall of the pelvic cavity.
- Wolffian Ducts develop into the vas deferens.
- Smooth muscular duct (inner circular and outer longitudinal muscles) responsible for transporting sperm to the ejaculatory duct.
- Ejaculation, mediated by the sympathetic nervous system, causes smooth muscle contraction and pumping sperm through the vas deferens.
- Ejaculatory Duct: Formed by the vas deferens and the duct of the seminal vesicle.
- Function: Transport sperm to the ejaculatory duct.
- Part of the spermatic cord.
Vasectomy
- Ligating the vas deferens to prevent sperm from reaching the penis.
- The vas is superficial on the posterior side of the scrotum, making the procedure relatively non-invasive.
- White blood cells help the epididymis break down sperm after vasectomy.
Accessory Glands
- Contribute to the volume of ejaculate.
Male Reproductive System
-
Seminal Vesicles:
- Located on the back of the bladder.
- Join the vas deferens to form the ejaculatory duct, which empties into the prostatic urethra.
- Contribute to the volume of semen.
- Secrete an alkaline, viscous fluid that neutralizes the acidic female reproductive tract and aids in sperm motility and viability.
-
Prostate:
- Found below the bladder, in front of the rectum.
- Walnut-sized gland that surrounds the urethra.
- Contains three zones: peripheral, transitional, and central.
- Secretes a watery liquid containing zinc, citric acid, prostaglandins, and proteolytic enzymes.
- Enhances sperm viability and maturation.
- Has multiple openings into the prostatic urethra.
-
Benign Prostatic Hypertrophy (BPH):
- Common in older men.
- Enlargement of the central prostate.
- Compresses and blocks the urethra, leading to an intermittent urinary stream.
- Direct rectal examination (DRE) reveals a large, soft prostate.
-
Prostate Cancer:
- A common malignancy in men.
- 70% occur in the peripheral region.
- Affects the entire prostate.
- Diagnosed through DRE (prostate feels hard) or blood tests.
- Treated with radiotherapy, chemotherapy, removal, or androgen deprivation therapy.
- Androgen deprivation therapy can shrink or remove tumor tissue if the tumor is androgen-dependent.
- If the tumor recurs, it is not androgen-dependent and is typically more aggressive.
-
Bulbourethral Glands (Cowper's Glands):
- Paired, pea-shaped glands located in the deep perineal pouch.
- Their ducts open into the spongy urethra.
- Secrete mucus that lubricates the urethra and forms pre-ejaculate.
External Genitalia
-
Hypospadias:
- A congenital disorder of the penis where the urethra opens along the shaft of the penis.
- Affects about 1 in 250 boys.
-
Penis:
- Covered by skin.
- Attaches to the perineal membrane and the pubic arch.
- Erectile tissue consists of two corpora cavernosa and one corpus spongiosum, which expands distally to form the glans penis.
- The urethra passes through the perineal membrane via the urogenital hiatus, enters the corpus spongiosum, and exits at the glans penis.
- Erection is mediated by the parasympathetic nervous system, causing arteries in the penis to relax and allow blood to fill the erectile tissues.
- Muscles: Ischiocavernosis and bulbospongiosus muscles move blood from the root of the penis to the body, and constrict venous drainage.
Kidneys & Urinary System
-
Kidneys:
- Located superior and medial to each adrenal gland.
- Responsible for urine production.
- Paired, solid organs.
- Retroperitoneal.
- Bean-shaped (10 x 2 x 2.5 cm).
- Healthy kidneys are reddish-brown.
- Extend longitudinally from T12-L3.
- Position changes with diaphragm contraction.
- Left kidney is higher than the right due to liver displacement.
- Two surfaces: anterior and posterior.
- Surgical approach involves lateral or posterior access due to their positioning.
-
Perinephric Fat and Renal Fascia:
- Perinephric fat surrounds the kidneys.
- Renal fascia encloses the perinephric fat and kidneys, situated behind the parietal peritoneum.
-
Kidney Structure:
- Renal capsule lines the kidney surface.
- Renal sinuses are spaces within the kidney filled with perinephric fat.
-
Medulla:
- Contains renal pyramids (cone-shaped structures with base at surface, apex towards hilum).
- Composed of secretory cells that produce urine.
- Pyramids are separated by the cortex.
-
Cortex:
- Continuous outer layer that surrounds the renal pyramids.
-
Renal Collecting System:
- Urine is secreted from the medulla and collected at the apex of the pyramids into the hilum.
- Minor calyx collects urine.
- Major calyx receives urine from multiple minor calices.
- Renal pelvis (upper part of the ureter) collects urine from multiple major calices and passes through the renal hilum.
-
Renal Hilum:
- Faces anteromedially.
- Contains the renal vein (anterior), renal artery (middle), and renal pelvis (posterior), along with nerves and lymphatics.
-
Renal Artery:
- The primary blood supply to each kidney.
- Arises from the paired branches of the abdominal aorta.
- Divides into five segmental arteries upon entering the hilum.
- Each segmental artery supplies a renal segment (a single functional unit, typically five, surgically resectable).
-
Accessory Renal Artery:
- An additional blood supply.
- Develops as kidneys move upward during fetal development.
- May persist alongside the renal artery.
- Not present in everyone or on both sides.
- Can enter the kidney through the hilum or surface.
-
Renal Vein:
- Drains venous blood directly into the inferior vena cava (IVC).
- The IVC lies to the right of the abdominal aorta.
- The left renal vein crosses the midline before draining into the IVC and has a longer course than the right renal vein.
-
Ureters:
- Paired hollow tubes.
- Transport urine from the kidneys to the bladder.
- Begin at the renal hilum as the renal pelvis, descend inferiorly in front of psoas major and the lumbar vertebra transverse processes, cross the pelvic brim, and enter the bladder.
- Constrictions at:
- The uretropelvic junction (where the renal pelvis meets the ureter).
- The pelvic brim crossing point.
- Where the obliquely traverses the bladder wall (acts as a functional sphincter, preventing reflux of urine).
- Constrictions can be problematic for kidney stones.
-
Urinary Bladder:
- A hollow muscular organ.
- Stores urine.
- Pyramid-shaped:
- Base: Posterior, against the uterus in females and rectum in males.
- Apex: Interior, against the pubic bone (males and females).
- The most anterior pelvic organ.
-
Bladder Neck:
- The inferior part of the bladder.
- Anchor point for bladder, held by ligaments.
- Expands as the bladder fills, while the neck remains fixed.
-
Bladder Base:
- Three openings form an inverted triangle (trigone).
- Two ureteric orifices: where the ureters enter the bladder.
- Urethral orifice: the internal opening to the urethra.
- The surface of the trigone lacks muscular ridges and is smooth.
-
Urethra:
- Transports urine from the bladder to the exterior.
-
Female Urethra:
- Short.
- Exits the bladder, passes quickly through the pelvic floor and perineal membrane.
- Increased susceptibility to UTIs due to length.
- Easy to insert a catheter.
-
Male Urethra:
- Long.
- Bends twice.
- Four parts:
- Preprostatic: Immediately after the bladder, before the prostate.
- Prostatic: Passes through the prostate.
- Membranous: Passes through the pelvic floor and perineal membrane.
- Spongy: Extends inside the penis (both bends are in the spongey part).
- Less prone to UTI s due to its length.
- Difficult to insert a catheter.
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Description
Test your knowledge on the anatomy and functions of the human reproductive and urinary systems. This quiz covers important topics like the function of seminal vesicles, prostate health, and the structures of the kidneys and urethra. Ideal for students studying human biology or health sciences.
