Male & Female Genital Systems

Overview of the Male Genital System

• Primary Sex Organs:     - Two testis.

• Accessory Sex Organs:     - Two Epididymis.     - Two Vas deference (Ductus deferens).     - Two Seminal vesicles.     - One Prostate gland.     - Male urethra and penis.

Anatomy of the Testis

• Function:     - Acts as both an endocrine gland (producing hormones) and an exocrine gland (producing sperm).

• Shape: Oval or ellipsoid.

• Measurements: Approximately $4 \times 3 \times 2.5\,\text{cm}$.

• Weight: An adult testis weighs about $10-15\,\text{gm}$.

• Location and Site:     - Each testis lies within a compartment of the scrotal sac.     - It is suspended by the spermatic cord.     - The left testis is typically situated slightly lower than the right testis.

The Scrotum

• Definition: A fibromuscular cutaneous sac located between the penis and the anus.

• Division: Divided into Right (Rt) and Left (Lt) portions by a median raph (scrotum septum).

• Structure: Consists of 5 layers.

• Contents:     - Organs: Testis, Epididymis, and the distal part of the Spermatic cord.     - Vessels: Anterior and posterior scrotal vessels.     - Lymphatics: Drainage proceeds into the superficial inguinal nodes.

External Features and Coverings of the Testis

• External Features:     - Poles: Upper pole and lower pole.     - Surfaces: Medial surface and lateral surface.     - Borders:         - Anterior border: Convex and covered by the tunica vaginalis.         - Posterior border: Related to the epididymis and the vas deferens.

• Coverings (3 Coats from outside inwards):     1. Tunica vaginalis: A remnant of the processus vaginalis.     2. Tunica albuginea: A layer of fibrous tissue.     3. Tunica vasculosa: The innermost vascular layer that lines the lobules.

Internal Structure of the Testis

• Glandular Structure:     - Contains $200-300$ lobules separated by septa sent from the tunica albuginea.     - Each lobule contains $2-3$ seminiferous tubules.

• Pathway of Sperm:     - Seminiferous tubules anastomose at the apices to form the Rete Testis.     - The Rete Testis gives rise to $12-30$ Efferent ductules.     - These lead to the Head of the epididymis, then the Ductus deferens.

Neurovascular Supply of the Testis

• Arterial Supply:     - Testicular artery: A branch of the abdominal aorta arising at the level of $L_2$.     - Course: Posterior abdominal wall \rightarrow Deep inguinal ring \rightarrow Spermatic cord \rightarrow Testis.

• Venous Drainage:     - Pampiniform plexus of veins \rightarrow Testicular vein.     - Right side: Drains directly into the Inferior Vena Cava (IVC).     - Left side: Drains into the Left renal vein.

• Lymphatic Drainage: Pre-aortic and para-aortic lymph nodes.

• Nerve Supply: Sympathetic fibers from $T_{10}$ lymph nodes.

The Epididymis and Spermatic Cord

• The Epididymis:     - Shape: Comma-shaped organ attached to the posterolateral aspect of the testis.     - Structure: Formed of a highly coiled single tube measuring $6\,\text{m}$ in length.     - Parts:         - Head: Expanded upper end; continuation of efferent ductules.         - Body: Single coiled tube.         - Tail: Attached to the lower pole of the testis; continues as the vas deference.

• The Spermatic Cord:     - Formation: As the testis traverses the abdominal wall into the scrotum during early life, it carries its vessels, nerves, and vas deferens, forming the cord.     - Extent: From the deep inguinal canal to the posterior aspect of the testis.     - Contents:         - Structures: Ductus deferens, remains of the processus vaginalis.         - Vessels: Testicular artery, cremasteric artery, artery of the ductus deferens, Pampiniform plexus of veins, and lymph vessels.         - Nerves: Ilioinguinal nerve, genital branch of the genitofemoral nerve, and the plexus of sympathetic nerves.

Vas Deferens and Seminal Vesicles

• Vas Deferens (Ductus Deferens):     - Description: A long muscular duct ($45\,\text{cm}$) transporting spermatozoa from the epididymis tail to the ejaculatory duct.     - Course: Arises from the tail of the epididymis \rightarrow Spermatic cord \rightarrow Inguinal canal \rightarrow Deep ring \rightarrow Passes downward on lateral pelvic wall \rightarrow Ischial tuberosity \rightarrow Turns medially to cross the ureter posterior to the bladder \rightarrow Dilates into the ampulla at the base of the bladder.     - Arterial Supply: Artery of the vas (from inferior or superior vesical arteries).

• Seminal Vesicle:     - Description: Two lobulated accessory glands, about $5\,\text{cm}$ long, on the posterior bladder surface.     - Relations:         - Medially: Ampulla of vas deferens.         - Anteriorly: Base of the bladder.         - Posteriorly: Rectum.     - Formation of Ejaculatory Duct: The narrowed end joins the lower part of the ampulla of the vas.     - Blood Supply: Arteries from inferior vesicle and middle rectal arteries; veins drain to internal iliac veins.

Ejaculatory Ducts and Prostate Gland

• Ejaculatory Ducts:     - Measurements: Each is less than $1\,\text{in.}$, or $2.5\,\text{cm}$ long.     - Formation: Union of the vas deferens and the duct of the seminal vesicle.     - Termination: Pierce the posterior surface of the prostate and open into the prostatic urethra near the prostatic utricle.

• Prostate Gland:     - Site: Immediately inferior to the bladder, above the urogenital diaphragm.     - Shape: Inverted rounded cone.         - Base: Large, continuous with the bladder neck.         - Apex: Narrow, rests on the pelvic floor.     - Capsules:         - True capsule: Dense fibrous capsule.         - False capsule: Prostatic sheath derived from pelvic fascia.         - Prostatic venous plexus: Located between the true and false capsules.

• Relations of the Prostate:     - Superiorly: Neck of the bladder.     - Inferiorly: Apex on the urogenital diaphragm.     - Anteriorly: Symphysis pubis and pubo-prostatic ligaments.     - Laterally: Anterior fibers of levator ani.     - Posteriorly: Rectal ampulla and fascia of Denon-Villiers.

• Internal Prostatic Structures: Prostatic urethra, two ejaculatory ducts, and the prostatic utricle.

• Lobe Division (5 Lobes): Anterior lobe, median lobe, posterior lobe, and two lateral lobes (right and left).

• Prostate Neurovascular Supply:     - Arteries: Internal pudendal, inferior vesical, and middle rectal arteries.     - Venous Drainage: Prostatic venous plexus into internal iliac veins.     - Lymphatics: Internal iliac and sacral lymph nodes.     - Nerve Supply: Parasympathetic (Pelvic splanchnic nerves $S_2, 3, 4$) and Sympathetic (Inferior hypogastric plexuses).

Female Genital System: Internal and External Organs

• Primary Sex Organ: Ovary.

• Secondary Sex Organs (Internal): Uterine tube, Uterus, Vagina.

• External Organs (Vulva):     - Labia majora.     - Labia minora.     - Glans clitoris.     - Vestibule.     - Hymen.

The Ovary

• Shape and Size: Oval or almond-shaped; measures $3 \times 2 \times 1\,\text{cm}$.

• Site: Located on the side of the lesser pelvis in the ovarian fossa, between external iliac vessels and internal iliac vessels/ureter.

• Ends:     - Upper (Tubal) end: Attaches to fimbria of fallopian tube and suspensory ligament of ovary.     - Lower (Uterine) end: Attached to the lateral end of the uterus by the ovarian ligament.

• Surfaces:     - Medial surface: Covered by the fimbriated end of the uterine tube.     - Lateral surface: Faces the pelvic wall; related to obturator nerve and vessels.

• Ligaments of the Ovary:     1. Suspensory ligament: From tubal end to the pelvic side wall.     2. Mesovarium: From the anterior border of the ovary to the broad ligament; transmits ovarian vessels and nerves.     3. Ovarian ligament: From the uterine end of the ovary to the lateral angle of the uterus.

• Blood and Nerve Supply:     - Artery: Ovarian artery from abdominal aorta at $L_1$.     - Veins: Right ovarian vein to IVC; Left ovarian vein to Left renal vein.     - Lymph: Para-aortic nodes.     - Nerves: From the aortic plexus.

The Uterine Tube (Fallopian Tube)

• Length: $10\,\text{cm}$.

• Location: Situated in the upper border of the broad ligament.

• Parts (4 Sections):     1. Infundibulum: Funnel-shaped lateral end with fimbriae.     2. Ampulla: The widest part of the tube.     3. Isthmus: The narrowest part, lateral to the uterus.     4. Intramural part: The segment piercing the uterine wall.

• Vascular and Nerve Supply:     - Arteries: Uterine and ovarian arteries.     - Veins: Uterine and ovarian veins.     - Lymph: Internal iliac and para-aortic nodes.     - Nerves: Inferior hypogastric plexuses (Sympathetic and parasympathetic).

• Function: Site of fertilization, transport, and nutrition of the fertilized ovum.

The Uterus

• Description: Hollow, pear-shaped organ with thick muscular walls.

• Measurements: $8 \times 5 \times 2.5\,\text{cm}$ (in a nulipara).

• Parts:     1. Fundus: Part above the uterine tube entrance.     2. Body: Part between the tubes and the isthmus.     3. Cervix: Narrow lower part. Divided into supra-vaginal and vaginal parts. Contains the cervical canal communicating via the internal os and external os.

• Anatomical Position:     - Anteverted: Long axis of uterus/cervix forms a $90^\circ$ angle with the long axis of the vagina.     - Anteflexed: Long axis of the body of the uterus forms a $170^\circ$ angle with the long axis of the cervix.

• Relations of the Uterus:     - Anteriorly: Uterovesical pouch, superior surface of bladder.     - Posteriorly: Rectouterine pouch (Pouch of Douglas) containing ileum or sigmoid colon coils.     - Laterally: Broad ligament, uterine artery, and vein.

• Wall Structure (3 Layers): Endometrium (inner), Myometrium (middle), Parametrium (external).

• Vascular and Lymphatic Supply:     - Uterine Artery: Branch of internal iliac artery; crosses above the ureter.     - Ovarian Artery: Assists and anastomoses with the uterine artery.     - Lymph from Fundus: Para-aortic nodes.     - Lymph from Body/Cervix: Internal and external iliac lymph nodes.

Ligaments of the Uterus and the Vagina

• Supporting Structures:     - Muscles: Levatores ani muscles and the Perineal Body.     - Pelvic Fascia Condensations:         1. Transverse Cervical Ligaments: Cervix/vagina to lateral pelvic walls.         2. Pubocervical Ligaments: Cervix to posterior pubis, surrounding the bladder neck.         3. Sacrocervical Ligaments: Cervix/vagina to the lower sacrum.     - Peritoneal Folds:         1. Broad ligaments: Folds around the uterine tubes.         2. Round ligament: Extends from the supero-lateral angle of the uterus, through the deep inguinal ring/canal to the labium majus. Helps maintain anteversion/anteflexion.

• The Vagina:     - Description: Muscular tube, $8\,\text{cm}$ long.     - Fornices: The vaginal lumen around the cervix is divided into four: anterior, posterior, right lateral, and left lateral.     - Relations:         - Anterior: Bladder (above), Urethra (below).         - Posterior: Upper 1/3 related to Pouch of Douglas; Middle 1/3 to rectal ampulla; Lower 1/3 to perineal body.         - Lateral: Upper part to ureter; Middle to levator ani; Lower to urogenital diaphragm and bulb of vestibule.     - Blood Supply and Drainage:         - Arteries: Vaginal artery (branch of internal iliac) and vaginal branch of uterine artery.         - Vaginal Venous Plexus: Drains to internal iliac vein.         - Lymph Drainage: Upper 1/3 (External/Internal iliac nodes); Middle 1/3 (Internal iliac nodes); Lower 1/3 (Superficial inguinal nodes).