Male reproductive anatomy/histology Flashcards
Contents of the root of the penis
- 2 crura
- Bulb
- Ischiocavernosus
- Bulbospongiosus
Contents of the body of the penis
- 2 corpora cavernosa
- Corpus spongiosum
What is the glans penis?
- The head of the penis - contains external urethral meatus
- Formed from expansion of corpus spongiosum
What are the three fascia of the penis?
- Colles’ fascia
- Buck’s fascia
- Tunica albuginea
What is Colles’ fascia continuous with?
Scarpa’s fascia
What is Buck’s fascia continuous with?
Deep perineal fascia
What is the tunica albuginea?
Capsule around each cavernous body in the penis.
Fused along the midline at the septum
What ligaments are in the penis?
Suspensory ligament:
- Condensation of deep fascia
- Connects erectile bodies to pubic symphysis
Fundiform ligament:
- Condensation of abdominal subcutaneous tissue
- Surrounds penis like a sling
4 paths of arterial supply to the penis
- Dorsal arteries of the penis
- Deep arteries of the penis
- Arteries of the bulb of the penis
- Superficial/Deep branches of the external pudendal
Venous drainage of the penis
- Deep dorsal veins drain the cavernous spaces
- Superficial dorsal veins drain the skin and subcutaneous tissues
Function of the epididymis
- Transport sperm from the testes to the vas deferens
- Stores sperm while it matures
Parts of the epididymis
- Head: from efferent tubules of testes
- Body: highly coiled duct
- Tail: origin of vas deferens
Arterial supply of epididymis
Testicular arteries (branches of abdominal aorta)
Venous drainage of epididymis
Pampiniform plexus drains to the testicular veins
- Left testicular vein goes to left renal vein
- Right testicular vein goes to IVC
Lymphatic drainage of epididymis
Lumbar and para-aortic lymph nodes
Innervation of the epididymis
Testicular plexus provides ANS and sensory fibres
How is temperature regulated in the testes?
- Descent of the testes from abdomen to scrotum via inguinal canal during development
- Cremaster muscle - raises testes in response to cold, sex or fear
- Dartos muscle - changes surface area of scrotum in response to change in temperature
- Pampiniform plexus of testicular veins also has a role
What type of epithelium lines the seminiferous tubules?
Complex stratified epithelium (cuboidal cells that can resist stretching and recoiling)
What are peritubular myoid cells?
Thin, contractile cells that line the external tubules
They propel spermatozoa towards vas deferens and provide structural support
What are Sertoli cells?
Tree-shaped columnar cells with tall cytoplasms found within the testes
They respond to FSH
What are the functions of Sertoli cells?
- Sex determination (SRY gene = male)
- Developmental (anti-Mullerian hormone = regression of female organs)
- Hormone regulation (regulates FSH secretion)
- Stem cell regulation (GDNF secretion to ensure self-renewal of spermatogonial stem cells)
- Forms blood-testis barrier (protect sperm from immune system)
What are Leydig cells?
- Primary component of interstitial space in the testes
- They contain the Crystals of Reinke and have abundant smooth ER
What are the functions of Leydig cells?
- Primary source of testosterone in response to luteinising hormone
- This testosterone will either diffuse into seminiferous tubules or enter peripheral circulation
What are the layers of the testes?
Tunica vaginalis:
- Most superficial
- Parietal and visceral layers separated by thin layer of fluid (excess build up of fluid = hydrocele)
Tunica albuginea:
- Divides testes into lobules by forming septa between each
Tunica vasculosa:
- Innermost layer
- Rich vascular supply and connective tissue
What are the layers of the scrotum?
- Skin
- Dartos fascia and muscle
- External spermatic fascia
- Cremasteric fascia
- Internal spermatic fascia
- Tunica vaginalis
- Tunica albuginea
Some Derelict English Cunts Invaded The Tunisians
Arterial supply to the scrotum
Anterior (from ext. pudendal) and posterior (from int. pudendal) scrotal arteries
Venous drainage of the scrotum
Scrotal veins empty into the external pudendal vein
Lymphatic drainage of the scrotum
Superficial inguinal nodes
Nervous supply to the scrotum
Anterior and posterior scrotal nerves
Coverings of the spermatic cord
- External spermatic fascia (from ext. oblique)
- Cremasteric muscle + fascia (from int. oblique)
- Internal spermatic fascia (from transversalis fascia)
Contents of the spermatic cord
Vessels:
- Testicular artery
- Pampiniform plexus of testicular veins
- Cremasteric artery and veins
- Artery to vas deferens
Nerves:
- Genital branch of genitofemoral nerve
- Autonomic fibres
Vas deferens
Processus vaginalis
Lymphatic vessels
What is the epididymis composed of?
- Ciliated pseudostratified squamous epithelium, epithelium becomes cuboidal in the body and tail
- Peritubular smooth muscle which thickens as it gets closer to the vas deferens
What is the course of the vas deferens?
Runs deep to scrotal skin though inguinal canal. Joins with duct from seminal vesicle to form ejaculatory duct. This then joins to the prostatic urethra
What are the layers of the vas deferens?
Inner: longitudinal smooth muscle
Middle: circular smooth muscle
Outer: longitudinal smooth muscle
What lines the lumen of the vas deferens?
Mucosa consisting of:
- Lamina propria
- Secretory pseudostratified columnar epithelium with apical stereocilia
What are the functions of the vas deferens?
- Propulsion of sperm through contractions
- Absorption of sperm
What are the seminal vesicles?
- Paired glands that produce the majority of constituents of semen
- Located between the fundus of the bladder and rectum
- They have pseudostratified columnar epithelium
What is the arterial supply to the seminal vesicles?
Arteries are derived from the inferior vesicle, internal pudendal and middle rectal
What is contained in the seminal vesicle secretions?
- Fructose
- Sugars
- Ascorbic acid
Where is the prostate gland located?
Inferior to the bladder and superior to the external urethral sphincter
What does the prostate gland secrete?
- Citric acid
- Seminal plasmin
- Prostate specific antigen (used to screen for prostate cancer)
What is the prostate gland?
It is the largest accessory gland. It has cuboidal, columnar and pseudostratified epithelium
Enlargement of the prostate gland
- Typically enlarges with age
- Median lobe more commonly affected by benign prostatic hyperplasia
- Outer zone susceptible to inflammation and cancer; zone around urethra also commonly enlarges
- Testosterone stimulates growth of the prostate
Neurovasculature of the prostate gland
Arteries:
- Prostatic arteries
Venous drainage:
- Prostatic venous plexus
Innervation:
- Inferior hypogastric plexus
What is a risk of a radical prostatectomy?
- Prostate is surrounded by nerves that are responsible for erections
- They can be damaged in the operation
What are the bulbourethral glands?
- Aka Cowper’s glands
- Posterolateral to membranous urethra
- Contain tubuloalveolar glands lined by columnar epithelium
- Secrete lubricating mucous that is included in semen
