3: Anatomy of Testes Flashcards
What is the testes?
A compound tubular gland enclosed in a thick fibrous capsule (tunica albuginea)
What is the thick fibrous capsule of the testes called?
Tunica albuginea

What does he tunica albuginea capsule form posteriorly?
The mediastinum testis

How does the mediastinum testis allow sperm to enter the duct system?
The mediastinum testis contains interconnected channels –> form a passageway for the sperm
SSREED

What do the strong connective tissue in he tunica albuginea do?
Divide the testes into 250 pyramid shaped lobules

What does each lobule of the testes contain?
1-4 highly convoluted seminiferous tubules

What do seminiferous tubules produce?
Spermatozoa
Where are spermatozoa produced?
In the seminiferous tubules inside the pyramids of the testes
What are the seminiferous tubules surrounded by?
Layer of connective tissue with flattened myofibroblasts and an inner basement membrane
What is the epithelium of the seminiferous tubules?
Stratified (seminiferous epithelium)
What types of cell does the seminiferous tubule epithelium consist of? (2 types)
- Sertoli cells (aka supporting cells)
- Spermatogenic cells (germ cells)
Which cells are more abundant, Sertoli or Spermatogenic cells?
Spermatogenic

Where are Sertoli cells?
On the basement membrane of the seminiferous tubule
How are Sertoli and Spermatogenic cells anatomically related?
The Sertoli cells on the BM form processes extending and surround the spermatogenic cells

What do the apical regions of Sertoli cells have?
Recesses where heads of sperms are embedded

How are Spermatogenic cells arranged?
In rows around Sertoli cells

Which Spermatogenic cells rest on the BM?
Spermatogonia (primitive spermatogenic cells)
The cells at later stages of development are at higher up levels of the epithelia nearer the lumen

Where Primary Spermatocytes located?
Adjacent to spermatogonia but nearer to the lumen
What do the nuclei of primary spermatocytes represent?
Different stages of meiosis 1
How do primary spermatocytes become secondary spermatocytes?
Meisos 1
What do secondary spermatocytes become after meiosis 2?
Spermatids
Where are spermatids located?
At the border of the lumen
Ones at top just before the spermatzoa

What do spermatids become when they mature?
Spermatozoa (sperms innit)
Where do the nuclei of spermatozoa embed?
Cytoplasm of Sertoli cells
(Tails hang into lumen of semineferous tubule)

Where are Leydig cells found?
In the connective tissue between seminiferous tubules.

What do leydig cells produce?
Testosterone in the presence of luteinizing hormone (LH)
What is special about the nucleus of leydig cells?
Can contain 1-3 nucleoli
Where does Spermatogenesis occur?
In seminiferous tubules
Where does steroidogenesis occur?
In Leydig cells
Where are the testes contained?
In the scrotal sac
What is the scrotum?
Layer of skin
Superficial fascia
What is found within the superficial fascia of the scrotum?
Dartos muscle
What is the purpose of the dartos muscle of the scrotum?
Regulates temperature of testes
- Contracts –> elevates scrotum
- Relaxes –> drops scrotum
What is the function of the spermatic cord?
Suspends the testes in the scrotum
Where does the spermatic cord extend to and from?
From deep inguinal ring – through the inguinal canal –> superficial inguinal ring
Ends at the posterior border of testis
What are the contents of the spermatic cord? (8 things)
- Pampiniform Venous Plexus
- Ductus (Vas) Deferens
- Cremasteric Artery
- Testicular Artery
- Artery of Ductus (Vas) Deferens
- Genital Branch of Genitofemoral nerve
- Sympathetic nerve fibres
- Lymphatic vessels
Piles Don’t Contribute To A Good Sex Life
What are the fascial coverings of the spermatic cord? (3 layers)
- Internal spermatic fascia
- Cremasteric fasica
- External spermatic fascia
What is special about the cremasteric fascia of the spermatic cord?
It has loops of cremasteric muscle –> draws scrotum superior when cold (thermoregulation)
What is the ductus (vas) deferens? (2 things)
- A continuation of the tail of the epididymis
- Primary component of the spermatic cord
Where does the vas deferens extend from and to?
- From tail of epididymis
- Goes through inguinal canal
- Crosses ant. pelvic bone
- Runs on lateral pelvic wall
- Goes around bladder
- Forms ampulla and joins with seminal glands to form: Ejaculatory duct

What is blood supply of the vas deferens?
artery of ductus (vas) deferens
What are the accessory glands of the male reproductive system?
- Seminal Glands
- Prostsate Gland
- Bulbourethral Glands
What do the Seminal Glands produce?
Thick alkaline fluid
What does the seminal gland secretion contain? (2 things)
- Fructose
- Coagulating agent
What percentage of the total ejaculated fluid volume is made by the seminal glands?
60%
What do the seminal glands join with to form the ejaculatory duct?
Vas Deferens
Called ductus deferens in the pic

Where does the ejaculatory duct extend to?
Runs through posterior part of prostate to join the prostatic urethra

Which is the largest of the accessory glands?
Prostate gland
What type of gland is the prostate gland?
Fibromuscular gland
What is the arterial supply of the prostate gland?
Internal iliac artery
What is the venous drainage of the prostate gland?
Prostate plexus –> drains into internal iliac vein
What is the lymphatic drainage of the prostate gland?
Internal iliac and sacral nodes
What are some important anatomical relations of the prostate gland?
- Base is near neck of bladder
- Apex in contact with superior aspect of urethral sphincter + deep perineal muscles
- Muscular anterior surface is part of the urethral sphincter
- Inferolateral surface is near levator ani

What are some important anatomical relations of the prostate gland?
- Base is near neck of bladder
- Apex in contact with superior aspect of urethral sphincter + deep perineal muscles
- Muscular anterior surface is part of the urethral sphincter
- Inferolateral surface is near levator ani

Where are the bulbourethral glands found? (2 things)
- Posterolateral to membranous urethra
- Within the deep perineal pouch (which is in the urogenital triangle)

What do the bulbourethral glands produce and when?
Clear watery secretion that lubricates urethra
Prior to ejaculation
What are the 3 parts of the penis?
- Root
- Body
- Glans

What does the root of the penis have?
- Bulb (associated with bulbospongiosus)
- Crus (associated with ischiocaverous)
What are the internal structures of the penis? (Dorsal & Ventral)
Dorsally: Pair of corpora cavernosa –> fills up with blood –> allows the penis to erect
Ventrally: Corpus spongiosum (surrounds urethra and prevents compression of urethra @ erection)

What surrounds the Corpora Cavernosa?
Tunica albuginea (fibrous capsule)

What is the arterial supply of the penis?
Internal pudendal artery gives off:
- Dorsal arteries of penis
- Bulbourethral arteries of penis

What is the venous drainage of the penis?
Blood from cavernous spaces drained by venous plexus that joins deep dorsal veins of penis
What is the nervous innervation of the penis?
Sensonary & Sympathetic:
S2-4 –> pedundal nerve –> dorsal nerve of penis
Parasympathetic:
Peri-prostatic nerve plexus –> Cavernous Nerves

What are the perineal muscles of the male? (2 muscles)
- Bulbospongiosus Muscle
- Ischiocavernous Muscle

What is the function of the Bulbospongiosus Muscle? (2 things)
- Compresses the bulb of penis and corpus spongiosum –> acts to empty spongy urethra of residual semen + urine
- Anterior fibres help maintain erections by increasing the pressure of the erectile tissue in the root of the penis
What is the function of the Ischiocavernous muscle?
Forces blood from the cavernous spaces in crura (plural of crus) –> distal corpus cavernosa
This helps maintain erection and turgidity

What is the function of the urethra?
Conveys urine from the internal urethral orifice –> external urethral orifice
What are the 4 parts of the urethra?
- Intramural part
- Prostatic part
- Intermediate (membranous) part
- Spongy urethra
IPIS (like I piss innit)
Where does the Intramural part of the urethra extend through?
Through neck of bladder
What is the Intramural part of the urethra surrounded by?
Internal urethral sphincter
Where does the Prostatic part of the urethra descend through?
Through anterior prostate
Which is the widest part of the urethra?
Prostatic Part
Phat Prostatic Part
Where does the Intermediate (Membranous) part of the urethra pass through?
Through the perineal pouch
Which is the least distensible (stretchy) part of the urethra?
Intermediate (membranous) part
Memb Never Extend (it rhymes)
Where does the Spongy urethra pass through?
Through corpus spongiosum of penis
Which is the longes part of the urethra?
Spongy part
Runs through the acc penis innit
What is the Rete Testis?
Network of tubules in mediastinum testis

What is the function of the Rete Testis?
Carries sperm from the seminiferous tubules –> efferent ductules

What does the epididymis connect?
Seminiferous tubules –> Vas Deferens
(via Rete Testis and Efferent Ductules)

What happens in the epididymis?
Sperm stored and matures here
What are the 3 parts of the epididymis?
- Head
- Body (convoluted ducts)
- Tail
