3.1 Clinical Anatomy - Male Flashcards
List 4 important structures in the male reproducrive system
1) Scrotum & testis
2) Spermatic cord
3) Seminal vesicles and Prostate gland
4) Penis
Describe the pathway of sperm before and during an ejaculation
1) immature sperm are produced in the seminiferous tubules
2) transported through ➞ the retes testes ➞ effernt ductules ➞ epididymis (stored while they mature)
3) during ejaculation, sperm exit tail of the epididymis pushed by SM contraction to the ductus deferens (contained in spermatic cord)
4) from ductus deferens sperm travel into the prostatic urethra to be expelled from the male tract
What embryological layer do the testis derive from and what was their original position prior to decent?
What accompanies the testis during their decent?
The testicle is an intermediate mesoderm derivative that develops high on the posterior abdominal wall
As the testes descend, their accompanying vessels, ducts, and nerves pass through the inguinal canal and are therefore surrounded by the same fascial layers of the abdominal wall.
Where does lymph from the testis drain?
Drains to para-aortic nodes L2 (not inguinal nodes!!)
Briefly describe the decent of the testis and what happens to it during its decent
The testis descend through inguinal canal following gubernaculum
As it passes through the inguinal canal it picks up coverings from the muscles of the anterior abdominal wall
These form the coverings of the spermatic cords and the testis itself.
Spermatic cord coverings = layers of anterior abdominal wall
What is the thick fibrous capsule that encloses the testis and what is it derived from?
What is the double layer of peritoneum found surrounding this structure?
Label the diagram below
Tunica albuginea formed from the distal ends of the proccessus vaginalis (proximal regions obliterate)
This is surrounded by a layer of tunica vaginalis
1) If a cyst forms in the epididymis what would this be known as?
2) If a cyst forms in tunica vaginalis what would this be known as?
3) If a cyst is blood filled, what would this be known as?
1) Spermatocoele/ Epididymal Cyst
2) Hydrocoele
3) Haematocoele
Label the image below and explain what the processus vaginalis is
In which structure is a potential weak spot that may cause an indirect inguinal hernia?
the processus vaginalis is a a peritoneal outpouching that forms and protrudes through the various layers of the anterior abdominal wall and acquires coverings
The processus vaginalis is a potential weak spot and is the
route taken by indirect inguinal hernias
What are the 3 coverings aquired by the Processus vaginalis? (from deep to superficial)
Why is there no covering by the Transversis abdominis as you may expect?
1) the transversalis fascia forms its deepest covering
2) second covering is formed by the musculature of the internal oblique
* There is NO covering acquired from the transversus abdominis muscle because the processus vaginalis passes under the arching fibers of this abdominal wall muscle
3) The most superficial covering is the aponeurosis of the external oblique
What is a hernia?
A hernia occurs when an organ or internal body part pushes through the tissue that usually surrounds and protects it
What are the 2 types of inguinal hernias?
State which is which on the image below and briefly explain each
Direct Hernias: Usually develops in adulthood. Occurs within a “weak area” known as Hesselbach’s triangle (usually acquired muscle weakness)
Indirect Hernias: Usually a congenital disorder. Caused by failure of deep inguinal ring to close up
List 3 arteries, 3 nerves and 3 deep structures found in the sepermatic cord
Arteries: Testicular, Ductus deferens and Cremasteric artery
Nerves: Genital, Autonomic and Ilioinguinal nerve
Deep structures: Pampiniform plexus, Ductus deferens, Lymphatics
List the 3 layers of fascia covering the spermatic cord and state which layer of the anteriolateral abdominal wall muscles is each derived from?
1) Internal spermatic fascia: continuation of the transversalis fascia
2) Cremasteric fascia: derived from internal oblique muscle
3) External spermatic fascia: derived from the external oblique muscle
What is a Varicocele?
lump in the scrotum caused by abnormal enlargement of the pampiniform venous plexus
What nerve is located between the internal spermatic fascia and cremasteric fascia?
What are its divisions and subsequent innervations?
The genitofemoral nerve which has two branches:
- genital branch: supplies the cremaster muscle (lowers and raises the testis)
- femoral branch innervates the medial thigh
Which fasical layer contains the 3 arteries?
Internal Spermatic fascia
State the following regarding the Cremasteric reflex:
- how it is performed
- nerve innervation
- normal response (positive CR)
1) ellicited by lightly stroking the superior-medial thigh
2) this stimulates sensory fibers of the ilioinguinal nerve which activate motor fibers of the genitofemoral nerve (genital branch)
3) normal response ➞ contraction of the cremaster muscle, pulling the testis UP on the same side of the body
List 4 reasons why the cremasteric reflex may be negative
- testicular torsion
- upper and lower motor neuron disorders
- spine injury of L1-L2
- accidental ligation of the ilioinguinal nerve during hernia repair
What is Testicular Torsion?
Testis are not attached well, can cause the testes to twist around the spermatic cord resulting in lack of/no blood flow to the testicle
Causes pain and swelling, and should be treated as a medical emergency!
What is the ONLY structure that runs superior to the ureter within the male pelvis and when could this be visualised?
The Ductus Deferens, can be seen on abdominal endoscopy
Describe the location, structure and function of the ductus deferens, incl its NS control
What embryological structure is it derived from? Compare this to females
DD is contained within the spermatic cord. It is a muscular (SM) tube capable of peristaltic action via sympathetic innervation
It functions to transports mature sperm to the ejaculatory duct
It is derived from the embryonic mesonephric duct (in females this duct does not remain)
Describe the pathway and blood supply of the Ductus Deferens
Pathway:
1) runs from the tail of the epididymis
2) travels through the inguinal canal (b/c its part of the spermatic cord)
3) passes superior to the ureter in the pelvis
4) combines with the duct of the seminal vesicles to form the ejaculatory duct
Blood Supply: branches from vesical & testicular arteries
The prostate surrounds the male urethra and is located between the _______ and ______ muscles.
It is 2/3 ______ and 1/3 ________ and contributes _____% of seminal fluid.
Anatomically it is closley related to the ______ which allows it to be felt during a ______. This is the important in the diagnosis of prostate cancer.
Bladder, levator Ani muscles, glandular, fibromuscular, 20, rectum, DRE
What is the arterial, venous and lymph supply to the prostate?
What significance does this have in terms of cancer metastisis?
arterial supply: internal iliac artery (vesical & rectal arteries)
venous blood ➞ prostatic venous plexus ➞ vertebral veins
lymph drains into the internal iliac nodes
Prostate cancer can easily spread to the vertebrae via the venous plexus. The veins that form the plexus have NO valves hence blood can flow in any direction and the plexus runs the entire length of vertebral column into cranium & through vertebral bodies. This makes it an easy route for cancer spread
The prostate can be divided into 3 lobes OR 3 zones… what are these?
Which zone do tumors tend to form in and how would you examine?
Lobes: median lobe, posterior lobe, anterior lobe
Zones: peripheral zone, central zone, transitional zone
Tumours tend to form in the peripheral zone of the prostate, use DRE to examine
What do seminal vesicles produce and how much of ejaculate volume does this contribute to?
Where are they located and what structure do they develop from?
What do the seminal vesicles combine with to form the ejaculatory duct?
They produce alkaline fluid which contribute 70-80% of ejaculate volume (they do NOT store sperm)
The seminal vessicles are small accessory glands thay lie between bladder and rectum (posterior to the prostate). They develop as outgrowths of the ductus deferens
duct of seminal vesicle + ductus deferens = ejaculatory duct
What is the blood and venous drainage of the seminal vesicles?
What lymph nodes do these drain into?
Blood Supply: Internal iliac artery (Inferior vesical & middle rectal)
Venous drainage: vesical & prostatic venous plexus
Lymph Drainage:
- Internal iliac nodes
- External iliac nodes
- Sacral nodes
In a DRE exam what 4 things should you normally be able to feel?
List 2 other things you may be able to feel
1) walls of anal canal
2) walls of inferior rectum
3) sacrum, coccyx & sacral lymph nodes
4) prostate (posterior and medial lobes and median sulcus)
May possibly be able to feel the Inferior bladder & seminal vesicles
What are the 3 regions of the prostate?
Lable the diagram below
1) Prostatic urethra
2) Membranous urethra
3) Penile (spongy ) urethra
Give 3 reasons why a male may require Catheterisation?
List 4 possible difficulties/dangers
Why?
1) Inability to void bladder (urinary retention)
2) Incapacitated (bladder stops working)
3) surgery
Difficulties/Dangers?
1) navicular fossa (mucosal fold superiorly)
2) angle at penile bulb & membranous urethra
3) prostate (crest /enlarged lobes)
4) sphincters
How would you insert a catheter and what structures would you pass?
1) catheter inserted through penile urethra at an angle
2) cathrer passed through:
spongy urethra ➞ membranous urethra ➞ external spincter ➞ prostatic urethra ➞ internal spincter ➞ into bladder
3) once in bladder push saline through to inflate baloon (stops catheter falling out)
What are the 3 erectile bodies (vascular structures) within the penis (in the shaft)?
What does EUM stand for and what is it?
1) 1x corpus spongiosium = located at the bottom
2) 2x corpus cavernosum = these are blood spaces
3) Roots = attached parts
EUM ➞ external urethral meatius➞ the enlarged portion (head)
What is the Pelvic floor?
What is found in the centre of the pelvic floor and what is its purpose?
the pelvic floor is a bowl-shaped group of sheet-like muscles that support the pelvic viscera and assist with sphincters
In the centre lies the perineal body ➞ a lump of connective tissue that divides the anterior structures from the ano-rectal junction
The Levator Ani is a broad, thin muscle, situated on either side of the pelvis, what 3 muscle components make up this muscle?
What is its nerve supply?
Iliococcygeus
Pubococcygeus
Puborectalis
Nerve supply = S4
What 2 structures would be found above and below the perineal membrane?
What are these?
Above the perineal membrane: ”The deep perineal pouch”
Below the membrane: “ The superficial perineal pouch”
perforation of the urethra will fill up what space?
Perforation of the urethra will fill up the entire superficial space
What are the 2 ligaments of the penis?
1) Suspensory ligament
2) Fundiform ligaments of the penis
What structure can be significantly damaged in a fracture of the penis?
Why is this so dangeous?
Fracture of penis can cause rupture of one or both of the tunica albuginea (the fibrous coverings that envelop the corpora cavernosa)
The corpus cavernosum is filled with vascular structures and spongy erectile tissue and hence a penile fracture will cause all the blood spaces to become broken
This is dangeous because it can cause major blood loss from the penis, medical emergency!!
Can also cause rupture to the suspensory ligaments or fundiform ligaments of the penis
How can the flacid penis length be lengthed surgically?
Cutting of the Suspensory and Fundiform liagaments of the penis
What is Priapism?
What causes this?
Priapism is a persistent (painful) non-stimulated erection that lasts more than 4 hours
Caused by an issue with vascular flow which causes blood to stay trapped within the erectile bodies of the corpus cavernosa, with no arterial flow.
This can progress to Ischaemic priapism which is considered a medical emergency
(typically the glands and corpus spongiosum are unaffected)
All major neurovascular supply to the penis travels inferior to pelvic floor via the _________ and through the ___________
All major neurovascular supply to the penis travels inferior to pelvic floor via the deep perineal pouch and through the Pudendal (Alcock’s) Canal
Give 2 regions where we could anaesthetise nerves in the pelvic area of a male (include what nerve)
Pudendal nerve passes close to the ischial spine where it can be anaesthetised
the neurovascular bundle runs close to the midline suspensory ligament, they can be anaesthetised in this region
What nerve provides somatic innervation to the penis?
Somatic nerve supply comes from the dorsal nerve of the penis (branch off the Pudendal nerve)
What is the MAIN arterial supply to the penis?
What additional arteries are required in an erection?
Main: Internal pudendal artery (branch of the internal iliac artery)
During an erection:
- dorsal arteries of the penis
- deep arteries of the penis
Both branches off internal pudendal artery
Describe the venous drainage of the penis
Dorsal Veins (superficial and deep) ➞ drain to prostatic venous plexus ➞ drains to vertebral plexus
DEEP dorsal veins drain the cavernosa spaces
SUPERFICIAL dorsal veins drain the superficial structures of the penis, such as the skin and cutaneous tissues
How do we maintain a Flaccid Penis?
We have many arterio-venous anastamoses which allows
blood to by pass the corpus cavernosum
Explain the vascular changes during an erection
1) Corpus cavernosum (CC) is filled with small, cloiled arteries ➞ “Helicine arteries”
2) Erotic stimulation causes SM in artery walls to relax ➞ Helicine arteries straighten
3) This allows increased BF into CC ➞ penis becomes engorged with blood
4) Ischiocavernosus (covers crura of penis) contracts to compress the venous plexus (+bulbospongiosus helps)
5) This retains blood in the CC ➞ ERECTION
Explain the nervous stimulation during an erection (POINT), include all nerves involved
Parasympathetic (S2-S4 plexuses)
Pelvic Splanchnic Nerves
⬇
Inferior hypogastric plexus
⬇
Prostatic plexus
⬇
Cavernous nerve
Explain the nervous stimulation during the emission phase during an erection (SHOOT)
What 3 changes does this do?
Sympathetic (L1-L2)
1) closes internal urethral sphincter
2) peristalsis of ductus deferens and seminal vesicles (SM contraction) in order for their contributions to be delivered into the ejaculatory duct
3) prostate smooth muscle contraction which squeezes the contents from the ejaculatory ducts into the penile bulb
Explain the nervous stimulation during the ejaculation phase (SCORE)
What does this cause?
Sympathetic (L1-L2) AND Somatic (Pudendal nerve: S2-S4)
The pudendal nerve innervates the Bulbospongiosus muscle which is essential for ejaculation
This muscle covers the bulb of penis and hence contraction helps urethral emptying (full of ejaculate fluid)
What is the lymphatic drainage for the following?
1) scrotal, penile and perineal skin
2) glans of penis
3) testicles
4) corpus cavernosum
5) urethra:
- proximal spongy and membranous urethra
- distal spongy urethra
5) prostate, seminal vesicles and ductus deferens:
1) scrotal, penile and perineal skin: superficial inguinal
2) glans of penis: deep inguinal
3) testicles: para-aortic (L2)
4) corpus cavernosum: Internal Iliac
5) urethra
- proximal spongy and membranous urethra: internal iliac
- distal spongy urethra: deep inguinal
5) prostate, seminal vesicles and ductus deferens: mostly internal iliac
