Anatomy 24 Flashcards
What are the anterior borders of the inguinal canal?
- External oblique aponeurosis
- Laterally only: internal oblique aponeurosis
What are the posterior borders of the inguinal canal?
- Transversalis fascia
- Medially only: medial fibres of the aponeuroses of the internal oblique and transversus abdominis (which are together known as the conjoint tendon)
What is the roof of the inguinal canal?
- Transversalis fascia
- Arching fibres of the internal oblique and transversus abdominis
What is the floor of the inguinal ligament?
Inguinal ligament (which is the ‘rolled-up ’lower border of the external oblique aponeurosis).
What are the contents of the inguinal canal in females?
- Round ligament of the uterus
- Ilioinguinal nerve
- Genital branch of the genitofemoral nerve
In males where are the contents of the inguinal canal (except for one) all contained within?
Spermatic cord
Which content of the inguinal canal in males is NOT contained in the spermatic cord?
Ilioinguinal nerve
What can the contents of the spermatic cord be divided into?
2 nerves
3 arteries
3 fascial layers
4 other structures
What are the 2 nerves in the spermatic cord?
- Genital branch of the genitofemoral nerve
- Sympathetic nerve fibres
What are the 3 arteries in the spermatic cord?
- Testicular artery
- Cremasteric artery
- Artery to the vas deferens
What are the 3 fascial layers in the spermatic cord?
- External spermatic fascia (derived from the external oblique aponeurosis)
- Cremaster muscle and fascia (derived from the internal oblique muscle)
- Internal spermatic fascia (derived from the transversalis fascia)
What are the 4 other structures found in the spermatic cord?
- Pampiniform venous plexus
- Lymphatics
- Vas deferens (plural: vasa deferentia)
- Processus vaginalis (derived from the peritoneum)
What is a hernia?
An abnormal protrusion of tissues or organs from one region into another through an opening or defect
Why may hernias of the anterior abdominal wall occur?
Muscles are weak or have been incised during surgery
What is an inguinal hernia?
A protrusion of abdominal contents (normally part of the
greater omentum or loops of small intestine) through the anterior abdominal wall into the inguinal canal.
What is an indirect inguinal hernia?
Intra-abdominal contents are forced through the deep
inguinal ring and into the canal
The abdominal contents may even be forced along the
canal and through the superficial ring.
From here, the hernia may extend into the scrotum in males or into the labia majora in females.
Which type of hernia is more common?
Indirect hernias as they are more likely to get stuck in the canal and become ‘irreducible’
How can hernias become a surgical emergency?
Herniated tissue can ‘strangulate’ and become ischaemic
What is a direct inguinal hernia?
Intra-abdominal contents are forced through the posterior wall
of the inguinal canal and directly through the superficial ring.
What happens to the herniated abdominal contents in direct inguinal hernias?
The herniated abdominal contents do not pass through the deep inguinal ring
Give features of scrotal skin
Thin
Wrinkled
Darkly pigmented than elsewhere
What is found underneath the scrotal skin?
- Thin layer of superficial fascia
- Thin, involuntary muscle called the dartos
Where does the superficial fascia extend?
Between the testicles to form a septum dividing the scrotum into right and left halves
What does each half of the scrotum contain?
Testis
Epididymis
Lower part of the spermatic cord
What do the testes produce?
Sperm
What do the testes secrete?
Sex hormone testosterone
What are the testes?
Ovoid structures which are covered by the same 3 layers of spermatic fascia that cover the spermatic cord
What are the testes partially surrounded by?
A sac derived from the peritoneum called the tunica vaginalis
What is the epididymis?
A coiled tube lying along the posterior border of each testis, which has an expanded head superiorly, a body and a pointed tail lying at the lower pole of the testis.
Where are the spermatozoa formed?
In the testis
Where are the spermatozoa stored?
Epididymis
What does the vas deferens do?
Carries sperm from the epididymis and travels with the testicular vessels in the spermatic cord
What are the testicular arteries direct branches of?
Abdominal aorta
Where does venous blood from the testis and epididymis enter?
The pampiniform venous plexus
What does the pampiniform venous plexus form?
Testicular vein
What does the right testicular vein enter?
Inferior vena cava
What does the left testicular vein join?
Left renal vein
What is hydrocoele?
Painless swelling caused by accumulation of peritoneal fluid between the layers of the tunica vaginalis around the testis
What happens when a light is shone through a hydrocoele and what is it called?
Light can be seen from the other side, called transillumination
What is transillumination used for?
Diagnosis of scrotal swellings
What is varicocele?
Abnormal dilation of the pampiniform venous plexus
What are varicoceles often described as?
Feeling like a ‘bag of worms’ on palpation due to the dilated veins
Which side are varicoceles more common on and why?
Left side, due to the fact that the left testicular vein drains into
the left renal vein before it drains into the inferior vena cava
What does a left-sided varicocele often warrant?
Intra-abdominal investigation to exclude a tumour that may be obstructing its venous drainage
What is epididymo-orchitis?
Painful inflammation of the epididymis and testis
What is epididymo-orchitis in a younger patient often caused by?
A sexually transmitted infection such as chlamydia or gonorrhea
What is epididymo-orchitis in an older patient often caused by?
Urinary tract infection
What is testicular torsion?
Twisting of the testis on the spermatic cord
What can testicular torsion lead to?
Ischaemia of the testis and is a surgical emergency
What can testicular torsion lead to if left untreated?
Can lead to necrosis and loss of the affected testis
What treatment can be used for testicular cancer?
Surgery to remove the testis and a length of cord (orchidectomy) with chemotherapy or radiotherapy if required.
What happens if testicular cancer metastasizes?
It will likely follow the lymphatic drainage which follows the testicular arteries back to lymph nodes around the aorta
Where does testicular cancer first metastasize?
Para-aortic or retroperitoneal lymph nodes
What is cryptorchidism?
During fetal development the testes form in the abdomen and descend through the inguinal canal to reach the scrotum before birth
If this fails to occur, the infant is born with one or both testes absent from the scrotum, and the affected testis will be stuck
somewhere along the path of descent
What happens if the undescended testis is left inside the abdomen?
There is an increased risk of testicular cancer, so undescended testes are often brought into the scrotum surgically
What is a vasectomy?
Means of male sterilisation (permanent male contraception)
What happens during a vasectomy?
Relatively uncomplicated surgical procedure where the scrotum is incised and the vasa deferentia are located on each side and separated, before ligating, cauterising or clamping each end
What is the penis primarily made up of?
3 cylinders of erectile tissue
2 ‘corpora cavernosa’ dorsally (along the ‘top’ of the penis)
1 ‘corpus spongiosum’ ventrally (along the ‘bottom’ of the penis)
What are the corpora cavernosa and corpus spongiosum enclosed within?
Deep fascia of the penis (‘Buck’s fascia’).
What is the end of the penis called?
The glans
What is the end of the penis (glans) an extension of?
Corpus spongiosum
Where does the penile urethra lie within?
Corpus spongiosum
What does the urethra approach the end of the penis via?
External urethral meatus
Where is the penile arterial supply via?
Penile arteries
Where do the penile arteries branch from?
Internal pudendal arteries, which themselves branch from the internal iliac arteries
What is the nerve supply to the penis?
S2 -S4 nerves
What are both general and sympathetic innervation carried by?
Dorsal nerve of penis
What is the dorsal nerve of the penis a branch of?
Pudendal nerve
Where do the parasympathetic nerve fibres responsible for causing erections arise from?
Peri-prostatic nerve plexus
What is the corpora cavernosa primarily responsible for?
Increase in size and rigidity of the penis during an erection
What happens to the corpora during sexual arousal?
Arterial blood flow into the corpora of the penis increases, so the corpora become engorged with blood
What is the main role of the corpus spongiosum during erection?
Prevents the urethra from being compressed, which would prevent ejaculation
What is erectile dysfunction?
Inability to achieve or maintain an erection during sexual activity.
It is considered common and will affect most males at some point
What can lead to erectile dysfunction?
Problems with:
- Nerve pathways and reflexes
- Blood flow in and out of the corpora of the penis
- Psychological arousal
What are treatments for erectile dysfunction?
- Identifying the cause and treating that
- Using of medications such as sildenafil (Viagra) which increase blood flow into the corpora of the penis
