Flashcards in Lecture 22 DA Deck (39):
Branches of which nerve are found within the prostates capsule? What is it responsible for? How is it clinically significant?
Branches of the pudendal nerve, which is responsible for erection in both males and females. It is susceptible in prostatectomy.
What is another name for the median and lateral lobes of the prostate?
Median - transition zone
Lateral - Peripheral zone
What is a problem with the transition zone with age?
It can be the origin of benign prostatic hyperplasia/hypertrophy, and can encroach on the prostatic urethra, difficult urinating.
What is a problem with the peripheral zone?
It is the site of prostatic cancer, which can be imaged.
What is the corpus cavernosum? Why is it called cavernosum?
A paired structure within the penis, and is so named as it has lots of space for veins during erection. Veins are compressed and fill with blood.
What state is the penis in the anatomical position?
What is the root of the penis called?
What is found at the midline of the penis? What passes through this structure?
Corpus spongiosum, which the urethra passes through. Bordered on both sides by corpus cavernosum.
What is the urethra called when within corpus songiosum?
What is the navicular fossa?
Dilation of the penile urethra at its termination.
What is the difficulty with catheter insertion through the urethra in males?
Catheter must navigate a 90° turn from the membranous urethra to the prostatic urethra.
What is the prepuce, and what is some pathology regarding HIV associated with it?
Prepuce is the foreskin, and is very sensitive to the HIV virus, and tends to concentrate there. Circumcision helps reduce risk.
What are the fascia layers of the scrotum and penile shaft?
Dartos fascia - most superficial (dartos muscle also found).
Deep penile fascia - deep to dartos fascia.
Where is the perineum found?
Beneath the pelvic floor, the levator ani.
What plane is the urogenital triangle found in?
The horizontal plane, but the anal triangle deviates posteriorly slightly.
How are the urethra and vagina angled as they exit the urogenital triangle? What does this form?
They are angled anteriorly as they exit, forming a functional sphincter. Allows for support from above.
How is the anal canal angled as it exits the anal triangle?
Angled posteriorly, which forms a sphincteric effect, but is not very capable of resisting forces.
What is the cloaca?
Developmentally, the urogenital hole and anal hole are connected as one hole, the cloaca, and seperates later in development.
Do birds have a cloaca?
Is there communication between the urogenital canal and anal canal?
Yes, via perforations.
What is the urogenital triangle supported by?
A sheet of fascia and muscle called perineal membrane, which has a mucous membrane on its upper surface.
It also has muscles within the deep perineal pouch, a shallow dish-like space formed by fascia.
What is the deep perineal pouch?
A sheet of fascia and muscle. Forms a shallow, dish-like structure with muscles within its space.
The muscles form a sphincter on this sheet.
What is sphincter urethrovaginalis?
An additional sphincter in females, which supports the vagina and acts as a sphincter by compressing it.
What are the three main components of the urethral sphincter in females?
External urethral sphincter
Where is the root of the external genitalia and urogenital muscles found?
At the superficial perineal pouch.
What is bulbospongiosus?
A skeletal muscle, which contracts to squeeze out all the urine from the urethra after micturition or sperm after ejaculation.
What is the perineal body? Is there sexual dimorphism?
A fibrous node, the site of attachment for bulbospongiosus and the anal sphincter. It is bigger in females.
How can bulbospongiosus be damaged, and what is a consequence of this?
Pelvic fracture. Urine will accumulate in the extraperitoneal tissue or superficial perineal space, called extravasation.
What is extravasation?
When liquid leaks from its container. Happens when bulbospongiosus is damaged.
What is the female analogue of the scrotal sac?
Labia majora, found laterally and superficial-most.
What is the female analogue of the penile urethra?
Labia minora, found medial to labia majora.
Where is the urethra in females?
A urethral opening can be found just inferior to the clitoris. It can open into the vagina posteriorly.
What does the urethral opening in females rest on?
Rests on the vestibule, superior to the vagina.
What is the hymen, and where is it?
A membrane that partially covers the vaginal opening. It lines the vagina.
What kind of muscles are found at the anal termination? What is it supported by?
Smooth muscle. Supported above by puborectalis sling, kinking it.
How is the perineal raphe formed?
By the reinforcement of the anus by a deep layer, a superficial layer, and subcutaneous layer, forming a raphe.
What innervates the structures of the anus, and where does it come from?
Inferior rectal nerve, which comes from the pudendal nerve and supplies the perineal floor.
Which spinal nerves innervate the anus?
S2,3,4 keeps the ass off the floor.