Penis & prostate Flashcards
What are the roles of the penis?
Sexual intercourse - becomes erect and ejaculates semen into the female reproductive tract
Micturition - contains the urethra
What are the 3 parts of the penis?
Root
Body
Glans
Describe the root of the penis?
- Proximal & fixed part
- In superficial perineal pouch of pelvic floor
- Not visible externally
- 3 erectile tissues (2 crura and 1 bulb)
- 2 muscles (ischiocavernosus & bulbospongiosus)
Describe the body of the penis?
- Free part of penis
- suspended from the pubic symphisis
- 3 cylinders (2 corpus cavernosa and 1 corpus spongiosum)
Describe the glans of the penis?
- Distal part
- Conical shape
- Formed by distal expansion of corpus spongiosum
- External urethral orifice
Describe the erectile tissues of the penis.
In the root - right & left crura and bulb
In the body - the crura form the 2 corpus cavernosa (which are separated by a septum).
The bulb forms corpus spongiosum.
What happens in an erection?
The erectile tissues fill with blood as a result of sexual arousal
Which erectile tissue compartment of the body of the penis fills to a greater pressure during an erection?
The corpus cavernosa
The urethra runs through the corpus spongiosum, so it fills to a lesser pressure to prevent occlusion
Name the muscles of the penis? What part of the penis are they in?
In the root
Bulbospongiosus x2 associated with the root
Ischiocavernosus x2 associated with L&R crura
What are the fascial coverings of the erectile tissue in the penis?
Superficial = deep fascia Deep = Tunica albuginea (forms an individual capsule around each cavernous body)
Name the 2 ligaments that support the root of the penis?
Suspensory ligament - connects erectile bodies of penis to pubic symphisis
Fundiform ligament - runs down from linea alba, surrounds penis, attaches pubic symphisis
What is the prepuce?
Foreskin - a double layer of skin and fascia at the neck of the glans
Blood supply of penis?
Dorsal arteries
Deep arteries
Bulbourethral artery
All branches of the internal pudendal artery
Venous drainage of penis?
Cavernous spaces drained by deep dorsal vein
Superficial penis drained by superficial dorsal veins
Innervation of penis?
What type of nerves?
S2-S4
Sensory and sympathetic = dorsal nerve (branch of pudendal nerve)
Parasympathetic = cavernous nerves
What is the function of the prostate?
A gland that secretes proteolytic enzymes into semen
These enzymes break down clotting factors, which allow semen to stay in a fluid state for easier movement in female reproductive tract
What is the structure of the prostate?
Size of walnut
2/3rds is glandular
1/3rd is fibromuscular
Surrounded by fibrous capsule
Where is the prostate?
Inferior to neck of bladder
Anterior to ampulla of rectum (used to examine prostate during a rectal exam)
What are the zones of the prostate?
CENTRAL
Surrounds ejaculatory ducts
TRANSITIONAL
Central, surrounds urethra
PERIPHERAL
Main body & posterior region
Blood supply of prostate?
Prostatic arteries - derived from internal iliac arteries
Venous drainage of prostate?
Prostatic venous plexus - drains into internal iliac veins
Innervation of prostate?
Sympathetic, parasympathetic & Sensory from inferior hypogastric plexus
