MALE REPRODUCTIVE ORGANS Flashcards
describe 10 differences between the male and female pelves
- general structure: M - thick and heavy, F - thin and light
- greater pelvis: M - deep, F - shallow
- lesser pelvis: M - deep, narrow and tapering, F - wide, shallow and cylindrical
- pelvic inlet: M - heart-shaped, narrow, F - oval and rounded
- pelvic outlet: M - comparatively small, F - comparatively large
- pubic arch and sub pubic angle: M - narrow (<70) , F - wide (>80)
- obturator foramen: M - round, F - oval
- acetabulum: M - large, F - small
- greater sciatic notch: M - narrow (roughly 70), inverted V, F - almost 90
- sacral promontory: M - prominent, F - flattened
what is the ductus deferens?
= a thick-walled tube that is continuous with the tail of the epididymis. transports mature sperm from the tail of the epididymis in the scrotum to the ejaculatory duct in the pelvic cavity. Part of the spermatic cord.
what forms the ejaculatory duct?
the convergence of the vas deferens and the seminal vesicles duct
describe the anatomical course of the vas deferens
- continuous with the tail of the epididymis
- travels through the inguinal canal as part of the spermatic cord
- moves down the lateral pelvic wall close to the ischial spine, posterior to the pubic spine
- turns medially to pass between the bladder and the ureter and then travels downward on the posterior surface of the bladder
- joins with the seminal vesicles duct to form the ejaculatory duct
what is the ejaculatory duct?
a duct formed by the merging of the vas deferens and the seminal vesicles, approx 1cm long, opens into the urethra
what is the function of the ejaculatory duct?
mixes the sperm stored in the ampulla with fluids secreted by the seminal vesicles and transports it to the prostate
what are the seminal vesicles?
sac-like pouches that attach to the vas deferens near the base of the bladder
what is the function of the seminal vesicles?
they produce secretions which make up to 70% of the total volume of semen.
describe the structure and anatomical relations of the seminal vesicles
- each seminal vesicles is an elongated structure that lies between the fundus of the bladder and the rectum
- placed anteriorly obliquely superior to the prostate
- internally has a honeycombed, lobulated structure
what is the mucosa in the seminal vesicles lined with and what is the importance?
= mucosa lined by pseudostratified columnar epithelium
- these cells are highly influenced by testosterone: high levels — grow taller
- cells responsible for the production of seminal secretions
what do secretions of the seminal gland contain?
secretions contain:
- alkaline fluid = neutralises the acidity of the male urethra and vagina in order to facilitate the survival of spermatozoa
- fructose = acts as an energy source for sperm: helps the sperm motility
- prostaglandins = have a role in suppressing the female immune response to foreign semen
- clotting factors = designed to keep semen in the female reproductive tract post-ejaculation
arterial supply and venous drainage of the seminal vesicles
arteries derived from inferior vesicles, internal pudendal, and middle rectal arteries — all stem from the internal iliac artery
- artery to ductus deferens and inferior vesical artery
- inferior vesical plexus
POINT AND SHOOT (innvervation)
erection/pointing = parasympathetic
ejaculation/shooting = sympathetic
- S: inferior hypogastric nerve
- PS: pelvic and inferior hypogastric nerves
seminal vesicles lymphatic drainage
internal iliac lymph nodes
what are the 3 layers of the vas deferens
- mucosa (folded lumen, pseudostratified columnar with serocilia (long microvilli), lamina propria)
- muscularis (inner longitudinal, middle circular, outer longitudinal fibres)
- adventitia (merges with connective tissue of spermatic cord, contains many blood vessels and nerves)
what is lamina propria?
dense irregular connective tissue with elastic fibres
what is the prostate and where is it located?
= the largest accessory gland in the male reproductive system
- located under the bladder
- walnut-sized
- stores and secretes prostatic fluid
what is prostatic fluid?
a slightly acidic solution which makes up 20-30% of the semen
anatomical relations of prostate: anterior, posterior, superior, inferior, lateral
anterior = pubis symphysis posterior = anterior surface of rectal ampulla superior = bladder inferior = urethra. pelvic floor lateral = anterior fibres of the levator ani
what are the pubis symphysis and prostate separated by?
separated by peritoneal fat in the retropubic space
what separates the rectal ampulla and the prostate?
the retrovesical septum
what proportion of the prostate is glandular, what is fibromuscular?
2/3 of prostate is glandular, 1/3 is fibromuscular
vasculature of prostate
arterial supply = inferior vesicles, internal pudendal middle rectal arteries ( same as seminal vesicles)
venous drainage = prostatic venous plexus
the fibrous capsule of the prostate is dense and neurovascular. what does it incorporate?
incorporates the prostatic plexuses of veins and nerves
innervation of the prostate
autonomic: inferior hypogastric plexus and prostatic plexuses
somatic: visceral afferent: pudendal nerve
lymphatic drainage of prostate
internal and external iliac lymph nodes
what are the bulbourethral glands?
= small glands located at the base of the penis
- their ducts empty into the urethral lumen
- during erotic stimulation their mucus-like secretions are added to the seminal fluid
- lie posters-lateral to the intermediate part of the urethra
what 4 parts is the male urethra divided into?
- intramural (preprostatic)
- prostatic
- intermediate (membranous)
- spongy
where is the internal urethral orifice?
the junction between the bladder and urethra
what does the internal urethral sphincter surround and what does it receive?
surrounds preprostatic urethra — receives autonomic innervation
intramural/preprostatic urethra
- extends almost vertically through the neck of the bladder
- surrounded by internal urethral sphincter
- diameter and length depend on whether the bladder is filing or emptying
prostatic urethra
- widest and most dilatable part
- where the ejaculatory duct opens into the prostatic urethra
membranous/intermediate urethra
- passes through deep perineal pouch
- penetrates perineal membrane
- surrounded by circular fibres of external urethral sphincter
- narrowest and least distensible part (except for external urethral orifice)
- ducts of bulbourethral glands enter here
spongy urethra
- runs along the length of the penis on the ventral surface
- 15-16cm ling and travels through the corpus spongiosum
- ducts from bulbourethral gland opens into the proximal part of the spongey urethra
- longest and most mobile part
what is the penis made of?
a mobile body and a fixed root
what does the body of the penis consist of?
3 cylindrical masses of erectile tissue enclosed in a fascia sheath - 2 dorsally located corpora cavernous a (continuations of the crura) and a corpus spongiosum which lies centrally and is a continuation of the bulb of the penis. the corpus spongiosum expands at the distal end of the penis to form the glans penis
what covers the the glans penis?
a double fold of skin, the prepuce/foreskin, covers the glans penis
what does erectile tissue consist of?
consist of a network of blood spaces separated by fibrous tissue and smooth muscle
what has to happen for an erection to occur and what does this allow?
dilation of the arteries must occur which allows blood to fill the 3 spongy erectile tissue chambers, causing it to stiffen and lengthen
roles of bulbospongiosus and ischiocavernosus muscles
bulbospongiosus — lies in the midline of the perineum, in front of the anus. it contributes to the erection, feelings of orgasm and ejaculation
ischiocavernosus — on the outer side of each bulbospongiosus muscle. helps to flex the anus and stabilises the erect penis
what 2 ligaments is the base of the penis supported by?
- suspensory ligament of the penis — attached superiorly to the pubic symphysis
- fundiform ligament of the penis — more superficial. attached to the linea alba of the anterior abdominal wall and split below into 2 bands that pass on each side of the penis and unite inferiorly
vasculature of the penis
- perineal branch of the internal pudendal artery and its tributaries
- superficial and deep dorsal vein of penis, crural veins
lymphatic drainage of penis
lymph drains into the superficial inguinal lymph nodes. vessels from the glans penis drain into the deep inguinal lymph nodes
superficial and deep inguinal nodes, internal iliac lymph nodes
innervation of the penis
- visceral afferent: dorsal penile and perineal nerves
- PS: pelvic splanchnic and cavernous nerves
- S: T11-L1 spinal nerves and deep cavernous nerve
what is the periprostatic plexus responsible for in the penis?
responsible for the vascular changes which cause erection
what is the spermatic cord and what does it contain?
- contains structures running to and from the testis and suspends the testis in the scrotum
- contains the structures that pass through the inguinal canal to reach/exit the testis
- contains vas deferens, pampiniform plexus, lymphatic vessels, tunica vaginalis
- contains arteries: testicular, deferential, cremasteric
- contains nerves: cremaster nerve, testicular nerve (sympathetic)
what are the 3 layers that cover the spermatic cord?
- external spermatic fascia
- cremasteric fascia
- internal spermatic fascia
what is the epididymis and where is it?
- lies posterior to the testis
- it is a highly coiled tube — increases SA, transports and stores sperm cells. where sperm mature
what are the 2 district areas of the epididymis?
- efferent ductules — form an enlarged coiled mass that sits on the posterior superior pole of the testis. forms the head of the epididymis
- true epididymis — a single, long coiled duct to which all the efferent ductules drain. forms body and tail of the epididymis
vasculature of the epididymis
arterial supply: internal spermatic arteries - gonadal artery, deferential artery
venous drainage: pampiniform plexus
lymphatic drainage of epididymis
lumbar nodes
innervation of epididymis
lumbar splanchnic nerves L1-L2
parasympathetic: S2-S4
what is the scrotum and what does it contain?
= a fibromuscular cutaneous sac, located between the penis and anus
- consists of the testis, epididymis, spermatic cord
why are the testis contained within a scrotum?
they function better at lower temps — evolution, more efficient
what is the tunica dartos?
smooth muscle which regulates the temp of the testes by expanding (increases SA doe heat loss) and contracting to wrinkle scrotal skin. in the superficial fascia of the scrotum
vasculature of the scrotum
arterial supply: anterior and posterior scrotal arteries. anterior derives from external pudendal artery and posterior arises from internal pudendal artery
venous drainage: scrotal veins follow the major arteries draining into the external pudendal veins
lymphatics of the scrotum
drain into the superficial inguinal lymph nodes
innervation of the scrotum
anterior/anterolateral - anterior scrotal nerves derived from the genitofemoral nerve (L1-L2) and iloilo inguinal nerve (L1)
posterior aspect - posterior scrotal nerves derived from the perineal branches of the pudendal nerve (S2-S4) and the posterior femoral cutaneous nerve (S2-S3)
what are the testis?
= the male gonads — paired ovoid reproductive glands that produce sperms and male hormones (mainly testosterone)
- suspended in the scrotum by spermatic cords
- left testis usually suspended more inferiorly than the right
what is the tunica albuginea?
a thick fibrous capsule that surrounds each testis
what do the lobules of the testes contain?
contains several seminiferous tubules which open into a network of tubes called the rete testes that drain into efferent ductules, which in turn open into the epididymis
what happens in the seminiferous tubules?
sperm are produced!!
- the interstitial cells of Leydig are adjacent to the seminiferous tubules in the testicle and are responsible for testosterone production
sperm made in seminiferous tubules. they then travel through the tubules and collect in rete testes. go to epididymis via the efferent tubules for storage and maturation.
vasculature of the testes
arterial supply: mainly via the paired testicular arteries (arise directly from abdominal aorta). also supplied by the cremasteric artery and artery of vas deferens
venous drainage: pampiniform plexus
lymphatics of testes
drainage into lumbar and para-aortic nodes
innervation of testes
testicular plexus — network of nerves derived from renal and aortic plexi. receive autonomic and sensory fibres
what does the superficial perineal pouch contain?
- contains erectile tissues of the penis
- bulb and crura of penis, spongy urethra, ischiocavernosus, bulbospongiosus and superficial transverse perineal muscles, branches of internal pudendal vessels and nerves
what does the deep perineal pouch contain?
urethra, part of external urethral sphincter, deep transverse perineal muscle, bulbourethral gland, dorsal nerves and vessels of the penis
at its base, what is the corpus spongiosum anchored to?
the perineal membrane
what does the urogenital triangle contain?
external genitalia, membranous urethra, bulbourethral glands, nerves, blood vessels and the muscles and fascia of the urogenital diaphragm
