Male reproductive system Flashcards
Where do the testes move in development
testes begin to move toward the scrotum (inguinal region)
they pull blood supply and innervation
Month 3 in development
the testes located close to the inguinal region, an increase in testosterone encourages the gubernaculum to shorten and draw the testis into the scrotum
Gubernaculum
a fibrous cord that attaches to the inferior portion of the testis and the floor of the developing scrotal sac
Processus vaginalis
an outpouching of the peritoneal lining in the abdomen
Passage of the testis
happens well before birth in most cases but in premature birth it can happen after birth
What does the testis pull with it?
layers of the abdominal body wall but there is no transverse abdominis in the scrotum
Where did the male ducts arise from?
degraded mesonephric duct
Where must the testis pass through in development?
the testis must pass thru the deep body wall to the scrotum forming the inguinal canal as it descends
Scrotum
a sac of skin that extends external to the abdominopelvic cavity
What muscles in the scrotum provide temperature regulation?
the dartos and cremaster muscle respond to changes in external temperature
Seminiferous tubules
sites of sperm production
Epididymis
an organ where sperm mature
How does sperm travel through the male ducts?
Seminiferous tubules
epididymis
ductus deferens
ejaculatory duct
urethra
What accessory sex glands contribute secretions to sperm?
Seminal vesicles
prostate gland
bulbourethral glands
Seminal glands
elongated structures that lie between the fundus of the bladder and rectum
What do the seminal glands secrete?
Secretes a thick alkaline fluid that mixes with sperm as they pass into the ejaculatory ducts and urethra
What do the secretions from the seminal glands contain?
Fructose and other nutrients to nourish sperm
Other substances to enhance fertilization
Provides energy for sperm to survive female reproductive tract
Ejaculatory ducts
slender tubes that arise by the union of the duct of a seminal gland with the ductus deferens near the neck of the bladder
Prostate gland
encircles the prostatic urethra
Prostatic secretions
1/3 if semen volume and contain enzymes that enhance sperm motility
Bulbourethral glands
inferior to the prostate, secrete mucus
Bulbourethral glands
two pea-sized bulb-urethral glands are situated posterolateral to the intermediate part of the urethra
Where do the bulbourethral glands pass through?
Their ducts pass thru the perineal membrane with the intermediate urethra and open thru very small apertures into the proximal part of the spongy urethra in the bulb of penis
What kind of secretions do the bulbourethral glands produce?
secretions are mucus-like and enter the urethra during sexual arousal
a basic solution that neutralizes traces of acidic urine
Penile structure
three cylindrical bodies of erectile cavernous tissue:
corpus spongiosum
corpora cavernosa
Glans penis
expanded tip of the penis surrounding the urethral opening, continuous with the corpus spongiosum
Prepuce (foreskin)
loose fold of skin surrounding the glans to a variable extent
Corpus spongiosum
single cylindrical body
surrounds the urethra, enlarged proximally (root, covered y the bulbospongiosus muscle), and distally (glans)
Corpora cavernosa
paired cylindrical body
covered by the ischiocavernosus muscles
Ischiocavernosus (muscle)
prevents outflow of blood/erection
Bulbospongiosus (muscles)
expels last drop of urine/semen
hardens erection
What is the crus composed of?
corpora cavernosum
What is the bulb composed of?
corpus spongiosum
Parasympathetic nervous system
pro-erection
Sympathetic nervous system
pro-detumescence
What does the parasympathetic nervous system allow for?
relaxation of smooth muscle and blood flows into the erectile tissues
What do the bulbourethral glands and vestibular glands secrete when stimulated by the parasympathetic nervous system?
secrete mucous, resulting in lubrication of the vaginal orifice in the female and the production of pre-ejaculatory fluid in the male
Erections in both genders have…
reflexogenic (stimulation)
psychogenic (thought induced)
nocturnal (REM sleep)
What are the two phases of ejaculation?
emission
expulsion
Emission (the sympathetic nervous system)
closes the neck of the bladder preventing retrograde ejaculation
contracts smooth muscle in the epididymis, ductus deferens, seminal vesicles and prostate to coordinately release their secretions into the urethra
Expulsion (somatic nervous system)
Coordinated, rhythmic contraction of the muscle in the bladder neck, external urethral sphincter, urethra, bulbospongiosus and pelvic striated muscles to propel semen thru the urethra
Hypospadias
In hypospadias, fusion of the urethral folds is incomplete and abnormal openings of the urethra occur along the inferior aspect of the penis
Hydrocele and hematocele
fluid of blood accumulation in the processus vaginalis
Testicular torsion
a twisting or torsion of the spermatic cord can dramatically affect blood supply to the testicle and surrounding tissues
Circumcision
The cutting away and removal of the prepuce (foreskin)
Phimosis/paraphimosis
Phimosis is present when the foreskin cannot retract normally comfortably over the glans
Paraphimosis occurs when a retracted foreskin gets caught behind the glans and cannot be moved
