Reproductive Systems Flashcards
Male Reproductive System
scrotum: skin and superficial fascia which surround the testes and epididymus
position of testes in scrotum provides an environment 3.1 degrees centigrade cooler than core body temperature for proper sperm development
dartos muscle: layer of smooth muscle responsible for wrinkling the scrotal skin
cremaster muscle: bands of skeletal muscle which contract to elevate the testes and relax to lower the testes
Blood Vessels and Nerves
testicular arteries supply blood to testes
testicular veins form the pampiniform plexus which surrounds testicular arteries and absorb heat from these arteries which helps cool the testes
testes innervated by parasympathetic and sympathetic divisions of ANS
The Spermatic Cord
the inferior part of the spermatic cord lies in teh scrotum and the superior part runs through the inguinal canal, an obliquely oriented trough in the anterior abdominal wall
spermatic cord contains: portion of ductus deferens, testicular blood vessels (artery and vein pampiniform plexus), nerves
The Testes and Epididymis
tunica vaginalis: serous sac in which the testes and epididymis are partially enclosed
tunica albuginea: fibrous capsule of the testes
septal extensions o fhte tunica albuginea divides each testis into 250-300 wedge-shaped lobules which contain seminiferous tubules
Sequence of Structures Sperm Passes Through From Site of Sperm Production to Urethra
seminiferous tubules straight tubules (tubuli recti) rete testes efferent ductules epididymis head epididymis body (ductus) epididymis tail ductus (vas) deferens ejaculatory ducts urethra
Epithelia From Testes to Vas Deferens
seminiferous tubules: stratified epithelium
straight tubules (tubuli recti): simple cuboidal epithelium
rete testes: simple cuboidal epithelium
efferent ductules: simple columnar epithelium
epididymis: mainly tall columnar pseudostratified epithelium with stereocilia
ductus (vas) deferens: mainly columnar pseudostratified epithelium
Seminiferous Tubules
separated by areolar connective tissue
has stratified epithelium which consists of:
spermatogenic cells: sperm-forming cells (spermatogonia, spermatocytes, spermatids) form 400 million sperm per day
columnar sustentocyte (Sertoli cells): support cells which provide nutrients to sperm, secrete androgen-binding protein, and have tight junctions which form the blood-testes border
Myoid Cells
several layers of smooth muscle like myoid cells surround seminiferous tubules and contract rhythmically to help squeeze sperm and testicular fluid through the tubulues into the epididymis
Interstitial (Leydig) Cells
located in loose connective tissue in between seminiferous tubules secrete androgens (mainly testosterone)
The Epididymis
comma shaped organ that arches over the posterior and lateral side of the testis
duct of epididymis is 6 meteres long (when uncoiled)
sperm mature in epididymis
the luminal surface bears tufts of stereocilia whcih are long immotile microvilli provide a large surface area to reabsorb testicular fluid and transfer nutrients and secretions to the development sperm
with ejaculation, sperm from as far down as the epididymis tail are projected through the ductus (vas) deferens, ejaculatory ducts, and urethra
The Ductus (Vas) Deferens
thick muscularis with three layers of muscle to facilitate movement of sperm and generates strong peristaltic waves during orgasm that rapidly propel sperm through the ductus deferens to the urethra
Ejaculatory Duct
the distal end of the ductus deferens forms ampulla which joins with the seminal vesicle gland duct to form the ejaculatory duct
each ejaculatory duct runs into the prostate
accessory sex glands (seminal vesicle gland, prostate, and bulbourethra glands) provide seminal plasma which mixes with sperm
The Urethra
sperm moves from ejaculatory ducts through urethra
three parts of male urethra: prostatic urethra in prostate, membranous urethra in urogenital diaphragm, spongy urethra in penis, urethra orifice
The Male Perineum
contains: scrotum, root of penis, anus
diamond-shaped area between pubic symphysis anteriorly, coccyx posteriorly, ischial tuberosities laterally
The Penis (External Anatomy)
shaft: body
glans penis: distal expanded end
prepuce: foreskin which is removed during circumcision