male reproductive Flashcards
MALE REPRODUCTIVE components
SLIDE
EMBRYOLOGICAL
DEVELOPMENT
Cortex and Medulla
* 6th week – Identical in both sexes.
- 7th week – with hormones -
- Cortex regresses, medulla progresses = testis.
- Medulla regresses, cortex progresses = ovary.
FUNCTIONS
- production of spermatozoa
- Delivery of spermatozoa into the female
reproductive tract
TESTES two of them in a scrotum sac
coverings
COVERINGS OF THE TESTES
TUNICA ALBUGINEA
* Collagenous capsule (DICT).
* Outer surface is lined by mesothelium simple cub
* Forms septae that divides the testes into lobules -250
TUNICAL VAGINALIS
* Serous coat (SSNK).
*parietal and visceral scrotal layers
* Inner layer of scrotum.
* Separated from the testes by a fluid-filled space.
* Allows friction-free movement in the scrotal
sac.
- Each lobule contains 1-4 seminiferous tubules. - Tightly coiled structures. - Stratified cuboidal
- Function as sperm-forming factories.
Lined by: - Germ cells – spermatogenesis (the development of mature spermatozoa) and spermiogenesis (the final stage of spermatogenesis, spermatids mature into mature, motile spermatozoa).
- Empty sperm into the rete testis (first part of the duct system).
- Sperm travels through the rete testis to the epididymis via efferent ducts.
as the sperm mature they move form the basal layer to the lumen
Spermatogonia A/B, primary and secondary spermatocytes, spermatids, and then spermatozoa
TWO MUSCLES AFFECTING THE
TESTICULAR TISSUE
CREMASTER MUSCLE (or fascia) – skeletal
muscle that elevates the testes when hot.
-heat liable
DARTOS MUSCLE – smooth muscle that pull
the testes together when cold.
SERTOLI CELLS
- Support and nourish the developing spermatozoa.
- Irregular cells facilitating constant movement of the developing spermatozoa.
Endocrine cell; secrete inhibin regulate hormone production
* cytoplasm is mostly is developing
spermatogenic series.
* rest on the basement membrane of the seminiferous tubules, cytoplasm extends to the lumen of the tubule.
* Enclose all cells of the spermatogenic series.
-better with different stain than H/E stain
- Oval nucleus perpendicular to the BM with prominent nucleolus + dense chromatin.
- Large cytoplasm with lots of organelles.
- Bound together by tight junctions.
LEYDIG CELLS
- Interstitial cells between the seminiferous tubules.
- Produce androgens such as testosterone
(endocrine cells). - Round nucleus with dispersed chromatin.
- 1 or 2 peripherally located nucleoli.
- Eosinophilic cytoplasm with lipid vacuoles.
RETE TESTIS
- Simple cuboidal with microvilli -absorption and ONE cilium which move the spermatozoa
- Seminiferous tubules that meet at
mediastinum testes.
Vascular, fibrous tissue with myoid cells –
* Contractions of these cells “mix” the
spermatozoa with testicular fluid and
move them to the efferent ducts →
epididymis.
* Reabsorb protein and potassium from the
testicular fluid.
THE DUCT SYSTEM composed of
- From rete testis to Efferent ducts (ductulus efferens)
- Epididymis
- Vas deferens or ductus
- Urethrae:
a. Prostatic
b. Membranous
c. Penile
EFFERENT DUCTS
-what the rete testis drain into
* Simple columnar with cilia that move spermatozoa to epididymis
* Simple cuboidal (without cilia) that reabsorb
testicular fluid.
*Thin band of circular smooth muscles also aid in propelling the spermatozoa.
EPIDIDYMIS
-shape of comma and tightly coiled where sperm gains motility
* Pseudostratified columnar with stereocilia - Absorption of excess testicular fluid.
* Found on the superior part of the testis and along the posterior lateral side.
* Functions to mature and store sperm cells (at least 20 days).
* removes sperm with smooth muscles contraction in the epididymis walls to the vas
deferens for ejaculation.
VAS DEFERENS
- Carries sperm from the epididymis to
the ejaculatory duct - Moves sperm by peristalsis. - Lumen is folded- Pseudostratified columnar with stereocilia
Muscular tube – 3 layers
* Inner: longitudinal
* Middle: circular
* Outer: longitudinal
- Strong contraction during ejaculation - smooth muscle in the walls of the vas deferens create peristaltic waves to squeeze sperm forward.
- Each tube passes through the inguinal canal and over the bladder one on each side
- contains Spermatic cord - blood vessels, and
nerves in a connective tissue sheath. - Expanded end is called the ampulla.
- Ends in the ejaculatory duct which unites with the urethra
- Vasectomy – prevent transportation of sperm
EJACULATORY DUCT
- Pseudostratified columnar +/- stereocilia
- Formed by union of the distal portion of the vas deferens (ampulla) and the ducts draining the seminal vesicles.
- Two short tubes that pass through the prostate gland to converge as the prostatic urethra.
URETHRA
Regions of the urethra 1st to last (length of the penis):
- Prostatic urethra :Surrounded by prostate gland - Transitional epithelium with dome cells
- Membranous urethra- From prostatic urethra to penis. Shortest part of the urethra
Surrounded by smooth muscles- Stratified or pseudostratified columnar - Spongy (penile) urethra: Runs the length of the penis. Surrounded by penile tissue
Stratified or pseudostratified columnar - Urethral meatus -urine (and semen in males) leaves the body -Stratified squamous keratinizing
- from base of the urinary bladder to the tip of
the penis. - Carries both urine and sperm.
- Sperm enters from the ejaculatory duct and exits through the urethral meatus (tip of penis).
Corpus cavernosum is the erectile tissue of the penis along with corpus spongiosum that surrounds the penile urethra
ACCESSORY ORGANS
- SEMINAL VESICLE
- PROSTATE GLAND
- BULBOURETHRAL GLANDS
SEMINAL VESICLE
- convoluted glands- honeycomb shaped
- Glandular morphology - Compound
tubuloalveolar (large lumen) - Surface epithelium- Pseudostratified tall
columnar type with secretory cells - Lipid droplets in the cytoplasm foamy look.
- May contain lipofuscin granules appear as a person ages result of wear and tear.
Secrete a thick, yellowish secretion alkaline fluid making up bulk of seminal fluid
* Fructose (sugar)
* Vitamin C
* Prostaglandins
* Other substances that nourish and activate sperm
- Located at the base of the bladder
- Surrounded by 2 layers of smooth muscles
PROSTATE GLAND
- Walnut sized gland.
- Glandular morphology: Compound tubuloalveolar with large lumen
- Surface epithelium: Stratified columnar
- Prostatic urethra passes through the middle of this gland; at the apex of the gland, it becomes the membranous urethra.
*surrounds the prostatic urethra - Secretes slightly acidic fluid (milky) that constitutes 25% of the seminal fluid. - Citrate, hyaluronidase, fibrinolysin and PSA (prostate specific antigen).
- called Prostatic fluid - For sperm activation, viabilityband motility
Age-related prostatic concretions: corpora
amylacea (CA) (from the Latin meaning “starchlike bodies”).
* Hyaline masses calcium filled hard
* Found in prostate gland, nervous tissue, lung and other organs of the body
BULBOURETHRAL GLANDS
- Pea-sized gland inferior/front of the prostate gland.
- Glandular morphology: Compound tubuloalveolar
- Surface morphology: Pseudostratified columnar
- Produces a thick, clear mucous – alkaline secretion.
- Cleanses the urethra of acidic urine.
- Serves as a lubricant during intercourse to prevent friction damage to the sperm cells during ejaculation.
- Ducts of these glands connect them with penile urethra.
SEMEN
Product of ejaculation - Spermatozoa and seminal fluid.
Advantages of accessory gland secretions
* Fructose provides energy for sperm cells.
* Alkalinity of semen helps neutralize the acidic environment of vagina.
* Semen inhibits bacterial multiplication.
* Elements of semen enhance sperm motility
