P, V, & Assoc. Flashcards
Define Sexual Reproduction
Production of offspring by making germ cells
Define Fertilization
Male gamete uniting w/ female gamete
Define Gonad
Produces gametes and secretes sex hormones
Define Ducts
Store and transport gametes
Define Accessory Sex Glands
Produce substance to protect gamete and facilitate movement
As supporting structures, what do the penis and uterus assist with?
Delivery of gametes
Organs of the male reproductive system include ? 4
Testes
Ducts
Accessory sex glands
Supporting structures
What are the 6 ducts of the male reproductive system?
Straight Tubules Rete Testis Efferent Ducts Ductus Epidiymis Epididymis Ductus Deferens
What are the 3 accessory sex glands of males?
Seminal vesicles
Prostate
Bulbourethral glands
What are the 2 male supporting structure?
Scrotum
Penis
What is the external ridge of the scrotum?
Where does is start and end?
Raphe
Urethral meatus -> anus
What does the scrotal raphe represent?
Fusion of genital tubercles from embryonic development
Where does the scrotal subcutaneous layer come from during development?
Abdominal structures during embryonic development
What are the 6 layers of the scrotum?
Dartos muscle (smooth) External spermatic fascia Cremaster muscle (skeletal) Internal Spermatic fascia Tunica vaginalis (parietal and visceral)
What are the functions of the Cremaster and Dartos reflexes?
Cremaster- brings testes closer to absorb heat
Dartos- tightens scrotum to reduce heat loss
Where/how do testicles descend into the scrotum during development?
Inguinal canal during month 7 of development
What structure is a part of the scrotum AND a part of the testes?
Tunica vaginalis
Inner most of scrotum
Outter most of testicle
What does the Tunica Vaginalis develop from?
Peritoneum during descent of testes
Where/what does the Tunica Albuginea do?
Internal to T. Vagainalis
Forms septa dividing testes into lobules
What are the functional units of testes?
Lobules
200-300/testis
What are testicle lobules made up of?
Seminiferous tubules
1-3/tubule
What are the 2 types of cells found in seminiferous tubules?
Spermatogenic cells- sperm forming
Sertoli/sustentacular cells- support spermatogenesis
Where is the location of spermatogenesis?
Seminiferous tubules
Begins w/ primordial germ cell differentiating into spermatogonia
When do spermatogonia enter the testes?
What happens to them once they’re there?
5th week of embryonic development
Dormant until puberty
What is the sequence of spermatogenesis?
Spermatogonia Primary spermatocyte Secondary spermatocyte Spermatid Sperm cell (spermatozoa)
What is the purpose of Sertoli Cells in seminiferous tubules?
Embedded among speratogenic cells to support and protect spermatogenic cells
What are the 5 functions of Sertoli Cells?
Nourish spermatocyte/spermatid/sperm
Phagocyte excesses
Control release of spem -> lumen
Produce fluid for sperm transport w/in tubules since they can’t swim
Produce Androgen Binding Protein to keep testosterone in local area
What is the Blood-Testis barrier?
Tight junctions between sertoli cells w/in seminiferous tubules to isolate developing gametes from blood
What is the function of the Blood-Testis barrier?
Prevents the immune response of the spermatogenic cells surface Ags from destroying developing sperm
What are Leydig cells?
Cell in tunica albuginea around seminiferous tubules to produce/secrete testosterone
How does spermatogenesis start?
Spermatogonia that undergo mitosis from stimulation by testosterone
Spermatogonia that lose contact w/ basement membrane, pass through blood-testes barrier and differentiate into primary spermatocyte
What happens to Primary Spermatocytes after differentiation?
Meiosis 1 creates two Secondary Spermatocytes
What happens to the two Secondary Spermatocytes after meiosis one?
Meiosis II
One secondary spermatocyte= 4 spermatids after two rounds of cell division
What is the last part of spermatogenesis?
Spermiogenesis
Haploids -> sperm
Gain of acrosome, mitochondria, flagellum
Define Spermiation
When does it occur?
Sperm released from Sertoli cells into lumen
Occurs during spermiogenesis
Define Acrosome and its contents
Enzyme vesicle for penetrating secondary oocyte
Contains hyaluronidase and protease
What are the 4 parts of a sperm tail?
What organelles do they contain?
Neck- contains centrioles
Middle- contain mitochondria
Principle- longest part of tail
End- terminal
What hormones starts hormonal control of testes?
GnRH
Stimulates gonadotrophs of anterior pituitary to secrete and release LH and FSH
What is LHs influence on the testes?
Leydig cells to produce/secrete testosterone
What is testosterone synthesized from?
Cholesterol allowing it to be lipid-soluble for diffusion out of Leydig cells and into blood/seminiferous tubules
How does 5-alpha-reductase influence hormones in the testes?
Converts testosterone to Dihydrotestosterone in prostate/external genitals
What is DHTs purpose/function?
More potent androgen thought to “spark” puberty in males
Combines with testosterone to influence sexual behavior/desires
What is FHSs influence on spermatogenesis?
Indirectly
Works w/ testosterone to act on Sertoli cells to secrete ABP to keep testosterone in tubule lumen
What hormone stimulates the final steps of spermatogenesis?
Testosterone
What happens once normal levels of spermatogenesis occurs?
Sertoli cells release small amounts of inhibin which reduces the production of FSH
3 fates of testosterone and DHT during prenatal development?
Development of male reproductive system/descent of testes
DHT stimulates development of external organs
Converted to estrogen in brain for region development
Male sexual characteristics include what characteristics?
Muscle/skeletal growth Wide shoulders/narrow hips Facial/chest hair Thick skin Increase sebaceous secretions Enlarged larynx
How do testosterone and DHT influence development of sexual function?
Contribute to sexual behavior
Spermatogenesis
Sex drive
What is the main source of androgen production in females?
Adrenal cortex
What stimulates/causes males to have heavier muscle/bone masses?
Testosterone and DHT stimulate protein synthesis
How do sperm get from seminiferous tubules to the straight tubules?
Fluids secreted by Sertoli cells
Define Rete Testis
At hilum of testicle
Network of ducts that bridge straight tubules and efferent ducts
Define Efferent Ducts
Coiled ducts in epidiymis leading to ductus epididymis
Define Ductus Epididymis
Single convoluted tube connecting efferent ducts and ductus deferens
How long is the ductus epididymis if stretched out?
20ft
What is the shape and location of each epididymis?
Comma shaped organ at posterior of each testis
What is the site of sperm maturation?
Epididymis
What is the epididymis’ job during sexual arousal?
Helps propel sperm into ductus deferens
Where is the ductus deferens located?
Within epididymis where tubule becomes less convoluted and diameter increases
What are the 5 ducts of the testes?
Straight tubule Rete testis Efferent duct Ductus epididymis Epididymis
What is the path of the ductus deferens?
Transverses through spermatic cord, enters pelvic cavity, loops over ureter, down posterior surface to ampulla at seminal vesicle
Where/what is the terminal portion of the ductus deferens?
Widens into ampulla where it meets seminal vesicle
What is the function of the Ductus deferens?
Carry sperm from epididymis to urethra during arousal
Can help with sperm storage
What is the function of the Spermatic cord?
Supporting structure ascending out of scrotum with ilioinguinal nerve
What are the components of the Spermatic Cord?
Ductus deferens Testicular artery Veins Lymphatic vessels Autonomic nerves Cremaster muscle
How does the spermatic cord help with transporting testosterone into systemic circulation?
Veins carry testosterone via pampiniform plexus
Where is the Pampiniform Plexus in relation to the vas deferens?
Anteriorly
Why is more pathology found on the left side of the scrotum/reproductive system in males?
R side of pampiniform plexus drains to inferior vena cava
L side drains to left renal vein
What 2 things joins to form the Ejaculatory duct?
Union of seminal vesicle and ampulla of ductus deferens
Terminate at the prostatic urethra
What is the function of the Ejaculatory duct?
Eject sperm and seminal vesicle secretions
Male urethra is a shared terminal duct for what two systems?
Reproductive
Urinary
What are the 3 sections of the male urethra?
Prostatic
Membranous
Spongy
Where does most of the fluid portion of semen come from?
Accessory sex glands
Small part from seminiferous tubules
What are the 3 contributors of fluid portion of semen?
Seminal vesicle secretion- most
Prostatic secretion
Bulbourethral secretion- least
What are the functions of the Seminal Vesicles?
Secrete alkaline fluids to neutralize urethra and female reproductive tract
Secrete viscous fluids to keep semen in female reproductive tract longer
Seminal vesicle secretions contain what 3 things?
Fructose- energy
Prostaglandins- motility, viability
Clotting proteins- coagulates after ejaculation
What do male sex gland prostaglandins do within the female reproductive tract?
Stimulate smooth muscle contractions to aid with semen movement to ova
Prostate is located ___ to bladder and surrounds ______
Inferior
Prostatic urethra
When does normal prostate growth occur?
Slowly until puberty
Rapidly from puberty -> 30
Additional enlargement at 45 y/o
What are the 3 parts of prostatic fluid and their purposes?
Citric acid- ATP synth.
Proteolytic enzymes- break down clotting factors (specific Ags, pepsinogen, lysozyme, amylase, hyaluronidase)
Seminalplasmin- decrease number of bacteria in semen
Where are bulbourethral glands located?
Inferior to prostate on either side of membranous urethra w/ ducts opening into spongy urethra
What are bulbourethral glands role during sexyal arousal?
Secrete alkaline fluid to protect sperm and neutralize urethra
What are the 4 fluids that make up the whole seminal fluid?
Seminiferous tubules
Seminal vesicles
Prostate
Bulbourethral glands
What give semen the milky color?
What give is the viscous/tacky consistency?
Prostatic fluid- color
Seminal fluid/bulbourethral fluid- viscosity/consistency
When/why does semen coagulate and reliquify?
5 min due to seminal vesicle clotting proteins
10-20 due to prostate specific antigens
Define Hematospermia
Blood in semen
What are the 3 parts of the penis?
Body
Glans penis
Root
What are the 3 parts of the penis body?
Corpora cavernosa: 2 dorsolateral masses, fibrous tissue
Corpus spongiosum: single midventral mass w/ spongy urethra
Glans penis is the distal end of ?
Corpus spongiosum
Define corona?
Margin surrounding the anatomical glans penis