Topic 17: Reproductive System Flashcards
what are the main structures of the reproductive system?
-gonads (testes/ovaries)
-ducts
-accessory glands
what is the purpose of ducts within the reproductive system?
-to transport + store gametes
what is the purpose of accessory glands within the reproductive system?
-to produce secretions that will support the gametes
where are the male gonads (testes) located? what surrounds them?
-located within the scrotum (skin + CT)
-surrounded by 2 tunics
-tunica vaginalis
-tunica albuginea
what is the tunica vaginalis?
-outer serous membrane
-derived from the peritoneum
what is the tunica albuginea (male)?
-inner fibrous CT capsule
-extends inward to divide testis into lobules
what does each lobule contain?
-seminiferous tubules
-leydig cells (interstitial endocrine cells)
what are seminiferous tubules purpose? what do they form?
-produce sperm (spermatogenesis)
-unite to form rete testis (network of testis) on the posterior side
what cells are contained in the walls of the seminiferous tubules?
-spermatogenic cells
-sustentocytes (nurse) cells
what is the purpose of the sustentocytes cells? where do they extend?
-surround, nourish, and protect developing gametes
-produce testicular fluid
-extend from the basement membrane to the lumen
what type of junctions are present in sustentocyte cells? what do these form? what is the purpose of this?
-tight junctions
-form the blood-testis barrier
-protects sperm from the immune system (not recognized as self), toxins, and drugs
what is the purpose of sustentocyte cells producing testicular fluid?
-for sperm transport within the tubule lumen
where are leydig cells located? what is their purpose?
-in CT between seminiferous tubules
-secrete testosterone
what is the pathway of sperm into the series of ducts located within the male reproductive system?
-from the seminiferous tubules to the retes testis
what is the epididymis? what is its purpose?
-posterior border of the testis
-store sperm
-where sperm develop the ability to swim (mature)
where does the vas deferens (ductus) enter?
-the anterior pelvic cavity
-loops over the posterior wall of the bladder
what are the ducts within the male reproductive system?
-epididymis
-vas (ductus) deferens
-ejaculatory duct
-urethra
what does the spermatic cord carry?
-vas (ductus) deferens
-nerves
-blood supply
-lymphatic vessels
-carries them through the body wall
what forms the ejactlatory duct?
-the union of the vas deferens + a duct from the seminal vesicle
what are the 3 regions of the urethra in males?
-prostatic urethra
-intermediate (membranous) urethra
-spongy (penile) urethra
where is the prostatic urethra located?
-through the prostate gland
where is the intermediate (membranous) urethra located?
-through the urogenital diaphragm (muscular floor of the pelvis)
where is the spongy (penile) urethra located?
-through the corpus spongiosum of the penis
where does the penile urethra open?
-the glans penis (enlarged tip)
-opening is the external urethral orifice
what are the 3 parts of the penis?
-root
-body (shaft)
-glans penis (enlarged tip)
what are the 3 cylindrical bodies of erectile tissue of the penis?
-blood sinuses bound by CT layers
-2 corpora cavernosa
-1 corpus spongiosum
what portion is the corpora cavernosa?
-dorsal/posterior portion (erect)
-most of the root + shaft
what portion is the corpus spongiosum?
-midventral/anterior portion (erect)
-surrounds the urethra
-forms the glans penis
what are the accessory glands that make up 95% of semen?
-seminal vesicles (2)
-prostate gland (1)
-bulbourethral (2)
what are the seminal vesicles?
-posterior to the bladder
-secrete a fluid that provides sperm with a source of nutrients
-majority of semen
what is the prostate gland?
-inferior to the bladder + encircles the prostatic urethra
-secretes a fluid that nourishes and activates sperm motility
-medium contribution of semen
what are the bulbourethral glands?
-below the prostate in the urogenital diaphragm
-in contact with the external urethral sphincter
-secretes a thick mucus to lubricate the urethra and glans penis
-small contribution of semen
what is spermatogenesis?
-production of sperm within the seminiferous tubules
-includes the process of SPERMIOGENESIS
what is spermiogenesis?
-differentiation of spermatids into sperm
-develop flagella + acrosomes
-lose most cytoplasm
what are the parts of a spermatozoa?
-head
-body (midpiece)
-tail (flagellum)
what are the characteristics of the head of a spermatozoa?
-nucleus (23 chromosomes (n) )
-largest portion
-top of the nucleus is covered by the acrosome
what is the acrosome?
-modified lysosome
-contains enzymes to penetrate the secondary oocyte
what are the characteristics of the body of the spermatozoa?
-large # of mitochondria
-produce ATP for movement of flagellum
what are the characteristics of the tail of the spermatozoa?
-propels sperm
-made of microtubules
what forms semen?
-sperm + testicular fluid (5%)
-accessory gland secretions (95%)
how much semen is released at ejactulation?
-2mL-5mL
-contains 20-150 million sperm per mL
what are the characteristics of semen?
-pH of 7.2-7.6 (slightly alkaline)
-provides sperm with a transportation medium, nutrients, and protection
where are the female gonads (ovaries) located?
-in the pelvic cavity on the lateral sides of the uterus
-connected to the body wall
what are the 4 histology layers of the ovaries?
-surface (germinal) epithelium
-tunica albuginea (CT)
-ovarian cortex
-ovarian medulla
what is contained within the ovarian cortex layer?
-contains ovarian follicles + CT (support)
what are the ovarian follicles?
-layer(s) of cells surrounding each developing oocyte
-supports + protects through development
what does the ovarian medulla contain?
-blood + lymph vessels
-nerves
-CT (support)
what connects the ovaries to the body wall?
-ligaments continuous with the peritoneum
what type of cells form the surface (germinal) epithelium?
-layer of cuboidal cells
-modified visceral peritoneum lacking CT
do the uterine tubes have a direct connection to the ovaries?
-no
-has fimbriae which are the indirect connection that help capture and move the oocyte into the uterine tube
what are the 3 sections of the uterine tubes?
-infundibulum
-ampulla (middle)
-isthmus
what is the infundibulum section of the uterine tubes?
-suspended over the ovary
-has fimbriae (fingerlike protection) that cover the ovary during ovulation
-opening of the uterine tube into the peritoneal cavity
what occurs in the ampulla section of the uterine tubes?
-fertilization
what does the isthmus section of the uterine tubes connect to?
-the uterus
what are the 3 histology layers of the uterine tubes?
-mucosa
-muscularis externa
-serosa
what is the mucosa layer of the uterine tubes?
-simple columnar epithelium with ciliated cells or non ciliated secretory cells with microvilli
what is the muscularis externa layer of the uterine tubes?
-smooth muscle for movement of the oocyte/cell mass along the tube
what is the serosa layer of the uterine tubes?
-visceral peritoneum
what is the uterus?
-a hollow muscular organ where development occurs
-located superior to the bladder
what are the 3 parts of the uterus?
-fundus
-body
-cervix
where is the fundus of the uterus located?
-superior to the isthmus of the uterine tubes
what is the body of the uterus?
-main portion
-space within = uterine cavity
-site where most embryo implantation and growth occur
what is the cervix of the uterus?
-inferior narrow passageway that opens into the vagina
what are the 3 histology layers of the uterus?
-perimetrium (serosa)
-myometrium (muscularis externa)
-endometrium
what is the perimetrium?
-outer layer
-visceral peritoneum
what is the myometrium?
-smooth muscle
what is the endometrium?
-mucous membrane of simple columnar epithelium
-lines the inner surface
-specialized lamina propria with 2 highly vascularized layers
what are the 2 highly vascularized layers of the endometrium?
-stratum functionalis (functional layer)
-stratum basalis (basal layer)
what is the stratum functionalis?
-superficial layer
-develops at puberty and sheds monthly (menstruation) along with the simple columnar epithelium
-contains endometrial glands (epithelial tissue)
what is the stratum basalis?
-permanent layer attached to the myometrium
-undergoes mitosis to replace the stratum functionalis and the simple columnar epithelium
what is the vagina?
-birth canal
-connects the uterus to external genitalia
-female copulation organ
what are the 3 histology layers of the vagina?
-mucosa
-muscularis externa
-adventitia
what is the mucosa of the vagina?
-thick stratified squamous epithelium (abrasion)
-has rugae to prevent tearing (expansion)
what is the muscularis externa of the vagina?
-smooth muscle
what is the adventitia of the vagina?
-fibroelastic CT
-adventitia to hold in place (no movement)
what is oogenesis?
-gamete production within the ovarian follicles
what are the follicle stages?
-primordial follicle
-primary follicle
-secondary follicle
-vesicular (antral) follicle
-vesicular (antral) follicle
-preovulatory (graafian) follicle
-corpus luteum
-corpus albicans
what are spermatogenic cells?
-germ cells in various stages of development
-become the sperm
what is the purpose of the vas (ductus) deferens?
-transports sperm from the epididymis during ejaculation
-part of the spermatic cord
what is the function of the penis?
-urinary and copulatory organ
what is the purpose of the accessory glands of the male reproductive system?
-contribute to secretions during sexual arousal
what is the process of spermatogenesis?
-type A spermatogonia (2n) go through mitosis to form type B spermatogonia (2n)
-type A spermatogonia remain at the basal lamina
-type B spermatogonia (2n) go through growth and mitosis to form 2 primary spermatocytes (2n)
-2 primary spermatocytes (2n) go through meiosis I to form 4 secondary spermatocytes (n)
-4 secondary spermatocytes (n) go through meiosis II to form 8 spermatids (n)
-8 spermatids (n) go through spermiogenesis to form 8 spermatozoa (n)
what is the tunica albuginea (female)
-dense connective tissue
what is the purpose of the ciliated cells within the mucosa of the uterine tubes?
-help move the oocyte/zygote/morula along the tube
what is the purpose of the non ciliated secretory cells with microvilli within the mucosa of the uterine tubes?
-secrete fluid that provides nutrients to the oocyte/cell mass
what is the purpose of the endometrial glands within the stratum functionalis?
-secretes a nutritive fluid for the embryo prior to the formation of the umbilical cord
what is contained within the vulva?
-mons pubis
-labia majora/minora
-vestibule
-greater vestibular glands
-clitoris
-reproductive structures that lie external to the vagina
what is the mons pubis?
-adipose tissue that overlies and cushions the pubic symphysis
what is the labia majora?
-two large skin folds that surround the labia minora
what is the labia minora?
-small inner folds of skin that surround the vestibule
what does the vestibule contain?
-vaginal opening
-external urethral orifice (anterior to the vaginal opening in anatomical position)
what do the greater vestibular glands secrete?
-mucus to lubricate the vestibule
what is the clitoris?
-mainly internal
-small external portion at the anterior junction of the labia minora
-contains erectile tissue
-derived from the same embryonic tissue as the penis
what is the general process of oogenesis before birth?
-oogonia (2n) goes through mitosis to create many more oogonia (2n)
-oogonia cells differentiate to form primary oocytes (2n)
what is the general process of oogenesis after puberty?
-primary oocytes (2n) go through meiosis I to form the 1st polar body (n) and the secondary oocyte (n)
-1st polar body (n) may undergo meiosis II to form another polar body (n)
-secondary oocyte (n) is ovulated
-if secondary oocyte (n) is fertilized then meiosis II completes to form the ovum (n) and the 2nd polar body (n)
what will the primary oocyte form at the end of oogenesis?
-1 ovum
-2 or 3 polar bodies
what are polar bodies?
-discarded nuclear (genetic) material
what are oogonia?
-diploid stem cells
-multiply by mitosis during fetal development
-differentiate into primary oocytes
what are primary oocytes?
-diploid cells
-approximately 1 million in ovaries at birth (at puberty less than half remain)
-enter meiosis I before birth but arrested in prophase I (until puberty)
what are secondary oocytes?
-haploid cells
-begins meiosis II and arrests in metaphase II
-is ovulated (1/month)
-approximately 500 ovulated from puberty to menopause
what is the process of follicular development in the late embryonic and fetal period?
-primordial follicle forms
-primary oocytes become surrounded by a single layer of flat pre-granulosa cells (for support)
-most primordial follicles with primary oocytes degenerate over time (fewer at birth)
what is the process of follicular development in childhood?
-ovary is mostly inactive
-some primordial follicles will develop into primary follicles
-single layer of flat pre-granulosa cells become cuboidal
-cells are now called granulosa cells
-primordial and primary follicles will continue to degenerate (less at puberty)
why do primordial and primary follicles degenerate over time?
-absence of reproductive hormones
what is the process of follicular development at puberty?
-ovarian cycles and reproductive hormone secretion begins
-each month primary follicles continue to form and reproductive hormones selectively stimulate some and continue their development in the ovarian cortex
-go through one or more of the remaining stages
what is the process of the secondary follicle?
-hormone secreting theca cells form from surrounding CT cells (in the transition from primary to secondary follicle)
-granulosa cells proliferate (stratify) and start to secrete fluid + estrogen
-fluid filled spaces develop between granulosa cells as fluid accumulates
what is the process of the vesicular (antral) follicle
-fluid filled spaces unite into a single large antrum
-granulosa cells still surrounding the oocyte are the corona radiata
-only one dominant vesicular follicle will continue development per each cycle
what is the process of the preovulatory (graafian) follicle?
-mature vesicular follicle
-follicle grows significantly in size and protrudes from the ovary surface
-hormone levels rise causing 2 events
what do the rising hormone levels cause for the preovulatory (graafian) follicle?
-formation of the secondary oocyte (meiosis I is completed)
-enters meiosis II and arrests in metaphase II
-ovulation (release of secondary oocyte surrounded by corona radiata) from follicle into the peritoneal cavity (follicle remains in the ovary)
-if fertilization occurs the acrosome of a single sperm will penetrate the corona radiata
what is the corpus luteum?
-follicle that remains after ovulation
-produces high levels of hormones that support fetal development (estrogen + progesterone)
-if no pregnancy occurs, degenerates into the corpus albicans
what is the corpus albicans?
-non-functional (does not release hormones)
-scar-like structure on the surface of ovary
