Reproductive System Flashcards
Vesicouterine pouch
- space between urinary bladder and uterus
- Female Reproductive System
Rectouterine pouch
- space between rectum and uterus
- Female Reproductive System
what is the primary reproductive organ of women
ovaries
what are the accessory reproductive organ of women
Uterine tubes, uterus, vagina, external genitalia, mammary glands
Ovaries anatomy
paired oval organs lateral to uterus, anchored by CT
Ovarian artery / vein
branch off of abdominal aorta
Mesovarium
o Double fold of peritoneum that attaches to each ovary at hilum
◦ Blood vessels / nerves (autonomic) enter
- part of Ovaries
Broad ligament
drape of peritoneum hanging over uterus
- paRT OF Mesovarium, part of Ovaries
Ovarian ligament
sticks ovary to side of uterus
- part of Mesovarium, part of Ovaries
Suspensory ligament
superficial anchor
- part of Mesovarium, part of Ovaries
Two layers of the ovary
◦ 1. Germinal epithelium – outer layer
o Simple cuboidal epithelial layer surrounding ovary
◦ 2. Tunica albuginea – inner layer
o Connective tissue capsule
Deep to the layers of the ovaries layers
o Cortex – outside
˗Contains ovarian follicles
o Medulla – inside
˗Contains branches of ovarian blood
vessels, lymph vessels, nerves
Ovarian follicles
◦ Consist of oocyte (egg) surrounded by follicle cells for support
o Thousands found in cortex
o 6 main types of ovarian follicle representing different stages of development
Primordial follicle -> primary follicle -> secondary follicle -> vesicular follicle ->
corpus luteum -> corpus albicans
Primordial follicle
- Most primitive type of ovarian
follicle - Primary oocyte and single
flattened layer of follicle cells
o Primary oocyte arrested in
meiotic prophase - 1.5 million present at birth
Primary follicle
- Primary oocyte + follicle cells which
matured aka granlulosa cells - Follicle secretes estrogen
- Thecal cells on periphery of follicle
o Help control follicle development
o Secrete androgens (precursor to estrogen)
Secondary follicle
- Primary oocyte, thecal cells, granulosa cells, fluid-filled space, antrum
o In the antrum, serous fluid increases as ovulation nears
o Oocyte forced to one side of follicle
Large vesicular (mature) follicle
- Contains a secondary oocyte
- Primary follicle divides from
46 chromosomes to 23
chromosomes in meiosis - One formed per month
Corpus luteum
- After mature follicle ruptures
(ovulation) and oocyte expelled - Remnants is left in ovary
- Secretes sex hormones progesterone and estrogen
o = buildup of uterine lining
o Prepare uterus for possible
implantation of fertilized oocyte
Corpus albicans
- Formed from regression of corpus luteum, scar tissue
ovaries before birth
- vary contains primordial germ cells, oogonia
o 1.5 million follicles within ovarian cortex at birth
o During puberty they divide by mitosis into primary oocytes
ovaries in childhood
- Ovaries inactive with no follicles developing
◦ Atresia
o Regression of some primordial follicles
◦ By puberty 400,000 follicles remain in ovaries
ovaries from puberty to menopause
◦ Hypothalamus release of gonadotropin-releasing hormone (GnRH)
◦ This stimulates release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH)
o Levels vary in cyclical pattern
o Produce monthly sequence of events, ovarian cycle
o 3 phases
˗ 1. Follicular
˗ 2. Ovulation
˗ 3. Luteal
Follicular phase
◦ Days 1–13 of 28-day ovarian cycle
◦ ~20 primordial follicles are stimulated to mature by FSH and LH
◦ Follicular cells
o Release hormone, inhibin which blocks FSH production
o Prevents excessive follicle development
◦ Few primary follicles maturing -> secondary follicles
o Usually only one matures -> vesicular follicle
◦ Volume of fluid increases within follicle antrum
◦ Oocyte forced to one side of follicle
◦ Primary oocyte in vesicular follicle
◦ Diploid – 46 chromosomes
o Finishes meiosis I and forms two cells (haploid)
◦ One polar body
o Nonfunctional, regresses
◦ One secondary oocyte
o Receives bulk of cytoplasm
o Completes meiosis if fertilized – ovum (diploid)
o Added ½ genetic information from sperm
Ovulation
◦ Release of secondary oocyte from mature follicle, one ovary
◦ Occurs on day 14 of 28-day cycle
◦ Increased LH causes antrum expands until ovarian surface thins
o Eventually ruptures, expelling secondary oocyte
Luteal phase
◦ Remaining follicle cells become corpus luteum
◦ Days 15—28 of cycle
◦ Corpus luteum
o Temporary endocrine gland
o Secretes progesterone and estrogen to build lining for fertilized oocyte
o Life span of 10 to 13 days if oocyte not fertilized
◦ Corpus luteum regression
o Causes drop in secreted progesterone and estrogen
o Causes shedding of uterine lining – menstruation
After menopause
◦ Women cease cycling for 1 year, menopause
◦ Age 45 to 55
◦ No more ovarian follicles remain or follicle maturation stops, uterine lining no longer growing, decrease in progesterone and estrogen production
Regulation of the ovarian cycle
- Hypothalamus secretes GnRH
o Stimulates anterior pituitary to secrete FSH and LH - FSH and LH target ovaries and stimulate follicular development
- Maturing ovarian follicles secrete inhibin and estrogen
o Negative feedback effect on hypothalamus and anterior pituitary - Estrogen assists development of mature ovarian follicle
- Mature follicle produces a larger amount of estrogen
o Positive feedback loop initiated - Feedback loop results in an LH surge from anterior pituitary
- Corpus luteum forms from ovulated follicle
- Corpus luteum secretes large amounts of progesterone, estrogen, and inhibin
o Inhibits hypothalamus and anterior pituitary and builds uterine lining - The cycle repeats
o LH levels reduced by negative feedback events
o Levels of estrogen, progesterone, inhibin drop
o Hypothalamus secretes GnRH to start new cycle
Uterine tubes (Fallopian tubes)
◦ Extend laterally from both sides of uterus toward ovaries
◦ Transport ovulated oocyte uterus
o Wall: Mucosa, muscularis, serosa
o Mucosa has cilia on cells to draw oocyte into uterine
Uterine tube regions
◦ Infundibulum
o Free, funnel-shaped, lateral margin of uterine tube
o Numerous fingerlike folds, fimbriae
◦ Ampulla
o Expanded region of tube medial to infundibulum
o Fertilization happens here
◦ Isthmus
o Region of tube extending from ampulla
◦ Uterine part of tube
o Extends medially from isthmus
o Penetrates wall of uterus
Uterus
◦ Muscular organ
◦ Implantation site for pre-embryo
◦ Supports, protects, nourishes developing embryo
o Forms vascular connection that develops into placenta
◦ Ejects fetus at birth
◦ Contracts and sheds lining if oocyte not fertilized
◦ Uterine arteries
◦ Uterine veins
Uterus— Main structures
- Muscles of pelvic floor
- Round ligaments
- Transverse cervical ligaments
- Uterosacral ligaments
Tunics
- 3 concentric tunics of uterine wall: perimetrium, myometrium, endometrium
o Endometrium sheds each month if not fertilized
Regions of uterus
Fundus, body (thick wall of smooth muscle), isthmus, cervix (projects to vagina)
Vagina
◦ Thick-walled, fibromuscular tube
◦ Thin, distensible wall with 3 tunics
o Mucosa, muscularis (lots of this), adventitia (elastic fibers)
Uterine cycle
◦ Cyclical changes in endometrial lining
◦ Influenced by estrogen and progesterone
◦ 3 phases
- Menstrual phase
- Proliferative phase
- Secretory phase
- Menstrual phase
◦ Days 1–5 of cycle
◦ Sloughing off of the functional layer
◦ Lasts through period of menstrual bleeding
- Proliferative phase
◦ Days 6–14 of cycle
◦ Development of new functional layer of endometrium
◦ Overlaps time of follicle growth and ovary estrogen secretion
- Secretory phase
◦ Days 15–28 of cycle
◦ Increased progesterone secretion from corpus luteum
◦ Results in increased uterine vascularization
◦ If fertilization does not occur
o Degeneration of corpus luteum
o Dramatic drop of progesterone
o Without progesterone, sloughs off functional layer
Ovarian cycle and uterine cycle phases
◦ Menstrual phase during ovarian follicular phase
◦ Proliferative phase during ovarian follicular phase and ovulation
◦ Secretory phase during ovarian luteal phase
Mammary gland
◦ Each located within anterior thoracic wall
◦ Composed of tubuloalveolar apocrine gland
◦ Secretory product, breast milk
o Proteins, fats, lactose sugar for infant nutrition
Breast milk release
◦ Occurs in response to internal and external stimuli
◦ Prolactin
o Produced in anterior pituitary and responsible for milk production
◦ Oxytocin
o Produced by hypothalamus and released form posterior pituitary
o Responsible for milk ejection
o Important structures: nipple, areola, lobe (individual section of breast tissue), lactiferous ducts (drain lobe of breast), lactiferous sinus (stores milk prior to release)
Mammary Glands
Primary reproductive organs in men
testes
Accessory reproductive organs
◦ Ducts and tubules leading from testes to penis
◦ Male accessory glands
◦ Penis
Scrotum
◦ Skin-covered sac between thighs
◦ Provides cooler environment
o Needed for sperm development and
maturation
Raphe
Midline seam in scrotal sac
Testis reside inside
o Sac has the ability to contract and relax based on temperature to move the testes towards and away from the body
\oTesticular artery / vein
muscles that control testes
o Position controlled by the dartos and cremaster muscles
Testes
◦ Relatively small organs housed within the scrotum
◦ Produce sperm and androgens
◦ Covered by a serous membrane with inner cavity
Tunica albuginea
o Thick fibrous capsule covering the testis
o Deep to visceral layer Testes and Spermatogenesis
Mediastinum testis
Thickening of tunica albuginea projecting into interior testis
basically hilum of testes
Septa
o Internal projections of tunica albuginea
o Subdivide internal space into 250 lobules
Seminiferous tubules
Extremely convoluted and elongated, up to 4 per lobule
Sustentacular cells
non-dividing support cells
˗ Nourish developing sperm
˗ Release hormone inhibin when sperm count high
˗ Inhibits FSH secretion and regulates sperm production
sustentacular cells also contain
Contain dividing germ cells continuously producing sperm
Blood-testis barrier
Protects developing sperm from material in blood
Interstitial spaces
Spaces surrounding seminiferous tubules
Interstitial cells
o Reside in interstitial spaces
o Stimulated to produce androgens by luteinizing hormone
o Most common androgen, testosterone
o Majority released from interstitial cells; small amounts secreted by adrenal cortex Testes and Spermatogenesis
how many steps of Hormonal regulation of testes
5 steps
- Hypothalamus secretes GnRH
Stimulates anterior pituitary to secrete FSH and LH
- FSH and LH stimulate spermatogenesis and androgen production.
o LH stimulates interstitial cells to secrete testosterone
o FSH stimulates sustentacular cells to secrete androgen-binding protein (ABP)
which binds to testosterone increasing level in testes
- Increased testosterone facilities spermatogenesis
o Also inhibits GnRH secretion and pituitary sensitivity to GnRH
o Has negative feedback effect
- Sustentacular cells release inhibin
o Respond to rising sperm count levels (negative feedback)
o Causes inhibition of FSH secretion from anterior pituitary
- Testosterone stimulates libido and development of secondary sex characteristics
Hair growth in axillary and pubic regions, deeper voice, facial hair
Spermatogenesis
o Process of sperm development, occurs within seminiferous tubule
o Begins during puberty with significant levels of FSH and LH
Spermatogonia
o Primordial germ cells from which all sperm develop
o Diploid cells near base of seminiferous tubule
o Surrounded by cytoplasm of sustentacular cell
o Divide by mitosis into new spermatogonia and primary spermatocyte > secondary spermatocyte > spermatid > sperm
Spermiogenesis
o Final stage of spermatogenesis
o Spermatid becomes mature spermatozoa, sperm
o Acrosome cap forms over nucleus
◦ Digestive enzymes to help penetrate secondary oocyte
o Tail forms from organized microtubules in cell Testes and Spermatogenesis
Ducts within the testis
◦ Right and left testes each with their own
set of ducts
◦ Transport and store sperm as they mature
Rete testis
o Meshwork of interconnected channels in mediastinum testis
o Receive sperm from seminiferous tubules
Epididymis
◦ Comma-shaped structure
◦ Three parts: head, body, and tail
◦ Stores sperm until fully mature
◦ Sperm first entering epididymis
o Look like mature sperm
o Can’t move like mature sperm
o If expelled too soon, not motile
o If ejected too late, old sperm degenerate and are resorbed by cells lining the duct of the epididymis
Ductus deferens (vas deferens)
◦ Sperm enter after leaving epididymis
◦ Thick-walled tube
o Travels up, around bladder and down
o Enlarges and forms ampulla
˗ Unites with proximal seminal vesicle to form ejaculatory duct
Ductus wall
Inner mucosa, middle mucosa, outer adventiva
Inner mucosa
lined by ciliated cells
(helps move sperm)
Middle muscularis
with three layers
of smooth muscle
◦ Necessary for moving sperm through ductus deferens
◦ Sperm not motile until ejaculation from penis
Ejaculatory duct
◦ Conducts sperm and a component of
seminal fluid toward urethra
◦ Opens into prostatic urethra
Urethra
Transports semen from ejaculatory ducts to outside of body
◦ 3 components
o Prostatic urethra, membranous urethra, spongy urethra
Seminal fluid
◦ Alkaline secretion needed to neutralize vaginal acidity
◦ Gives nutrients to sperm traveling in female reproductive tract
◦ Produced by 3 accessory glands
- Seminal vesicles (60% of fluid)
◦ Paired elongated hollow organs
◦ Secretes alkaline fluid with fructose and prostaglandins
o Fructose nourishes sperm
o Prostaglandins promote widening of external cervix
- Prostate gland (30% of fluid)
◦ Submucosal glands produce mucin
◦ Tubuloalveolar glands open into prostatic urethra
◦ Secretes milky fluid rich in citric acid, seminal plasmin, prostate-specific antigen (PSA)
o Citric acid, nutrient for sperm health
o Seminalplasmin, antibiotic that combats UTIs
o PSA, enzyme to liquefy semen
- Bulbourethral gland (5%of fluid)
◦ Paired glands each with short duct projecting into base of penis
o Enters spongy urethra
◦ Tubuloalveolar glands
o Produce clear, viscous mucin that forms mucus
o Coats and lubricates urethra during intercourse
Semen
◦ Formed from seminal fluid (95-97%) and sperm (2-5%)
◦ 200 to 500 million spermatozoa
◦ Transit time from seminiferous tubules to ejaculate is about 2 weeks
Root
Internally attached portion of penis
Body
Elongated movable portion
Glans
o Tip of penis
o Contains external urethral orifice
Prepuce
Circular fold of skin
3 parts of penar erect tissue
Paired corpus cavernosa
Corpus spongiosum
tunica albuginea
