A&PII Ch.28 Reproductive System pt.2 Flashcards
Female Reproductive System Organs
- Primary is the Ovaries
- Accessory is the fallopian (uterine tubes), uterus, cervix, vagina, external genitalia, and the mammary glands
Mammary Gland
- found in the breast
- each located within the anterior thoracic wall
- composed of modified exocrine glands
- secretory product, breast milk
- proteins, fats, lactose sugar for infant nutrition
Mammary gland Components
- Nipple which is a cylindrical projection in the center of the breast, has multiple tiny openings of the excretory ducts, transports breast milk
- Areola is the pigmented ring around the nipple and is an uneven surface due to sebaceous glands, areolar glands (glands of Montgomery)
- Suspensory Ligaments which are fibrous connective band supporting the breast, extend from the skin and attach to deep fascia overlying the pectoralis major
Alveoli
- secretory units of mammary glands
- produce milk in lactating female
- become more numerous and larger during pregnancy
- drained by lactiferous ducts
Pelvic Structures
- Mons pubis: rounded cushion of fatty tissue covered by skin and pubic hair
- Labia Majora: connective tissue, adipose tissue and thickened skin
-homologous to scrotum in male - Pudendal Cleft: a furrow separating the paired labia majora
- Labia Minora: highly vascular layer of areolar CT
-normally covers vaginal orifice, but swells and separates when sexually aroused
Vulva
- consists of the labia majora and minora
- the vestibule lies between and is hidden by the paired labia minora
- secretes mucin, mucous lubricant
Clitoris
- Partly homologous to the male penis
- Consists of small external glans with deeper internal body
-consists of a cylindrical shaft containing corpora cavernosa and vestibular bulbs - Rich in pressure and temperature receptors
- Glans and vestibular bulbs are considered erectile tissue (swells/ engorges)
Ovaries (What are they?)
- Portion of Female Reproductive system
- Paired, oval organs containing follicles
-ovarian follicles are the site of oocyte production and sex hormone release - Slightly larger than an almond in an adult
-size varies during each menstrual cycle and during pregnancy
Features of the Ovaries
- positioned on either side of the uterus, anchored by the ovarian and suspensory ligaments
- Ovarian arteries, veins, and nerves pass out of the ovary at the hilum
- Outer cortex of the ovary: dense connective tissue interspersed with thousands of ovarian follicles containing developing germ cells
- Inner medulla: areolar connective tissue with arteries, veins, nerves and lymphatic vessels
Ovarian Follicles
- consists of an oocyte surrounded by follicle cells
- support the oocyte
- Numerous, found in the cortex
- 6 main types of ovarian follicles representing different stages of development
Ovaries Have What Types of Follicles with what descriptions? (1st 3)
1) Primordial Follicles
* most primitive type of ovarian follicles
* primary oocyte and a single flattened layer of follicle cells
-primary oocyte arrested in first meiotic prophase
* 1.5 million present at birth
2) Primary Follicle
* primary oocyte with a single layer of cuboidal follicular cells, now called granulosa cells
* secretes estrogen as it matures
* stimulates changes in the uterine lining
* immediately surrounding the primary oocyte is the zona pellucida
-translucent structure containing glycoproteins
3) Secondary Follicle forms from the primary follicle
* primary oocyte with many layers of granulosa cells
* thecal cells on the periphery of follicle
-help control follicle development
-secrete androgens converted to estrogen by granulosa cells
Ovaries Have What Types of Follicles with what descriptions? (2nd 2)
4) Antral Follicle forms from secondary follicle
* Primary oocyte, many layers of granulosa cells, fluid-filled space, antrum
-in the antrum, serous fluid increases as ovulation nears
-oocyte forced to one side of the follicle
- immediately surrounding the oocyte is zona pellucida and corona radiata
-corona radiata is external to zona pellucida; is the innermost layer of cumulus oophorus cells
5) Graafian Follicle (Mature Follicle)
* forms from secondary follicle
* contains a secondary oocyte
-surrounded by zona pellucida and corona radiata
* numerous layers of granulosa cells
* fluid-filled antrum
* completed meiosis I
* arrested in second meiotic metaphase (metaphase II)
* one formed per month
Corpus Types (continuation of follicle types)
5.5) Corpus hemorrhagicum
* a temporary structure that forms immediately after ovulation
-follicle fills with blood and clots
6) Corpus Luteum
* forms from remnants of follicle
-after mature follicle ruptures and oocyte is expelled
* persists and secretes hormones if pregnancy occurs
-stimulate buildup of uterine lining
-prepare uterus for possible implantation of fertilized oocyte
7) Corpus Albicans
* formed from regressed corpus luteum
* white connective tissue scar
* most structures completely reabsorbed
Folliculogenesis and Ovarian Cycle
- occurs puberty to menopause
- Folliculogenesis (follicle development) begins at puberty
-regulated by hypothalamus releasing GnRH, which stimulates release of FSH and LH
-produces monthly sequence of events, known as the ovarian cycle - 3 phases: follicular phase, ovulation, and luteal phase
Follicular Phase
- typically shown as days 1-13 of 28-day ovarian cycle
- around 20 primordial follicles stimulated to mature into primary follicles by LH and FSH
-unclear why some are stimulated and some not - granulosa cells release inhibin
-helps inhibit further FSH production
-prevents excessive follicle development
-usually only one matures to Graafian follicle - Volume of fluid increases within follicle antrum
-oocyte forced to one side of follicle
Oogenesis and the Ovarian Cycle
- During the follicular phase, arrested primary oocytes resume growth, finish meiosis I and divide into 2 daughter cells
-In antral follicle - One, polar body
-Nonfunctional, receives minimal cytoplasm and regresses - Other cell derived from primary oocyte
-receiving bulk of cytoplasm
-becomes secondary oocyte
-reaches metaphaseII before arrested again
-completes meiosis if fertilized
-if not, breaks down in 24 hours
Ovulation
- release of secondary oocyte from mature follicle
- occurs on day 14 of 28-day cycle
- usually only one ovary ovulates each month
- induced with peak in LH secretion
- antrum increases in size and swelling
-expands until ovarian surface thins
-eventually ruptures, expelling secondary oocyte
Luteal Phase
- remaining follicle cells become corpus luteum
- occurs on days 15-28 of cycle
- Corpus luteum
-temporary endocrine gland
-secretes progesterone and estrogen
-builds up uterine lining, prepares for fertilized oocyte
-lifespan is 10-13 days if oocyte is not fertilized
Luteal Phase Continued
- Corpus luteum regression
-causes drop in secreted progesterone and estrogen
-causes shedding of uterine lining, menstruation
-sheds lining, menses
-marks end of luteal phase
If secondary oocyte is fertilized and implants
- called a pre-embryo
- starts secreting human chorionic gonadotropin hCG
- mimics effects of LH and continues to stimulate corpus luteum
- corpus luteum continues to produce estrogen and progesterone
- maintains and builds uterine lining
- placenta produces its own progesterone and estrogen after 3 months
- corpus luteum has regressed into corpus albicans
Fallopian Tubes
- AKA uterine ducts
- extend laterally from uterus; divided into 4 distinct regions
1) Infundibulum: has fimbriae that sweep oocytes into the ostium
2) Ampulla: site of fertilization
3) Isthmus: accounts for 1/3 of length
4) Intramural segment: where isthmus enters the uterine cavity
Layers of the Fallopian Tube
- Outermost layer: thin, protective serosa
- Middle layer: two smooth muscle layers; contractions serve to transport the oocyte/ blastocyte to the uterus
- Inner layer: highly-folded mucosa lined with ciliated epithelium
-epithelial cells produce tubular fluid that promotes gamete/zygote survival
The Uterus
- structurally divided into 4 regions
1) Fundus (base of inverted pair shape)
2) Body (broad region)
3) Isthmus (narrow region)
4) Cervix (projects into vagina) - Function: structure of gestation (receives, retains and nourishes fetus)
- Anchored in place by several ligaments
The Layers of the Uterus
- Perimetrium: outer serosa
- Myometrium: 3 layers of smooth muscle
- Endometrium: site of implantation
-Basal layer: permanent structure; contains arteries and acini from uterine glands - Functional Layer: hormone-responsive layer; grows in the presence of hormones and degenerates/ sheds during menses
Uterine Cycle
- cyclical changes in endometrial lining
- influenced by estrogen and progesterone
- 3 distinct phases of development
-menstrual phase, proliferative phase, secretory phase - Timeline based on 28-day uterine cycle
-Varies, 21 to 35 day cycle
Uterine Cycle phases
1) Menstrual Phase: characterized by menses
* days 1-5 of cycle
* sloughing off of the functional layer
* lasts through a period of menstrual bleeding
2) Proliferative Phase: dominant follicle rapidly growing; estrogen-priming for endometrial repair, regeneration
* days 6-14 of cycle
* development of new functional layer of endometrium
* overlaps time of follicle growth and ovary estrogen secretion
3) Secretory Phase: endometrium becomes vascularized in preparation for pregnancy
*days 15-28 of cycle
*increased progesterone secretion from corpus luteum
*results in increased vascularization and uterine gland development
*w/out fertilization
-degeneration of corpus luteum
-dramatic drop of progesterone
-without progesterone, sloughs off functional layer
Cervix
- Dome-like structure of uterus that projects into vagina
- The endometrium is NOT shed during menses, and myometrium is much thinner
- Cervical canal joins uterus to vagina
- Mucosa produce secretions that create a mucous plug for pregnancy
Vagina
- Functions: copulatory organ, passageway for outflow of menstruation, and birth canal during parturition
- Consists of three layers: outer adventitia middle muscularis and inner mucosa
- Natural home to several non-pathogenic microorganisms, due to warm and moist environment
- Acidic secretions prevent infection from foreign microbes
Histology of the Vagina
- Mucosa contains the epithelium of non-keratinized stratified squamous epithelium and the Lamina propria
- It also contains the Muscularis Layer
What is the Climacteric and Female v.s. Male?
- The termination of the reproductive years :( Females its called Menopause
- Males have decreased testosterone production which leads to loss in testicular volume and sperm production
- Males experience diminished sex drive, occasional mood swings, erectile dysfunction/impotence, and prostate enlargement
- Females have a drop in circulating estrogen, ovaries are devoid of follicles and menstruation stops, reproductive organs undergo modest atrophy; vagina lubrication is reduced, breast tissue atrophies
- Females may experience hot flashes (hypothalamus controlled by estrogen), figure becomes more androgynous; bones become brittle
Menopause and Perimenopause
- Perimenopause= time near menopause, irregular or skipped periods without pregnancy
- Menopause is when women cease cycling for a year and are not pregnant and dont have any other medical conditions
- Normal onset is ages 45 to 55
- No more ovarian follicles remain or follicular maturation stops
- Significant amounts of progesterone, estrogen no longer secreted
- Uterine lining no longer growing
-no further menstrual periods
Menopause again
- “Hot flashes” with periodic elevation in body temperature
- Thinning scalp hair and increased facial hair
- Increased risk of osteoporosis and heart disease
Tubal Pregnancy
- A.k.a Ectopic Pregnancy
- Fertilized oocyte implants outside of the endometrium
- Tubal Pregnancy is a type of Ectopic pregnancy
- fertilized egg implants in the uterine tube
-unable to expand as embryo grows
-embryo viable only until week 8
-uterine wall ruptures if embryo is not removed
-hemorrhage and loss of mother’s life is possible
Endometriosis
- Parts of the endometrium are displaced
- Tissue becomes implanted on external surface of organs within the abdominopelvic cavity
- May grow under influence of hormones
- Cannot be expelled normally
- May cause pain and scarring
- Often linked to fertility problems
- Treatment includes hormones to slow the growth of endometrial tissue or surgery
Cervical Cancer
- Common Malignancy of the female reproductive system
- Its most important risk factor is Human papillomavirus (HPV) infection
-vaccine available for 4 most common types
*Pap Smear is used to detect cervical cancer in early stage
-epithelial cells scraped from cervix edge
-examined for abnormal development
