Anatomy And Physiology Flashcards
What is the vulva
External female repro organs
Vulva components (MLLCVP)
Mons Pubis. Labia Majora Labia Minora. Clitoris. Vestibule. Perineum
Fund of labia minora
protect the labia minora, urinary orifice and vaginal introitus
Describe the Labia minora
Lateral ant part is pig,enter Internal part is sim to vag mucosa Pink, moist and vascularised
What’s the clit
Erectile organ. highly vascular, highly sensitive tempe, touch, and pressure
Describe vestibule
Oval shape containing Vaginal opening lower mid Urethral orifice above vag opening Brarthonli glands
PERINEUM Loc and func
Most post part Supports pelvic structures w/ muscles and fibrous tissue
Internal femal struc Vag UFO
Vagina Uterus Fallopian tubes Ovaries
what is the broad ligament
broad ligament is a flat sheet of peritoneum, holds the U,F&O. extends from the lateral pelvic walls on both sides, and folds over the internal female genitalia, covering their surface anteriorly and posteriorly. 3 subdivisions mesometrium= surrounds uterus and proximal part of the round ligament of the uterus. largest Mesovarium= attaches to the hilum of the ovary, enclosing its neurovascular supply. It does not, however, cover the surface of the ovary itself. Mesosalpinx= superiorly to the mesovarium, enclosing the fallopian tubes.
ligaments of the ovary
Ovarian Ligament -attached to inferior ovary -connects ovary to the side of the uterus.
- w/in the broad lig
Suspensory Ligament of Ovary -outward from ovary to the lateral abdominal wall.
- function of this ligament is to contain the ovarian vessels and nerves (ovarian artery, ovarian vein, ovarian nerve plexus and lymphatic vessels).
Ligaments Associated with the aspects of the Uterus
Superior aspect – supported by the broad ligament and the round ligaments.
Middle aspect – supported by the cardinal, pubocervical and uterosacral ligaments.
Inferior aspect - supported by the structures in the pelvic floor – the levator ani, perineal membrane and perineal body.
what is the Round Ligament
- remnant of the embryonic gubernaculum that aids gonadal descent and passage through the inguinal canal.
- originates at the uterine horns (point the fallopian tubes enter the uterus), and attaches to the labia majora, passing through the inguinal canal.
- source of pain during pregnancy, due to the increased force placed on the ligament by the expanding uterus.
what are the Cardinal Ligaments
aka transverse cervical, or Mackenrodt’s ligaments
- located at the inferior border of the broad ligament
- arise from the side of the cervix and the lateral fornix of the vagina
- house the uterine artery and uterine veins.
- provide an extensive attachment on the lateral pelvic wall at the level of the ischial spines
When a hysterectomy is being performed due to a malignancy, the cardinal ligaments are often removed as they are common reservoir of cancerous cells.
what are the pubocervical & uterosacral ligaments
Pubocervical Ligaments
bilateral structures, which attach the cervix to the posterior surface of the pubic symphysis.
They function to support the uterus within the pelvic cavity.
Uterosacral Ligaments
aka recto-uterine ligaments or sacrocervical ligaments
bilateral fibrous bands, which attach the cervix to the sacrum.
This supports the uterus and holds it in place.
Fallopian tubes
bilateral tubes from the corn of the uterus to the ovary
Length 8 to 14 cm average 10 cm
4 parts.
isthmus: part that joins the uterine cavity
ampulla: site of fertilization
infundibulum : widest part
fimbriae: finger like projections guide 2o oocyte to from ovaries to fallopian tube
3 basic funtions of fallopian tubes
- Transport (ovum pickup, ovum transport, sperm transport):
- Transport of fertilized and unfertilized ovum to the uterus.
- Fluid environment for early embryonic development.
High concentrations of estrogen that occur around the time of ovulation induce contractions of the smooth muscle along the length of the uterine tube. These contractions occur every 4 to 8 seconds, and the result is a coordinated movement that sweeps the surface of the ovary and the pelvic cavity. Current flowing toward the uterus is generated by coordinated beating of the cilia that line the outside and lumen of the length of the uterine tube. These cilia beat more strongly in response to the high estrogen concentrations that occur around the time of ovulation. As a result of these mechanisms, the oocyte–granulosa cell complex is pulled into the interior of the tube. Once inside, the muscular contractions and beating cilia move the oocyte slowly toward the uterus. When fertilization does occur, sperm typically meet the egg while it is still moving through the ampulla.
disease significance
open-ended structure of the uterine tubes
if bacteria or other contagions enter through the vagina and move through the uterus, into the tubes, and then into the pelvic cavity. If this is left unchecked, a bacterial infection (sepsis) could quickly become life-threatening. The spread of an infection in this manner is of special concern when unskilled practitioners perform abortions in non-sterile conditions. Sepsis is also associated with sexually transmitted bacterial infections, especially gonorrhea and chlamydia. These increase a woman’s risk for pelvic inflammatory disease (PID), infection of the uterine tubes or other reproductive organs. Even when resolved, PID can leave scar tissue in the tubes, leading to infertility.
Ovaries
Oval solid bilat structure,
gross anatomy
thickness: 1.5 cm
width 2.5 cm
length 3.5 cm
weight 4–8 grams
inferior/posterior to fallopian tubes
held by ovarian, suspensory & broad ligaments
structure : outer covering of cuboidal epithelium called the ovarian surface epithelium that is superficial to a dense connective tissue covering called the tunica albuginea. Beneath the tunica albuginea is the cortex, or outer portion, of the organ
Cortex: composed of a tissue framework called the ovarian stroma that forms the bulk of the adult ovary.
follicles and oocytes are found within the stroma
Medulla
where the ovarian vasculature, nerves and lymphatics are found
Hilum
Ovarian follicles:
consists of an oocyte surrounded by granulosa cells.
function of ovaries
secretion of oestrogen and progesterone
productino of ovum
describe oogenesis (female gametogenesis)
- ovarian stem cells, or oogonia formed during fetal development, and divide via mitosis to form primary oocytes in the fetal ovary prior to birth.
- 1-2 million primary oocytes are then arrested in prophase 1 of meiosis I
- Just B4 ovulation, a surge of luteinizing hormone triggers the resumption of meiosis in only 400,000 primary oocytes remaining at puberty and initiates the transition from primary to secondary oocyte with residuial polar body
- initiation of ovulation—the release of an 2o oocyte from the ovary—marks the transition from puberty into reproductive maturity for women
- 2o oocyte arrests at metaphase 1 of Meiosis II
- penetration of 2o oocyte barrier causes resumption of Meiosis II to form temporary haploid ovum which is fertilized by the sperm to form a diploid zygote
- larger amount of cytoplasm contained in the female gamete is used to supply the developing zygote with nutrients during the period between fertilization and implantation into the uterus
- sperm contribute only DNA at fertilization —not cytoplasm. Therefore, the cytoplasm and all of the cytoplasmic organelles in the developing embryo are of maternal origin. This includes mitochondria, which contain their own DNA
explain folliculogenesis
ovarian follicles: oocytes and their supporting cells.
folliculogenesis is the development of ovarian follicles leading to ovulation of just 1 follicle every 28 days
atresia: death of ovarian follicle d/2 failure to ovulate at any point during follicular development.
follicles progress from primordial, to primary, to secondary and tertiary stages prior to ovulation—with the oocyte inside the follicle remaining as a primary oocyte until right before ovulation where it becomes secondary
- Primordial follicles are present in newborn females and are the prevailing follicle type in the adult. contain single flat layer of supporting granulosa cells that surround the oocyte. they can stay in this resting state for years—some until right before menopause.
- after puberty primordial follicles respond to FSH to form a pool of growing follciles called primary follicles
- granulosa cells then become active and transition from a flat /squamous round/cuboidal shape as they increase in size and proliferate.
- growth of granulosa cells causes the follilces to increase in diameter to form secondary follicles and acquire new outer layer of connective tissue, blood vessels, and theca cells—cells that work with the granulosa cells by stim of LH to produce estrogens.( theca cells make androgens. granulosa cells make aromatase )
- primary oocyte in secondary follicles secretes a thin acellular membrane called the zona pellucida for fertilization. A thick fluid(follicular fluid) forms betw/ granulosa cells also begins to collect into one large pool like central cavity, aka the antrum begins to form.
- Follicles when the antrum has become large and fully formed are considered tertiary follicles (Graffian/antral follicles) who’s growth is stim by FSH. Several follicles reach the tertiary stage at the same time, and most of these will undergo atresia.
- The one that does not die will continue to grow and developas the Dominant follicle. Once the follicle is mature, it ruptures to expel its secondary oocyte surrounded by several layers of granulosa cells from the ovary= OVULATION
- Cells remaining in the follicle then develop into the corpus luteum.
what is the menstrual cycle
cycle lasts 21–35 days on average 28 days
divided into the ovarian or uterine cycle.
The ovarian cycle describes changes that occur in the follicles of the ovary
uterine cycle describes changes in the endometrial lining of the uterus.
uterine cycle:
Menstruation(days 1–4) & proliferative (days 4–14) phase
secretory phase (14-28)
what are the 3 phases of the ovulatory cycle
- follicular phase= 12-14 days before ovulation (day 1-14) ovulation
- luteal phase = fixed 14 days after ovulation (day14-28)
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explain the hormonal control of the ovarian cycle
- The hypothalamus releasesgonadotropin-releasing hormone (GnRH) → stimulates anterior pituitary gland to release FSH & LH
- FOLLICULAR PHASE : FSH stims a group of maturing tertiary follicles in the ovary and stims inhibin A&LHstim theca & granulosa cells to produceestradiol increasing levels
- negative feedback by inhibin A to the pituitary gland → inhibits the release of FSH whereas estradiol inhibits GnRhand thus inhibits both hormones butLH to a higher degree causing atresia of most follicles
- One follicle becomes the dominant follicle secretes more H.M than previous follicles and estradiol levels peak at the day before LH surge → high levels of estradiol induce positive feedback to the pituitary gland → LH levels increase (LH surge)
- OVULATION: LH surge induces ovulation by -stim meiosis 1 resumption in primary oocyte to form secondary oocye & -triggers proteases to break down structural proteins in the ovary wall → mature oocyte is released from the dominant follicle w/ granulosa cells
- LUTEAL PHASE: LH causes corpus luteum formation →stims residual granulosa to produce inhibin b=>FSH suppression and theca to produces progesterone =>induction& maintenance of preg by negative feedback at the hypothalamus and pituitary, which keeps GnRH, LH, and FSH secretions low, so no new dominant follicles develop at this time → increase in progesterone inhibits LH surge
- pregnancy does not occur within 10 to 12 days Falling LH levels cause resolution of the corpus luteum into corpus albicans → fall in progesterone and estradiol levels
- low progesterone & estradiol allows Gnrh begin stim pit gland to release FSH & LH and the cycle repeats
uterus -anatomy
hollow, pear shaped muscular organ.
weighs 50-60 grams
5 cm wide by 7 cm long
position is anteverted (rotated forward) & antiflexed (flexed forward)
3 parts
Body of the uterus
- 5cm long
- corpus
- fundus- part of corpus that is superior to fallopian tube insertion
Isthmus
- transition zone between the corpus of the uterus
and cervix. - elongates in late pregnancy, to become “lower
uterine segment”
Cervix
- lower position aka neck
- length is about 2.5 to 3 cm.
- cervical os: opening between the uterus and vagina.
- internal os- upper part of cervix
- external os- lower cervix
*
uterine layers
Perimetrium:
- outer peritoneal layer of serous membrane that covers most of the uterus & is continuous w/ peritoneum
- Laterally continuous with the broad ligaments on either side of the uterus.
Myometrium
- middle layer of thick muscle.
- muscle fibers are concentrated in the upper uterus, and diminishes progressively toward the cervix.
Endometrium
- inner layer of the uterus.
- responds to cyclic variations of estrogen and progesterone during the female reproductive cycle
- has 3 layers:
*Compact layer
*The basal layer: adjacent to the myometrium; contains glandular portion
*The functional/Sponge layer: thickens in response to increased levels of estrogen and progesterone for implantation & shed during each menstrual period and after child birth in the lochia
uterine function
Menstruation —-the uterus
sloughs off the endometrium.
Pregnancy —the uterus supports
fetus and allows the fetus to grow.
Labor and birth—the uterine
muscles contract and the cervix
dilates during labor to expel the
cervix
produces mucus secretions that become thin and stringy under the influence of high systemic plasma estrogen concentrations to facilitate sperm movement through the reproductive tract.
fetus
muscle
horizontally, vertically, and diagonally contraction of muscle fibers
- cause the powerful contractions during labor and the
- less powerful contractions (or cramps) that help to expel menstrual blood during a woman’s period.
Anteriorly directed myometrial contractions near the time of ovulation, facilitate the transport of sperm through the female reproductive tract.
explain the UTERINE CYCLE
Days 1–14
Desquamation//menstruation at days 1–4
- Absence of a pregnancy → resolution of corpus luteum → progesterone concentration decreases
- → induces vasospasms in the uterine spiral arteries, ischemia, and sloughing off of the functional layer of the endometrium
Proliferation (days 4–14)
- growing follicles produce estrogen → increases chances of fertilization which is highest netw/ 11-5 days
- stimulates proliferation of the endometrium by mitosis
- changes vaginal secretions to thin instead of mucoid
- Uterine spiral arteries start to regenerate and extend two-thirds of the way into the endometrium
- uterine glands grow
Days 14–28
secretory phase
Endometrial differentiation promoted by progesterone → preparation of the functional layer of the endometrium for oocyte implantation by
- Increased endometrial gland tortuosity
- Glycogen-rich secretions
- Edematous stromal cells
- Uterine spiral arteries extend the full length of the endometrium.
if no pregnancy occurs
- ↓ progesteronelevels → apoptosis of the functional layer of the endometrium (seen as shrinkage and fragmentation of endometrial cell nuclei) → menstruation and cycle repeats
explain menstrual cycle
series of changes in which the uterine lining is shed, rebuilds, and prepares for implantation inb response tp hormones resleased by follicles
28 days begining w/ first day of menses
calculation: days between the onset of bleeding in two subsequent cycles.
3 phases:
menses phase, the proliferative phase, and the secretory phase.
menses phase
phase during which the lining is shed; that is, the days that the woman menstruates
2 to 7 days average 4 days
occurs during the early days of the follicular phase of the ovarian cycle, when progesterone, FSH, and LH levels are low.
progesterone concentrations decline as a result of the degradation of the corpus luteum, marking the end of the luteal phase.
decline in progesterone triggers the shedding of the stratum functionalis of the endometrium.
Proliferative Phase(& follicular)
days 4–14
menstrual flow ceases, the endometrium begins to proliferate again,
d/2 granulosa and theca cells of the tertiary follicles begin to produce increased amounts of estrogen in response to FSH and LH. These rising estrogen concentrations stimulate the endometrial lining to rebuild.
LH surge in respose to dominant follice causing estrogen mediated positive feedback triggers ovulation bringing proliferative and follicular phases tob an end
Secretory Phase (& leutenizing)
high estrogen from LH surge
progesterone from corpus leuteum
(oral contraceptive pills engage this stage to prevent menses by mainatining progesterone and estrogen levels to suppres ovulation )
Days 14–28
- high estrogen levels increase the uterine tube contractions that facilitate the pick-up and transfer of the ovulated oocyte.
- High estrogen levels also slightly decrease the acidity of the vagina, making it more hospitable to sperm.
- progesterone from the corpus luteum begins the secretory phase of the menstrual cycle, in which the endometrial lining prepares for implantation
- for 10 to 12 days progesterone causes the endometrial glands secrete glycogen rich fluid . If fertilization has occurred, this fluid will nourish the zygote.
- progresterone causes
spiral arteries develop to provide blood to the thickened stratum functionalis.
ovary
- luteinization of the granulosa cells of the collapsed follicle forms the progesterone-producing corpus luteum, marking the beginning of the luteal phase of the ovarian cycle
if no pregnancy occurs in secretory phase within approximately 10 to 12 days?
- the corpus luteum will degrade into the corpus albicans.
- Levels of both estrogen and progesterone will fall, and the endometrium will grow thinner.
- Prostaglandins will be secreted that cause constriction of the spiral arteries, reducing oxygen supply.
- The endometrial tissue will die, resulting in menses—or the first day of the next cycle
Vagina anatomy
elastic fibro-muscular tube and membranous tissue
8 to 10 cm long.
between the bladderanteriorly and the rectum posteriorly.
acidic pH of 4.5 that protects the vagina against infection.
functions
- allow discharge of the menstrual flow.
- As the female organs of coitus.
- To allow passage of the fetus from the uterus.
bony pelvis anatomy
supports and protects the lower abdominal and internal reproductive organs.
Composed of 4
bones:
- Two hip bones each w/ : *Ilium*Ischium*Pubis
- Sacrum: wedge shaped bone w/ five vertebrae. concave anterior surface. upper border of the first sacral vertebra known as the sacral
promontory - Coccyx: four vertebrae forming a small triangular bone.
birth canal divisions
bone and soft parts
soft: cervix, vagina, muscle-fascial system of the pelvic floor.
bone: small pelvis?
anatomy of the female pelvis
Female pelvis is divided large and small pelvis.
The boundary between them passes through an unmarked line (**linea innominata**).
functions of te inihibins
inhibin B role?: reduction in FSH in mid follicular phase
inhibin A role?: Secreted from the corpus luteum to inhibit LH
