female reproductive system Flashcards
what is The only human organ system significantly different between female and males
human reproductive system
what in both sexes is designed to facilitate the continuation of the species
anatomy and physiology
wheres the uterus located
between bladder & rectum.
what are the 2 female gonads and their function
Female gonads
Two ovaries; produce egg cells (ova) & sex hormones
whats the shape of the ovaries
almond-shaped organs (3x1.5x1cm)
what is within the capsule of the ovaries
tunica albuginea
what happens in the outer cortex of the ovaries
germ cells develop
what is found in the inner medulla of the ovaries
major arteries & veins
what is oogenesis
production of secondary oocyte
what is ovulation
release of secondary oocyte
what the name of the fertilised oocyte
zygote
what happens after ovulation
After ovulation, follicle still has important function:
- transformed into glandular structure ‘corpus luteum’: secretes progesterone (& oestrogen), lasts through pregnancy, otherwise 10-12 days then degenerates (corpus albicans)
where does your life as an egg actually start
Your life as an egg actually started in your mother’s developing ovary, before she was born; you were wrapped in your mother’s foetal body as it developed within your grandmother.
explain the process of oogenesis when oogonium develops into a zygote
during foetal development meiosis 1 begins
then
after puberty, primary oocytes complete meiosis 1, which produces a secondary oocyte and a first polar body that may or may not divide again
then
secondary oocyte begins meiosis 2
then
a secondary oocyte (and first polar body) is ovulated
then
after fertilisation, meiosis 2 resumes. the oocyte splits into a ovum and a second polar body
then finally
the nuclei of the sperm cell and the ovum unite, forming a diploid (2n) xygote
what is oogenesis for and when does it occur
Development of oogonium to mature ovum
Occurs at different stages of female life
eg:
- pre natal -> mitosis and growth, forming primary oocyte from oogonium.
- puberty -> meiosis 1, forming secondary oocyte
- fertilization -> meiosis 2 , forming ovum
name the 9 stages of the ovarian cycle
1 = primordial follicle;
2 = primary follicle;
3 & 4 = growing primary follicle;
5 = secondary follicle with antrum forming;
6 = mature follicle;
7 = ruptured follicle, ovulation; 8 = corpus luteum;
9 = corpus albicans.
name the secondary follicles
Oocyte
Zona pellucida = layer of glycoprotein
Granulosa cells
Thecal cells = = cells adjacent to granulosa cells but in the ovarian stroma, form a layer around the follicle;
Primordial follicles
An atretic (degenerating) follicle (single arrow)
both the zona pellucida and thecal cell types work together to produce oestrogens.
how many oviducts are there and whats another name for them
2
fallopian tubes
whats the length of the uterine tubes and where do they branch from and to
10cm long from ovary to uterus
explain the shape of the uterine tubes
Trumpet-shaped infundibulum at ovary with feathery projections (fimbrae)
explain some of the arts to the uterine tubes
Ampulla = middle part of tube
Narrow isthmus near uterus
SMC ( smooth muscle cell) wall
convoluted mucosa
Ciliated & secretory cells
what do Ciliated cells of oviduct do
Sweep the egg along the oviduct towards the uterus
describe the uterus shape
Pear-shaped
size (7 x 4 x 2.5 cm)
what does the uterus do
Harbours embryo, provides nutrition, expels foetus at end of development
whats the the main parts of the uterus
Fundus (top), body, cervix
Cervical canal to vagina
Cervical glands secrete mucus
how many layers does the uterus have and name them
3
endometrium
myometrium
perimetrium
what ages are at rick of cervical cancer
20-60 years
what causes an increased risk of obtaining cervical cancer
smoker, early sexual activity, STIs & cervical inflammation begins lower cervix epithelial cells
how fast does cervical cancer develop
Develops slowly
- local lesion –> years
does cervical cancer spread
Invasive
- spread to subepithelial connective tissue leading to hysterectomy
how can cervical cancer be detected early
Detect early by cervical smear
- moving from solely cytology to additional HPV testing
what happens in a cervical smear
scrapes loose cells (epithelial cells) form the cervix to be microscopically examined via a 5-point scale:
- Class 1 = no abnormal cells
- Class 5 = invasive cancer
what do cervical cancer cells look like compared to normal cells when analysed in a smear test
large darker staining nuclei with irregular shapes
normal cells have small , regular nuclei
explain the vagina
10cm long tube from uterus to outside
Receives penis during intercourse
Allows menstrual flow & childbirth
Wall has outer smooth muscular layer
Inner mucous membrane produces lubricating secretions
Hymen at vaginal opening (thin mucous membrane)
the female reproductive system is under the control of what
of hormonal & nervous regulation (as in males)
the Development of reproductive organs & normal function depends on what
on relative levels of a number of hormones
what happens in females during puberty
1st menstrual bleeding = menarche
Enlargement of:
- Vagina
- Uterus
- Uterine tubes
- External genitalia
Breasts deposit fat, develop ducts
Pubic & axillary hair grows
Voice changes
Development of sexual drive
what causes puberty to occur
increased oestrogen & progesterone by ovaries
Due to increased FSH & LH (cyclic secretion)
Due to GnRH (Gonadotropin-Releasing Hormone) from the hypothalamus
how long does the menstrual cycle last
Typically 28 days long
explain the day 1 of the menstrual cycle
= menses = mild haemorrhage when uterine epithelium sloughed off & expelled (lasts 4-5 days)
- Follicular/Proliferative Phase (follicles rapidly develop/uterine mucosa rapid proliferate)
explain day 14 of the menstrual cycle
= ovulation (timing varies between & within individual)
- Luteal/Secretory Phase (corpus luteum/maturation, secretion uterine glands)
what controls the menstrual cycle events
Hormones:
Oestrogen
Progesterone
FSH
LH
explain the hierarchy of control
ovaries –> pituitary
uterus –> hypothalamus
feedback control
explain the process of the ovarian cycle
FSH from anterior pituitary
- initiates development of 1o follicles
25 folicles mature
- But only one develops, the rest degenerate
As folicles enlarge
- begin to secrete oestrogen
High levels
- cause +ve feedback to anterior pituitary so rapid FSH & LH secretion= LH surge
- initiates ovulation
Once egg released
- granulosa cells of empty follicle become luteal cells & secrete progesterone
High progesterone
– negative feedback on GnRH from hypothalamus, so decreases FSH & LH from anterior pituitary
Rapid fall in oestrogen & progesterone
- as corpus luteum atrophies, results in menses
explain the process of the uterine cycle
Oestrogen causes epithelial cells of basal layer to rapidly divide to replace cells of functional layer which were sloughed
Stimulates synthesis of progesterone receptors on uterine cells
Low cuboidal & columnar endometrial cells form folds
- spiral glands with spiral arteries
After ovulation
- progesterone from corpus luteum results in cellular hypertrophy
As corpus luteum degenerates
- low oestrogen & progesterone causes lining to degenerate
Spiral arteries constrict
Ischaemic then necrotic
- menses
Myometrial SMC contraction to expel menstrual fluid
The cycle begins again
what happens if the egg is fertilised
Developing embryonic mass secretes human chorionic gonadotropin (HCG)
HCG prevents degeneration of corpus luteum
Thus oestrogen & progesterone levels do not fall & so menses not occur.
how does the pill prevent pregnancy
Birth control pill
- oral contraceptives
Synthetic oestrogen & progesterone
Negative feedback on pituitary
Prevents LH surge, so no ovulation
