Reproductive Flashcards
What is the purpose of the menstrual cycle
Generate oocyte
Facilitate fertilisation
Optimise endometrium for implantation
Protect developing embryo
What are the starting and end stages of menstrual cycle
Begins at menarche
Ends at menopause
When are the follicular phase, luteal phase, menstrual phase, proliferative phase, secretory phase
Ovarian cycle:
Follicular: days 1 -14
Luteal: days 14-28
Uterine cycle:
Menstrual: days 1-5
Proliferative: 5-14
Secretory: 14-28
What is GnRH
Decapeptide
Secreted by mid basal hypothalamic neurons
Hourly pulses
Transported to pituitary via hypophyseal portal blood system
How is GnRH secretion affected
Bereavement Anxiety Time zone Day/night Exercise Weight loss/gain
What is the function of FSH
Stimulates follicular activity thus promoting estradiol production from gransulosa cells
What is the function of LH
Triggers release of egg from dominant follicle
Promotes development of the corpus lute and the production of progesterone
What are the stages of follicular development
Primordial follicle -> primary/preantral follicle -> secondary/antral follicle -> preovulatory follicle -> ovulation
What is oral contraception
Combined: contains estradiol and progesterone Stead state levels Inhibit GnRH/FSH/LH Prevent ovulation Thin endometrium Tenacious mucus
What are the stages of implantation
Shedding of ZP Pre-contact blastocyst orientation Apposition cellular contacts Adhesion Penetration of endometrium
What is hCG
Produced by trophoblast cells
Glycoprotein
Similar structure to LH, FSH
Luteotrophic: continues to stimulate the corpus luteum which produces progesterone
Production is autonomous (independent of hypothalamus and pituitary
Though to be the cause of morning sickness
Used in pregnancy test
What is seen at each week, since last menstrual period, of pregnancy from an ultrasound
5 weeks: gestation sac
6 weeks: foetal pole, yolk sac
7 weeks: foetal heart activity
8 weeks: foetal limbs, movement
What cardiovascular changes are seen from the mother
40% increase in blood volume Increase in red cell mass Physiologic anaemia of pregnancy Increased cardiac output Mechanism: oestrogen stimulation of renin-angiotensin-aldosterone system
What respiratory changes are seen from the mother during pregnancy
Increased oxygen consumption
Respiratory compensation
Change in central control of respiration
What renal changes are seen from the mother during pregnancy
Increased renal blood flow
Increased GFR
Pelvicalyceal and ureteric dilation
Blasser capacity decreases
What GI changes are seen from the mother during pregnancy
Altered appetite
Lower oesophageal pressure
Incompetence of cardia (causes nausea)
Decreased motility (causes constipation)
What is the function of the placenta
Hormone production
Preferential acquisition nutrients and removal of toxins
Gas exchange
What is myometrial activity
Gradual preparation for labour as pregnancy progresses
Mechanical/ endocrine/ paracrine influences
What is labour
Regular painful contractions
Progressive effacement and dilation of the cervix
descent of the presenting part
What is the sequence signalling for labour
Endocrine from foetus -> cytokines -> prostaglandins -> oxytocin -> labour
What causes preterm parturition
Uterine capacity
Cervical weakness
Placental abruption
Infection
What is the pelvis
Basin-shaped caudal end of body cavity
Continuous with abdomen above, surrounded by bony pelvis, limited below by pelvic floor/diaphragm
What is the perineum
Area inferior (superficial) to pelvic floor, bound by pelvic outlet, limited inferiorly by the skin
What bones make up the pelvis
Ilium
Pubis
Ischium
What are the functions of bony pelvis
Surface for muscle attachment: muscles of trunk and lower limb
Transfers weight of trunk to: lower limbs (standing) or ischial tuberosity (sitting)
Protect pelvic organs and developing embryo/ foetus
What is the SRY gene
The sex-dermining region of the Y chromosome
Initiates production of testis-determining factor
So determines male rather than female
Where does the reproductive system derive from
Intermediate mesoderm -> urogenital ridge -> urinary system and reproductive system
What happens to the indifferent gonad
Splits developmentally into two regions:
outer cortex,
inner medulla
Fate of the regions is dependent on TDF production
Female: cortical cords develop, medullary cords regress, no development of tunica albuginea
Male: no cortical cords, medullary cords develop, tunica albuginea develop
How do the testis develop
Under influence of TDF primitive sex cords continue to develop into:
Medullary (testis) cords:
rete testis (hilum)
Seminiferous tubules
Tunica albuginea: connective tissue that develops around the testes
How do the ovaries develop
Medullary cords degenerate
Surface epithelium continues to proliferate and produce secondary generation of cords: cortical cords
Cortical cords split and surround oocytes in 5th month
All oocytes are present at birth
How do the testes descend
Extraabdominal gubernaculum shortens, pulling tests towards the internal inguinal ring where the remain from 3rd to 7th month
Gubernaculum shortens chain and bulls testes through the inguinal canal aided by pressure of growing abdominal organs
Testes reach the scrotum by 9th month just before birth
How do the ovaries descend
Descend to pelvic brim
Gubernaculum passes through inguinal canal and inserts into labia majora
Persists in adult as the ovarian ligament proper and the round ligament of the uterus
What is the ideal contraceptive
Effective Convenient Reversible Safe Cheap Independent of medical profession Acceptable to every religion and culture Have non-contraceptive benefits
how do the uterus and vagina form
Cloaca divides into urogenital sinus and anus
Urogenital sinus develops sinovaginal bulbs that fuse with caudal tips of paramesonephric ducts to form vagina
What are the abnormalities of the uterus
Failure of paramesonephric ducts to fuse
Failure of uterine septum to degenerate
Failure of one paramesonephric duct to elongate
How do external genitalia develop
Mesoderm cells migrate to surround cloaca membrane and form elevated cloaca folds which unite anteriorly to form genital tubercle (future penis/ clitoris
Cloacal folds divide into anal and uterus divisions
Genital swellings appear next to urethral folds (future scrotum or labia majora)
Male: genital tubercle elongates to form phallus
genital swellings enlarge and move caudally
Female: genital tubercle elongates to form clitoris
Urethral folds do not fuse so form labia minora
Genital swellings form labia majora
Urogenital groove remains open
How is the penile urethra formed
Urethral folds pulled forward and form lateral walls of the urethral groove
This is lined by epithelium and form urethral plate
End of 3rd month: urethral folds close over urethral plate to form penile urethral groove and scrotal swellings fuse in midline (separated by scrotal septum)
What is hypospadias
Incomplete fusion of urethral folds
Urethra opens on ventral surface of penis
Difficulty urinating
Can be repaired surgically using foreskin
What is epispadias
Condition usually arises as a result of the urethra opening on the dorsal surface of the penis
Often associated with exstrophy of the bladder
Results from the improper location of the genital tubercle posterior to urogenital sinus, urethral groove located on dorsal surface of penis
What is fertility
Measure of reproductive output, usually expressed as a fertility rate such as number of births per woman
What is fecundity
Potential to reproduce
What is maternal death
Death of a woman while pregnant or within 42 days of the end of the pregnancy from any cause related to or aggravated by the pregnancy or its management but not from accidental or incidental causes
What is direct maternal death
Resulting from obstetric complications of the pregnant state, from interventions, omissions, incorrect treatment, or from a chain of events resulting from these
What is indirect maternal death
Deaths resulting from previous existing disease or disease that developed during pregnancy and which was not the result of direct obstetric causes but which was aggravated by the physiological effects of pregnancy
What is late maternal death
Deaths resulting between 42 days and 1 year after the end pf pregnancy that are the result of direct or indirect maternal causes
What is coincidental maternal death
Deaths from unrelated causes which happen to occur during pregnancy or the puerperium
What are examples of direct maternal deaths
Thrombosis Haemorrhage Amniotic fluid embolism Genetic tract sepsis PET Early pregnancy Anaesthesia
What is endometritis
Infection within uterus Day 2-10 More common following section Offensive vaginal loss Symptoms: fever, malaise, headaches, abdominal pain, offensive lochia, secondary PPH
What is post part haemorrhage
Sudden and profuse blood loss or persistent increased blood loss
Faintness, dizziness
Palpitations, tachycardia
Causes: tone, trauma, tissue infection, thrombin
What are the 2 triangles of the perineum
UT: urogenital triangle (urethra/vagina)
AT: anal triangle: anus
What are the boundaries of the anal triangle
Medially: external anal sphincter and elevator and
Laterally: obturator interns
Inferiorly: subcutaneous tissue
