15: Parturition And Lactation Flashcards
What happens to uterine myometrium during pregnancy
Significant hypertrophy
Braxton Hicks contractions
Weak, irregular contractions towards end of pregnancy to prepare uterus for parturition, but not strong enough to induce labor
Ferguson reflex
Distention of cervix -> release of oxytocin -> further distention of cervix (positive feedback loop)
What is relaxin structurally related to?
Insulin
What is elevated relaxin associated with?
Premature birth
What is one reason twins have shorter gestation period?
Twins cause increased uterine stretch -> increased prostaglandin production
Where is cervix drawn up to during labor?
Just below pelvic inlet
How long is the first and second stage of labor usually?
First stage: majority of the time
Second: less than 1 hour
How is the placenta expelled?
Uterus contracts after giving birth, reducing area of attachment to placenta
What hormone constricts uterine blood vessels after birth to minimize bleeding?
Oxytocin
Two ways to increase oxytocin post-partum to minimize bleeding?
Nipple stimulation, synthetic oxytocin
Mammary gland anatomy
15-20 lobes of glandular tissue separated by CT and adipose, each containing lobules with glandular units
Lactiferous ducts
Collect milk from lobules -> lactiferous sinus -> nipple
Alveolar epithelium
Luminal epithelium responsible for milk synthesis and secretion
Myoepithelial cells
Between ep cells, contract to move milk from alveoli into ducts
