Parturition and Lactation Flashcards
first trimester
embryo and placenta development
second trimester
fetus and development of all organs, tissues, systems
third trimester
fetus and growth of all parts in prep for afterbirth life
factors that trigger parturition
-weight of uterus and fetus
-hormone levels in fetus and dam
what does the placenta and uterus release to begin labor from fetus signal
Prostaglandins to destroy CL
when the CL is destroyed, what hormones increase in the dam?
progesterone and estrogen
why does the uterus begin to contract and start labor?
uterus becomes more sensitive oxytocin
stage 1 of labor - contractions
-cervix relaxes
-fetus against cervix to dilate
-restlessness
stage 2 of labor - delivery of offspring
-uterine and abdominal contractions
-straining and pushing
-water bag delivery
stage 3 of labor - delivery of placenta
-placenta separates from uterine wall
-weaker contractions
involution of uterus
-uterus contracts down to original size
-lining and material is expelled out
-healing
3 functions of mammary glands
-produce colostrum
-produce milk for newborn
-produce milk for $$
do all species have the same mammary glands?
no, they vary among species
what are the 2 ligaments that support the udder?
-median suspensory
-lateral suspensory
what is the role of alveoli in the udder?
-milk secreting
-look like cluster of grapes around ducts
how is milk transported to the teat?
alveolar ducts and large ducts join to transport
what are the 2 milk holding areas?
-gland cistern
-teat cistern
what is the streak canal?
passageway from teat cistern to outside body
what does the sphincter muscle do?
keeps steaks canal closed
alveolar cells are covered by myoepithelial cells which are covered by what?
capillaries
what do myoepithelial cells do?
squeeze alveoli to move milk into duct system
streak canal function?
-keep bacteria out of mammary gland
-first barrier!
mastitis
inflammation of mammary gland
what changes can mastitis cause to the udder?
-heat
-pain
-swelling
-decrease in production
what changes can mastitis cause to the milk?
-clots
-flakes
-chunks
what 2 hormones encourage mammary gland development?
growth hormone and prolactin
what 2 hormones encourage alveoli and duct development?
estrogen and progesterone
when does colostrum production begin?
near the end of pregnancy
what 2 hormones are needed to begin lactation?
prolactin and growth hormone
what is milk let down?
movement of milk from alveoli to duct system at time of nursing or milking
what hormone causes contraction of myoepithelial cells around alveoli?
oxytocin
how does oxytocin travel from the posterior pituitary to mammary gland?
travels to bloodstream to mammary gland
