Parturition and Lactation

Question 1

first trimester

Answer 1

embryo and placenta development

Question 2

second trimester

Answer 2

fetus and development of all organs, tissues, systems

Question 3

third trimester

Answer 3

fetus and growth of all parts in prep for afterbirth life

Question 4

factors that trigger parturition

Answer 4

-weight of uterus and fetus
-hormone levels in fetus and dam

Question 5

what does the placenta and uterus release to begin labor from fetus signal

Answer 5

Prostaglandins to destroy CL

Question 6

when the CL is destroyed, what hormones increase in the dam?

Answer 6

progesterone and estrogen

Question 7

why does the uterus begin to contract and start labor?

Answer 7

uterus becomes more sensitive oxytocin

Question 8

stage 1 of labor - contractions

Answer 8

-cervix relaxes
-fetus against cervix to dilate
-restlessness

Question 9

stage 2 of labor - delivery of offspring

Answer 9

-uterine and abdominal contractions
-straining and pushing
-water bag delivery

Question 10

stage 3 of labor - delivery of placenta

Answer 10

-placenta separates from uterine wall
-weaker contractions

Question 11

involution of uterus

Answer 11

-uterus contracts down to original size
-lining and material is expelled out
-healing

Question 12

3 functions of mammary glands

Answer 12

-produce colostrum
-produce milk for newborn
-produce milk for $$

Question 13

do all species have the same mammary glands?

Answer 13

no, they vary among species

Question 14

what are the 2 ligaments that support the udder?

Answer 14

-median suspensory
-lateral suspensory

Question 15

what is the role of alveoli in the udder?

Answer 15

-milk secreting
-look like cluster of grapes around ducts

Question 16

how is milk transported to the teat?

Answer 16

alveolar ducts and large ducts join to transport

Question 17

what are the 2 milk holding areas?

Answer 17

-gland cistern
-teat cistern

Question 18

what is the streak canal?

Answer 18

passageway from teat cistern to outside body

Question 19

what does the sphincter muscle do?

Answer 19

keeps steaks canal closed

Question 20

alveolar cells are covered by myoepithelial cells which are covered by what?

Answer 20

capillaries

Question 21

what do myoepithelial cells do?

Answer 21

squeeze alveoli to move milk into duct system

Question 22

streak canal function?

Answer 22

-keep bacteria out of mammary gland
-first barrier!

Question 23

mastitis

Answer 23

inflammation of mammary gland

Question 24

what changes can mastitis cause to the udder?

Answer 24

-heat
-pain
-swelling
-decrease in production

Question 25

what changes can mastitis cause to the milk?

Answer 25

-clots -flakes -chunks

Question 26

what 2 hormones encourage mammary gland development?

Answer 26

growth hormone and prolactin

Question 27

what 2 hormones encourage alveoli and duct development?

Answer 27

estrogen and progesterone

Question 28

when does colostrum production begin?

Answer 28

near the end of pregnancy

Question 29

what 2 hormones are needed to begin lactation?

Answer 29

prolactin and growth hormone

Question 30

what is milk let down?

Answer 30

movement of milk from alveoli to duct system at time of nursing or milking

Question 31

what hormone causes contraction of myoepithelial cells around alveoli?

Answer 31

oxytocin

Question 32

how does oxytocin travel from the posterior pituitary to mammary gland?

Answer 32

travels to bloodstream to mammary gland