Test 4: parturition

Question 1

The physiological processes involved in the birth of offspring which includes the delivery of the fetus and fetal membranes through the vaginal canal and involution of the uterus.

Answer 1

parturition

Question 2

Processes Involved with Parturition
• Myometrial ___

• ____ of the birth canal
• Maternal abdominal straining
• Expulsion of the fetus
• Expulsion of the ___
• Onset of lactogenesis
• Development of maternal behavior

Answer 2

contractions

Relaxation and dilation

fetal membranes and fluids

Question 3

how does ACTH affect pregnancy

Answer 3

Increase fetal ACTH

• Elevation of cortisol causes conversion of progesterone → estrogen by placenta
• Estrogens increase and cause the synthesis of PGF-2alpha by the uterus

• Cervix softens • Uterus contracts

Question 4

___ will decrease and ___ will increase to cause cervix to soften and uterus to contract

Answer 4

progesterone

estrogen

Question 5

___ cause uterine contractions

Answer 5

PGF2alpha

oxytocin

Question 6

___ are luteal dependent

Answer 6

doe

sow

bitch

camelids

Question 7

___ are not CL dependent

Answer 7

will get progestogen from the conceptus

Ewe –after 50 days • Mare –after 60 days • Queen-after 45 days

Question 8

cortisol in cattle, goats and swine

Answer 8

these are luteal dependent (need CL to produce progesterone throughout the entire pregnancy)

Cortisol stimulates placental estrogen production

• Uterine release of PGF2α
• Rapid luteolysis→ CL dies
• Progesterone decreases

• Cervix relaxation • Uterine contractions

In cattle, goats, and sows, the circulating cortisol stimulates placental estrogen production causing uterine release of PGF-2α and rapid luteolysis of the CL, which results in a rapid decline in progesterone concentrations and subsequent uterine contractions. Cortisol production by the fetus during late gestation is essential for rapid lung maturation and the production of pulmonary surfactant, which is necessary for the survival of the fetus. Also during late gestation, there is an increase in estrogens and relaxin. Along with the rapid decline in progestogens and rise in prostaglandins, uterine contractions occur, the cervix softens and dilates, and parturition results. As the fetus enters the birth canal, The Ferguson Reflex occurs and oxytocin is released from the posterior pituitary. Oxytocin along with PGF-2α causes peristaltic uterine contractions, which result in delivery of the fetus and placenta. Estrogens are important in inducing receptors in the uterine tissue for oxytocin.

Question 9

___ enzymes are needed to convert progesterone to estrogen(estradiol)

Answer 9

17 alpha hydroxylase

17-20 desmolase

aromatase

Question 10

hormone profile of cow during parturition

Answer 10

cortisol increases and convert progesterone → estrogen

this causes release of PGF2alpha

progesterone decreases

cervix relaxes and uterine contraction

Question 11

estrogen causes

Answer 11

secretion of the repro tract

increased contraction → oxytocin

Question 12

how does PGF2 effect uterus

Answer 12

Question 13

ferguson reflex

Answer 13

stretching of the cervix causes release of oxytocin which will cause uterus to contract → positive feedback

Question 14

signs of parturition in cow

Answer 14

Relaxin → Relaxed pelvic ligaments

• Elevated tail head
• Edematous vulva
• Udder development
• “springers” → tail head ligaments relaxed (looks sprung up)

Question 15

mare impending parturition

Answer 15

Relaxed pelvic ligaments

• Relaxed vulva
• Udder development
• “Waxed” with colostrum → dried beads of colustrum

Question 16

ewe impending parturition

Answer 16

relaxed ligament

udder development

(shear before lactation)

Question 17

presentation longitudinal

Answer 17

fetus spine parallel to mothers

can be anterior or posterior (head or feet first)

Question 18

transverse presentation

Answer 18

dorsal or ventral

spine of fetus is perpendicular to mother (fetus is sidways ( back or legs first)

Question 19

___ refers the relation of the fetus to the maternal pelvis

Answer 19

position

Question 20

what do you use to orient fetus position during longitudinal presentation

Answer 20

dorsum (spine) of the fetus

(spine to the spine of the mother, or spine to the belly of the mother (upside down))

Question 21

__ is used to determine position during transverse presentation

Answer 21

head

(transverse = spine perpendicular to spine of mother)

Question 22

___ is the relation of the fetus extremities to the body

Answer 22

posture

flexed or extended

Question 23

normal parturition of a horse

Answer 23

Anterior longitudinal presentation

• Dorso-sacral position
• Extended head and forelegs Posture

Question 24

___ is the normal presentation in polytocous animals

Answer 24

anterior or posterior longitudinal presentation (head first or butt first)

Question 25

stages of parturition

Answer 25

Stage I – myometrial contractions Stage II – expulsion of fetus Stage III – expulsion of fetal membranes and uterine involution

Question 26

stage 1 of parturition

Answer 26

myometrial contractions (organized) * cervical relaxation * birth canal dilation * fetal positioning (dorso pubic to dorso sacral position → rolls over) * ends with chorioallantois rupture

Question 27

stage II of parturition

Answer 27

uterine contractions * abdominal contractions (ferguson reflex → contractions cause dilation and stretch which cause oxytocin which cause more contractions) * passage of fetus through birth canal

Question 28

stage III of partuition

Answer 28

expulsion of fetal membranes • involution of uterus Myometrial contractions continue after expulsion of the fetus and help to expel the fetal membranes. There is vasoconstriction of the arteries of the villi/microvilli and endometrium which help decrease the size of the villi and allow them to be released from the uterine crypts/ microcaruncles. There are also proteolytic enzymes that help to degrade the placental connection in cotyledonary type of placentae. With the exception of the mare, females of the domestic animals may eat the expelled fetal membranes. Uterine Involution 1. Evacuate the uterus of any fetal fluids and fetal membranes 2. Compress the uterine vasculature 3. Reduce the size of the uterus repeated release of oxytocin associated with frequent suckling. lochia discharge

Question 29

Answer 29

amnion feet ventrally and nose chorion has ruptured

Question 30

\_\_ tethers the amnion to the allantosis

Answer 30

mesamnion - will cause amnion to rupture during birth (not in horse)

Question 31

uterine involution

Answer 31

cow 30-50 ewe 30 days mare 7-10 days sow 9-10 days bitch 4-5 weeks

Question 32

Answer 32

caruncle- on uterus brown fluid/vaginal discharge → lochia

Question 33

4 drugs to induce parturition

Answer 33

**glucocorticoids**- help mature fetus- surfactant **estrogens- not in food animals** **PFG 2 alpha-** lyses corpus luteum and forceful contraction **oxytocin-** contractions

Question 34

when can you induce a cow

Answer 34

\<7-14 days before due

Question 35

when can you induce a mare

Answer 35

\>330 days pregnant

Question 36

when can you induce a ewe or doe?

Answer 36

\<5 days before due

Question 37

when can you induce a sow

Answer 37

\<3 days before due

Question 38

Answer 38

anterior longitudinal dorsal sacral (back of fetus against sacrum) posture: head to right side

Question 39

Answer 39

presentation: anterior longitudinal position: dorsal sacral posture: right leg and neck extended, left leg flexed at shoulder

Question 40

Answer 40

presentation: posterior longitudinal position: dorsal sacral posture:

Question 41

Answer 41

posterior longitudinal dorsal sacral legs flexed at the hip (breach)

Question 42

Answer 42

dorsal transverse R cepheloilial (head of fetus to R ilium of mare)

Question 43

Answer 43

ventral transverse cephilo L ilium all limbs extended