Estrous cycle and anestrus

Question 1

Estrous cycles:

Answer 1

Time period between periods of estrus (sexually receptive to male), physiological events occurring between successive periods of estrus

Question 2

Average estrous cycle length in cow (include range):

Answer 2

Average length: 21 days
Range: 17-24 days

Question 3

Average estrous cycle length in ewe (include range):

Answer 3

Average length: 17 days
Range: 13-19 days

Question 4

Average estrous cycle length in sow (include range):

Answer 4

Average length: 21 days
Range: 17-25 days

Question 5

Average estrous cycle length in mare (include range):

Answer 5

Average length: 21 days
Range: 15-26 days

Question 6

Reproductive cyclicity importance:

Answer 6

Provides the female with repeated opportunities to become pregnant.

Question 7

Estrous cycles begin and end with:

Answer 7

estrus

Question 8

Menstrual cycle:

Answer 8

Predictable reproductive events beginning and ending with menses

Question 9

Estrus is commonly referred to as:

Answer 9

heat

Question 10

Estrus is a ______.
Estrous is an _______.
Estrual is an ________.

Answer 10

noun
adjective
adjective used to identify a condition related to estrous

Question 11

Different types of reproductive cyclicity:

Answer 11

Polyestrus, seasonally polyestrus, monoestrus

Question 12

Estrus causes a dramatic increase in:

Answer 12

estradiol

Question 13

Domestic canids have about ____ estrous cycles every two years. Estrus lasts _______.

Answer 13

three
several days

Question 14

The four periods of the estrous cycle:

Answer 14

Estrus, metestrus, diestrus, proestrus

Question 15

Estrus

Answer 15

Period of sexual receptivity and mating

Question 16

Estrus length:

Answer 16

12-18 hours in cow

Question 17

Dominant hormone in estrus and its function:

Answer 17

Estradiol
Behavior changes (receptive rather than disinterested), changes in reproductive tract

Question 18

Metestrus

Answer 18

Period between ovulation and formation of a functional corpus luteum

Question 19

Events of metestrus:

Answer 19

Ovulation occurs 27-30 hours after start of estrus or 12-18 hours after end of estrus. CH to CL formation. Progesterone rises. Metestrus bleeding

Question 20

Metestrus bleeding:

Answer 20

Noticed 35-45 hours after estrus. Capillary breakage causes blood in mucus. Occurs in 90% of heifers and 45% of cows. If seen, you have missed the window for breeding.

Question 21

Diestrus

Answer 21

Period for preparing the uterus for pregnancy

Question 22

What is present during diestrus?

Answer 22

A functional corpus luteum

Question 23

Diestrus ends with (when pregnancy does not occur):

Answer 23

Luteolysis

Question 24

Proestrus:

Answer 24

Begins with CL destruction and terminates at beginning of estrus

Question 25

Proestrus is a major:

Answer 25

endocrine transition

Question 26

Proestrus events:

Answer 26

Progesterone declines. Recruitment and rapid follicle growth. Estradiol increases (prepares estrus, positive feedback)

Question 27

Proestrus only happens if:

Answer 27

progesterone decreases

Question 28

Estrous cycle order:

Answer 28

Estrus -> metestrus -> diestrus -> proestrus -> estrus

Question 29

What happens because of the GnRH-LH surge:

Answer 29

Ovulation, CL formation

Question 30

Tonic LH secretion function:

Answer 30

CL function, follicle growth and turnover

Question 31

When estradiol decreases, inhibin _______, resulting in an ______.

Answer 31

decreases, FSH surge

Question 32

FSH surge results in _______ inhibin, _______ inhibin, resulting in ________.

Answer 32

increases, decreased, decreased, secondary surge

Question 33

The bitch is receptive to the male during:

Answer 33

declining estrogen and rising progesterone

Question 34

Anestrus length in bitch:

Answer 34

5 months

Question 35

Proestrus length in bitch:

Answer 35

9 days

Question 36

Estrus length in bitch:

Answer 36

9 days

Question 37

Diestrus length in bitch:

Answer 37

2 months (pregnancy does not alter length)

Question 38

In the bitch, ovulation occurs:

Answer 38

2-3 days after LH surge

Question 39

In the bitch, fertilization is delayed _______ after ovulation because:

Answer 39

48-72 hours, ovum is not ready

Question 40

Estrous cycle in the queen:

Answer 40

Proestrus -> estrus -> postestrus -> diestrus -> anestrus

Question 41

In the queen, unless induced:

Answer 41

ovulation will not occur, so hormonal changes will not occur, P4 levels remain low.

Question 42

In the queen, estrus lasts __ days and occurs every __ days.

Answer 42

9, 17

Question 43

In the queen, during lactation:

Answer 43

cycling continues

Question 44

What occurs after parturition in the queen?

Answer 44

Lactation and anestrus

Question 45

Induced ovulators:

Answer 45

Alpaca, llama, queen

Question 46

Anestrus

Answer 46

When cyclicity stops

Question 47

Normal reasons for anestrus:

Answer 47

Pregnancy, parturition, uterine involution, lactation, offspring presence, season of the year.

Question 48

Abnormal reasons for anestrus:

Answer 48

Stress, pathological conditions

Question 49

Another name for pregnancy:

Answer 49

Gestational anestrus

Question 50

Progesterone during pregnancy:

Answer 50

Negative feedback

Question 51

After pregnancy, anestrus:

Answer 51

continues

Question 52

Another name for lactation:

Answer 52

induced anestrus

Question 53

Induced anestrus purpose:

Answer 53

Prevents new pregnancy before weaning young