Final Flashcards
1
Q
In what phase do oocytes arrest in until recruited in adult life?
A
prophase 1
start meiosis 2 w/ follicle recruitment
2
Q
Once recruited, what phase do oocytes arrest in at ovulation?
A
If fertilized, arrests in metaphase 2
except in dogs - still in prophase 1
3
Q
Capacitation
A
changes in sperm so it can bind to ZP and fertilize egg
becomes hyperactive
4
Q
Barriers to the transport of sperm in the F
A
cervix
uterotubal junction
5
Q
What triggers the acrosomal reaction & starting meiosis 2?
A
Calcium
6
Q
Things that protect against polyspermy (more than 1 sperm penetrating egg)
6 things
A
- # of sperm that enter oviduct
- # of sperm in sperm reservoir (in cervix or ut junc)
- # of sperm that get to site of fertilization @ ampulla/isthmus junc
- # of sperm that penetrate cumulus
- plasma membrane block
- ZP hardening/block
7
Q
Names of different stages of embryo during development
A
M/F pronculei fuse –> mitosis, cleavage into 2 blastomeres –> morula –> blastocyst w/ blastocoele and trophoblast components
8
Q
What stage are embryos at when the reach the uterus?
A
morula (16-32 cells) or early blastocyst
9
Q
What is unique about EQ embryo phys
A
Embryo must produce prostaglandin E2 to relax circular smooth m. of oviduct and pass through to uterus
10
Q
What differs between Rum & EQ embryo’s leaving ZP
A
Rum - pressure to crack ZP, blastocyst hatches out
EQ - ZP just thins, gets shed, maintains an embryonic capsule for further protection
11
Q
What hormone is required to maintain a pregnancy and where is it secreted from?
A
Progesterone (but not an indicator of pregnancy)
Corpus luteum, later placenta in sheep, cow, horse
12
Q
What is maternal recognition of pregnancy (MRP)?
A
- LA embryo signals uterus to maintain progesterone/CL
- prevents prostaglandin secretion that triggers luteolysis
13
Q
What do bovine and ovine embryos secrete for MRP? How does it cause MRP?
A
interferon tau (IFN-t) inhibits oxytocin receptors in endometrium no oxytocin = no PGF2alpha synthesis & luteolysis countercurrent release of PGF
14
Q
What do pig embryos secrete for MRP? How does it cause MRP?
A
estradiol (E2)
re-routes PGF secretion into uterine lumen
At least 4 embryos required for MRP, at least 1 in each horn
15
Q
EQ MRP
A
exact signal unknown
embryos migrate throughout uterine body and both horns multiple times
systemic circulation of PGF
16
Q
Why do horses not often have twins?
A
placental insufficiency = early loss or abortion
17
Q
What happens if have embryonic loss after MRP?
A
CL persists –> delayed return to estrus
Have to admin prostaglandins to expedite
18
Q
histotrophic support for embryo
A
early pregnancy
endometrial glands provide nutrients
19
Q
hemotrophic support for embryo
A
later pregnancy
occurs after maternal endometrium and fetal membranes become closely assoc’d
20
Q
amniotic vs. allantoic sac
A
amniotic - cushion, surrounds embryo
allantoic - resp exchange, Ca transport, waste storage “Water break”
21
Q
Diffuse placenta
A
EQ, pig
microcotyledons evenly spread out across placenta
22
Q
Cotyledonary placenta
A
rum
discrete attachment sites btwn placental cotyledons and uterine caruncles (called placentoms)
23
Q
zonary placenta
A
carnivores
placenta and endometrium in band around fetus
24
Q
discoid placenta
A
primates, humans
25
epitheliochorial placenta
LA
6 layers of separation = no Ig transfer
colostrum intake critical
26
endotheliochorial placenta
dogs, cats
4 layers of separation = some ig transfer
colostrum intake important
27
hemochorial placenta
primates, rodents
3 layers of separation = significant Ig transfer
colostrum not a thing
28
when do EQ endometrial cups form? when do they regress?
start on day 35, regress day 120-150
29
What to EQ endometrial cups do?
produce eCG
| eCG --> LH/FSH activity --> accessory CL = additional progesterone to support early pregnancy
30
What happens when endometrial cups regress?
placenta making progesterone to maintain pregnancy
| Can supp progesterone until this stage is mares struggle to hold pregnancy
31
what happens w/ preg loss after day 35?
cups remain, mare can't re-breed for season - won't cycle back b/c of eCG production
Giving prosteglandins won't help
32
Fetal gonads
most visible between 3-8 mo, peak at day 200
| Produce androgen precursors - can cause stallion-like behavior in male
33
does estrus = pregnant or not pregnant?
likely not pregnant
34
what is a common technique for detecting pregnancy in LA?
transrectal palpation +/- transrectal US
35
4 positive signs of pregnancy in cows
palpation of amnionic vesicle
fetal membrane slip
palpation of a placentome
palpation of a fetus
36
US in SA and pregnancy detection
good for detection, not great for total number of fetuses
37
At what point will rads detect pregnancy in dogs
>43 days - enough mineralization of bones has occured
38
What endocrine preg tests could you run for SA
relaxin (2nd half of preg)
| not progesterone - doesn't indicate pregnancy in dogs
39
What endocrine preg tests could you run for cows
complete absence of progesterone = not pregnant (presence not an indicator)
estrone sulfate (from placenta)
IFN-t from trophoblasts
EPF - really early pregnancy
40
What endocrine preg tests could you run for EQ?
EPF
eCG
Relaxin (later in pregnancy)
Estrogen
41
what organ systems would be incompatible w/ fetal survival if had major defects?
urinary
| hematopoietic
42
what organ systems would be compatible w/ fetal survival if had major defects?
GI, msk, lungs, CNS
43
What is the most critical stage of development to avoid teratogens
organogenesis - can lead to major morphological defects (vs. later in pregnancy get functional and minor defects0
44
2 important principles of teratology
- 1 agent can cause very different dz's at different periods of gestation (e.g. Veratrum toxicity)
- totally different agents cause cause the same pathology b/c affect same cell types/pops (e.g. arthrogryphosis)
45
Veratrum toxicity and pregnant sheep
day 14 gestation = cyclopia
day 28-31 = chondrodysplasia
day 30-36 = tracheal hypoplasia --> collapse & "stillbirth'
46
arthrogryphosis
joints fixed in flexion
| heritable, viral (akbane or cache valley), plants (lupine, acorn)
47
fates of abnormal conceptus (x6)
early embryonic death
abortion (after organogenesis complete) - mummification or maceration
premature (still)birth
prolonged gestation
congenital malformation
defects manifesting later in life (e.g. CV, metabolic)
48
What is the top infectious cause of congenital defects
cytomegalovirus (herpesvirus)
49
Bluetongue (orbivirus)
Culicoides gnats or attenuated MLV vacc's crossing placenta
| causes hydranencephaly
50
How does bluetongue present in sheep vs. cattle
sheep - severe, large outbreaks
| cattle - usually subclinical
51
Akbane (bunyavirus)
Culicoides gnats, mosquitos
cattle sheep goats - but adults subclinical
causes abortion/stillbirth/premature birth. arthrogryphosis, hydranencephaly
currently not in US
52
Schmallenberg (orthobunyavirus)
Culicoides
cattle, sheep, goats
hydranencephaly, arthrogryphosis, kyphosis, scoliosis
currently not in US
53
How could you could you figure out the cause of a hydranencephalic calf in CO?
Ab test for BTV and cache virus
| if negative, send to feds to test for akbane, schmallenberg
54
Cytopathic infection of BVDV (pestivirus)
infected <1 mo - don't know
infected 1 mo - 90 days - fetal death
infected 90-150 days - teratogenesis
infected 150-parturition (280 days) - minor to no lesions (b/c fetus can mount IR)
55
Types of teratogenesis caused by BVDV
```
cerebellar hypoplasia (#1)
hydranencephaly, arthrogryphosis, hypertrichosis
```
56
non-cytopathic infection of BVDV
persistently infected "poor doer" - herd issue
| will get mucosal dz if exposed later b/c immunocompromised
57
Border Dz (pestivirus)
sheep - hairy shaker lamb syndrome
hypomyelination = shaking
wool is hairy
58
cache valley fever (bunyavirus)
mosquito
adults - mild dz
preg: death <32 days, then msk & CNS dz, > 38 days CNS effects, > 48 few effects
59
when is parturition triggered?
When fetus is physiologically ready to give birth
60
how does the fetus signal it's ready to be birthed in most spp?
Fetal ACTH, cortisol which increases estradiol/estrogen from placenta, which decreases progesterone, increases PGF2alpha
61
What drives parturition once it's triggered?
Prostaglandin(F2alpha) from placenta, endometrium --> uterine contractions
ferguson reflex causing oxytocin release (enhances PGF2a release to magnify contractions)
62
How does parturition differ in litter-bearing spp
entire litter signals parturition
| fetuses can be delivered anywhere from 30 min - 3/4 hrs apart
63
stages of labor
1. initial contractions lasting hours, ends w/ water break
2. fetus delivery, < 1 hr for LA, ~6 hrs for dog
3. passage of placenta, mins to hrs (or days for cow, cat)
64
When is a placenta deemed pathologically retained, and why is that a concern?
>3 hrs
| concern is bacterial buildup --> peritonitis, laminitis, etc. especially for EQ
65
What drugs can you give to induce labor for rum, goat, EQ?
rum - corticosteriods (e.g. dexamethasone)
goat - PG to lyse CL
EQ - oxytocin
66
Presentation
long axis of fetus position vs. birth canal
| anterior (nx), posterior or transverse
67
Position
dorsum of fetus position vs. dam's pelvis quadrants
| dorsal-sacral is normal
68
Posture
position of fetal extremities vs. fetus itself
| Nx is diving position
69
Why is a transverse presentation reason to recommend C-section
difficult to correct
| no ferguson reflex = no oxytocin = no contractions
70
Primary vs. secondary uterine inertia
Primary - failure to initiate labor (e.g. hypocalcemia)
| secondary - uterine fatigue d/t prolonged labor or retained placenta
71
Ways you can manipulate a fetus to improve dystocia
- mutation (repel, rotation, version)
| - extraction using the force of 2 people pulling during contractions only, stagger shoulders
72
what special dog type experiences dystocia all the time?
brachycephalics
73
in dogs, what is a sequelae to secondary uterine intertia?
delayed uterine involution = SIPS, persistant inflamma and discharge/bleeding
74
T/F breeding date gives you an accurate due date
false. impossible to determine due date based on breeding date
75
at what point do you need to intervene when a delivery is not occuring but animal is in stage 2 of parturition?
20-30 mins of pushing
76
If you have a dystocia SA case, what are two supportive care things you do before any other decision is made
IV catheter w/ shock fluid dose
| provide oxygen
77
When is medical intervention considered for a mild dystocia case?
4 or less pups remaining and unobstructed birth canal
78
what medical interventions can you do for mild dystocias in dogs
oxytocin to initiate contractions (unhelpful if already pushing)
Calcium gluconate to increase strength of contractions
79
what is the most common cause of feline dystocia?
primary uterine intertia
obstruction (e.g. uterine torsion) also more common than in dogs
Giving oxytocin to cats is RISKY
80
how do you diagnose primary uterine intertia in a cat?
>70 days from first breeding
| serum progesterone is <2 ng/ml
81
What is special about cows and lactation?
mammary development continues - size increases w/ parity vs. other spp it stops w/ first lactation
82
Hormones that influence lactogenesis
progesterone (inhibitory)
| Estrogen & prolactin, also lactogen (stimulatory)
83
hormones that maintain lactation
prolactin, GH - synthesis, secretion of milk
oxytocin - milk letdown
Epinephrine - stress inhibits milk ejection
84
what increases milk production
more frequent milking
85
What decreases milk production
decreased milking, GH, increased hydrostatic pressure causes reabsorption
86
who has the greatest milk fat percentage
marine spp (e.g. fur seal), cow and horse least
87
what is absolutely required in the udder for milk production
glucose
| provides E and is precursor for lactose synth
88
What does lactose do and what modulates it?
controls milk volume
| stim'd by prolactin, inhibited by progesterone
89
What do rumm use to synth milk fat? non rum/
rum - acetate, lactate, butyrate
| non rum - glu
90
ratio of bloodflow to milk
400:1 but even greater when higher producer
91
MMA
Masitis, metritis, agalactia
multifactorial dz often in older/fatter sows or poor facility
typically culled b/c limited treatment, pigs starve away
92
Ergotism in mares
fescue alkaloid is dopamine agonist
| prolactin inhibited --> prolonged gestation, agalactia
93
Swollen udder and decreased milk let-down - what are your ddx's?
udder edema
| mastitits
94
causes of udder edema
perparturient heifer
excess salt in diet
obesity, inactivity
95
Mastitis
infection of streak canal, then progressing --> bad tasting milk
signs: red, hot, hard, painful, loss of func
96
test for mastitis
california mastitis test - increase purple if increased SCC (increased WBC's)
milk culture
97
Ways to treat for mastitis
Intrammamary or systemic antibiotics
NSAIDs, fluids, supportive care
cull if super severe or amputate quarter/teat
98
Single most effective practice to reduce mastitis
post-milking teat dip
99
If a calf has a non-infectious problem, they die in ____ days after birth
<2
| Dystocia most significant cause of neonatal death
100
If a calf has an infectious problem, they die in ____ days after birth
>3
101
The majority of neonate death occurs
within 7-21 days
102
How do calves generate heat
brown fat - high mitochondria
shivering (unless hypoglycemia, hypoxemic)
physical activity - most important, standing is key
103
Expected transient problems in neonates at birth
transient hypoxia/ischemia (birth asphyxia)
mild mixed resp/metabolic acidosis
mild hypoxemia, lactic acidosis
104
Goals for calf after birth
head right in 3 min, sternal in 5 min, attempting to stand in 20, standing in <1hr, suckling in <2 hrs
105
How do you enhance respiration in a neonate?
rubbing/drying calves vigorously
place in sternal recumbency
mechanically ventilate if need to
106
Commone neonate problems after birth
```
hypothermia - supp heat if <100 temp
hypoglycemia - colostrum key
hypoxemia
acidosis - get calf moving around
passive transfer issues
inactivity/lethargy
```
107
If wanted to cause superovulation (stim development of multiple follicles), you'd admin _____
FSH, ecg
| works better in rum than eq
108
How does embryo transfer work
fertilized embryo taken from one female via lavage, then transferred into surrogate F
109
how do you sex an embryo?
biopsy/aspirate blastomere or trophoblasts, use DNA probes to detect Y chrom
110
IVF (in-vitro fertilization)
best in cattle - hasn't been repeated in eq
| oocyte collected via US/needle aspirate, fertilized in petri dish (in vitro), then frozen or transferred to recipient
111
GIFT (gamete intrafallopian transfer)
oocyte taken from donor, transferred into recipient, then recipient AI'd/fertilized
112
ICSI (intracytoplasmic sperm injection)
- single sperm injected into cytoplasm of oocyte in vitro
embryo transferred back into donor or recipient
- only way ivf works in EQ right now
113
How can you select for sex w/ AI?
X & Y bearing sperm can be separated by high-speed flow cytometry + fluorescent DNA binding dye (bind to extra X)
