estrous, embryonic development, placentation

follicular phase

stage of estrous under estrogen control; proestrus and estrus

luteal phase

stage of estrous under progesterone control; metestrus and diestrus

luteolysis

occurs at beginning of proestrus in cow

cow ovulation

occurs just after estrus in metestrus phase; 48 hours between LH surge and ovulation

mare/sow/ewe ovulation

occurs just before end of estrus

totipotent

cell that can form all types of tissues

pluripotent

cell that can form all three germ layers but not the placenta

multipotent

cell that can form any type of cell or tissue appropriate for its location

cleavage

rapid cell division at beginning of development

blastomeres

cells produced by each cleavage

blastocoel

cavity in the central portion of the blastocyst

blastocyst

an early embryo consisting of an inner cell mass, blastocoel, and trophoblast

ectoderm

forms skin, hair, nervous system

mesoderm

forms musculoskeletal, cardiovascular, reproductive systems

endoderm

forms lungs, digestive system, endocrine system

formation of first polar body

occurs after Meiosis I of oocyte, 2nd occurs before union of male and female nuclei

endotheliochorial

dog and cat placenta, endometrial epithelium is mostly eroded (zonary placenta)

epitheliochorial

sow and mare placenta, endometrial epithelium completely exposed to chorion epithelium (diffuse)

hemochorial

chorionic epithelium in direct contact with maternal blood layer