Changes

After hatching, the conceptus undergoes massive growth.  

After hatching, the conceptus undergoes massive growth.  

'''Cow''': The blastocyst is 3mm in diameter at day 13 of gestation and enlarges to 250mm in length (elongation) between day 14-16 and appears as a fillamentous thread. By day 18 of gestation, the blastocyst occupies space in both uterine horns.

'''Cow''': The blastocyst is 3mm in diameter at day 13 of gestation and enlarges to 250mm in length (elongation) between day 14-16 and appears as a filamentous thread. By day 18 of gestation, the blastocyst occupies space in both uterine horns.

'''Pig''': The blastocysts are 2mm spheres at day 10 of gestation. During the next 24-48 hours, they elongate to ~200mm in length. By day 16, the blastocyst reaches lengths of 800-1000mm.

'''Pig''': The blastocysts are 2mm spheres at day 10 of gestation. During the next 24-48 hours, they elongate to ~200mm in length. By day 16, the blastocyst reaches lengths of 800-1000mm.

For further information on extraembryonic membranes, attachment, placentation and maternal recognition of pregnancy follow [[:Category:Pregnancy and Parturition|this link to Pregnancy and Parturition]].

For further information on extraembryonic membranes, attachment, placentation and maternal recognition of pregnancy follow [[:Category:Pregnancy and Parturition|this link to Pregnancy and Parturition]].

Implantation is critical to the survival of the embryo; the embryo must adhere and embed itself in the endometrium in order to exchange waste and nutrients. For this reason, the first differentiation of cells is into trophoblasts and syncytiotrophoblasts and the inner cell mass (ICM). Trophoblastic cells posses adhesion molecules to adhere to the endometrium, whilst ICM cells form the organism. The extent of cellular growth and division, and the time taken for [[Implantation - Anatomy & Physiology|implantation]] differs between species. Shortly after implantation, cells of the ICM differentiate into different layers:

Implantation is critical to the survival of the embryo; the embryo must adhere and embed itself in the endometrium in order to exchange waste and nutrients. For this reason, the first differentiation of cells is into trophoblasts and syncytiotrophoblasts and the inner cell mass (ICM). Trophoblastic cells posses adhesion molecules to adhere to the endometrium, whilst ICM cells form the organism. The extent of cellular growth and division, and the time taken for implantation differs between species. Shortly after implantation, cells of the ICM differentiate into different layers:

1.'''Epiblast''' - facing towards the uterine lumen, adjacent to syncytiotrophoblasts.

1.'''Epiblast''' - facing towards the uterine lumen, adjacent to syncytiotrophoblasts.

[[Category:Developmental Biology]]

[[Category:Developmental Biology]]

[[Category:Pregnancy and Parturition]]

[[Category:Pregnancy and Parturition]]

[[Category:To Do - AimeeHicks]][[Category:To Do - Review]]

[[Category:A&P Done]]