AP Biology

1
AP Biology

• Cow Uterus Dissection

2
Cow Uterus Ovaries

• 2 horns
• Contralateral
• occurs if implantation is in opposite horn from
  where ovulation occurred
• Ipsilateral
• implantation occurs in horn on same side as
  ovulation
• Corpus luteum
• secreting tissue in ovaries

3
Pregnant Cow Uterus
1. Fetus 2. Cervix 3. Ovary
4
Structures

• Amnion
• innermost layer of uterus
• Chorion
• outermost membrane of uterus
• Caruncle
• maternal tissue
• connecting structure that serves to bind fetus to
  uterus
• Cotyledons
• fetal tissue
• provides food for fetus which also serves to
  connect fetus to mother along with caruncles
• Umbilical cord
• tubes for exchange of gases, food wastes
  between mother and fetus

5
Ovary Corpus luteum
6
Maternal Fetal Tissues
Cotyledons (fetal)
Caruncles (maternal)
Cervix
7
Amniotic Sac
8
Umbilical Cord
9
Determining Age of Fetus

• Measure length calculate
• age (days)2.46 x length (cm) 54 days