BIRTH TO PUBERTY

1
BIRTH TO PUBERTY
Extensive duct development into fat pad / tissue
Fat pad is ESSENTIAL!!
2
BIRTH TO PUBERTY
3
BIRTH TO PUBERTY
How many layers thick? 1, 2, 5, ?
4
PUBERTY TO CONCEPTION

• Considerable ductal growth / branching associated
  with estrus cycles
• TDLU terminal ductule lobular unit
• No secretory tissue / alveolus!!!
• Acyclic vs. cyclic animals?

• Acyclic extended estrus in absence of
• copulation (rabbit) lots of ducts/ few alveoli

• Cyclic estrus cycles, bursts of ductal
• development around proestrus/ estrus

5
PUBERTY TO CONCEPTION
Extensive duct growth and branching
6
PUBERTY TO CONCEPTION
7
PUBERTY TO CONCEPTION
8
PUBERTY TO CONCEPTION
9
PREGNANCY
Hamster - 94 Mouse - 78 Sheep - 78 Rabbit -
66 Rat - 60
10
PREGNANCY
Rodent Day 9
11
PREGNANCY
Rodent Day 16
12
PREGNANCY
13
PREGNANCY
14
PARTURITION - CALVING
15
PARTURITION - CALVING
16
PARTURITION - CALVING
17
PARTURITION - CALVING
18
PARTURITION - CALVING
19
PARTURITION - CALVING
20
PARTURITION - CALVING
21
PARTURITION - CALVING
22
A. Fully differentiated alveolar epithelial cells
characterized by presence of numerous vacuoles
(V), rounded basally positioned nuclei (N),
abundant cytoplasm, and frequent occurrence of
large apically located lipid droplets (F)
alveolar lumen is L. B. Intermediately
differentiated alveolar epithelial cells showing
fewer cellular vacuoles, more irregularly shaped
nuclei, and greater nuclear to cytoplasmic
ratio. C. Undifferentiated alveolar epithelial
cells displaying relative absence of cellular
vacuoles, highly irregularly shaped nuclei, a
mixture of large and small lipid droplets, and
very large nuclear to cytoplasmic ratio, (X4,000).
23
INVOLUTION
24
INVOLUTION
25
INVOLUTION
26
ALVEOLUS
27
ALVEOLUS
28
ALVEOLUS