Inhibitory Proteins in Cell Cycle-

Sic1 - Binds and inhibits S phase CDKs

CKIs p27, p57, and p21- Bind and inhibit CDKs

INK4 - Binds and inhibits G1 CDKs

Rb - Binds E2Fs

TLS Online TPP Program

#Id: 1201

#Unit 7. System Physiology – Animal

Theca cells synthesize and secrete progesterone.

TLS Online TPP Program

#Id: 1202

#Unit 7. System Physiology – Animal

Three estrogens are present in the plasma of the human female:

1. β-estradiol

2. Estrone

3. Estriol

TLS Online TPP Program

#Id: 1203

#Unit 7. System Physiology – Animal

The principal estrogen secreted by the ovaries is β-estradiol.

TLS Online TPP Program

#Id: 1204

#Unit 7. System Physiology – Animal

Estrogens inhibit osteoclastic activity in the bones and therefore stimulate bone growth.

TLS Online TPP Program

#Id: 1205

#Unit 7. System Physiology – Animal

During female reproductive cycle, Estrogen stimulate rapid proliferation of the stromal cells and the epithelial cells of endometrium, before ovulation.

TLS Online TPP Program

#Id: 1206

#Unit 7. System Physiology – Animal

During female reproductive cycle, Progesterone promote secretory changes in the uterine endometrium, after ovulation