Topic 90 - Cyclic function of female reproductive organs

Question 1

Words to include

Answer 1

• Morphological and physological changes
• Location of cyclic functions:
  • ​Ovaries
  • Uterine ducts
  • Uterus
  • Cervix
  • Vagina

Cycle of ovary

• LH peak →ovulaton
• Ovulated oocyte
• 1^st meiotic division (Ca, eq)
• 2^nd meitotic division
  
  • Secondary polar bodis
  • Tertiary polar bodies
• Follicular phase
  
  • E2 ↑
  • Recruitment
    
    • Primary follicles → secondary follicles
  • Late secondary / early teritary
  • Theca cells & granulos cells
    
    • Gonadotropins sensitive
  • Selection
  • Rapid growth
    
    • Graafian follicle protrudes
    • Primary follicle finish first meitotic division
      
      • Arrested in metaphase of second meitotic division
    • Corpus hemorrhagicum
    • Luteinization
    • Luteal phase
      
      • Corpul luteum fully developed
• Luteal phase
  
  • Growing luteal phase
    
    • Plasma progesterone peak
  • Flourishing luteal phase
    
    • P4 peak
  • Late luteal phase
    
    • P4 high
    • Plasma levels of E2 ↑
    • PGF2 alpha secretion
    • Luteolysis

Cycle of uterine tube (fallopian tube)

• Proestrus
  
  • E2 perfusion → tube gets rigid
  • Movement towards uterus
    
    • Reception of egg into ampulla
• Estrus / ovulation
  
  • Cilia of mucosa transports the ovum
  • Tube feeds ovum / zygote
• Metestrus
  
  • P4 dominates

Cycle of uterus

• Proliferative phase
  
  • Proestrus / estrus
  • E2 effect
  • Hyperemia
  • Glandular proliferation
• Secretory phase
  
  • Metestrus
  • Implantation of morula / blastocyst
  • Hyperemia fades
  • Endometrial motility hepls implantation
• Involution phase
  
  • Diestrus
  • If no fertilization
• Anestrus
  
  • Monestrus and diestrus animals
  • Endometrium: single layer
  • Uterine lumen: narrow
  • Uterine horns: smaller

Cycle of cervix

• Evolutionary stage
  
  • Proestrus /estrus
  • E2 makes cervical duct facilitate spermatozoa transport
• Involutuon stage
  
  • Anestrus
  • Fertlization
  • Cervical mucus sticky (CORK)
  • protecting embryo

Cycle of vagina

• Evolutionary stage
  
  • Proestrus / estrus
  • E2 high
  • Intensive secretion
  • Promoting copulation and fertilization
• Involution stage
  
  • Metestrus / diestrus
  • P4 dominance
  • Swelling ↓
• Dogs:
  
  • Vaginal smears
    
    • Estrous cycle information
  • Cornification index
    
    • Keritinized cells ratio
    • Rising levels of E2 induce cornification

Question 2

Where are the cyclic function of the female reproductive organs located?

Answer 2

1. Ovaries
2. Uterine cervix
3. Uterus
4. Cervix
5. Vagina

Question 3

List the stages that should be included in the essay

Answer 3

Cycle of ovary

1. Follicular phase
   
   1. Recruitment
   2. Late secondary / early tertiary
   3. Selectation
   4. Rapid growth
   5. Corpus hemorrhagicum
   6. Luteinization
   7. Lutel phase
2. Luteal phase
   
   1. Growing luteal phase
   2. Flourishing luteal phase
   3. Late luteal phase

Cycle of uterine tube

1. Proestrus
2. Estrus / diestrus
3. Metestrus

Cycle of uterus

1. Proliferative phase = proestrus / estrus
2. Secretory phase = metestrus
3. Involution phase = diestrus
4. Anestrus

Cycle of cervix

1. Evolutionary stage = proestrus / estrus
2. Invution stage = anestrus (fertilization)

Cycle of vagina

1. Evolutionary stage = proestrus / estrus
2. Involution stage = metestrus / diestrus

Question 4

Cycle of the ovary

Answer 4

• Following the LH peak → ovulation
• The ovulated oocyte completes the 1^st meiotic division (Ca, Eq)
• Then the 2^nd meiotic division (all species)
  
  • Secondary and tertiary polar bodies are formed

Follicular phase

• Primary follicle is formed
• Follicular phase begins
  
  • E2 ↑
• Recruitment
  
  • ​Primary follicle → secondary follicle
• Late secondary / early tertiary
  
  • ​Theca and granulosa cells of follicles becomes sensitive to gonadotropins
  • Follicles starts E2 synthesis
• Selection
• Rapid growth
  
  • Graafin follicle protrudes from the surface of the ovary, and forms the stigma (ø eq)
  • Primary oocyte finishes 1^st meiotic division, then arrested in the metaphase of 2^nd meiotic division
• Corpus hemorrhagicum
  
  • Bleeding after ovulation → hemostasis → development of corpus hemorrhagicum
• Lutenization
  
  • ​Lutenizing cellular islets appear within the hemorrhagic body​
• Luteal phase
  
  • ​Corpus luteum is fully developed

Luteal phase

• Growing luteal phase
  
  • ​Plasma progesterone peak is formed
  • All follicles become atretic
• Flourishing luteal phase
  
  • ​P4 peak
• Late luteal phase
  
  • ​P4 high
  • Plasma level of E2 ↑
  • PGF2 alpha secretion
  • Luteolysis

Question 5

Cycle of the uterine tube (fallopian tube)

Answer 5

​Proestrus

• The tube gets rigid due to E2 perfusion
• Slow movement towards the uterus
  
  • Promoting peception of egg into the ampulla

Estrus / ovulation

• Cilia of mucosa help transporting the ovum
• The tube feeds the ovum /zygote

Metestrus

• P4 dominates
• Transport of ovum to the uterus is accelerated

Question 6

Cycle of the uterus

Answer 6

Proliferative phase

• Proestrus / estrus
• E2 effect
• Hyperemia
• Glandular proliferation

Secretory phase

• Metestrus
• Helps the implantation of morula / blastocyst
• Hyperemia fades
• The endometrial motility helps implantation

Involution phase

• Diestrus
• (If no fertilization) involution phase begins

Anestrus

• Only in monoestrus and diestrus animals
• Endometrium: single layer
• Uterine lumen: narrow
• Uterine horns: smaller

Question 7

Cycle of cervix

Answer 7

Evolutionary stage

• Proestrus /estrus
• Due to E2, cervical duct facilitates spermatozoa transport, plus intensive secretion, clear mucus

Involution stage

• Anestrus (fertilization)
• Cervical mucus sticky (CORK)
• Protecting the embryo

Question 8

Cycle of vagina

Answer 8

Evolutionary stage

• Proestrus / estrus
• E2 high
• Insensive secretion
• Promoting copulation and fertilization

Involution stage

• P4 dominance
• Swelling ↓

In dogs:

• Examination of vaginal smears provides good indication of estrous cycle
• Cornification index: ratio of keratinized cells
• Cornification protects vagina against the strong mechanical effect of copulation