1. Physiology of Pregnancy and Labour PHG 224 by Dr Agbaraolorunpo F.M

2. What is pregnancy
marriage
sex
agbaraolorunpo

3. Ovulation Ejaculation Fertilization Cell division Implantation
pregnancy
agbaraolorunpo

4. Physiology of pregnancy
Release of 400 millions of sperm into vagina
Swimming of sperm → vagina → cervix
→→uterus → fallopian tube
About sperms reach the ovum
agbaraolorunpo

5. Takes place in the midportion of the fallopian tube.
Fertilization= a single egg fuses with a single sperm to form a cell refer to as zygote
Takes place in the midportion of the fallopian tube.
Ovum releases chemical that attract the sperm to its.
Sperm swims towards ovum in the fallopian tube
The first sperm penetrate the Zona Pellucida of ovum via ZP 3 receptors.
agbaraolorunpo

6. Mixing of genetic make up of sperm and ovum =zygote=embryo
Acrosomal reaction takes place:acrosin in the head of the sperm (acrosome) bore hole in the zona pelllucida for the sperm to penetrate into the ovum
Fusion of sperm and ovum facilitated by fertilin from the head of sperm
Mixing of genetic make up of sperm and ovum =zygote=embryo
Polysmermy is prevented
agbaraolorunpo

7. Initiation of signals that brings about development of the embryo
3-5days
Zygote
Within 24 to 36 hours of fertilization the singe cell divides into two cells,after the next 12 hours to four cells and after another 12 hours to eight cells
Initiation of signals that brings about development of the embryo
Division of zygote →two cells→four cells→eight cells
The Zygote continually divides to form a clusters of cell called morula
agbaraolorunpo

8. The morula moves into the uterus after 3-4 days of fertilization
Zygote
The morula moves into the uterus after 3-4 days of fertilization
The morula form a cell with cavity known as blastocyst
The blastocyst burrow into the wall of uterus, a process know as implantation
agbaraolorunpo

9. Implantation of blastocyst in the endometrium
agbaraolorunpo

10. From zygote to fetus=amazing wonder of creation
agbaraolorunpo

11. Implanted blastocyst develop into fetus and grow for 37-42 week before delivery
agbaraolorunpo

12. Fetus growing in the uterus
agbaraolorunpo

13. Identify the following states its function and its mportance
agbaraolorunpo

14. Human Chorionic Gonadotropin (hCG)
Placenta hormones
Human Chorionic Gonadotropin (hCG)
Human Chorionic Somatomammotropin (hCS)
Estradiol
Progesterone
Relaxin
agbaraolorunpo

15. placenta
The placenta take over corpus luteum function after six weeks of conception
The function of corpus luteum decline after 8 weeks of conception but persist throughout pregnancy
agbaraolorunpo

16. agbaraolorunpo

17. Functions of placenta Nutritive Excretory Respiratory
Edocrine function
agbaraolorunpo

18. hCG Effect on corpus luteum Is Glycoprotein
Preservation and secretory activity of corpus luteum
Progesterone and estrogen secreted by corpus luteum= maintenance of pregnancy.
Absence of hCG within 2 months of pregnancy →involution of corpus luteum →abortion
Is Glycoprotein
Secreted by syncytiotrophoblast
Has effect similar to LH
Action is luteinizing
Can be detected in blood 6days after conception
Detected in urine as early as early as 14 days after conception
Not specific to pregnancy .i.e seen in other several tumor as tumour marker
agbaraolorunpo

19. Effect of hCG on fetal testes Similar to the effects of LH on adult testes Stimulates the interstitial cells of leydig→secretion of testosterone→development of male sex organs
agbaraolorunpo

20. Human Chorionic Somatomammotropin
Also called human placental lactogen(hPL)
Secreted by syncytiotrophoblast of placenta
Similar to growth hormone and prolactin
Believe to act on mammary glands and to enhance the growth of fetus by influencing metabolic activities
Act as maternal growth hormone of pregnancy to bring about nitrogen, potassium and calcium retention, mobilization of lipid, protein and glucose from mother to fetus decreased→ glucose utilization.
It increases the amount of glucose and lipid in maternal blood which are transfer to the fetus
Amount secreted is proportional to placenta size(normally weight one-sixth of fetus)
Low hCS indicates placenta insufficiency
agbaraolorunpo

21. Estrogen Uterus:enlargement of uterus to accommodate the growing fetus
Breast: enlargement of breast and growth of breast system
External genitalia:enlargement
Pelvis:relaxation of pelvic ligament-for facilitation of fetal passage in the birth canal during labour
agbaraolorunpo

22. progesterone
Endometrium of uterus: increase secretory activity by stimulating decidual cells→nutrition of embryo during the early stage of conception
Myometrim of uterus: inhibit contraction of uterus to prevent abortion.decreases the activity of oxytocin, estrogen and uterus sensitivity.
Breast-development lobules and alveoli of breast=further breast enlargement =readiness for lactation
agbaraolorunpo

23. Inhibits myometrial contraction Secreted by both corpus luteum
Relaxin
Inhibits myometrial contraction
Secreted by both corpus luteum
Also secreted by placenta at the time of labour
agbaraolorunpo

24. Possible changes in reproductive system during pregnancy
agbaraolorunpo

25. Physiological changes during pregnancy
Ovaries: suppression of follicular development due to inhibition of LH and FSH secretion→suppression of menstruation/menstrua cycle
Uterus and vagina size increase
Cervix-soft and closed by mucus plug
Mammary glands:enlarges
Body weight: increases
Metabolic activities increase:increase in protein metabolism, blood glucose→pregnancy induced diabetes(Gestational Diabetes)
agbaraolorunpo

26. Physiological changes in pregnancy
7. Blood volume increases by 20% or 1L due to fluid retention→dilutional aneamia
8. Cardiac output increases in first trimester
9. Blood pressure remain unchanged with the tendency to increase during 3rd trimester
Pre-eclampsia(toxeamia of pregnancy) in 3-4% of pregnant women during 3rd trimester
Cause:autoimmune reaction to placenta or fetus,substance release by placenta
agbaraolorunpo

27. Eclampsia-severe form of pre-eclampsia characterise by
Severe hypertention ,convulsion, coma,kidney failure,heart failure,liver failure
10.urine formation and output increases due to increase RBF and GFR
GIT: Morningsickness, nausea,vomiting,indigestion due to hormonal imbalance
CNS:Psychological imbalance:change in mood,excitement,depression
agbaraolorunpo

28. PARTURITION -LABOUR
agbaraolorunpo

29. parturition
Is the expulsion of fetus from the uterus at the end of pregnacy.
Occur through a process called labour
agbaraolorunpo

30. labour
Preceded by Braxton Hicks contraction/false labour:weak, irregular, short and often painless
True labour involves
Descending of presenting part(head) in the pelvis
Strong ,Regular, uterine contraction
Dilatation of cervix from 0cm to 10 cm
Shortening of length of cervix(effacement)
Softening of Cervix
agbaraolorunpo

31. Stages of labour Stage 1:dilation of cervix
Stage 2:fetus descend through the birth canal
Stage 3: expulsion of placenta
agbaraolorunpo

32. STAGES OF LABOUR
agbaraolorunpo

33. Parturition(neuroendocrine reflex) It is a positive feedback mechanism
The head of the baby is the stimulus that stimulate the stretch receptors in the cervix
Neural signal is conducted to the brain which is communicated to pituitary gland
This result in oxytocin release from posterior pituitary glands
Oxytocin causes the contraction of myometrium of the uterus
The fetus is pushed further towards the cervix
The head of the fetus further stimulate the receptor and the process continues until the fetus is expelled from the womb
agbaraolorunpo

34. Hormone that participates in labour progesterone↓ estrogen↑
Oxytocin**(maternal↑↑
Cortisol
Cathecholamines
relaxin
agbaraolorunpo

35. Congratulation
agbaraolorunpo

36. agbaraolorunpo