Physiology

Question 1

what are the early stages of development?

Answer 1

fertilisation and implantation

Question 2

where is the site of fertilisation?

Answer 2

upper 3rd of oviduct

Question 3

when does fertilisation occur?

Answer 3

24 hours after ovulation

Question 4

what happens if fertilisation doesnt occur 24 hours after ovulation?

Answer 4

the ovum starts to disintegrate

Question 5

how long do sperm survive in the reproductive tract?

Answer 5

48 hours to 5 days

Question 6

how many sperm reach site of fertilisation?

Answer 6

0.0001%

Question 7

what does the fertilised ovum divide and differentiate to become?

Answer 7

blastocyst

Question 8

where is the site of implantation?

Answer 8

endometrium in the uterus

Question 9

what happens during implantation of the blastocyst?

Answer 9

blastocyst adheres to endometrial lining
trophoblastic cells begin to penetrate endometrium

Question 10

what happens after implantation?

Answer 10

inner cell mass differentiation which gives rise to start of amniotic cavity

Question 11

what happens when implantation ends?

Answer 11

blastocyst is buried in the endometrium

Question 12

when is the feotus in position at full term?

Answer 12

placentation

Question 13

what does the placenta form?

Answer 13

kidneys
digestive system
respiratory system

Question 14

how do nutrients and O2 reach the foetus?

Answer 14

maternal blood
acquired by mothers digestive and respiratory system

Question 15

how does CO2 and waste dispose from the feotus?

Answer 15

transferred into maternal blood
eliminated by mothers kidneys and lungs

Question 16

what travels across placenta by simple diffusion?

Answer 16

CO2
O2
H20
electrolytes

Question 17

what travels across placenta by facilitated diffusion?

Answer 17

glucose

Question 18

what travels across the placenta by secondary active transport?

Answer 18

amino acid

Question 19

what travels across the placenta by receptor mediated endocytosis?

Answer 19

cholesterol

Question 20

what are the 3 endocrine systems that interact and support the growth and devlopment of feotus?

Answer 20

placental hormones
maternal hormones
foetal hormones

Question 21

what are the 3 most important placental hormones?

Answer 21

HCG
oestrogen
progesterone

Question 22

what is HCG?

Answer 22

Human chorionic gonadotropin
- peptide placental hormone

Question 23

what is the role of HCG?

Answer 23

prolongs lifespan of corpus luteum

stimulates secretion of testosterone

Question 24

what is the CL of pregnancy?

Answer 24

ovarian endocrine unit
- produces oestrogen and progesterone for 10 weeks post implantation

Question 25

in males, what does HCG stimulate?

Answer 25

precursor Leydig cells in testes

Question 26

where is HCG eliminated?

Answer 26

urine

Question 27

what does synthesis of oestrogen require?

Answer 27

complex interaction between placenta and foetus

Question 28

what is the role of oestrogen?

Answer 28

stimulate growth of myometrium - stronger uterine muscle - mammary gland ducts

Question 29

where is progesterone made?

Answer 29

placenta soon after implantation

Question 30

when does progesterone increase to reflect placental growth?

Answer 30

last 7 months of gestation

Question 31

what is the role of progesterone?

Answer 31

prevent miscarriage by supressing contractions of uterine myometrium promotes mucus plug in cervical canal milk glands

Question 32

what is the job of the mucus plug in cervical canal?

Answer 32

prevent contaminants reaching foetus

Question 33

what secretes both oestrogen and progesterone?

Answer 33

CL of pregnancy - trimester 1 placenta - trimester 2

Question 34

how long is the gestation period?

Answer 34

38 weeks from conception 40 weeks from end of last period

Question 35

what are physical changes that happen to mother during pregnancy?

Answer 35

- Uterine enlargement - Breasts enlarge and develop ability to produce milk. - Blood volume increase by 30% - Weight gain - Increased respiratory activity 20% - Increased urinary output. - Kidneys excrete additional waste from foetus.

Question 36

what does parturition require?

Answer 36

1. Dilation of cervical canal 2. Contractions of uterine myometrium

Question 37

what are contractions called in the last trimester, preparing for birth?

Answer 37

braxton-kicks

Question 38

what causes cervix to soften?

Answer 38

dissociation of cervical collagen fibres caused by relaxin

Question 39

what is the role of relaxin?

Answer 39

dissociation of cervical collagen fibres relaxes birth canal by loosening connective tissue between pelvic bones

Question 40

what is relaxin?

Answer 40

peptide hormone produces by CL of pregnancy and placenta

Question 41

what is a breech birth?

Answer 41

any part of body other than head approaches the birth canal first

Question 42

when is oxytocin secreted?

Answer 42

once parturition has begun

Question 43

what does oxytocin secretion do?

Answer 43

increases uterine secretions

Question 44

where is oxytocin secreted from?

Answer 44

posterior pituitary

Question 45

what happens during cervical dilation?

Answer 45

the membrane of surrounding amniotic sac ruptures. Amniotic fluid escapes out of vagina and helps lubricate the birth canal

Question 46

how much can the cervix dilate?

Answer 46

up to 10cm

Question 47

when does delivery occur?

Answer 47

once cervical dilation is complete - 30-90 minutes

Question 48

how is the baby pushed out?

Answer 48

- Stretch receptors in vagina activate a neural reflex that triggers contraction of abdominal wall in synchrony with uterine contractions. - Mother can also voluntarily contract abs.

Question 49

what happens 15-30 minutes after delivery?

Answer 49

delivery of placenta

Question 50

what is involution?

Answer 50

After delivery, the uterus shrinks to its pregestational size – takes 4-6 weeks

Question 51

what is involution induced by?

Answer 51

Fall in oestrogen and progesterone when the placenta is lost at delivery

Question 52

what enhances involution?

Answer 52

mothers who breast-feed their infants as oxytocin promotes myometrial contractions that help maintain uterine muscle tone

Question 53

what do breasts develop during pregnancy?

Answer 53

- Develop glandular structure. - Each duct terminates in a lobule. - Lobule made of milk producing glands – alveoli. - Milk is secreted from epithelial cells into lumen

Question 54

what promotes duct development?

Answer 54

oestrogen

Question 55

what stimulates alveolar-lobular formation?

Answer 55

progesterone

Question 56

what induce synthesis of enzymes needed for milk production?

Answer 56

prolactin hCS

Question 57

What stimulates milk production?

Answer 57

prolactin

Question 58

how is action of prolactin blocked in later stages of pregnancy?

Answer 58

high levels of oestrogen and progesterone

Question 59

how can prolactin induce milk immediately after parturition?

Answer 59

oestrogen and progesterone levels fall

Question 60

what does suckling trigger?

Answer 60

a neuroendocrine reflex that leads to secretion of: - prolactin - oxytocin

Question 61

what is prolactin for?

Answer 61

milk production

Question 62

what is oxytocin for?

Answer 62

milk ejection

Question 63

what nutrients does breast milk contain?

Answer 63

water, triglyceride, lactose, proteins, vitamins, calcium. and phosphate. In addition; immune cells and antibodies

Question 64

other than nutrients, what else does breast milk contain?

Answer 64

immune cells and antibodies

Question 65

what is the colostrum?

Answer 65

milk produced in first 5 days post delivery

Question 66

what does colostrum contain?

Answer 66

lower concentrations of fat and lactose but higher concentrations of immunoprotective agents

Question 67

what are advantages of breastfeeding to the mother?

Answer 67

- Oxytocin release triggered hastens uterine involution. - Prolactin inhibits GnRH, suppressing FSH and LH secretion. - Prevents ovulation, decreasing likelihood of another pregnancy