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Regulatory Physiology and Pharmacology > Human Reproduction > Flashcards

Flashcards in Human Reproduction Deck (59):
1

what are the 4 stages of sexual arousal?

excitement
plateau
orgasm
resolution

2

What happens to males during excitement?

testicular vasocongestion
erection

3

What happens to females during excitement?

vasodilation of vagina and swelling of labia
erection of clitoris
lubrication of vagina
enlargement of breasts
flush to skin

4

What kind of nervous supply causes the erection?

parasympathetic

5

What is the plateau phase in men?

increase HR, BP, resps, muscle tension

6

What is the plateau phase in women?

same as males but also uterus raises, lifts cervix and enlarges upper 1/2 of vagina to make room for ejaculate

7

What happens during orgasm?

rhythmic contractions of pelvic muscles every 0.8s
increase HR, BP, resp rate muscle tension
ejaculation in men
intense physical pleasure

8

What are the phases of ejaculation?

emission and explusion

9

What happens during emission?

sympathetic response causes contraction of the glands in prostate, reproductive ducts and seminal vesicles into the urethra

10

What happens during expulsion?

motorneurons induce rhythmic contraction of skeletal muscle and force semen out

11

What is the amount of semen produced per ml?

66million/ml

12

What is considered to be clinically infertile?

>20million/ml

13

Approximately what percentage of sperm reach the ovum and when?

0.001% about 30-60 mins after ejaculation

14

What is capacitation?

the process sperm must go through in order to be capable of fertilisation

15

What happens during capacitation?

surface of sperm altered by removal of glycoprotein
tail movements become whip-like
cAMP levels rise to promote acrosomal reaction

16

What happens upon sperm entry to the ovum?

stimulates Ca release which blocks polyspermy

17

What happens upon sperm entry to the ovum?

stimulates Ca release which blocks polyspermy

18

What are the chemicals used by the sperm to penetrate the egg?

Allurin
Fertilin
Acrosomal reaction

19

What is allurin?

released by mature ovum to guide sperm to the egg using an olfactory receptor

20

What is fertilin?

protein on sperm that binds to integrin on oocyte

21

How is the ovum guided to the oviduct?

by fimbriae sweeping it in by smooth muscle contraction and cilia

22

What is a trophoblast?

the blastocyst that accomplishes implantation and develops into fetal portions of the placenta

23

What happens upon implantation?

trophoblast cells burrow into the endometrium carving a hole for the blastocyst

24

What happens when implantation is finished?

the blastocyst is completely buried in the endometrium

25

How do the trophoblasts burrow into the endometrium?

by releasing proteases

26

What becomes the foetal placenta?

synctiotrophoblast

27

What occurs with decidualisation?

increased local vascularisation and nutrient storage for the blastocyst

28

When is the blastocyst completely buried?

by day 12

29

How does the embryo get nutrients from the maternal blood supply?

sends capillaries into the synctiotrophoblast to form placental villi

30

What prevents the mixing of maternal and feotal blood?

the villi and maternal blood are separated by a thin layer of tissue

31

When are the placenta and foetal heart functional?

by week 5

32

What hormones maintain during the 1st trimester?

hCG - produced by blastocyst

33

What is the function of hCG?

maintains corpus luteum and thus progesterone and oestrogen until week 10

34

What is the function of hCG?

maintains corpus luteum and thus progesterone and oestrogen until week 10

35

Why does oestrogen not come from the placenta initially?

the placenta does not posses DHEA from the feotal adrenal cortex to convert progesterone to oestrogen at first

36

What is the role of oestrogen in pregnancy?

stimulates growth of myometrium musculature
stimulate development of mammary gland ducts

37

What is the role of progesterone in pregnancy?

suppresses contraction of uterine myometrium
promotes formation of mucus plug
stimulate development of mammary milk glands

38

What are the physical changes the mother undergoes?

enlargement of uterus and placenta
enlargement of breasts
increase blood vol
weight gain
increase ventilation
increase GFR
increased nutritional requirements

39

Why does the blood vol increase?

oestrogen stimulates angiotensin and renin secretion which results in aldosterone which retains Na and water

40

What are the endocrine secretions of the placenta?

hCG
oestrogen and progesterone
hCS
PTH-related peptide
Relaxin
Placental CRH

41

What is the function of hCS?

decreases maternal blood glucose use, increases plasma FA
prepares breasts for lactation

42

What is the function of pTH-rp?

mobilises maternal Ca for calcification of foetal bones

43

What is the function of relaxin?

softens cervix, loosens pelvic connective tissue

44

What is the function of placental CRH?

stimulates DHEA production by fetal adrenal cortex, important for initiating partuition

45

What does partuition require?

dilation of cervical canal
contractions of uterine myometrium

46

What happens in preparation of partuition?

Braxton-hicks
softening of cervix - relaxin and prostaglandins - breaks down cervical collagen fibres
relaxation of pelvic bones - relaxin
foetus drops

47

What appears to initiate labour?

increased oxytocin receptors triggered by increase estrogen and prostaglandins which increases uterine contraction

48

What happens in the first stage of labour?

cervix dilates
rupture of amniotic sac

49

What happens during the second stage of labour?

delivery of baby by uterine and abdominal contractions

50

What happens during the third stage of labour?

delivery of placenta

51

What is involution?

shrinkage of uterus to pre-pregnancy size
lochia

52

What is involution induced by?

fall in oestrogens and progesterone
oxytocine released in response to breast feeding

53

What do breast ducts terminate in?

lobules made of milk producing glands

54

What triggers development of the breast?

increased oestrogen (duct) and progesterone (lobule)
prolactin - enzymes that produce milk

55

What does suckling trigger?

neuroendocrine reflex -> prolactin and oxytocin

56

What are the roles of prolactin and oxytocin in breast feeding?

prolactin - milk production
oxytocin - milk ejection

57

What is the role of oxytocin in gestation and post-partum?

stimulates contraction of myoepithelial cells
hastens involution
suppresses LH and FSH and thus menstrual cycle

58

What are the components of breast milk?

water, particles isotonic with plasma, lactose, lipids, vitamins, minerals, immunoprotective agents, other proteins including immunoglobulins

59

How many calories does breast milk have per L?

600-750kcal