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𝚙𝚑𝚢𝚜𝚒𝚘𝚕𝚘𝚐𝚢 𝟸 : 𝚛𝚎𝚙𝚛𝚘𝚍𝚞𝚌𝚝𝚒𝚘𝚗 > Fertilization > Flashcards

Flashcards in Fertilization Deck (42)
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1

What does seminal fluid consist of?

→ Prostatic and seminal vesicle secretions

2

What is the function of seminal fluid?

→ It coagulates to prevent loss and later liquefies

3

What is the function of the cervical mucus?

→ To remove seminal fluid
→ removing morphologically abnormal sperm and cellular debris

4

When is cervical mucus less viscous and why?

→ in the absence of progesterone
→ allows sperm to pass

5

What forms a reservoir of sperm in the female?

→ Cervical crypts

6

When does fertilisation occur within?

→ 24-48 hours
→ sperm have been found alive after 5 days

7

What attracts the sperm to the egg?

→ Chemoattractants released from the oocyte cumulus complex
→ Sperm become hyperactivated near the egg

8

How do sperm become hyperactivated near the egg?

→ Forceful tail beats with increased frequency and amplitude
→ mediated by Ca2+ influx via CatSper channels

9

How is capacitation achieved?

→ Removing the sperm from the seminal fluid
→ uterine or tubal fluid may contain factors which promote capacitation

10

What must occur to the sperm before the acrosome reaction?

→ Biochemical rearrangement of the surface glycoprotein
→ changes in membrane composition

11

What time does capacitation occur?

→ 4-16 hours

12

Where does the acrosome reaction occur?

→ within the zona-cumulus complex

13

How does the acrosome reaction occur?

→ Acrosomal membrane on the sperm fuses
→ releases enzymes that cut through the zona-cumulus complex
→ acrosin bound to the inner acrosomal membrane digests the zona pellucida so sperm can enter

14

What causes the oocyte to undergo meiosis?

→ LH spike

15

What does the LH spike make the oocyte change into?

→ Primary oocyte becomes seconday oocyte + 1st polar body

16

What does the corpus luteum produce?

→ Progesterone

17

What does progesterone do to the endometrium?

→ Makes it secretory and receptive to implantation

18

What does progesterone do to the cilia?

→ Suppresses cilia in uterine tubes once the oocyte has passed

19

What does progesterone do the the cervical mucus?

→ It makes it viscous to prevent further sperm penetration

20

What is the function of estrogen in the luteal phase?

→ Maintains the endometrium

21

What causes the LH spike?

→ sustained levels of estrogen produced by the dominant follicle

22

After ovulation what happens to the follicle?

→ it becomes the corpus luteum

23

What does progesterone do in the secretory phase?

→ Makes the stratum functionalis thicker
→ uterine glands become more secretory

24

What causes the proliferative phase?

→ Estrogen from the follicular phase

25

What is the life span of the CL?

→ 14 days

26

What causes the inter cycle rise of FSH?

→ the fall in CL derived steroids

27

What does the CL becomes when it dies?

→ Corpus albicans

28

What happens to the CL in pregnancy?

→ It is rescued by the HcG from the embryo binding to the LH receptors
→ it continues to produce progesterone and maintain the endometrium

29

What does the menstrual cycle achieve?

→ Selection of a single follicle and oocyte
→ Correct number of chromosomes in the oocyte
→ Changes in cervix and uterine tubes to enable egg transport and sperm access
→ Preparation of the endometrium
→ Support of the implanting embryo

30

What are cumulus cells?

→ Remnants of the granulosa cells