Reproductive System Flashcards Preview

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Flashcards in Reproductive System Deck (49):
1

What does sexual reproduction require?

-Production of functional gametes
-Fertilization forms zygote
-Zygote -- adult

2

Where are gametes produced?

-Gonads (testes in seminiferous tubules and ovaries produce oocytes-eggs)

3

Which species include hermaphrodites?

-Hydra and earthworm

4

What is gametogenesis called in males? Females?

-Spermatogenesis
-Oogenesis

5

Internal fertilization is practiced by...

..terrestrial vertebrates.

6

Do females produce more or less eggs in external fertilization?

-More
-Less chance for fertilization

7

What other factors decrease amount of eggs produced?

-Species cares for young
-Development occurs inside mother's body

8

Where are the testes located?

-Scrotum 2-4*C

9

Trace the path of sperm.

Testes --> vas deferens --> ejaculatory duct --> urethra --> glans

10

What systems is the urethra involved in for men?

-Reproductive and excretory

11

Where is testosterone produced?

-Testes

12

Where does spermatogenesis occur?

-Seminiferous tubules

13

Describe spermatogenesis.

Diploid spermatogonia differentiate into diploid primary spermatocytes --> meiosis --> haploid secondary spermatocytes --> meiosis --> 4 haploid spermatids --> spermatozoa (mature sperm)

14

What is in the head of the sperm?

-Nucleus

15

What is in the neck/body of the sperm?

-Mitochondria

16

What is the acrosome?

-Caplike structure derived from GOlgi that develops over the anterior half of head
-Contains enzymes needed to penetrate ovum

17

What are follicles in the ovaries?

-Multilayered sacs of cells that contain, nourish, protect the immature ovum
-Produces estrogen

18

Follow the path of an immature ovum.

Released from ovary --> abdominal cavity --> drawn by cilia into oviduct (fallopian tube) --> uterus --> cervix

19

Where does fetal fevelopment occur?

-Uterus

20

What is the narrow end of the uterus called?

-Cervix

21

Where does oogenesis occur?

-Ovarian follicles

22

When have most of the immature ova (primary oocytes) formed?

-At birth of female

23

What are primary oocytes?

-Diploid cells formed by mitosis that will be released once a month to complete meiosis I

24

What forms after meiosis I of primary oocyte?

-One secondary oocyte and a small polar body

25

What occurs to the secondary oocyte?

-Expelled from follicle during ovulation and undergoes meiosis II after fertilization triggered by one of the layers being penetrated

26

What are the two layers that surround the oocyte cell membrane?

-Inner zone pellucida layer
-Outer corona radiata layer

27

What forms from meiosis II of secondary oocyte?

-Mature ovum and another polar body
-Mature ovum contains cytoplasm, RNA, organelles, nutrients for embryo

28

Where are female sex hormones produced?

-Ovaries
-Estrogen, progesterone secretion regulated by LH and FSH which is regulated by GnRH

29

Estrogens

-Steroid hormone
-Stimulate development of female reproductive tract
-Secondary sex traits
-Influence libido
-Thickening of endometrium (inner lining of uterine wall)
-Secreted by ovarian follicles and corpus luteum

30

Progesterone

-Steroid hormone
-Corpus luteum secretes during luteal phase
-Dev/maintenance of endometrium prepare for implantation

31

What are the phases of the menstrual cycle?

Follicular phase --> Ovulation --> Luteal phase --> Menstruation (-->Fertilization does not occur)

32

Follicular phase

-Cessation of menstrual flow from previous cycle
-FSH --> dev follicles --> secrete estrogen

33

Ovulation

-Mid-cycle
-Mature ovarian follicle bursts --> ovum
-Caused by surge in LH, preceded by peak estrogen

34

When does ovulation not occur?

-Pregnancy, lactation, menopause

35

What occurs in menopause?

-Ovaries less sensitive to FSH and LH and atrophy
-Follicles disappear
-Estrogen/progesterone decrease
-Ovulation stops

36

What occurs during luteal phase?

-LH maintains corpus luteum

37

What occurs during menstruation?

-Corpus luteum atrophies
-Progesterone/Estrogen decrease --> endometrium slough off

38

What does the developing placenta produce to maintain the corpus luteum and progersterone/estrogen?

-hCG (human chorionic gonadotropic)

39

When can the egg be fertilized?

12-24 hrs after ovulation at lateral/widest portion of fallopian tube

40

How many days does sperm remain viable?

1-2 days after intercourse

41

What is the course the sperm travels to fertilize egg?

Vaginal canal --> Cervix --> Uterus --> Fallopian tubes --> ovum

42

What is the first barrier the sperm must penetrate?

-Corona radiata then zona pellucida (acrosome enzymes)

43

What occurs when sperm makes contact with the ovum membrane?

-Form tube-like structure (acrosomal process) to fuse allowing sperm nucleus to enter ovum's cytoplasm

44

When does the ovum complete meiosis II?

-When sperm enters ovum's cytoplasm

45

What is the cortical reaction resulting from acrosomal process?

-Ca++ released to cytoplasm --> form fertilization membrane and increases metabolic rate of ovum

46

What is the fertilization membrane?

-Hard layer surrounding ovum cell membrane to prevent multiple fertilizations

47

What is the difference between monozygotic and dizygotic twins?

-Mono is single zygote splitting into two embryos (identical)
-Di is two ova released and fertilized by diff sperm (fraternal)

48

At which stage of splitting will the embryo have separate chorions/placentas?

-2-cell stage
-At blastula stage, embryos have one chorionic sac and one placenta/possibly one amnion

49

In dizygotic twins, how does implantation occur?

-Individually, produce separate placenta, amnion, chorion