Reproductive System Flashcards Preview

MD2001 > Reproductive System > Flashcards

Flashcards in Reproductive System Deck (64):
1

What is the vas deferens?

The duct which conveys spent from the testes to the urethra.

2

Describe the seminal gland

+ Holds the liquid that mixes with sperm to form semen

+ Also called the seminal vesicle

3

Describe the ejaculatory duct

+ Formed by the union of the vas deferens with the duct of the seminal vesicle

+ Pass through the prostate and open into the urethra at the Colliculus seminalis.

4

Describe the epididymis

+ A highly convoluted duct behind the testis

+ Sperm passes to the vas deferens via the duct

5

Describe the seminiferous tubules

+ Tubules made up of columnar Sertoli cells surrounded by spermatogenic cells

+ Produce sperm and house Sertoli cells

+ The site of the germination, maturation, and transportation of the sperm cells within the male testes

6

Describe the features of the scrotum

+ Skin is rugose

+ Contains dartos muscle

+ Has a midline raphe

+ Divided by a septum

7

Describe the uterus

+ A central pelvic organ
+ Inner lining: endometrium
+ Middle muscular layer: myometrium
+ Outer later: perimetrium
+ Responsible for the implantation of the fertilised ovum and growth of the foetus
+ Pear shaped

8

Describe the uterine tube

+ a.k.a Fallopian tubes/Oviducts
+ Transport the ova from the ovary to the uterus

9

Describe the ovaries

+ Female reproductive organs in which ova are produced

+ Present as a pair

10

How is the ova/oocyte transported to the uterine tube?

It is "picked up" by the fimbriated end of the uterine (Fallopian) tube.

11

Describe fascial thickenings.

+ Supportive uterine ligaments
+ On the pelvic floor
+ Pass from the uterus and cervix to the sacrum, pubis and lateral pelvic walls

12

Describe the features of gonads

+ Produce gametes

+ Female gonads produce oocytes (eggs) by oogenesis

+ Male gonads produce sperm by spermatogenesis

13

What are the gonadal hormones involved in?

+ Gamete production
+ Supporting conception
+ Pregnancy
+ Lactation
+ Affect bone
+ Affect muscle
+ Affect blood vessels

14

What is the hypothalamic signalling hormone involved?

Gonadotropin-releasing hormone (GnRH)

15

What are the pituitary hormones involved?

+ Luteinising hormone (LH)

+ Follicle stimulating hormone (FSH)

16

What do the ovaries secrete?

+ Oestrogens

+ Progestins

17

What are the main hypothalamic areas involved in ovarian control?

+ Preoptic nucleus

+ Supraoptic nucleus

18

What do the neurons of the preoptic and supraoptic nucleus secrete?

GnRH, a peptide hormone

19

What are the features of GnRH?

+ Produced as a prohormone

+ Modified to active form

+ Secreted into the hypophyseal portal system

+ Release is pulsatile
- requires less energy
- does not desensitise target tissue receptors
- stress and other inputs influence secretion

20

What is the relationship between GnRH and the pituitary gland?

GnRH is delivered via hypophyseal portal circulation to the anterior pituitary gonadotropes, where they then bind to receptors.

21

What hormones do gonadotropes secrete?

+ LH
+ FSH
+ They target the gonads

22

What is an oocyte?

+ An immature ovum
+ Contain follicles

23

What are the various stages of follicular development?

+ Primordial
+ Primary
+ Secondary
+ Tertiary
+ Graafian

Endocrine ovaries primarily related to latter follicles.

24

Describe the features of theca cells

+ Superficial layer of follicle
+ LH receptors
+ Convert cholesterol into prenenolone
+ Then produce androstenedione and testosterone

25

Describe the features of granulosa cells

+ Deep compared to theca cells
+Layer increases in size markedly during 1° to 2° follicle development
+ Lh and FSH receptors
+ Also convert cholesterol into prenenolone and activate aromatase
+ Then produce testosterone and oestradiol

26

What do theca cells donate to granulosa cells, and why?

They donate androstenedione because granulosa cells cannot produce it due to a lack of key enzymes.

27

What does FSH activate?

It activates aromatase, which facilitates the formation of oestradiol.

28

What is oogenesis?

The process by which female gametes/ova are produced

+ Begins in foetal stage of females
- primordial germ cells (oogonia) increased in number

+ Some/many oogonia mature into oocytes

+ At ~20 weeks gestation, oocyte number reach max.

+ Oocyte numbers then decline until exhausted

29

What are the main 3 oestrogens?

+ Oestradiol
+ Oestrone
+ Oestriol

30

What are the effects of oestrogens on bone?

+ Increases growth via osteoblasts

31

What are the effects of oestrogen on the endocrine system?

+ Increases progesterone responses

32

What are the effects of oestrogens on the liver?

+ Increases clotting factors
+ Increases steroid-binding proteins
+ Decreases total and LDL
+ Increases HDL

33

What are the effects of oestrogen on the reproductive organs?

+ Increases uterine growth
+ Increases vaginal and fallopian tube growth
+ Increases breast growth
+ Increases cervical mucus secretion
+ Increases LH receptors in granulosa cells

34

What type of feedback do oestrogens (and progestins) provide?

+ Mainly negative feedback except in the mid-cycle, where it shifts to positive due to activins
- caused by upregulation of receptors ( e.g GnRh in anterior pituitary) when oestrogen levels are increased
- results in LH and FSH surge prior to ovulation

35

What type of progestins are there and where are they produced?

+ Progesterone (& 17α-hydroxyprogesterone)

+ Produced in theca and granulosa cells

+ Has short half life (5mins) in circulation

+ Secretion regulation intrinsically linked to oestrogen secretion

36

What are the effects of progestins on breast tissue?

+ Increases lobular development

+ Decreases milk production

37

What are the effects of progestins on reproductive organs?

+ Decreases endometrial growth

+ Increases endometrial secretions
- mucosal secretions become thicker

38

What is the effect of progestins on temperature?

+ Increases internal temperature

39

What two cycles are associated with the female reproductive system?

+ Ovarian cycle

+ Endometrial cycle

40

Describe the follicular phase of the ovarian cycle

- main result is the development of mature Graafian follicle and secondary oocyte

41

Describe the luteal phase of the ovarian cycle

+ Dominated by corpus luteum actions i.e synthesis/secretion of oestrogen and progesterone
- needed for implantation and maintenance of any fertilised oocytes

+ Corpus luteum regresses and degenerates in 10-12 days if no fertilisation

42

What are the phases of the ovarian cycle?

+ Follicular phase

+ Luteal phase

43

What are the phases of the endometrial cycle?

+ Proliferative phase

+ Secretory phase

+ Menstruation

44

Describe the proliferative phase of the endometrial cycle

+ Endometrial growth mediated by increased oestrogens
- from 1-2mm to 8-10mm thick
- blood vessels and gland growth occur

+ Ovulation marks the end of this phase

45

Describe the secretory phase in the endometrial cycle

+ Maturation (not growth) of the endometrium due to decreasing oestrogens

+ Mucus glands more fully develop

+ Glands and blood vessels increase surface area

46

Describe the menstruation phase in the endometrial cycle

+ If no conception, endometrial lining is replaced
- vasoconstriction of spiral arteries
- local ischaemic injury
- inflammatory cell infiltration

47

What is lactation?

Milk production and secretion

48

Breast tissue is prepared during puberty via female gonadal hormones. Via which hormones during pregnancy is there further development?

+ Oestrogens
+ Progestins
+ hCG from fetus
+ Prolactin

49

What is the role of prolactin?

It mediates milk production

50

What is the role of oxytocin?

Mediates milk "let down"/ejection

51

What are the hormones involved in lactation regulation?

+ Prolactin

+ Oxytocin

52

Describe the testis

+ Glands where sperm and testosterone are produced

+ Contained in the scrotum

53

Describe what the testis conatin

+ Leydig cells (produce testosterone)
+ Blood vessels
+ Seminiferous tubules (produce sperm ad house Sertoli cells)

54

Where do testicular endocrine functions occur?

Leydig and Sertoli cells (cf theca and granulosa cells)

55

What are the processes of testicular endocrine function?

+ LH stimulation increases testosterone

+ Testosterone enter the Sertoli cell

+ Estradiol helps to regulate protein synthesis int he nucleus of the Leydog cell

+ FSH stimulation activates aromatase, which forms more oestradiol

56

What are the various stages of spermatogenesis?

1. Spermatogonia
2. Primary spermatocyte
3. Secondary spermatocyte
4. Spermatids
5. Spermatozoa

57

What is spermatogenesis regulated by?

Testosterone

58

What are the effects of testosterone on bone?

+ Increases growth of bone and connective tissue

59

What are the effects of testosterone on muscle?

+ Increases the growth of muscle and connective tissues

60

What are the effects of testosterone on reproductive organs?

+ Increases growth and development of testes, prostate, seminal vesicles and penis

+ Increases growth of facial, axillary, and pubic hair

+ Increases growth of the larynx

+ Increases spermatogenesis

61

What are the effects of testosterone on the skin?

+ Increases sebaceous gland size and secretions

62

What hormones provide negative feedback in the female reproductive system?

+ Oestrogens
+ Progestins
+ Inhibins

63

What hormones provide positive feedback in the (female?) reproductive system?

Activins

64

What hormones provide negative feedback in the male reproductive system?

+ Testosterone
+ Inhibin B