Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Endocrinology > The Gonads > Flashcards

The Gonads Flashcards

1
Q

where do the testes and ovaries develop from

A

Gonads

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the functions of the gonads

A

Production of gametes and steroid hormones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How is gametogenesis specific to sex

A 
Males = spermatogenesis
Females = Oogenesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How is steroidogenesis specific to sex

A

Males = androgens - oestrogen, progestogens

Females - oestrogen, progestogens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe the process of spermatogenesis

A
  1. Germ cell proliferates via mitosis to produce spermatogonia
  2. Spermatogonia undergoes the first meiotic division
  3. primary spermatocytes undergo second meiotic division to produce spermatids
  4. Maturation into spermatozoa
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How long does spermatogenesis take

A

70 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe the process of oogenesis

A
  1. Germ cell divides by mitosis
  2. Oogonia undergo the first meiotic division to produce primary oocytes
  3. Meiotic arrest in prophase of meiosis 1
  4. At puberty meiosis 1 finishes to produce the secondary oocytes and a polar body
  5. secondary oocytes enter the second meiotic division at fertilisation
  6. Production of the ovum and a second polar body
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How long may meiotic arrest occur for

A

12-50 years

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Where does spermatogenesis occur

A

Testes - Sertoli cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How does testes production/development occur

A

Development in the abdomen and descent into the scrotum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe the anatomy of the testes

A

Lumen surrounded by Sertoli cells which contain the spermatogonia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the function of the Sertoli cells

A

Spermatogenesis + development
Location of the spermatogonia
Forms the seminiferous tubules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the relationship of there Sertoli cells with FSH

A

Stimulated by FSH to release inhibit which has a negative feedback effect on FSH release

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Where are the Leydig cells located

A

Outside of the seminiferous tubules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the function of Leydig cells

A

Synthesis of testosterone in response to LH to have a -ve feedback effect
Source of testicular androgens. mainly testosterone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe the anatomy of the ovaries

A 
Graafian follicle:
Ovum 
granulosa cells
Follicular fluid
Thecal cells

Follicles that are under different stages of development in the stroma e.g. follicles undergoing atresia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How long does the menstrual cycle take

A

28 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

When does ovulation occur

A

Day 14

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the two cycles occurring during the menstrual cycle

A

Ovarian and Endometrial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the 3 stages of the ovarian cycle

A

Follicular phase, ovulation, luteal phase

21
Q

What are the 2 stages of the endometrial cycle

A

Proliferative phase - oestrogen dominant

secretory phase - progesterone dominant

22
Q

How does basal body temperature change during menstruation

A

Slight increase in the second half due to the increase in progesterone

23
Q

Describe how cholesterol is converted to androstenedione

A 
Cholesterol 
Pregnenolone
Progesterone
17-OH progesteron
Androstenedione
24
Q

What is testosterone and oestrone converted to

A

dihydrotestosterone

17β-Oestradiol

25
Q

What can testosterone be converted to

A

reduction to dihydrotestosterone or aromatisation to oestrogen

26
Q

What is testosterone bound to in seminiferous fluid

A

androgen binding globulin (ABG)

27
Q

How does testosterone travel in the blood

A

60% - sex hormone binding globulin (SHBG)
38% - albumin
2% - free

28
Q

What are the actions of androgen

A

fetus - development of male internal and external genitalia
fetal growth
adult - spermatogenesis
growth and development of male genitalia
protein and bone anabolism
sexual behaviour
pubertal growth spurt

29
Q

Describe oestrogens

A

any substance which induces mitosis in the endometrium

e.g. 17β-Oestradiol, oestrone, oestriol

30
Q

Give the actions of oestrogen

A

stimulates proliferation in the endometrium to thicken the womb
triggers an LH surge for ovulation
secretions from vagina and cervix
Stimulated growth of the ductile system in the breasts
Decreases sebaceous gland secretion in the skin
Feedback regulation of GnRH
Stimulation of osteoblasts
Metabolic actions
Behavioural effects
Increases salt and water reabsorption
Increases plasma protein synthesis
Influences the release of other hormones e.g. prolactin thyrotrophin

31
Q

Describe progestogens

A

Any substance including secretory changes in the endometrium
e.g. progesterone, 17𝛼-hydroxyprogesterone

32
Q

What are the actions of progestogens

A

Stimulates secretory activity in the endometrium and cervix
Negative feedback on hypothalamic GnRH
Increase in basal body temperature
Decease in sodium chloride re-absorption in the kidney
Stimulated growth of alveolar system in the breast.

33
Q

What is the difference between LH and FSH action

A

LH - stimulates hormones

FSH - stimulates gametes

34
Q

Describe the process of endocrine control of testicular function

A
  1. GnRH is released in pulses every hour, triggering pulses of LH and FSH
  2. LH stimulated the Leydig cells to synthesise testosterone
  3. FSH stimulates the Sertoli cells (lining of the seminiferous tubules) to support spermatogenesis
  4. Testosterone is used in the final stage of spermatogenesis
  5. Testosterone has a -ve feedback effect on the hypothalamus + adenohypophysis (OH/LH)
    Inhibin produced buy the Sertoli cells 4 -ve inhibits LH and FSH
35
Q

What are the 5 phases of the menstrual cycle

A 
Early follicular phase
Early mid follicular phase
mid follicular phase
late follicular phase
luteal phase
36
Q

When is progesterone produced in the menstrual cycle

A

second half of the cycle or when pregnant

37
Q

How is LH and FSH controlled in females

A

Oestrodiol produces the -ve feedback

38
Q

Describe what occurs in the early follicular phase

A

FSH causes the ovaries’ follicles to enlarge/grow
5-10 eggs grow under the influence of FSH
The follicles begin to produce oestradiol (and little progesterone)

39
Q

Describe what occurs in the early mid follicular phase

A

LH and FSH remain the same form early follicular phase
More oestradiol as the follicles grow larger
1 egg grows more than the rest (Graafian follicle)
Positive feedback as the increase in oestrogen from the Graafian follicle stimulates the surrounding granulosa cells to grow which in turn allows for increased oestrogen production etc.

40
Q

Describe what occurs in the mid follicular phase

A

As the oestrogen levels increase, it causes a -ve feedback effect on the adenohypophysis so LH and FSH levels decrease, causing the other follicles in the ovary die

41
Q

Describe what occurs in the late follicular phase

A

High oestrogen levels triggers a +ve feedback (hypothalamus and pituitary) to cause an LH surge
Ovulation as the follicle breaks open and egg moves to the uterus

42
Q

Describe what occurs in the luteal phase

A

Once the follicle has broken the corpus luteum is left, which produces progesterone
Progesterone prepares the endometrium for implantation (secretory lining)
No fertilisation with high levels of oestradiol, inhibin and progesterone causes a decline in LH and FSH which leads to menstruation

43
Q

What is the Graafian follicle

A

The largest follicle that no longer requires FSH to develop and proliferate
Keeps growing and producing large amounts of E2

44
Q

What is amenorrhoea and oligomenorrhoea

A 
Amenorrhoea = The absence of menstrual cycles
Oligomenorrhoea = infrequent cycles 
primary = if a women has never had a period
secondary = periods that hone stop
45
Q

What is infertility defined as

A

The inability to become pregnant after 12 months of unprotected sex

46
Q

What are the causes of infertility

A

Pituitary failure
Prolactinoma
Testicular failure e.g. mumps, Klinefelter’s syndrome
Ovarian failure e.g. Turner’s syndrome
Polycystic ovarian syndrome (most common metabolic disorder in women)
Infrequent periods
Hyper-androgenaemia e.g. increased male pattern hair, acne
Polycystic ovaries (increased number of enlarging ovarian follicles)

47
Q

Describe the blood-testes barrier

A

Sertoli cells are connected via tight junctions to form a blood-testes barrier
Prevents large molecules from entering the testes

48
Q

What are thecal cells

A

Surrounds the ovum in the ovaries

Has LH receptors which allows stimulation of steroidogenesis

49
Q

Describe the pathway of spermatids through the testes

A
  1. Spermatogenesis in the seminiferous tubules
  2. Spermatids enter the lumen of the tubules and collected in the Rete testis
  3. Drainage into the Vasa efferentia
  4. Drainage into the epididymis
  5. +nutrient secretion to mature and gain motility
  6. Expelled by the vas deference

Endocrinology (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions