Brainscape's Knowledge GenomeTM

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


See full index

Module 203, Theme 2- Reproductive System, Fetal Development, Pregnancy and Birth > T2 L20 Physiology of Puberty > Flashcards

T2 L20 Physiology of Puberty Flashcards

1
Q

Define puberty

A

The stage of physical maturation in which an individual becomes physiologically capable of pro-creation (sexual reproduction)

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

List some of the physical changes that occurs during puberty (both male + female)

A

Growth spurt

Secondary sex characteristics

Menarche/spermatogenesis

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

Between what ages do girls begin their growth spurt? How long does it last?

A

Age: 8 - 14 yrs
Duration: 2.5 yrs

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

How many cm do girls grow per year during their growth spurt?

A

6 - 10 cm (per year)

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

Between what ages do girls begin to have breast growth? What is this called?

A

Age: 8 - 13 yrs ( avg: 11 yrs )
THELARCHE

NOTE: This is usually the first pubertal sign

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Between what ages do girls begin to grow pubic hair? What is this called?

A

9 - 13 yrs

PUBARCHE

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

What % of girls have pubarche as their first pubertal sign?

A

25%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Between what ages do girls begin to grow axillary (armpit) hair? What is this called?

A

Age: 9.5 - 15 yrs

ADRENARCHE

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

Between what ages do girls begin to menstruate? What is this called?

A

10 - 16 yrs ( avg: 13 yrs )

MENARCHE

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

What may adrenarche follow?

A

Menarche

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

When is H-P-G synchrony established? (in females)

A

Established in fetal life

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

What happens to GnRH release before puberty? (in females)

A

GnRH release is suppressed via neural mechanisms

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

Between what ages does mini puberty occur? What happens? (in females)

A

At 6-9 yrs

Pulsatile nocturnal GnRH release begins

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

What test is carried out to check for puberty?

A

A LHRH test

If this hormone is switched off the person is not experiencing puberty.

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

What endocrine changes occur during puberty?

A

Pulsatile GnRH release (nocturnal) every 90-120 min - (between 6 to 9 yrs)

Increased GnRH leads to increased FSH and LH
Ovaries/testes become sensitized to the effects of FSH and LH

Final phase: development of positive/negative feedback mechanism

ACTH stimulates the adrenals – Pubic & Axillary hair

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

What is the role of the testes?

A

Production of gametes (sperms)
-Sertoli cells under FSH control

Production of androgens (Testosterone)

  • Leydig cells under LH control
  • 95% from testes, 5% from adrenals
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is testosterone converted to in target organs?

A

DHT (dihydrotestosterone)

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

What happens in the follicular phase of the ovarian cycle?

A

Initially oestrogen rises (due to FSH) with LH surge in mid cycle

Ovulation occurs

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

What happens in the luteal phase of the ovarian cycle?

A

Negative feedback after ovulation

No further ovulation in the same cycle

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

What is the age of menarche related to?

A

General health

Genetic

Nutritional factors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is happening to the mean age of menarche?

A

Mean age is falling at a rate of 4 months per decade

Mean age in 1840 = 16.5 y; 1990 = 12.8 y

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How many girls reach menarche whilst in primary school?

A

1 in 8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the mean weight and body fat % during menarche?

A

Mean weight at menarche is 47.8kg

16-24% fat

NOTE: Without enough fat stores, the body does not undergo menarche

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Which groups of people are likely to have a late onset of menarche?

A

Athletes

Patients with anorexia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Which hormone is responsible for axillary and pubic hair?

A

Adrenal androgens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

BONUS: Which zone of the adrenal cortex produces adrenal androgens?

A

Zona reticularis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Which hormone stimulates the zona reticularis?

A

ACTH (from pituitary gland)

28
Q

At what age do girls start producing DHEAS & androstenedione? At what age do girls have adequate levels of DHEAS & androstenedione?

A

Starts producing : 6 yrs

Adequate levels : 8 yrs

29
Q

At what age do boys start producing DHEAS & androstenedione? At what age do boys have adequate levels of DHEAS & androstenedione?

A

Starts producing : 8 yrs

Adequate levels : 10 yrs

30
Q

What test can be carried out to find out which androgens are responsible for adrenarche?

A

Urine profile test

31
Q

What is the chronological order of puberty in girls?

A

1) Growth spurt
2) Breast development
3) Pubic hair
4) Axillary hair
5) Menarche

32
Q

What is the chronological order of puberty in boys?

A

1) Testicular volume
2) Penile length
3) Pubic hair
4) Growth spurt
5) Axillary / Facial hair
6) Deep voice

33
Q

Below what age does early or precocious puberty begin in girls and boys?

A

Girls – under 8 yrs

Boys – under 9 yrs

34
Q

After what age does delayed puberty begin in girls and boys?

A

Girls – over 14 yrs

Boys – over 14 yrs

35
Q

What is precocious puberty?

A

Early or Premature puberty

Presence of true pubertal features at an young & inappropriate age

36
Q

Describe the two subtypes of precocious puberty

A

Central or True precocious puberty
-Gonadotrophin dependent

Peripheral or Pseudo-precocious puberty
-Gonadotrophin independent

37
Q

What are the normal variants of precocious puberty?

A

Premature Thelarche : isolated breast development. Usually seen in children <2-3 yrs of age. Do a LHRH test and investigate the gonadal axis.

Premature Adrenarche : isolated pubic hair development (take caution as this can be the first pubertal sign in some children)

38
Q

Name the concerns raised by early onset of puberty

A

Possible underlying sinister cause
-Boys – up to 80%

Emotional & pyscho-social upheaval at an inappropriately young age

Early cessation of growth leading to decreased final adult height

39
Q

What is a hypothalamic hamartoma?

A

A benign tumour of the hypothalamus

40
Q

What can a hypothalamic hamartoma lead to?

A

Central precocious puberty

41
Q

What can high oestradiol levels be indicative of?

A

Activated pubertal axis

42
Q

How can central precocious puberty be treated?

A

Long acting LHRH analog therapy

  • sustained supra-physiological LHRH levels
  • paradoxical cessation of gonadotrophin release
  • stops further pubertal progression
43
Q

What happens when the LHRH analog therapy is stopped?

A

Pubertal progression resumes

44
Q

At what age is the LHRH analog therapy usually stopped?

A

10 - 12 years

45
Q

What is pseudo-precocious puberty

A

Oestrogen and testosterone are secreted by tumours in the adrenal gland or in the testis or ovaries

The ovaries or the testes do not mature (unlike in precocious puberty)

46
Q

What could be the underlying cause of iso-sexual or feminising features in pseudo-precocious puberty? (in females)

A

MAS (McCune-Albright syndrome) : a disorder that affects the bones, skin, and several hormone-producing (endocrine) tissues

Ovarian/Adrenal

Exogenous oestrogens

47
Q

What could be the underlying cause of heterosexual or masculinising features in pseudo-precocious puberty? (in females)

A

CAH (Congenital Adrenal Hyperplasia)

Ovarian/Adrenal

Exogenous androgens

48
Q

What could be the underlying cause of iso-sexual or feminising features in pseudo-precocious puberty? (in males)

A

CAH (Congenital Adrenal Hyperplasia)

Adrenal/Leydig cell tumor

Exogenous androgens

49
Q

What could be the underlying cause of heterosexual or masculinising features in pseudo-precocious puberty? (in males)

A

Adrenal

Exogenous oestrogens

50
Q

What can be the effect of androgens in females?

A

Androgens block the normal cycle and can cause conditions like PCOS

51
Q

Describe the characteristics of delayed puberty

A
  • Absence of true pubertal onset at an appropriate age
  • Not necessarily lack of periods in a girl
  • X-files – very important

BUT there are some normal variants with constitutional growth & pubertal delay

52
Q

What concerns are raised by a delay in puberty?

A

Possible sinister underlying cause

Fear that puberty will never occur

Emotional and psychosocial upset of immaturity, especially when associated with short stature

Long term sequelae: Reduced bone mineralization

53
Q

What is Klinefelter syndrome?

A

A chromosomal abnormality

47 XXY / Multiple X

54
Q

How many male infants are affected by Klinefelter syndrome?

A

1 in 1000

55
Q

What are the effects of Klinefelter syndrome?

A

Behavioural problems

Androgen deficiency

Azoospermia / Infertility

(Micro genitalia which can result in Sex change)

Lifelong testosterone replacement therapy

56
Q

What is Turner syndrome?

A

Chromosomal abnormality

45 X (one missing X chromosome)

57
Q

How many female infants are affected by Turner syndrome?

A

1 in 2000

Surprisingly common

58
Q

What are the effects of Turner syndrome?

A

Triad - Short stature, streak gonads, primary amenorrhoea

Dysmorphic features – Webbing of neck, cubitus valgus

Coarctation of aorta, horse shoe kidneys

59
Q

What is an early clue for Turner syndrome?

A

Lymphedema

60
Q

How is Turner syndrome treated?

A
  • Growth Hormone therapy
  • Pubertal induction + ongoing HRT
  • Active monitoring to detect co-morbidities
  • Assisted conception

NOTE: Exclude co-existing congenital anomalies first

61
Q

What is Kallmann syndrome?

A

A condition that causes hypogonadotrophic hypogonadism.

Leads to GnRH deficiency

Present at birth

62
Q

What could be a sign of Kallmann syndrome in early infancy?

A

Undescended testicles or a small penis

63
Q

Name another presentation of Kallmann syndrome

A

Loss of smell

64
Q

How is hypogonadotrophic hypogonadism treated?

A

Lifelong testosterone treatment

65
Q

What is the normal variant for delayed pubertal growth?

A

(Constitutional delayed growth & puberty)

Late onset of puberty

Bone age delayed slightly

Family history is often present

66
Q

Is the normal variant for delayed pubertal growth more common in boys or girls?

A

BOYS

67
Q

Do people that fall within the normal variant for delayed pubertal growth reach their adult height?

A

YES

NOTE: Pubertal induction is sometimes necessary

Module 203, Theme 2- Reproductive System, Fetal Development, Pregnancy and Birth (17 decks)

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