Brainscape's Knowledge GenomeTM

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


See full index

Reproductive System > Physiology > Flashcards

Physiology Flashcards

1
Q

What are the 3 levels of sexual dimorphism?

A

1) Genetic (M: XY, F: XX)
2) Gonadal (M: testes, F: ovaries)
3) Phenotypic
a) external genitalia
b) secondary sex characteristics

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

What gene encodes for the testis determining factor (TDF) and which chromosome is it located on?

A

SRY gene on Y chromosome

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

What is testis determining factor?

A

Nuclear transcription factor
- expressed in gonad immediately before divergence of ovarian/testicular development
- incites testis differentiation → formation of Sertoli and Leydig cells → produce MIS/Testosterone respectively

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

What is the key factor needed for the determination of male characteristics?

A

SRY/TDF

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

What are 5 genes that promote sexual differentiation in humans?

A

Male promoting:
1) SRY
2) SOX 9

Female promoting:
3) FOXL2
4) WNT4
5) FST

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

What essential hormone is produced by Leydig cells and what is its function?

A

Testosterone
- Wolffian duct development

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

What essential hormone is produced by Sertoli cells and what is its function?

A

Mullerian inhibiting substance/Anti-mullerian hormone (MIS)
- promotes Mullerian duct regression (to allow for Wolffian duct development)

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

What is Turner syndrome?

A

X0 chromosomal disorder
- F
- 1/2500
- Low IQ
- Infertile
- small stature

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

What is Klinefelter syndrome?

A

XXY chromosomal disorder
- M
- 1/700
- Low IQ
- Infertile
- Higher in stature
- Gynaecomastia/ small testes

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

What is hermaphroditism?

A

Having characteristics of both male and female

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

What is the difference between true hermaphroditism and pseudohermaphroditism?

A

True hermaphrodite:
- gonadal tissue and germ cells of both sexes present
- 50%: 1 testis/ovary + 1 ovotestis
- 30%: 1 testis + 1 ovary
- 20%: 2 ovotestes

Pseudohermaphrodite:
- inconsistency between internal and external genitalia
- 2 aetiologies:
i) Androgen insensitivity syndrom (AIS)/Testicular feminisation syndrome
ii) 5α-reductase deficiency

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

Describe the process of sexual differentiation in humans?

A

Male:
1) XY → SRY+

2) Testicular formation →
a) MIS → no mullerian duct → no uterus
b) Testosterone → (i) DHT (ii) Wolffian duct → Vas deferens, Epididymis, Seminal vesicles

3) DHT → Penis, Penile Urethra, Scrotum

Female:
1) XX/X0→ SRY-

2) Ovary formation →
a) No MIS → Mullerian duct → Uterus, Fallopian tube, Upper vagina
b) Estradiol → Clitoris, Labia minora/majora, Lower vagina

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

Describe the HPT axis in males.

A

Hypothalamus: GnRH
→ Anterior pituitary:
(i) LH → Leydig cells → Testosterone
- -ve feedback to AP and hypothalamus

(ii) FSH → Sertoli cells →
(i) Spermatogenesis
(ii) Androgen-binding protein w testosterone
(iii) inhibin
- -ve feedback to AP

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

Describe the function of GnRH.

A

Hypothalamus → GnRH → Gonadotrope cells in pituitary glands → FSH + LH

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

What are the hormones produced from the testes and which cells are they secreted from?

A

LH → Leydig cells → Testosterone

FSH → Sertoli cells →
i) Estradiol
ii) Inhibin
iii) Activin
iv) Follistatin

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

Inhibin and follistatin are secreted by ___________ and act to suppress _____ secretion.

A

Secreted by Sertoli cells under FSH stimulation
- act to suppress FSH secretion
- -ve feedback loop

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

What are 2 fates of plasma testosterone?

A

1) Estradiol (via aromatase in Sertoli cells)
2) DHT (via 5-α reductase)
3) Conjugated by liver
4) 17-Ketosteroids (via 17ß-dehydrogenase)

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

What are 6 functions of testosterone?

A

1) Control development of internal male genitalia

2) Support spermatogenesis

3) Support puberty

4) Support development of male secondary sex characteristics

5) Promote sex drive/libido (both M and F)

6) Promote protein synthesis and muscular growth

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

What is the enzyme responsible for DHT production?

A

5α-reductase

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

True or false. DHT is more potent than testosterone and thus its production is localised at specific target cells.

A

True

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

What are 3 effects of DHT?

A

1) Development of male external genitalia

2) Development and growth of prostate gland

3) Growth of male body/pubic hair (baldness)

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

What is the moa of DHT?

A

1) Testosterone diffuses across cell membrane

2) Testosterone converted to DHT by 5α-reductase

3) DHT binds to intracellular androgen receptor

4) DHT-AR complex undergoes dimerisation and phosphorylation

5) New complex passes through nuclear membrane to act at androgen-response element + recruits coactivator (ARA70)

6) Transcription of proteins → testosterone/DHT effects

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

How long does spermatogenesis take?

A

65-70 days

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

Describe the process of spermatogenesis.

A

1) Proliferation (3-4wks)
- Spermatogonium → 1° spermatocytes
- mitosis

2) Growth (3-4wks)
- 1° spermatocytes → 2­° → spermatids
- meiosis

3) Differentiation (3-4wks)
- spermatids → spermatozoon
- Spermiogenesis

4) Maturation
- Spermatozoon → Mature spermatozoa
- in epididymis

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

Where does the maturation of sperm cells take place?

A

Epididymis

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

Describe the structure of a matured sperm.

A

1) Head
- acrosome and nucleus

2) Neck

3) Midpiece
- mitochondria

4) Tail

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

What are 5 hormones that exert their effects of spermatogenesis?

A

1) Testosterone
- essential for growth of germinal testicular cells

2) LH
- stimulates testosterone secretion from Leydig cells

3) FSH
- needed for spermiogenesis (spermatids → matured sperm)

4) Estrogens
- essential for spermiogenesis

5) Growth hormones
- essential for controlling background metabolic functions of the testes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the usual age range for puberty in males?

A

10-12 years old

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What are the 2 main physical changes during puberty?

A

1) Secondary sexual characteristics
2) Somatic growth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

At puberty, the hypothalamus increases the _________ secretion leading to the eventual incipience of adult sexual life.

A

GnRH → FSH LH (by AP) → Testosterone (by Leydig cells)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is the clinical criteria for infertility?

A

After a couple failed to conceive after 12 months of regular unprotected sexual intercourse.

1/3 due to male
1/3 due to female
1/3 due to both

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

In true hermaphroditism, what is the
(i) Genetic sex
(ii) Gonadal sex
(iii) Phenotypic sex

A

i) 46 XX, 46XY or 47XXY

ii) Both testes & ovaries

iii) Female
- ambiguous with both male and female features

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What are 2 causes of pseudohermaphroditism?

A

1) 5-ARD
- l.o.f mutation in 5α-reductase gene
- similar but less severe phenotypes than AIS before puberty
- during and aft puberty → development of male sexual characteristics

2) AIS
- partial or complete l.o.f of androgen receptor
- may be (i) complete, (ii) partial, (iii) mild

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What are the 3 levels of sexual dimorphism in px with CAIS (complete androgen insensitivity syndrome)?

A

1) Genetic: XY-male

2) Gonadal:
- hidden testes
- no ovaries
- no cervix or uterus

3) Phenotypic:
- normal breast
- normal lower vagina (no upper)
- infertile
- higher testosterone than males

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What are 4 differences between 5-ARD and AIS?

A

5-ARD:
1) mutation of 5-ARD gene (non-functional enzyme)
2) External genitalia may include micropenis or hypospadia
3) Male internal genitalia present (have Wolffian structures)
4) Develops male 2° sexual characteristic during puberty

AIS:
1) mutation of androgen receptor gene (non-functional receptor)
2) only female external genitalia
3) neither Wolffian nor Mullerian structures
4) Normal female 2° sexual characteristics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What are 4 similarities between 5-ARD and AIS?

A

1) XY
2) Testes present
3) Infertile
4) Primary amenorrhea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is Kallmann syndrome?

A

Cause of hypogonadotropic hypogonadism
- mutation of more than 25 genes leading to failure in GnRH function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Kallmann syndrome:
Symptoms:________________
Diagnosis:_______________
Treatment:_______________

A

Kallmann syndrome:
Symptoms:
i) no/slow puberty, poor 2° sexual characteristics
ii) hypogonadism (low level of sex hormones)
iii) Infertile
iv) occurring both in M and F

Diagnosis:
i) Delay or no puberty
ii) low level of testosterone/estrogen and LH and FSH

Treatment: Hormone replacement (GnRH)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

How is Kallmann syndrome differentiated from Klinefelter or Turner syndrome?

A

LH/FSH levels
Kallmann: ↓
Klinefelter/Turner: ↑ (no problem with hypothalamus + no -ve feedback from testosterone/estrogen)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

True or false: There is a reduction in oocyte number from birth till menopause.

A

True
- 1 mil primary oocyte @ birth
- 200k primary oocyte @ puberty
- only 400 oocytes ovulated during entire reproductive years

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

All primary oocytes remain arrested at which stage of the cell cycle?

A

Prophase of Meiosis I

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What is the main hormone controlling folliculogenesis?

A

FSH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What are 6 differences between spermatogenesis and oogenesis?

A

1) Cell cycle
- M: from interphase of mitosis + both mitosis and meiosis
- F: from P1 of meiosis + only meiosis

2) Meiosis
- M: full meiosis I and II
- F: starts @ P1 of meiosis and stops @ M2 of meiosis

3) Output
- M: 1 1° → 4 spermatozoa
-F: 1 1° → 1 oocyte

4) Length
- M: 7wks
- F: 13-50years

5) Duration
- M: puberty till death
- F: birth to menopause

6) Quantity
- M: millions/billions at a time
- F: 1 oocyte/month

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What stage of the cell cycle is a primary oocyte in a primary follicle?

A

Arrested at P1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What stage of the cell cycle is a ovulated secondary oocyte?

A

Arrested at M2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Describe the process of folliculogenesis.

A

1) Primordial follicle
- oocyte + granulosa cells

2) Primary follicle

3) Formation of zona pellucida

4) Secondary follicle
- formation of fluid filled vesicles
- theca interna and externa

5) Mature/Graafian follicle
- Formation of antrum and cumulus mass

6) Ovulation
- oocytes released with zona pellucida and outer corona radiata
- granulosa cells converted to corpus luteum cells

7) Corpus luteum
- produce progesterone

8) Corpus albicans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What are the hormones produced from the ovaries and which cells are they secreted from?

A

LH → Theca cell → Testosterone

LH → Granulosa cell → Progesterone
FSH → Granulosa cell → Estradiol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What is the most reactive estrogen?

A

Estradiol (E2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What are 6 functions of estrogens?

A

1) Control development of female external genitalia

2) Control folliculogenesis

3) Support puberty

4) Promote female secondary sex characteristics

5) Promote libido/sex drive

6) Promote metabolism (lipid synthesis)

7) Control menstrual cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What are 2 physiological sources of progesterone?

A

1) Ovaries (Granulosa cells in follicle and corpus luteum)

2) Placenta (during pregnancy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

What are 3 functions of progesterone?

A

1) Converts endometrium into secretory stage for implantation

2) Reduce the maternal immune response

3) Decrease contractility of uterine smooth muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What are 5 differences between estrogen and progesterone?

A

1) Source
- E: placenta @ late stage
- P: placenta @ early stage

2) 2º sex characteristics:
- E: development
- P: maintain

3) Endometrium:
- E: Proliferation
- P: converts to secretory stage to prepare implantation

4) Metabolism:
- E: Anabolic
- P: Catabolic

5) Timing:
- E: Before ovulation
- P: After ovulation

6) Libido
- E: ↑
- P: ↓

7) Cancer risk
- E: ↑
- P: ↓

53
Q

Where is a mature ovum released from?

A

Graafian follicle

54
Q

What is ovulation is stimulated by?

A

Sudden increase of LH in the middle of menstrual cycle

55
Q

How many oocytes are released during ovulation physiologically?

A

1

56
Q

What does the corpus luteum secrete?

A

Progesterone and estrogen?

57
Q

What are the 3 phases of the ovarian cycle?

A

1) Follicular (growing follicle → ↑estradiol)

2) Ovulation (release of ovum after spike in LH and FSH)
- drop in estradiol
- rise in basal body temp

3) Luteal (Formation of corpus luteum → ↑progesterone, estrogen)
- degradation of corpus luteum to corpus albicans if not fertilised

58
Q

What are the 3 phases of the uterine cycle?

A

1) Menses (Shedding of endometrium)

2) Proliferative (Thickening of endometrium by estradiol)

3) Secretory (glycogen and glycoproteins secreted from endometrium under LH)

59
Q

When does puberty usually occur in females?

A

9-12 years

60
Q

What is menarche?

A

Onset of menstrual cycle

61
Q

What is thelarche?

A

Breast development

62
Q

What are the hormonal changes in a female during puberty?

A

Hypothalamus → GnRH
→ AP → ↑FSH and LH + GH
→ ↑Estrogen

63
Q

What is the difference between primary and secondary amenorrhea?

A

Primary: failure of onset of menstrual cycle by 16y/o

Secondary: absence of menstrual for 6mths

64
Q

What are 4 possible causes of female infertility?

A

1) Genetic:
-eg. Turner syndrome (X0)

2) Developmental:
- Hypogonadotropism
- Hypogonadism
- Hyperprolactinemia

3) Environmental:
- Toxins
- Chemotherapy

65
Q

The ovum lives up to _____________ after ovulation while sperm live up to_____________ in female genital tract.

A

Ovum: 12-24hrs
Sperm: 72hrs

66
Q

Where does fertilisation usually occur?

A

Fallopian tube

67
Q

What are 3 factors that facilitate the transport of sperm in the female reproductive tract?

A

1) Sperm motility
2) Contractions of uterus and oviduct
3) Chemical attraction to ovum

68
Q

What is capacitation?

A

Activation of sperm for sperm to penetrate egg
- occurs after ejaculation in female genital tract

69
Q

What is the acrosome reaction?

A

Redistribution of membrane constituents and ↑membrane fluidity and permeability when sperm binds to zona pellucida of egg

70
Q

What are 2 changes to sperm that occur that facilitate fertilisation?

A

1) Capacitation
- ▲to sperm head for acrosome rxn

2) Acrosome rxn
- ↑membrane fluidity and permeability + redistribution of membrane constituents

71
Q

What are the 3 changes to the ovum during/after fertilisation?

A

1) Cell membrane depolarises
- prevent membrane fusion w other sperm

2) Cortical/zona reaction
- inactivation of sperm receptor
- hardening of zona pellucida to impair subsequent sperm binding

3) Resumption of 2nd meiotic division
- start from M2 (was arrested)

72
Q

Describe the fertilisation process after the sperm cell comes into contact with the ovum.

A

1) Acrosome rxn between sperm and egg
2) Contact between sperm and zona pellucida
3) Entry of sperm and contact w oolemma
4) Resumption of 2nd meiotic division (from M2)
5) Completion of meiosis
6) Formation of M and F pronuclei
7) Migration and union of M and F pronuclei
8) Zygote ready for 1st mitotic division

73
Q

How can the estimated date of delivery be calculated?

A

1) 40 weeks from last mensus
2) Head to rump length → compare to chart

74
Q

What are the 3 periods of prenatal development?

A

1) Pre-embryonic (1st 2 wks)
2) Embryonic (3-8wks)
3) Fetal period (9-38wks)

75
Q

Describe the pre-embryonic stage of fetal development.

A

Day
0: fertilisation
1: 1st cleavage division → Blastomere (2cell)
2: 4 cell zygote
3: Early morula
4: Advanced morula
6: Blastocyst (inner cell mass + blastocoele w trophoblasts)
7-10: implantation

76
Q

What are the components of a blastocyst?

A

1) Embryoblast (inner cell mass)
2) Blastocoele (blastocyst cavity)
3) Trophoblasts (lining)

77
Q

Describe the process of implantation.

A

1) Blastocyst receptors bind to endometrium lining

2) Trophoblastic cells secrete enzymes to digest uterine cells

3) Endometrium thickens and becomes more vascularised

78
Q

What is menopause?

A

End of female reproductive period
- due to depletion of oogenesis
- arnd 50y
- more fibrosed ovary w loss of dominant follicles

79
Q

What are 3 effects of menopause other than infertility?

A

1) Osteoporosis
2) Atherosclerosis
3) Uterus/vagina atrophy
4) Breast atrophy

80
Q

What are the changes to the pH and temperature as a sperm leaves the testes and enters the oviduct?

A

pH goes down then up by oviduct
Temp increases

Leaving testis: pH=7.4, 35°C
Epididymis: pH=6.5, 35°C
Seminal plasma: pH=6.9, 37°C
Oviduct/IVF: pH=7.4, 38.5°C

81
Q

What are the 2 parts of the placenta?

A

1) Fetal part (chorionic plate)

2) Maternal part (decidua basalis)

82
Q

What are 5 functions of the placenta?

A

1) Endocrine
- Estrogen, Progesterone
- Relaxin
- HCG
- hPL, hCS

2) Nutritional
- glucose, aa, FA, minerals, vitamin from maternal → fetal blood

3) Respiratory
- O2 from mother to fetus
- CO2 from fetus to mother

4) Immune
- Maternal Abs (esp IgG) → passive immunity to fetus

5) Excretory roles
- Nitrogenous waste from fetal blood to maternal blood

83
Q

How late after ovulation does implantation usually occur?

A

7-10 days

84
Q

What are the hormonal changes during pregnancy?

A

1) hCG rise to peak at 10weeks
- declines to basal level after 40weeks

2) Progesterone ↑ till delivery

3) Estrogen ↑ till delivery

4) Prolactin ↑ till delivery

85
Q

Where is hCG produced?

A

By syncytiotrophoblasts in placenta

86
Q

True or false: hCG can be detected immediately after fertilisation has occured.

A

False.
hCG produced by syncytiotrophoblasts in placenta AFTER implantation (6-8days)

87
Q

hCG binds to __________ receptor on __________ to promote its function.

A

LH receptor on corpus luteum

88
Q

What are 3 functions of hCG?

A

1) Maintain function of corpus luteum to secrete progesterone

2) Promote progesterone function by placenta

3) Promote testosterone production by fetus

4) Coordinate sexual differentiation of baby

89
Q

What are 2 causes of a false negative urinary pregnancy test?

A

1) Too early
2) Too diluted

90
Q

What are 2 causes of a false positive urinary pregnancy test?

A

1) Gestational trophoblastic disease (Hydatidiform mole)

2) Choriocarcinoma

91
Q

How long after the last menstrual period would a urine pregnancy test be accurate?

A

30 days after LMP

92
Q

What are 2 functions of a hCG urinary pregnancy test?

A

1) Early detection of pregnancy
2) Indicator of embryonic development

93
Q

What are 3 changes to estrogen and progesterone production during pregnancy?

A

1) <8wks, both produced by corpus luteum, >8wks by trophoblasts in placenta

2) Both ↑ till delivery

3) Main estrogen during pregnancy E2 (Estradiol) → E3 (Estriol)

94
Q

What are 3 functions of estrogen during pregnancy?

A

1) Promote growth of uterus and ↑uterine blood flow

2) Enhance function of progesterone and oxytocin

3) Enhance fetal development

4) Stimulate breast cell development and fat deposition

95
Q

What are 3 functions of progesterone in pregnancy?

A

1) Support endometrium for nurturing the fetus
2) Inhibit myometrial contraction
3) Suppress maternal immunologic responses to fetal Ag

96
Q

Human placental lactogen (hPL):
- produced by: ______________
- function: _______________

A

Human placental lactogen (hPL):
- produced by: placental syncytiotrophoblasts (same as hCG)
- function: support fetal nutrition

97
Q

Prolactin (PRL):
- produced by: ______________
- function: _______________

A

Prolactin (PRL):
- produced by: Lactotrophs in Anterior Pituitary
- function: stimulate lactation

98
Q

Relaxin:
- produced by: ______________
- function: _______________

A

Relaxin:
- produced by: corpus luteum of varies and placenta
- function: (i) soften cervix (ii) loosen connective tissues of pelvis

99
Q

What are 4 maternal adaptations during pregnancy?

A

1) ↑ function
- Lung, CVS, Renal

2) Weight gain

3) Endocrine system:
- Sex hormones
- Thyroid hormones

4) Metabolism
- Fat deposition
- Insulin resistance

100
Q

What are 3 sites of ectopic pregnancy and which is most common?

A

1) Tubal (95%)
2) Ovarian
3) Peritoneal

101
Q

What are 4 causes of female infertility?

A

1) Anovulation
2) Endometriosis
3) Tubal disease
4) Fibroid
5) Gonadal failure
6) Luteal phase defect
7) Cervicitis
8) Antisperm Abs
9) Fertilisation/genetic issues

102
Q

What are 3 causes of male infertility?

A

1) Varicocoele
2) Gonadal failure
3) Idiopathic oligo or azoospermia
4) Chemotherapy
5) Retrograde ejaculation
6) Genetic defects

103
Q

Which part of the blastocyst do the embryological germ layers arise from?

A

Inner cell mass

104
Q

What are the 3 stages of partuition?

A

1) Dilation
- dilation of cervix (3cm to 10cm) → effacement (thinning)
- duration: 8-10hrs (decreases w number of previous child births)

2) Fetal expulsion
- From when cervix is fully dilation to when baby is born
- duration varies

3) Delivery of placenta
- Fetal expulsion to delivery of placenta
- duration: 10-15mins

105
Q

With increasing parity, the duration of the ______ stage of parturition decreases.

A

Dilation

106
Q

What are 5 hormones involved in the control of parturition?

A

1) Progesterone

2) Estrogen

3) Prostaglandins

4) Oxytocin

5) Relaxin

107
Q

What is the moa of progesterone in parturition?

A

1) Hyperpolarises myometrial cells → suppress uterine contractions

2) Inhibits Phospholipase A2 and thus subsequent prostaglandin synthesis

108
Q

What is the moa of estrogen in parturition?

A

1) Depolarises myometrial cells → promotes uterine contractions

2) Promotes Phospholipase A2 and thus subsequent prostaglandin synthesis

109
Q

During parturition, prostaglandins are produced by ____________________ due to the activation of PLA2 by ____________.

A

PE:
- produced by myometrium decidua and chorion (sharp ↑ before labor)
- by activation by estrogen

110
Q

What is the moa of prostaglandins in parturition?

A

↑ Intracellular [Ca2+] to activate actin myosin →
1) Stimulate uterine contractions
2) Cause cervical ripening and dilation

111
Q

True or false: Oxytocin is produced in the posterior pituitary gland.

A

False.
Oxytocin produced in Hypothalamus and STORED in posterior pituitary gland.

112
Q

What type of receptors are oxytocin receptors and where are they expressed to facilitate parturition?

A

Cell surface GPCR

Expressed in both myometrium and endometrium

113
Q

How does estrogen enhance oxytocin effects?

A

Increases expression of oxytocin GPCR receptors on uterine myometrium and endometrium

114
Q

What are 4 functions of oxytocin?

A

1) Uterine contraction
2) Lactation
3) Social behaviour (love, sexual arousal, bonding, etc.)
4) Inflammation and wound healing

115
Q

Relaxin is produced in _______________________ during pregnancy and bind to ________________ receptors found on _________________.

A

Relaxin:
- produced in (i) corpus luteum of ovary (ii) placenta during pregnancy
- bind to relaxin GPCR receptors expressed in smooth muscle

116
Q

What is the moa of relaxin?

A

Bind to relaxin GPCR receptor LGR7 and LGR8 →
Pregnancy:
i) ↑CO
ii) ↑Renal blood flow
iii) ↑arterial compliance

Parturition:
i) ↑oxytocin receptor
ii) assist cervical ripening
iii) soften pubic symphysis

117
Q

Describe the hormonal control of parturition.

A

1) Estradiol from placenta readies uterus for oxytocin response

2) Fetus head pushes against cervix → activates stretch receptors → send signals to hypothalamus

3) Hypothalamus stimulates secretion of oxytocin from posterior pituitary

4) Oxytocin stimulates stronger uterine contractions

5) Prostaglandins from uterus also enhance contractions

6) Enhanced contractions → ↑2-6 (+ve feedback until fetal expulsion)

118
Q

Development of the the breast is mainly controlled by ________ during puberty, however, ________ converts epithelium into secretory cells.

A

Mainly controlled by estrogen

but progesterone converts epithelium into secretory cells

119
Q

Which 3 hormones influence the development of the breast in pregnancy?

A

1) Estrogen
2) Progesterone
3) Prolactin

120
Q

Estrogen and progesterone (promote/inhibit) milk secretion during pregnancy.

A

Inhibit

121
Q

What is the physiological trigger for milk production in females?

A

Sudden reduction of estrogen and progesterone after birth.

122
Q

What are the 2 main hormones that control lactation?

A

1) Prolactin

2) Oxytocin
- stimulates myoepithelial cells for milk ejection

123
Q

Human milk has (more/less) fat and carbohydrates and thus (more/less calories) than cow milk.

A

More
(but less protein)

124
Q

What are 4 functions of prolactin?

A

1) Lactation
2) Immunity
3) Haematopoiesis
4) Angiogenesis

125
Q

What are 5 benefits of breastfeeding?

A

To mother:
1) ↓risk of breast and ovarian cancers
2) ↓risk of T2DM
3) ↓Stress and prevents postpartum depression
4) ↑bonding w child
5) ↑intervals between pregnancies

To baby:
1) Protection against infections (from Abs, hormones, digestive enzymes, etc.)
2) Brain development (eg. from LCFAs)
3) Sucking and swallowing motions may ↓risk of bacterial colonisation of tubes and promote craniofacial development

126
Q

What are the 3 main effects of the lactation reflex in breastfeeding?

A

1) Maintain lactation
2) Promote release of prolactin and oxytocin for milk production and ejection
3) Suppression of gonadal function and ovulation

127
Q

What is the WHO recommended period of breast feeding?

A

Exclusively breastfed for 6mths, can continue w other foods up to 2 years or beyond

128
Q

Why is the possibility of pregnancy reduced when a woman is fully breastfeeding?

A

Lactational amenorrhoea:
1) Breastfeeding → lactation reflex → ↑prolactin

2) ↑prolactin inhibit GnRH (↓) → ↓oestrogen

3) ↓oestrogen → cannot surge to incite ovulation

129
Q

What is the usual time period for lactational amenorrhoea?

A

If fully breastfeeding, 6mths after delivery

Reproductive System (7 decks)

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