Brainscape's Knowledge GenomeTM

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


See full index

My Phase 1 > urogenital and repro > Flashcards

urogenital and repro Flashcards

1
Q

where do the male and female gonads derive from embryologically?

A

the urogenital ridge

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

when do primordial gonads begin to differentiate?

A

during the 6th-7th week

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

what determines sex differentiation?

A

a gene on the Y chromosome known as the SRY gene

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

Before differentiation, what does the undifferentiated reproductive tract consist of?

A

A double genital duct system:

  • Wolffian ducts
  • Mullerian dicts
  • cloaca: common opening to the outside for the genital ducts and urinary system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe the process of gonadal development if the SRY gene is present

A

Primordial gonads differentiate into fetal testes.
Sertoli cells produce mulelrian-inhibiting sybstance, causing regression of the Mullerian ducts.
Leydig cells produce testosterone, acting on the wolffian ducts to stimulate their development to form the epididymis, vas deferens, seminal vesicles and ejaculatory duct.
Also produce dihydrotestosterone which lead to development of the penis, scrotum and prostate.

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

Describe the process of gonadal development if the SRY gene is not present

A

No SRY.
Primordial gonads become fetal ovaries.
Absence of Mullerian inhibiting factor allows Mullerian ducts to form uterus, fallopian tubes and inner vagina.
Absence of testosterone means Wolffian ducts regress and development of outer vagina and female external genitalia occurs.

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

Where do germ cells originate?

What will they develop to form?

A

Originate from yolk sac of the hindgut.

Develop onto gametes.

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

WHat are the stages of gametogenesis?

A
  • proliferation of the primordial germ cells by mitosis
  • meiosis forming haploid gametes
  • second meoitic division - in females only occurs after fertilisation of a secondary oocyte by a sperm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How does the second meiotic division differ in males and female spermatogenesis?

A

Male: occurs continuously after puberty with the production of spermatids and ultimately mature sperm cells
Female: does not occur until after fertilisation of a secondary oocyte by a sperm resulting in the production of a zygote

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

How does the timing of mitosis in germ cells (first phase) differ in females and males?

A

In males, some mitosis occurs in the embryonic testes to generate the population of primary spermatocytes present at birth, but properly begins during male puberty.
In females, mitosis of germ cells in the ovary occurs primarily during fetal development resulting in the generation of primary oocytes - born with all potential eggs.

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

where does meoisis occur in a female? male?

A

male - seminiferous tubules

female - ovaries

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

What are the results of the first meiotic divisions in gametogenesis in:
females
males

A

females - secondary oocyte

male - secondary spermatocytes

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

Results of meiosis 1

A

Separates homologous chromosome pairs producing 2 haploid cells

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

results of meoisis 2

A

separates duplicated sister chromatids producing 4 haploid cells

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

3 collagenous compartments of the penis

A
  • 2 corpus cavernosum

- 1 corpus spongiosum, which the urethra passes through

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

At what point of gestation do the testes descend into the scrotum? why is this essential?

A

Usually 7th month.
This is essential for normal spermatogenesis because it requires temperatures approx 2 degrees lower than normal body temperature.

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

How is the temperature of the testes maintained at 2 degrees below normal body temp?

A

Cooling is achieved by air circulating around the scrotum and by a heat-exchange mechanism in the blood vessels supplying the testes: the pampiform plexus

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

HPG axis - what is the effect of GnRH release from the hypothalamus?

A

Stimulates the anterior pituitary to produce FSH and LH

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

HPG axis - What is the effect of FSH and LH produced by the anterior pituitary in response to GnRH on the cells of the ovaries?

A

LH stimulates theca cells to produce androgens, used by granulosa cells in oestrogen production.
FSH stimulates granulosa cells to produce inhibin and oestrogen.

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

What are the effects of different oestrogen levels on the HPG axis?

A
  • in presence of progesterone, has a negative feedback effect on the hypothalamus and anterior pituitary (decreasing levels of GnRH, FSH and LH)
  • moderate oestrogen levels = negative feedback effect
  • high oestrogen levels (no progesterone) = positive feedback
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Describe the follicular phase of the menstrual cycle?

  • GnRH levels
  • FSH and LH levels
  • inhibin levels
  • oestrogen production and effect
A
  • follicles begin to mature
  • GnRH not yet released
  • low steroid and inhibin levels mean little negative feedback on HPG axis
  • this allows increased FSH and LH levels, stimulating follicle growth and oestrogen production
  • As oestrogen levels rise, negative feedback effect reduced FSH levels, and only 1 dominant follicle continues to maturity and completes menstrual cycle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is a primordial follicle?

A

primary oocyte surrounded by a single layer of epithelial granulosa cells

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

describe ovulation

  • oestrogen levels
  • GnRH levels
  • inhibin levels
  • FSH levels
  • LH levels
A
  • follicular oestrogen becomes high enough to initiate positive feedback at HPG axis
  • FSH levels remain low due to inhibin, but there is an LH surge due to high oestrogen and GnRH levels
  • this spike causes the follicle to rupture and mature oocyte is assisted to the fallopian tube by fimbra - ovulation
    here it is viable for fertilisation for 24hrs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Describe the luteal phase following ovulation

  • what is corpus luteum
  • what hormones does it produce
  • effect of these hormones
A

Corpus luteum - tissue at site of ruptured follicle

  • as it degrades, it produces oestrogen, inhibin and progesterone
  • INHIBIN -ve feedback on FSH production so no more follicles mature
  • oestrogen + progesterone = -ve feedback on HPG axis
  • oestrogen and progesterone maintain conditions for fertilisation and implantation - stimulate endometrial growth - for 14 days
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

If fertilisation does not occur within 14 days of luteal phase what happens

A
  • corpus luteum degenerates (forming corpus albicans)
  • inhibin oestrogen and progesterone it was producing decrease
  • endometrium no longer maintained = period
  • HPG cycle no longer inhibited = follicular maturation can begin again
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Which stage of the menstrual cycle does the proliferative phase correspond to?

A

Runs alongside the follicular phase

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

The uterine cycle - what happens in the proliferative phase?

A

Oestrogen released from maturing follicles
- oestrogen initiates:
Fallopian tube formation
Thickening of the endometrium
Increased growth and motility of the myometrium
Production of a thin alkaline cervical mucus to facilitate sperm transport

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

Which stage of the menstrual cycle does the secretory phase correspond to?

A

The luteal phase

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

The uterine cycle - what happens in the secretory phase?

A

Progesterone released by the corpus luteum as it degrades
Stimulates:
- further thickening of the endometrium
- reduction of motility of the myometrium
- changes in mammary tissue
- thick acidic cervical mucus

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

What occurs during the secretory phase to prevent polyspermy?

A
  • progesterone causes production of thick acidic cervical mucus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

when does oogenesis begin?

A

in the foetus prior to birth - female is born with 2 million primary oocytes, arrested in prophase stage of meiosis 1

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

Role of human chorionic gonadotrophin in normal pregnancy

A
  • stimulates production of oestrogen and progesterone
  • pregnancy test hormone: present in urine throughout pregnancy
  • levels diminish once the placenta is mature enough to produce its own
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Role of oestrogen in normal pregnancy

A
  • regulates progesterone levels
  • prepares uterus for baby
  • prepares mammary glands/breasts for lactation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Role of progesterone in normal pregnancy

A
  • prevents miscarriage
  • builds up endometrium
  • prevents uterine contraction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Role of prolactin in normal pregnancy

A
  • produced by the pituitary gland

- following drop in oestrogen and progesterone levels after birth, it stimulates production of milk producing cells

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

Role of relaxin in normal pregnancy

A
  • levels are high in early pregnancy
  • limits uterine activity
  • softens cervix (cervical ripening) in preparation for delivery
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Role of oxytocin in normal pregnancy

A
  • ‘caring’ reproductive behaviour
  • uterine contractions during labour and pregnancy
  • contractions during breastfeeding
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Role of prostaglandins in normal pregnancy

A
  • tissue hormones

- work locally to induce labour

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

what synthetic hormones are used to induce labour?

A
  • oxytocin

- prostaglandins

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

What are some maternal adaptations of the cardiovascular system?

A
  • increased cardiac output
  • decreased blood pressure, decreased peripheral resistance
  • increased blood flow to uterus, vasodilation
  • increased blood volume and red cell mass
  • increased alveolar ventilation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

what must occur in order for the secondary oocyte to complete meiosis 2?

A

Fertilisation

Once meoisis 2 is completed it gives off a third polar body and a fertilised egg

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

basic definition of conception

A
  • sperm deposited in the vagina at the level of the cervix (coitus) is transported to the uterus where it fertilised the ovum and implants in the uterine stroma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

why is a reduction in gastric motility a maternal adaptation?

A
  • increases transit time in stomach/bowel
  • this increases absorption in the bowel
    may lead to symptoms of constipation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

what happens when a primordial follicle develops into a primary follicle?

A
  • oocyte ncreases in size
  • oocyte becomes separated from the inner granulosa cells by the zona pellucida
  • stroma develops into connective tissue sheath
45
Q

describe what happens when a primary follicle develops into a secondary follicle

A

stages preantral and early antral (before antrum forms)

  • stroma differentiates into theca externa and theca interna
  • continued proliferation of granulosa cells occurs
  • spaces form between granulosa cells - ANTRUM - and fill with follicular fluid
46
Q

which layer of the theca cells secrete androgens?

A

externa

47
Q

describe a mature/graafian follicle

A
  • one antral follicle continues to develop - the dominant follicle
  • antrums coallesce
  • corona radiata = layer of granulosa cells lining the oocyte
  • cumulus oophorus = stalk connecting oocyte to granulosa cells surrounding antrum
48
Q

describe hormonal levels before puberty

A
  • low pulsality amplitude of HnRH and GHRH from hypothalamus

Therefore low levels of FSH, LH and gonadal sex steroids

49
Q

Describe hormonal changes at pubertal age?

A

unknown trigger - increased amplitude GnRH and GHRH

Therefore increased lebels of FSH, LH and sex steroids, as well as GH

50
Q

what 2 types of daughter cells (spermatogonia) are produced as a result of mitosis of the initial pool of diploid germ cells?

A

Type A: remain outside blood-testes barrier and produce more daughter cells until death (replenish the pool of spermatogonia) - allows males to be fertile throughout adult life
Type B: differentiate into primary spermatocytes

51
Q

Where does sperm production occur?

A

In the seminiferous tubules

52
Q

How are seminiferous tubules kept separate from the systemic circulation?

A

By the blood-testis barrier

53
Q

What forms the blood-testis barrier?

A

Sertoli cells

54
Q

why is the blood-testis barrier so important?

3 reasons

A
    • important in preventing hormones and constituents of the systemic circulation from affecting the developing sperm
    • prevents the immune system from recognising the sperm as foreign: the sperm are genetically different from the male and will express different surface antigens
    • sertoli cells have a role in supporting the developing spermatozoa
55
Q

What happens to type B spermatagonia?

A
  • replicate by mitosis several times to form identical diploid cells linked by cytoplasm bridges: now known as primary spermatocytes
56
Q

What happens to primary spermatocytes formed by the mitosis of type B spermatogonia?

A

Undergo meiosis:
Meiosis 1 produces 2 haploid cells known as secondary spermatocytes
Meiosis 2 produces 4 haploid cells known as spermatids

57
Q

What is spermiogenesis?

where does this occur?

A

Spermatids undergo differentiation (sprouts tail, sheds cytoplasm, acrosomal vesical forms acrosome) to form mature spermatozoa.
Occurs as they travel along the seminiferous tubules until they reach the epididymis.

58
Q

what happens to spermatozoa from their formation from spermiogenesis in the seminiferous tubules?

A

They travel to the rete testis which acts to concentrate the sperm by removing excess fluid.
Then to the epididymis where the sperm is stored and undergoes the final stages of maturation.

59
Q

How long does spermatogenesis take?

What must therefore occur for sperm production to be continuous?

A

approximately 70 days, therefore in order for sperm production to be continuous and not intermittent, multiple spermatogenic processes are occurring simultaneously within the same seminiferous tubule
A spermatogenic cycle is therefore said to be 16 days as this is how often new groups of spermatogonia arise.

60
Q

what is the final stage of sperm maturation and where does this occur?

A

capacitation
this occurs in the female reproductive tract and involves the removal of cholesterol and glycoproteins from the head of the sperm cell to allow it to bind to the zona pellucida of the egg cell

61
Q

when does oogenesis begin?

A

in the foestus prior to birth - female is born with 2 million primary oocytes, arrested in prophase stage of meiosis 1

62
Q

once puberty begins, what happens to the primary oocytes each month?

A
  • 15-20 mature oocytes begin to mature each month, although only one of these reaches full maturation to become an oocyte
63
Q

What are the 3 stages 15-20 primary oocytes undergo each month?

A
  • preantral
  • antral
  • preovulatory
64
Q

describe the preantral stage of primary oocyte development

A
  • dramatic growth whilst still arrested in meiosis 1
  • follicular cells grow and proliferate to form a stratified cuboidal epithelium
  • these cells are now known as granulosa cells. They secrete a zona pellucida.
  • surrounding connective tissue cells differentiate to become the theca
65
Q

what is the theca folliculi?

A

a specialised layer of cells surrounding the follicle, that is responsive to LH and can secrete androgens under its influence

66
Q

describe the antral stage of primary oocyte development

what is the finished product of the antral stage called?

A
  • fluid filled spaces form between granulosa cells
  • these combine to form a central fluid filled space - the antrum
    Now called secondary follicles
67
Q

what happens to the secondary follicles formed by the antral stage of oogenesis?

A

1 each monthly cycle becomes dominant and develops further under the influence of FSH, LH and oestrogen.
- takes part in ovulation

68
Q

what happens to the follicle in the preovulatory stage to form a secondary oocyte? (following the formation of secondary oocytes)
how is the stage induced?

A

Induced by the LH surge (at end of follicular stage in the menstrual cycle)

  • Meoisis 1 is now complete
  • 2 haploid cells of unequal size are formed within the follicle
  • 1 receives far less cytoplasm and forms the 1st polar body
  • the other is known as the secondary oocyte
69
Q

What happens to the 2 daughter cells (products of meoisis 1) just prior to ovulation following their development into 1 polar body and 1 secondary oocyte?
What is the follicle now called?

A

Both undergo meoisis 2.
First polar body forms 2 polar bodies.
Secondary oocyte arrests in metaphase of meiosis 2
The follicle has grown in size and is now mature - called a Graafian follicle.

70
Q

What occurs to induce the release of the ovum from the ovary?

A
  • LH surge weakens the follicular wall
  • this combined with muscular contractions of the ovarian wall result in release of the ovum
  • ovum is taken up into the fallopian tube via the fimbriae
71
Q

what must occur in order for the secondary oocyte to complete meiosis 2?

A

Fertilisation

Once meoisis 2 is completed it gives off a third polar body and a fertilised egg

72
Q

basic definition of conception

A
  • sperm deposited in the vagina at the level of the cervix (coistus) is transported to the uterus where it fertilised the ovum and implants in the uterine stroma
73
Q

what processes aid the sperm to travel from the cervix to the ampulla in the fallopian tube?

A
  • uterine contraction stimulated by oxytocin

- propulsive activity of the sperm thanks to its tail

74
Q

what occurs in capacitation to help the sperm to reach and penetrate the oocyte?

A
  • sperm cell membrane is reorganised: removal of the protein coat
  • this changes its tail movement from beat-like to thrashing, propelling the sperm forward
  • capacitation also exposes acrosome enzymes meaning the acrosome reaction is able to occur, allowing penetration of the zona pellucida
75
Q

endocrine adaptations to pregnancy

A
  • increasing levels of progesterone and oestrogen throughout
  • oestrogen causes more TSH to be released from the anterior pituitary - ensures a contstant supply of thyroxin to the foetus as it can not produce its own
  • anti-insulin hormone levels rise: prolactin, cortisol, oestrogen, progesterone = insulin resistance = less uptake of glucose = constant supply for foetus
76
Q

during pregnancy, where is progesterone produced?

and oestrogen?

A

Progesterone: produced by the corpus luteum and later the placenta
Oestrogen: produced by the placenta

77
Q

CVS adaptations in normal pregnancy

A
  • increased CO
  • progesterone leads to decreased vascular resistance and therefore decreased diastolic blood pressure
  • increased blood flow to uterus
  • activation of RAAS = total blood volume increases
78
Q

RS adaptations in pregnancy

A
  • increased metabolic rate means increased demand for oxygen, so tidal volume and minute ventilation rate increases
79
Q

GI adaptations in pregnancy

A
  • increased progesterone = smooth muscle relaxation = decreased gut motility
  • this increases transit time in gut so more nutrient absorption can occur, but can lead to constipation
  • relaxation of the gall bladder = predisposition for gallstones
80
Q

urinary system adaptations in pregnancy

A
  • increased CO means an increase in renal plasma flow so GFR increases by about 50-60%
    = increased renal excretion
  • progesterone = relaxation of the uteter and muscles of the bladder. Cause urinary stasis, predisposing woman to UTIs.
81
Q

why do pregnant woman have an increased risk of embolism?

A

In pregnancy there is an increase in fibrinogen and clotting factors in the blood and a decrease in fibrinolysis. Additionally, due to an increase in progesterone levels stasis of blood and venodilation occurs.

82
Q

Why do pregnant women have physiological dilutional anaemia?

A
  • plasma volume increases significantly

- red cell mass does not increase by as much –> dilutional anaemia

83
Q

Describe the hormonal changes in the foetus that lead to the initiation of labour in the mother via the placenta

A

Foetus:
- anterior pituitary –> increased ACTH, stimulates the adrenal gland to increase production of glucocorticoids and androgens
Placenta:
- these factors lead to increased oestrogen and decreased progesterone in the placenta
Mother:
- Decreased progesterone - increasted uterine sensitivity which leads to uterine contractions
- Increased oestrogen leads to increased prostaglandins, increasing oxytocin sensitivity and leading to uterine contractions
- prostaglandins also cause softening of the cervix, leading to cervical stretching –> labour

84
Q

Describe the positive feedback loop in the initiation of labour, caused by the interaction between the head of the foetus and the mother’s pelvis

A
  • oxytocin release leads to contractions which exert pressure on the cervix
  • this signals the brain to secrete more oxytocin from the pituitary gland
85
Q

When does the placenta begin developing?

A

during implantation of the blastocyst

86
Q

describe the implantation of the blastocyst - what allows this to occur?

A

Day 6:
Zona pellucida disintegrates.
Trophoblast cells interact with the endometrial decidual epithelia to enable the invasion into the maternal uterine cells.
Embryo secretes proteases to allow deep invasion into the uterine stroma.
Day 8
throphoblast cells differentiate into outer multinucleated scyncytiotrophoblast.
Secreted hCG which supports the corpus luteum, interacts with endometrium and is crucial to sustain early pregnancy.

87
Q

basic steps of implantation

A
  1. apposition
  2. attachment/adhesion
  3. invasion (scyncytiotrophoblast formation)
    Decidual reaction
88
Q

Key metabolic functions of the placenta

A

synthesis of glycogen and fatty acids

89
Q

key transport functions of the placenta

A

Supplies nutrients, eliminates waste products of the foetus and enabling gas exchange via the maternal blood supply.

e. g.
- water, glucose, vitamins, hormones, electrolytes
- maternal antibodies: IgG but not IgM
- drugs and their metabolites
- infection
- unconjugated bilirubin (not conjugated)

90
Q

what does the blastocyst comprise?

what do these parts develop into?

A

Outer trophoblast - becomes the placenta

Inner cell mass - becomes the foetus and foetal membrane

91
Q

after implantation, describe the development of the placenta - how is early uteroplacental circulation established?

A

Day 9:
Lacunae form within the scyncytiotrophoblast, which also erodes the maternal tissues. This allows maternal blood from uterine spiral arteries to enter the lacunar network - thus establishing uteroplacental circulation

92
Q

describe the formation of primary, secondary and tertiary chorionic villi

A

week 2
cytotrophoblast begins to form primary chorionic villi which expand into surrounding syncytiotrophoblast
3rd week
secondary chorionic villi: extraembryonic mesoderm grows into these villi forming a core of loose connective tissue
end of 3rd week
tertiary chorionic villi:
embryonic vessels form in mesoderm

93
Q

What 2 different types of villi do the tertiary chorionic villi develop into and how do their roles differ?

A
  • cytotrophoblast cells from tertiary villi grow towards the decidua basalis of the maternal uterus and spread across it - forming a cytotrophoblastic shell
  • villi connected to decidua basalis through the shell = anchoring villi
  • villi growing within the intervillous space = branching villi, provide surface area for exchange of metabolites between mother and foetus
94
Q

how do cytotrophoblast cells establish vessels with reduced resistance? why is this important?

A
  • cells invade the maternal spiral arteries and replace maternal endothelium
  • they then undergo an epithelial to endothelial differentiation, increasing the diameter and reducing the resistance of the vessels
    This remodelling of maternal spiral arteries is important to produce low resistance, high blood flow conditions to meet the demands of the foetus
95
Q

What are the 2 components of the placenta by the fourth month?

A
  • decidua basalis (maternal portion)

- chorion frondosum (the foetal portion)

96
Q

describe the decidual reaction that occurs following the implantation of the blastocyst and formation of the scyncytiotrophoblast.
Which hormone plays an important role in this process?

A

Stromal cells next to blastocyst differentiate into metabolically active secretory cells called decidual cells.
Progesterone plays an important role.

97
Q

What prevents the mother rejecting the implanted blastocyst?

A

Interleukin 2 secreted by leukocytes

98
Q

define puberty

A

the physiological morphological and behavioural changes that take place as the gonads switch from infantile to adult forms

99
Q

What are the definitive signs of puberty for boys vs girls?

A

Boys - first ejaculation, often nocturnal

Girls - menarche

100
Q

Secondary sexual characteristics - girls

Regulatory hormones?

A
  • ovarian oestrogens regulate growth of breast and female genitalia
  • pubarche, thelarche
  • ovarian and adrenal androgens
101
Q

Secondary sexual characteristics - boys

Regulatory hormones?

A
  • increased testicular size due to:
  • increased LH stimulates Leydig cells to synthesise testosterone
  • increased FSH stimulates Sertoli cells to produce sperm
  • growth of penis
  • pubarche
  • larynx and vocal cords enlarge - voice deepens in pitch
102
Q

Which hormones interact to cause the pubertal growth spurt?

A

gonadal sex steroids (oestradiol/testosterone), GH and insulin-like growth factor 1 (IGF-1).

103
Q

Basic mechanism of menopause - hormonal changes due to depletion of follicles in the ovaries

A
  • ovaries depleted of follicles
  • this means there are fewer binding sites for FSH and LH, so the ovary is less sensitive to them
  • this leads to decline in oestrogen production (gradual, fluctuates)
  • gradual rise in FSH and LH due to lack of negative feedback from oestrogen
  • decrease in developing follicles also means less inhibin release, further enhancing the rise in FSH
104
Q

physiological changes during menopause

A
  • vaginal dryness (can lead to dyspareuria, psychological and vasomotor symptoms, osteoporosis)
  • hot flushes due to peripheral vasodilation and transient rise in body temp
  • atrophy of the vagina and thinning of the myometrium
  • increase in bone resorption (oestrogen reduces activity of osteoclasts)
  • oestrogen has a protective effect against CHD - after menopause, risk is the same as men
105
Q

Pelvic nerve: how is involved in (motor) neural control of continence?
Which nervous system?
Spinal root?

A
  • autonomic, parasympathetic
  • S2-S4
  • Function: bladder contraction
106
Q

Hypogastric nerve: how is involved in (motor) neural control of continence?
Which nervous system?
Spinal root?

A
  • autonomic, sympathetic
  • T10-L2
  • Function: bladder relaxation, bladder neck contraction
107
Q

Pudendal nerve(motor): how is involved in neural control of continence?
Which nervous system?
Spinal root?

A
  • somatic nervous system
  • S2-S4
  • Supplies external urethral sphincter and the external anal sphincter
108
Q

What control is passing of urine under?

A

parasympathetic

109
Q

Describe micturition following bladder afferent signals regarding the need to void

A
  • bladder afferent signals ascend through spinal cords
  • project to pontine micturition centre and cerebrum
  • following voluntary decision to urinate, neurones of pontine micturition centre fire to excite sacral preganglionic neurones
  • subsequent parasympathetic stimulation to the pelvic nerve –> ACh causes detrusor muscle to contract
  • conscious reduction in voluntary contraction of the external urethral sphincter (pudendal nerve)

My Phase 1 (14 decks)

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