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PHGY 216 > reproductive physiology > Flashcards

reproductive physiology Flashcards

1
Q

what are the primary reproductive organs

A

males gonads= testes

female gonads= ovaries

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2
Q

successful reproduction needs

A

a union of male and female gametes ( reproductive cells)

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3
Q

external genitalia

A

externally visible portions of reproductive systems

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4
Q

what are the 2 roles of the male reproductive system

A

1) production of sperm ( gamete cells )which are made in testes
2) delivery of sperm to females

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5
Q

Most important female reproductive functions are?

6 total

A

1) production of ova
2) reception of sperm ( occurs in the vagina )
3) transport of ovum and sperm to common site of fertilization
4) maintenance of the developing fetus
5) birth of baby
6) milk production to nourish baby

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6
Q

embryonic development of both external genitalia and reproductive tract can be seen at what levels ?

A

genetic , gonadal and phenotypic

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7
Q

Genetic embryonic development is characterize by

A

combination of sex chromosomes at conception

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8
Q

how are gametes produced ?

A

through meiosis in which diploid parent cells will divide to make haploid gamete cells , half sperm carry x and half sperm carry y , while all ovum carry single x

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9
Q

when 2 haploids combine

A

sperm+ovum = fertilized ovum

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10
Q

gondola development is determined by :

A

the presence or absence of a Y chromosome

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11
Q

what takes placate week 7 of gestation ?

A

sex determining region of Y chromosome(SRY) stimulates the production of H-Y antigen

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12
Q

what happens when there is no H-Y antigen ?

A

ovaries will form because H-Y acts on gonads to form testes

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13
Q

phenotypic development is determined by ?

A

dependent on the gonadal sex, is known as the apparent anatomical sex

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14
Q

how will male reproductive system develop ?

A

androgens will be secreted by developing testes

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15
Q

what are the 2 primitive duct systems in the undifferentiated embryo ?

A

the wolffian ducts and the mullerian ducts

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16
Q

What happens in meiosis one ?

A

replicated chromosomes that contain identical pair of chromatids sort themselves into homogenous pairs before separating so each daughter cell receives single set of chromosome

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17
Q

each 2 daughter cell contains ?

A

each contain a sister set of chromatids with a single set of chromosomes

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18
Q

what happens in meiosis 2 ?

A

sister chromatids within the chromosomes of each of the daughter cells separate and distribute to 2 cells and creates 4 daughter cells each containing a single set of chromosomes and one chromatid each

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19
Q

What is the wolffian duct ?

A

??

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20
Q

Human chrorioic gonadotropin (hCG )

A

hCG will stimulate testes to produce testosterone, which will stimulate wollfian ducts to develop into male reproductive system.

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21
Q

testosterone is also converted to :

A

dihydrotestosterone which is responsible for male genitalia

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22
Q

testes will secrete ?

A

mullerian- inhibiting factor , which allows for degradation of mullerian ducts

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23
Q

In the absence of testosterone

A

wolffian ducts will degrade and mullerian will develop which will create female reproductive tract and external genitalia

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24
Q

males whose testes fail to develop or target tissues that lack testosterone receptors will result in :

A

a phenotypic female that is sterile due to lack of ovaries

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25
Q

A deficiency in the enzyme that converts testosterone to DHT

A

results in having a male reproductive tract with female external gentialia

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26
Q

genetic female with excessive adrenal secretions of DHEA in fetal development

A

reproductive tract and external genitalia are masculinized

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27
Q

the testes are :

A

outside the abdominal cavity and within the scrotal sac

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28
Q

descension of testes

A

descend in early childhood, however will sometimes remain in body cavity = cryptorchidism and sterility

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29
Q

why is location of testes important ?

A

temperature within the scrotum is several degrees less than body temperature because sperm production needs cooler temps

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30
Q

what is the role of the cremaster muscle and the dartos muscle?

A

testes too cold to make sperm, the muscles will contract to bring them closer , when too hot, they will relax and move them away from body

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31
Q

where are the sperm produced ?

A

in the seminiferous tubules in the testes

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32
Q

leydig cells

A

produce and secrete testosterone under control of luteinizing hormone , cells are found between the seminiferous tubules

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33
Q

what are the various effects of testosterone in the body ?

A

1 causes masculinization of the reproductive tract and external genitalia and descent of testes
2 maintains the reproductive tract throughout adult life and promotes sperm production and maturation of system at puberty
3develop of sex drive at puberty and controls the release of gonadotropin releasing hormones
4causes voice to deepen and body hair growth

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34
Q

non reproductive actions of testosterone

A

bone growth at puberty , closing of the epiphyseal plates as well as drives aggressive behaviour

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35
Q

spermatogenesis

A

diploid ( 46 chromosomes primordial germ cells are converted into motile sperm cells with haploid ( 23 chromosomes)

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36
Q

primordial germ cells

A

known as spermatogonia and are found in the outermost layer of the seminiferous tubules

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37
Q

Sperm forming daughter cells will undergo mitotic divisor how many times?

A

twice more to produce 4 identical primary spermatocytes that enter resting stage to prepare for meiosis 1

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38
Q

each primary spermatocyte forms :

A

2 secondary spermatocytes each with 23 double stranded chromosomes

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39
Q

what happens in meiosis 2

A

each secondary spermatocyte results in 2 spermatids, each with 23 chromosomes

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40
Q

each spermatogonia can produce

A

16 spermatids

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41
Q

what is the packaging process ?

A

maturation of spermatid into spermatozoa where the cells are stripped of all non essential organelles

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42
Q

what are the 4 parts of the spermatozoa

A

head, acrosome , mid-piece and tail

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43
Q

acrosome is

A

the enzyme packed vesicle at tip of head needed for penetrating ovum

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44
Q

mid piece contains

A

mitochondria

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45
Q

tail is needed

A

for movement and requires ATP

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46
Q

Sertoli cells are found ?

A

single layer of Sertoli cells make up walls seminiferous tubules

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47
Q

relationship between sperm cells and Sertoli cells

A
  • developing sperm can get engulfed by the Sertoli cells as they move toward the lumen, where the sperm head will remain embedded until mature
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48
Q

what are the functions of the Sertoli cells ?

A

1 - create tight junctions and allows for the cells to control intra tubular environment which make it optimal for developing spermatozoa
2- nourish sperm cells
3- Absorb sperm cytoplasm and remove defective germ cells
4- secrete seminiferous tubule fluid into the lumen to flush released sperm to epididymis for storage
5- secrete androgen - binding protein that helps concentrate testosterone in lumen
6- site of action for testosterone an FSH to regulate sperm production

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49
Q

testes are under control of

A

LH and FSH

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50
Q

what is the role of GnRh ?

A

is secreted from hypothalamus and acts on anterior pituitary gland to secrete both FSH and LH

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51
Q

LH stimulates

A

leydig cells to secrete testosterone and FSH acts on Sertoli cells to stimulate spermatogenesis and secret inhibin ??

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52
Q

Testosterone has direct negative feedback pathway meaning

A

is able to decrease GnRh and anterior pituitary to decrease LH and FSH release

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53
Q

Inhibin is used as ?

A

feedback to anterior pituitary to decrease FSH release

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54
Q

where does sperm move from seminiferous tubules ?

A

swept to the epididymis a highly coiled tube , sperm however are not motel due to low Ph

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55
Q

epididymal ducts converge to form

A

ductus deferens which each tube empties to the urthrea

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56
Q

sperm can be stored in epididymis for how long ?

A

months

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57
Q

what are the male accessory glands ?

A

3 glands which make up the bulk of semen ( accessory gland secretion and sperm )

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58
Q

the accessory glands provide?

A

support for the continuing viability of sperm inside the female reproductive tract

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59
Q

seminal vesicles

A

there are 2 which each one will empty into the ductus deferens before the urethra

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60
Q

seminal vesicles provide

A

bulk of the semen and supply fructose as energy source for ejaculated sperm as well as secrete prostaglandins to cause smooth muscle contractions in male and female reproductive tract
- secrete fibrinogen

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61
Q

Prostate glands are ? what do they secrete ?

A

large gland that surrounds the ejaculatory ducts and the urethra , secretes alkaline fluid to neutralize the acidic environment of vagina

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62
Q

what clotting enzymes does the prostate secrete?

A

clotting enzymes which act on the fibrinogen from seminal vesicles to create fibrin which clots the semen and keeps it within female reproductive tract

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63
Q

bulbourethral gland

A

pair of glands that empty into the urethra , before urethra empties to penis

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64
Q

what does the bulbourethral gland secrete ?

A

a clear substance in sexual arousal which helps lubricate the urethra for sperm to pass

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65
Q

male accessory glands incude

A

seminal vesicles, prostate glands and bulbourethral glands

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66
Q

what happens at 5th month gestation ?

A

oogenia divide to give rise to 6 to 7 million primary oocytes

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67
Q

each ooycte is surrounded by ?

A

Granulosa cells

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68
Q

primary oocyte +granulosa cell =

A

primordial follicle

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69
Q

by birth how many primordial follicles ?

A

2 million ( potential ovum women have for lifetime

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70
Q

what happens when follicles begin to develop?

A

structure will turn into a primary follicle which will either release ova or undergo atresia ( turn into scar tissue )

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71
Q

before puberty all primary follicles ?

A

go through atresia

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72
Q

After puberty , only about how many follicles will mature ?

A

400 primary follicles will mature and release ova

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73
Q

what is menopause ?

A

pool of eggs is exhausted and womens reproductive capacity ceases

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74
Q

why will the primary follicle get larger ?

A

due to cytoplasmic materials that are necessary for early embryonic development

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75
Q

what happens prior to ovulation ?

A

primary oocyte undergoes first meiotic division to create 2 daughter cells each with 23 chromosomes

76
Q

majority of cytoplasm will ?

A

go to one of the daughter cells which will become the secondary oocyte and other daughter cell will degenerate ( first polar body )

77
Q

secondary oocyte is released when

A

in ovulation

78
Q

what happens if sperm fertilizes egg ?

A

second meiotic division will take place in which 23 single stranded chromosomes form second polar body
23 remaining chromosomes combine with 23 from sperm ?

79
Q

what is the ovarian cycle ?

A

occurs in the ovaries and prepares for ova to release

80
Q

what is the uterine cycle ?

A

prepares the uterus for implantation

81
Q

at the onset of puberty ovarian cycle will alternate between 2 phases ?

A

the follicular phase ( preps mature egg),
luteal phase (prepares the reproductive tract for possible implantation)
cycle will last 28 days

82
Q

follicular phase takes place when ?

A

in the first 14 days of the ovarian cycle

83
Q

stage 1 in follicular phase

A

proliferation of granulose cells in primary follicle , which will divide to form several layers around the oocyte

84
Q

Stage 2 follicular phase

A

granulosa cells secrete glycoproteins which form thick extracellular matrix which surrounds oocyte and separates it from granulosa cells

85
Q

ovarian connective tissues cells surround ?

A

granulosa cells with layer of thecal cells

86
Q

thecal cells+ granulosa cells =

A

follicular cells

87
Q

development of primary follicle is due to ?

A

influence of FSH and estrogen

88
Q

stage 3 follicular phase

A

follicle enlarges and becomes a secondary follicle which an now secrete estrogens ( mostly estradiol )

89
Q

secondary follicle develops from?

A

FSH and estrogen

90
Q

stage 4 follicular phase

A

fluid filled cavity ( Antrum ) is formed within the granulosa cells - expansion of Antrum increases size of the follicle as it matures and estrogens secretion increases

91
Q

stage 5 follicular phase

A

one follicle will develop faster than others into mature follicle by 14 days of cycle
mature follicle , oocyte has undergone its first meiotic division to become secondary oocyte

92
Q

stage 6 follicular cycle

A

ovulation will occur around day 14 under the influence of LH and FSH

93
Q

what happens when ovum is released

A

ovarian follicle will rupture to release ovum in abdominal cavity and adoral fluid will push ovum into oviduct

94
Q

end of follicular phase =

A

when ovum is released

95
Q

Luteal phase takes place ?

A

during the last 14 days of the ovarian cycle

96
Q

stage 1 luteal phase

A

ovum has been released , remaining follicular cells go through luteinization to form corpus luteum which produces estrogen and progesterone

97
Q

stage 2 luteal phase

A

If in the 14 days the ovum is not fertilized and implanted , the corpus luteum will degenerate into the corpus albicans ( scar tissue ) which signals the end of the ovarian cycle and follicular phase will begin again

98
Q

FSH and estrogen are needed because ?

A

early stimulation of follicular development and the formation of the secondary follicle

99
Q

LH is needed for ?

A

estrogen production

100
Q

actions of the LH surge

A

1) stops estrogen synthesis by follicular cells
2) reinitiates meiosis in oocyte
3) triggers release of local factors that increase swelling of follicle ,weakens wall
4) differentiates the follicular cells into luteal cells

101
Q

in follicular phase , anterior pituitary releases LH as?

A

circulating estrogen inhibits actions of GnRH on FSH secreting cells of the anterior pituitary

102
Q

estrogen will ?

A

continue to rise and will exert a positive feedback action on anterior pituitary to cause a surge LH secretion

103
Q

in luteal phase

A

Lh will continue to maintain the corpus luteum

104
Q

corpus luteum will begin secreting ?

A

large amounts of progesterone to prepare to for possible pregnancy

105
Q

what does progesterone do ?

A

causes changes in the uterine lining to prepare for potential implantation of embryo to establish pregnancy

106
Q

what happens if no implantation ?

A

rapid degeneration of the corpus luteum and results in rapid drop of circulating progesterone

107
Q

Uterine/ menstrual cycle lasts ?

A

28 days in which the uterus is being prepared for possible implantation of fertilized ovum

108
Q

the 2 layers of the uterus are :

A

myometrium ( outer layer and smooth muscle )

endometrium ( inner lining that is highly vascularized and have many glands )

109
Q

how will estrogen effect the 2 layers ?

A

stimulates the growth of both endometrium and myometrium

- causes expression of progesterone receptors in the endometrium

110
Q

how will progesterone act on endometrium ?

A

transforms lining to be suitable for implantation of fertilized ovum
- reduces the contractibility of uterus to further enhance implantation and embryo development

111
Q

menstrual phase of the uterine cycle

A

endometrial growth ceases with end of luteal phase

-decrease in estrogen and progesterone results in local release of prostaglandins

112
Q

what is the role of prostaglandins ?

A

constrict blood supply to the endometrium and cause the myometrium to rythmically contract
- endometrial lining will shed and is excreted from vagina

113
Q

proliferative phase of menstrual cycle

A

menstrual flow ceases and coincides with later stages of the ovarian follicular phase , cells of the endometrium being to proliferate with the help of estrogen where there is growth of glands until lining is 3-5 mm thick

114
Q

where does ovulation occur ?

A

in the proliferative phase in which the ovum leaves ovary and travels to the uterus

115
Q

Secretory Phase of menstrual cycle :

A

begins as the corpus luteum begins to form and the beginning of the ovarian luteal phase

116
Q

What happens in the secretory phase ?

A

large amounts of progesterone and estrogen convert the The endometrium into highly vascularized and glycogen filled tissues needed to support early embryo —> ovum is in the uterus

117
Q

what happens if no implantation ?

A

corpus luteum degrades and triggers next menstrual cycle

118
Q

endometriosis

A

when the endometrium grows outside of the uterus and grows over the ovaries , Fallopian tubes and connective tissues

119
Q

what is the problem with endometriosis ?

A

bleeding can’t escape, cysts often develop endometriomas near ovaries and develop scar tissues

120
Q

what happens at menopause ?

A

no more viable primary follicles in ovaries and follicular growth stops where the ovarian and uterine cycles cease, will see a dramatic decrease in estrogen secretion , this will impact cardiovascular and skeletal systems

121
Q

estrogen is linked to?

A

building strong bones through the inhibition of osteoclast activity —-> after menopause could develop osteoporosis because osteoclast activity increases

122
Q

Male sex act:

A

involves erection and ejaculation

123
Q

erection is when :

A

penile tissues fill with blood allowing penis to become rigid and entry to vagina

124
Q

erectile tissue is made of :

A

3 columns of sponge -like vascular spaces known as corpora cavernosa

125
Q

what is the erection reflex ?

A

initiated through thought about sex / stimulation of mechanoreceptors in the glans of penis ( head) and is a spinal reflex in lower spinal cord

126
Q

what are the 3 actions of erection reflex

A

1- inhibiting the sympathetic supply to the penile arterioles ( removes the tonic vasoconstrictor actions of sympathetic nervous system )
2- activates the parasympathetic supply to the penile arterioles to cause vasodilation
3- activates parasympathetic supply to the bulbourtehral gland to secrete mucous for lubrication

127
Q

erectile dysfunction :

A

the inability to main erection rigid enough for sex

128
Q

ejaculation is:

A

a spinal reflex, mediated by the same stimuli for erection

129
Q

2 stages of ejaculation

A

1 emission and 2 expulsion

130
Q

step 1 emission in ejaculation :

A

increased sympathetic activity causes smooth muscle to contract in the prostate , reproductive ducts and seminal vesicles

131
Q

order of fluids delivered to urethra

A

1 prostatic fluid , 2 sperm , 3 seminal vesicle fluid ( sphincter contracts to stoop urine from coming out)
all 3 together make semen

132
Q

step 2 ejaculation : expulsion

A

filling of the urethra with semen triggers the skeletal muscles at the base of the penis , which increases the pressure and forcibly expels semen

133
Q

male sexual response cycle consists of :

A

excitement phase, plateau phase, orgasmic phase, and resolution phase

134
Q

1) excitement phase of sexual response cycle

A

heightened sexual awareness and erection

135
Q

2)plateau phase of sexual response cycle

A

generalized response of increased heart rate , blood pressure and respiratory rate

136
Q

3)orgasmic phase of sexual response cycle

A

includes ejaculation and physical and emotional response

137
Q

4) resolution phase

A

return of the body to pre arousal phase

138
Q

refractory period after sex

A

sexual stimulation can’t trigger erection

139
Q

female sexual response cycle : 1 excitement

A

stimulation of clitoris , activates spinal reflex which activates spinal reflex that activates parasympathetic system to dilate arterioles of vagina - clitoris becomes erect ,

140
Q

dilation of arterioles in vaginal wall cause :

A

vasoconstriction of capillaries —> forces fluid out of vagina
fluid from bartholins gland acts as lubricant for intercourse

141
Q

plateau phase female sexual response cycle

A

uterus raises upward lifting cervix and enlarging upper portion of vagina ( creating space for ejaculated semen , heart rate and blood pressure increase

142
Q

orgasm phase female sexual response cycle

A

sexual response culminates in orgasm , sympathetic impulses lead to rhythmic contractions of the pelvic musculature ( no female ejaculation )

143
Q

resolution female sexual response cycle

A

heart rate , blood pressure and breathing go back to normal

144
Q

what is fertilization ?

A

the joining of a female egg and a male sperm which takes place in the ampulla of the Fallopian tube

145
Q

the stages of fertilization :

A

ovum transport to the oviduct, sperm transport to oviduct fertilization

146
Q

1) ovum transport to oviduct

A

end of follicular phase , ovum is released into abdominal cavity fimbrae guide ovum into oviduct
- ovum gets to the ampulla through peristaltic contractions

147
Q

2) sperm transport to oviduct

A

sperm must pass through cervical canal which contains large amounts of mucous

148
Q

large amounts of estrogen at ovulation will :

A

cause the mucous the be thin enough that sperm can pass ( only a few days a month )

149
Q

what are the role of contractions?

A

myometrial contractions help propel sperm to the oviducts and peristaltic contractions move sperm to ampulla

150
Q

3) fertilization

A

sperm have to penetrate the corona radiata( enzyme on sperm head ) and the zone pellucida ( bind to it )

151
Q

plasma membrane of sperm contain

A

protein called fertilin which binds to ZP3 glycoprotein on outer layer of zone pellucida –> binding causes the release of acrosomal enzymes that digest the zone pellucida

152
Q

First sperm reaches the ovum

A

will fuse with ovum membrane and the head will enter and tail is left behind and triggers release of intracellular Ca+

153
Q

actions of Ca+

A

1 causes inactivation of ZP3 so no further sperm can bind

2) hardens the zone pellucida so no more sperm can penetrate
3) triggers second meiotic division in ovum

154
Q

sperm and and ovum nuclei fuse to form

A

zygote 1 hour after fertilization

155
Q

zygote will transform into

A

morula ( solid ball of cells ) in which progesterone allows it to move to uterus and will be nourished by the endometrial secretions

156
Q

within week of ovulation,

A

endometrium is suitable for implantation and morula has transformed to blastocyst where the fetus will arise

157
Q

implantation is finished when

A

entire blastocyst is completely buried in endometrium

158
Q

identical twins occur when

A

single egg is fertilized with sperm cell and forms q zygote which divides into 2 separate embryos

159
Q

Fraternal twins occur when

A

after 2 eggs are released from the ovary , both eggs are fertilized by 2 different sperm cells which are implanted in uterine wall at same time

160
Q

monozygotic =

dizygotic=

A

identical , fraternal

161
Q

ecotopic pregnancy

A

fertilized egg implants outside main uterine cavity ( usually in fallopian tubes but can happen in cervix or abdominal cavity

162
Q

Placenta

A

specialized organ which will sustain embryo for duration of pregnancy - endometrial glycogen are only sufficient for a few weeks for nutrients

163
Q

4 weeks into pregnancy embryo is

A

embryo is completely embedded in endometrial tissues at implantation site and tissue will contribute to placenta forming

164
Q

at 8 weeks pregnant , placenta is

A

not fully developed but well established and operational by week 5 after implantation

165
Q

at 12 weeks , placenta is ?

A

completely developed to support embryo

166
Q

at 40 weeks placenta is ?

A

will continue to grow in pregnancy and acts as digestive, respiratory and kidneys for the fetus , exchange of nutrients and blood takes place in placenta

167
Q

what is unique about the placenta

A

does not need any external control to secrete hormones

168
Q

hCG is the ?

A

first hormone that placenta secretes as it develops and is similar to LH structurally and functionally ( can bind to LH )

169
Q

role of hCG ?

A

maintains the corpus luteum which allows it to get larger and become the primary source of estrogen and progesterone until the placenta is able to take over at 10 weeks

170
Q

hCG will decrease when

A

the placenta secretes sufficient estrogen and progesterone and hCG will stay at a low stable level

171
Q

hCG and male fetuses ?

A

stimulates the precursor leading cells to secrete testosterone needed for masculinization of reproductive tract

172
Q

hCG is associated with

A

morning sickness and can be used as marker for pregnancy tests ( found in urine )

173
Q

fetal adrenal cortex secretes DHEA into fetal blood which,

A

placenta takes it and converts it to estrogen which secretes into maternal blood —-> mainly estradiol

174
Q

estrogen secreted by ovaries is primarily

A

estradiol

175
Q

why is the corpus Luteum the primary source of estrogen in the first trimester ?

A

takes time for the fetal adrenal glands to secrete sufficient DHEA

176
Q

what is estrogens role in pregnancy ?

A

increase the size of the myometrium as the uterus expands and to make sure the muscle mass is sufficient for child birth

177
Q

estradiol promotes

A

the ducts development in the mammary glands

178
Q

how long does intake for the placenta to take over progesterone production from the corpus leuteum ?

A

10 weeks

179
Q

circulating levels of progesterone will increase as

A

placenta continues to grow throughout entire pregnancy

180
Q

what is progesterones role in pregnancy

A

maintains the cervical mucous plug, stimulates milk , suppresses uterine contraction

181
Q

parturition

A

requires dilation of cervical canal where fetus will passs

182
Q

when baby is getting ready to come out

A

there is an increase in estrogen , to prepare cerix and uterus for delivery

183
Q

first role of estrogen in birth

A

late surge allows for myometrium smooth muscle cells to synthesize connections and form gap junctions sp myometrium can contract smoothly

184
Q

second role of estrogen in birth

A

increases the synthesis of oxytocin receptors in myometrium

185
Q

positive feedback of oxytocin

A

estrogen-stimulated increase in oxytocin receptors , high levels of estrogen increase uterine responsiveness to oxytocin , to the point where uterine contractions will begin and initiates the positive feedback cycle ***

PHGY 216 (2 decks)

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