CH 28 Flashcards
(245 cards)
1
Q
what are the reproductive systems specialized to do?
A
produce, nourish, and deliver haploid gametes
2
Q
what are the three categories of reproductive structures?
A
- gonads
- ducts
- supporting structures
3
Q
what do the gonads do?
A
produce gametes, secrete hormones
4
Q
what do the reproductive ducts do?
A
store and deliver gametes and sexual secretions
5
Q
what do the reproductive supporting structures do?
A
help in transport of gametes
6
Q
what is urology?
A
branch of medicine dedicated to studying the urinary system, also encompasses disorders of the male genital system
7
Q
what is the scrotum?
A
loose skin pouch and adipose CT containing the testes
8
Q
what composes a testicle?
A
scrotum + testis
9
Q
what is the raphe of the testes?
A
the median seam that divides scrotum into 2 compartments and smooth muscle fibres forming dartos muscle
10
Q
what is the dartos muscle?
A
smooth muscle in the scrotum
11
Q
what is the cremaster muscle?
A
fibres of the internal oblique muscle that descend into the scrotum around each testis
12
Q
what do the cremaster and dartos muscle do?
A
contract in cold temperatures, pulling testings superiorly and posteriorly toward pelvic cavity
13
Q
what is the benefit of the scrotum wrinkling in cold temps?
A
provides cover and insulation for the testes
14
Q
what is the benefit of the testes being outside the pelvic cavity?
A
ensures temps remains constant for spermatogenesis
15
Q
what is the optimal temperature for spermatogenesis to occur?
A
35°C
16
Q
where do the testes develop during fetal development?
A
near kidneys, they descend during 7th month of fetal development
17
Q
when and through where do the testes descend?
A
during 7th month of fetal development through inguinal canals
18
Q
what does the CT layer covering the testes do?
A
divides the testes into lobules
19
Q
what does each testis lobule contain?
A
1-2 coiled seminiferous tubules
20
Q
what are seminiferous tubules?
A
site of spermatogenesis in the testes
21
Q
what are germ cells?
A
reproductive stem cells that divide via meiosis
22
Q
what are spermatogonia?
A
undifferentiated, somatic cells that are inactive during childhood and begin maturation at puberty
23
Q
where are the most mature cells found in the seminiferous tubules?
A
found close to the lumen of tubules
24
Q
what are nurse cells?
A
sheet of cells joined by tight junctions found in the seminiferous tubules
25
what cells form an impermeable barrier to blood?
nurse cells
26
what is the function of the blood-testis barrier?
sperm express foreign antigens, so the barrier prevents immune system from recognizing and destroying the sperm
- also prevents inflammation in the testes
27
what do the nurse cells do?
- **form blood-testis barrier**
- provide nutrients to spermatogonia
- phagocytize extra spermatids
- **control release of mature sperm to lumen**
- release inhibin and control FSH effects and testosterone on testes
28
what are interstitial endocrine cells?
cells between seminiferous tubules in the testes
29
what do the interstitial endocrine cells do?
secrete androgens such as testosterone
30
what are androgens?
hormones that support secondary sexual characteristics and libido
31
what is libido?
sex drive
32
spermatogonium: diploid or haploid?
2n (diploid)
33
primary spermatocyte: diploid or haploid?
2n (diploid)
34
secondary spermatocyte: diploid or haploid?
n (haploid)
35
spermatid: diploid or haploid?
n (haploid)
36
why is there no intervening interphase between Meiosis I and Meiosis II?
DNA is already replicated, don't need to go through S phase again
37
what happens during meiosis I?
homologous chromosomes separates into 2 HAPLOID daughter cells
38
what happens during meiosis II?
sister chromatids of replicated chromosomes are separated
39
how long does spermatogenesis occur?
65-75 days
40
where does spermatogenesis start?
at basement membrane of seminiferous tubules with spermatogonia (2n)
41
how do primary spermatocytes form?
when some 2n spermatogonia break loose from basement membrane of seminiferous tubules and squeeze through blood-testis barrier into tubule lumen
42
how do secondary spermatocytes form?
each primary spermatocyte (2n) undergoes interphase (DNA replication) then undergoing Meiosis I
43
how do spermatids form?
each secondary spermatocyte undergoes Meiosis II
44
do sperm undergo cytokinesis during meiosis?
NO! heads remain connected by cytoplasmic bridges
45
what may be a reason why sperm remain connected by cytoplasmic bridges?
genes on X chromosome may be required for regular development, so sperm w/o an X chromosome may not develop properly if no cytoplasmic bridge
46
what is spermiogenesis?
full maturation of spermatids into sperm
47
what happens during spermiogenesis?
- formation of acrosome
- formation of flagellum
- replication of mitochondria
48
what is an acrosome?
vesicle full of digesting enzymes
49
how do sperm form?
spermatids undergo spermiogenesis
50
what is spermiation?
process of nurse cells releasing sperm into lumen of seminiferous tubules
51
why do sperm need help from nurse cells during spermiation?
sperm cannot swim yet, not motile
52
what enzymes can be found in the acrosome?
- hyaluronidase
- proteases
53
what does hyaluronidase do?
breaks down hyaluronan in extracellular matrix of cells (like the ones surrounding the oocyte)
54
what do proteases do?
catabolize proteins (like the ones surrounding the oocyte)
55
what are four parts of a sperm's tail?
- neck
- middle piece
- principal piece
- end piece
56
what is the neck of the sperm's tail?
contains centrioles that grow flagellar microtubules
57
what is the middle piece of the sperm's tail?
contains mitochondria required for swimming
58
what is the principal piece of the sperm's tail?
most of the flagellar tail of the sperm
59
what is the end piece of the sperm's tail?
tapered terminus of the flagellum
60
what happens to GnRH levels during puberty?
increases, acts on anterior pituitary's gonadotrophic cells to release FSH and LH
61
what does LH stimulate in males?
stimulates **interstitial endocrine cells** to release testosterone
62
what does testosterone do to GnRH levels?
exerts negative feedback on both hypothalamus and gonadotrophic cells to decrease GnRH and LH secretion
63
where is dihydrotestosterone made?
in prostate gland and external genitals
64
how is dihydrotestosterone made?
in prostate and external genitals:
testosterone binds enzymes (e.g. 5-alpha-reductase), forming dihydrotestosterone
65
what does dihydrotestosterone do?
support development of external genitals
66
what does testosterone do in utero?
support brain development
67
what do both DHT and testosterone do?
- bind same receptors on target cells
- support male secondary sex characteristics
- responsible for libido in both sexes
- stimulate anabolism
68
what are some male secondary sex characteristics?
- pattern of hair growth
- sebaceous gland activity
- muscle and skeletal growth
- deepening of voice
69
high testosterone levels exert negative feedback on what organ?
hypothalamus - decreasing GnRH production - decreases LH release - decreases testosterone synthesis
70
what is the stimulus for the negative feedback of testosterone on the hypothalamus?
**HIGH** levels of testosterone in blood
71
what are the receptors for the negative feedback of testosterone on the hypothalamus?
hypothalamus's neurosecretory cells
72
what is the control centre for the negative feedback of testosterone on the hypothalamus?
anterior pituitary's gonadotrophic cells
73
what are the effectors for the negative feedback of testosterone on the hypothalamus?
interstitial endocrine cells
74
what is the response for the negative feedback of testosterone on the hypothalamus?
decrease in blood testosterone levels
75
how do nurse cells push sperm through seminiferous tubules?
they produce fluid that exerts pressure on mature sperm to push them
76
what is the stimulus for spermiation?
complete cytokinesis of the spermatids
77
what is the path sperm take to get to epididymis?
seminiferous tubules → rete testis → efferent ductules duct of epididymis → epididymis
78
what is the rete testis?
system of ducts within each testis
79
what is the epididymis?
coiled organ that wraps each testis superiorly and posteriorly
- where sperm matures and develops motility
80
what is the histology of the duct of epididymis?
lined by pseudostratified columnar epithelium, surrounded by smooth muscle and CT
81
what does the apical surface of the duct of epididymis's epithelium consist of?
stereocilia: microvilli that absorb dead/damaged sperm
82
how long do sperm gain the ability to be motile?
14 days in epididymis
83
how does epididymis move sperm itno vas deferens to prepare semen for ejaculation?
during sexual arousal, epididymis performs **peristaltic contractions** pushing sperm into vas deferens
84
what is the function of the vas deferens?
performs peristaltic contractions to facilitate sperm delivery during ejaculation
also stores and absorbs old sperm
85
what is the ejaculatory duct?
duct formed by fusion of ampulla of vas deferns and the ducts from the seminal gland
86
what goes through the ejaculatory duct?
sperm + seminal fluid
87
what is seminal fluid?
alkaline fluid containing fructose, prostagandins, and clotting proteins
- contributes 60% of semen volume
88
what does alkaline fluid in seminal fluid do?
neutralizes acidity of vagina
89
what does fructose in seminal fluid do?
used by sperm for ATP production
90
what does prostalgandin in seminal fluid do?
unknown
91
what do clotting proteins in seminal fluid do?
allows semen to coagulate in vagina, prevents sperm from falling out
92
what is prostatic fluid?
acidic secretion w/ pH 6.5 containing citric acid, proteolytic enzymes, acid phosphatase, and seminalplasmin
- contributes to 25% of semen volume
93
what does citric acid in prostatic fluid do?
used by sperm in Krebs cycle to generate ATP
94
what do proteolytic enzymes in prostatic fluid do?
catabolize clotting proteins in semen, contributing to liquefaction
(especially prostate-specific antigen)
95
what is prostate-specific antigen?
proteolytic enzyme in prostatic fluid that catabolizes clotting proteins in semen
96
what does acid phosphatase in prostatic fluid do?
unknown
97
what does seminalplasmin in prostatic fluid do?
antibiotic that decreases bacterial load in semen, and maybe, in female vagina
98
what are the bulbourethral glands?
pea-sized glands inferior to prostate and lateral to membranous urethra that secrete alkaline fluid and mucus
99
what does alkaline fluid secreted by the bulbourethral glands do?
protect sperm from acidic urine in male urethra
100
what does mucus secreted by bulbourethral glands do?
lubricates spongy urethra to decrease sperm damaged during ejaculation
101
what is semen?
fluid containing secretions from seminal glands, prostate gland, bulbourethral glands, and sperm
102
what is the composition of semen?
- alkaline (pH 7.2-7.7)
- milky appearance
- 2.5-5mL/ejaculation
- 50-150million sperm/mL
103
why does semen coagulate ~5min after ejaculation?
because of clotting proteins
104
why does semen become more liquid after 10-20 minutes post-ejaculation?
proteolytic enzymes from prostate catabolize clotting proteins
105
why is liquefaction of semen important?
liquefaction allows release of sperm so they can swim away, facilitates sperm motility
106
what three cylinders of tissue is the body of the penis made out of?
1. deep dense CT
2. intermediate corpora cavernosa penis
3. corpus spongiosum penis
107
what is the function of the corpus spongiosum?
contains the spongy urethra, keeps it open during ejaculation
108
what is erectile tissue?
tissue composing the penis that engorge with blood during sexual arousal
109
what is the glans penis?
distal acorn-shaped end of the penis that may be covered by the prepuce
110
what is the bulb of the penis?
the expanded base at the point of the attachment to the pubis
- attached to muscles that facilitate both urination and ejaculation
111
what is the root of the penis?
attaches the penis to the rest of the pelvis, contains the bulb of the penis
112
what do the ligaments of the root of the penis do?
suspend the penis and support its weight
113
what is an erection?
enlargement and stiffening of the penis, usually during sexual arousal
114
what is the stimulus for erections?
- mechanical stimulation of the penis
- erotic thoughts, sights, smells, sounds
115
what division of the ANS is responsible for erections?
parasympathetic system
116
what is the control centre for erections?
sacral spinal cord
117
what are the effectors for erections?
parasympathetic motor neurons from the sacral spinal cord release nitric oxide to **blood vessels in erectile tissues**, stimulating vasodilation and increasing perfusion to penis
- also relaxes **smooth muscles**, widening sinuses
118
how are erections maintained?
increased perfusion in erectile tissues **compresses veins**, slowing blood draining from penis
119
why does the internal urethral sphincter close during ejaculation?
to prevent urine from mixing with semen and prevents semen from entering urinary bladder
120
how do components of semen move into spongy urethra prior to ejaculation?
through peristaltic contractions in ducts
121
what is emission?
Propulsion of sperm into the urethra due to peristaltic contractions of the ducts of the testes, epididymides, and ductus deferens as a result of sympathetic stimulation
122
where is the control centre for ejaculation?
in the lumbar spinal cord
123
what division of the ANS is responsible for ejaculation?
sympathetic nervous system
124
what are the effectors for ejaculation?
contraction of the **ducts and urethra** and **muscles of the penis**
- contraction of the **internal urethral sphincter**
125
what is ejaculation?
lumbar, sympathetic reflex; powerful expulsion of semen
126
what happens when sexual stimulation has ended in males?
less nitric oxide is released by parasympathetic motor neurons, arterioles constrict, pressure on veins is relieved, and penis drains of blood and becomes flaccid
127
what is gynecology?
the medical study of the female genital system
128
what hormones do the ovaries produce?
- estrogen
- progesterone
- inhibin
- relaxin
129
what anchors the ovaries to the uterus?
ovarian ligaments
130
what holds the ovaries in place in the pelvic cavity?
the broad ligament
131
what is the broad ligament?
fold of the peritoneum that holds the uterus and ovaries in place in the pelvic cavity
132
what is oogenesis?
production of mature **ova** in the ovaries
133
when does oogenesis occur in a female's lifespan?
before birth
134
what is atresia?
degeneration and reabsorption of an ovarian follicle before it fully matures and ruptures
135
what is the ovarian mesothelium?
serous membrane that wraps the ovaries, supported by dense irregular CT
136
what is the ovarian cortex?
outer layer of the ovaries containing the ovarian follicles
137
what is the ovarian medulla?
centre of the ovary consisting of CT
138
what do the ovarian follicles contain?
oocytes
139
what are follicular cells?
singular layer of cells that surround oocytes to form a follicle
- divides and differentiates into granulosa cells
- nourishes the developing ova
140
what are granulosa cells?
multiple layers of cells that surround oocytes to form a follicle
- nourishes the developing ova
141
at what time of a female's life do surviving oogonia turn into primary oocytes?
during fetal development, where the oogonia start meiosis I but is arrested at prophase I before puberty
142
what kinds of follicles can be found in a female before puberty?
primordial follicles, which contain primary oocytes
- no primary or secondary follicles before puberty
143
what happens to follicles when a female reaches puberty?
once per month, FSH and LH stimulates follicles several follicles to mature
144
what are primary follicles?
what primordial follicles grow into after being stimulated by LH and FSH
145
what is the zona pellucida?
a layer of glycoprotein that a primary ovarian follicle will start to accumulate
146
what are theca folliculi?
layer of cells found in the follicular cortex
147
what happens to the theca folliculi when a primary follicle becomes a secondary follicle?
differentiates into 2 layers: theca interna and theca externa
148
what is the theca interna?
cuboidal cells of a secondary follicle that secrete androgens
149
what is the theca externa?
stromal CT layer of a secondary follicle
150
what happens to the oocyte when a secondary follicle becomes a tertiary follicle?
the primary oocyte completes meiosis I, forming a first polar body and a secondary oocyte
151
what happens to the oocyte during ovulation?
secondary oocyte erupts from the follicle
152
when does the oocyte complete meiosis II?
at fertilization, producing a second polar body and an ovum
153
within which ligament are the uterine tubes found?
the broad ligament
154
what do the uterine tubes do?
provide path for oocytes and fertilized ova to reach uterus
155
what are the fimbriae of the uterine tubes?
finger-like processes of the uterine tubes that attach to ovaries
156
what is the infundibulum of the uterine tubes?
distal arc where fimbriae of the uterine tubes attach to
157
what is the ampulla of the uterine tubes?
long, wide portion of the uterine tubes where fertilization usually occurs
158
what is the isthmus of the uterine tubes?
thin, short attachment of the uterine tubes to the uterus
159
why is the mucosa of the uterine tubes ciliated?
ovum are not motile unlike sperm, so the mucosa acts as conveyor belt
160
what are peg cells?
nonciliated microvillous simple columnar epithelium found in mucosa of the uterine tubes, microvilli secrete nutrients
161
what is the muscular layer of the uterine tubes?
thick inner circular layer
thin outer longitudinal layer
162
what does the muscular layer of the uterine tubes do?
perform peristalsis to move ova
163
what happens in the uterine tubes during ovulation?
- fimbriae sweep 2° oocytes into uterine tubes
- fertilization usually occurs within ampulla
164
what is fertilization?
sperm (n) + ovum (n) = zygote (2n)
165
why is the uterus smaller in nonpregnant and menopausal females?
lower hormone levels (estrogens + progesterone)
166
what is the internal os?
opening btwn cervix and uterus
167
what is the external os?
opening btwn cervix and vagina
168
what are round ligaments?
bands of dense irregular CT btwn broad ligaments that connect uterus to external genitalia
169
what is the perimetrium?
serous membrane of the uterus (visceral peritoneum)
170
what is the myometrium?
three layers of muscle
- thick intermediate circular layer
- thin outer and inner longitudinal layers
171
what are the layers of the endometrium?
- compact layer
- functional layer
- basal layer
172
what is the compact layer?
ciliated + nonciliated epithelium w/ thick underlying areolar CT containing parts of uterine glands
173
what is the functional layer?
thick layer of areolar CT containing most of the uterine glands
174
what is the basal layer?
thick layer of areolar CT contain parts of the uterine glands AND **stem cells that replenish overlying layers**
175
what happens to the endometrial layers during menstruation?
the compact and functional layers are sloughed off
176
describe the blood supply of the uterus
iliac arteries → uterine arteries → arcuate arteries → radiate arteries → straight/spiral arteries
177
what are straight arterioles?
branch of radiate arteries that service the basal layer of the endometrium
178
what are spiral arterioles?
branch of radiate arteries that service the functional layer of the endometrium, blood flow varies during menstruation
179
what is the epithelium of the vagina?
nonkeratinized stratified squamous epithelium
180
why does the vagina contain a lot of glycogen?
glycogen decomposes into organic acids that lower pH
181
what is the function of the vagina's rugae?
permits vagina to change in size
182
what is the function of the vagina?
- receives penis during coitus
- passageway for fetus to be delivered during labour
183
what is the muscular layer of the
inner circular layer
outer longitudinal layer
184
what is the function of the muscular layer of the vagina?
stretches during intercourse and childbirth
185
what is the adventitia of the vagina?
areolar CT, anchors vagina to other pelvic organs
186
what is the vulva?
all the external female genitalia
- mons pubis
- labia major + minora
- vestibule
187
what is the mons pubis?
mound of adipose tissue, pubic hair, and skin that pads pubic symphysis
188
what is the labia majora?
fatty skin folds homologous to scrotum, contains sebaceous and sudoriferous glands and hair
189
what is the labia minora?
smaller skin folds medial to labia majora, have less fat and sudoriferous glands
- contains sebaceous glands
190
what is the function of the labia minora's sebaceous glands?
secretes antimicrobial substances and some lubrication during intercourse
(homologous to spongy urethra)
191
what is the clitoris?
structure located at anterior union of labia minora made of erectile tissue and contains nerves + blood vessels
- may be covered by prepuce of clitoris
192
does the clitoris become erect?
yes, erectile tissue of clitoris engorges with blood and increases in size during sexual arousal
193
what structures are found in the vestibule?
- external urethral orifice
- hymen
- vaginal orifice
194
what are the paraurethral glands?
laterally borders the external urethral orifice, secretes mucus
(homologous to prostate)
195
what is the hymen?
thin membrane that may or may not cover the vaginal orifice
196
what are the greater vestibular glands?
laterally borders the vaginal orifice, secretes mucus
197
what is the major contribution to lubricating the female's genital canal during sexual arousal?
higher perfusion to areas → greater fluid filtered from capillaries
- cervical mucus and glandular secretions only play minor role in lubrication
198
what is the bulb of the vestibule?
columns of erectile tissue within the walls of the labia that engorge with blood during sexual arousal and produce pressure on penis during coitus
(homologous to corpus spongiosum penis and bulb of the penis)
199
what is the perineum?
area between the vulva and the anus in females
200
what are mammary glands?
modified sudoriferous glands in breasts that secrete milk
- suspended by ligaments that slacken with age/impact
201
what are lactiferous ducts?
openings found in nipples formed from the merging of mammary ducts that permit milk to flow from mammary glands
202
what are areolae?
areas found around the nipples that contain sebaceous glands
203
what secretes breast milk?
glandular alveoli found in the mammary glands
204
what are myoepithelial cells?
contractile epithelial cells that surround glandular alveoli, permits milk to flow into mammary ducts
205
describe passage of milk out of breasts
glandular alveoli → mammary ducts → lactiferous sinuses → lactiferous ducts
206
what hormone stimulates milk production?
prolactin
207
what hormone stimulates milk ejection?
oxytocin
208
what is the stimulus for the let-down reflex?
baby suckling on breasts
209
what are the control centres for the let-down reflex?
- excites posterior pituitary, stimulates oxytocin secretion
- inhibits the inhibited prolactin cells of the anterior pituitary, stimulates prolactin secretion
210
what are the effectors for the let-down reflex?
- increased oxytocin secretion → mammary gland contraction
- increased prolactin secretion → increased milk production
211
what is the female reproductive cycle?
cycle encompassing events that occur monthly from puberty to menopause
- includes ovarian and uterine cycles, and hormones from ant. pit.
212
what does GnRH do?
Gonadotropin-Releasing Hormone from the hypothalamus stimulates gonadotrophic cells in ant. pit. to secrete FSH and LH
213
what does LH do to theca cells?
stimulates them to secrete androgens
214
what does FSH do to granulosa cells?
stimulates them to uptake androgens from theca cells to convert them into estrogen
215
what does LH do in the middle of the female reproductive cycle?
- promotes ovulation
- stimulates formation of corpus luteum by degeneration of leftover follicular tissue
216
what hormones do the corpus luteum make?
- estrogens
- progesterone
- inhibin
- relaxin
217
what do estrogens do?
- Support development and maintenance of secondary sexual characteristics
- Promote anabolism, especially bone growth > works synergistically with
GH
- Lowers blood cholesterol
- Exert negative feedback on GnRH synthesis
218
what are some secondary female sexual characteristics?
- fat accumulation in breasts, abdomen, mons pubis, hips
- widening of pelvis
- pubic and body hair growth
219
what does inhibin do?
inhibits FSH secretion
220
what does relaxin do?
relaxes pubic symphysis
221
what are the four phases of the female cycle?
- menstrual (d. 1-5)
- preovulatory (d. 6-13)
- ovulatory (d.14)
- postovulatory (d.15-28)
222
what occurs in the ovaries during the menstrual phase?
- FSH promotes primary ovarian follicles to grow into secondary ovarian follicles
- one follicle becomes dominant
223
what occurs in the uterus during the menstrual phase?
low levels of estrogen and progesterone stimulate **prostaglandin** secretion that constrict spiral arterioles
- endometrial tissues die, no perfusion
- compact and functional layers sloughed off and exit out the vagina
224
what occurs in the ovaries during the preovulatory phase?
- secondary follicles secrete estrogens + inhibin, becoming a tertiary follicle
- higher estrogen levels inhibit FSH secretion, causing other follicles to degenerate
225
what occurs in the uterus during the preovulatory phase?
estrogens made by the dominant follicle stimulate stem cells in basal layer of the endometrium to undergo mitosis
- functional + compact layers replenished, including glands and spiral arterioles
- endometrium thickness is doubled
226
what occurs in the ovaries during ovulation?
- really high estrogen levels promote more GnRH release from hypothalamus → more FSH and LH (moderate lvls inhibit GnRH secretion)
- LH promotes oocyte rupture, oocyte remains surrounded by zona pellicuda
227
what occurs in the uterus during ovulation?
estrogens continue to promote endometrial thickening to prepare for possible implantation of a fertilized ovum
228
what occurs in the ovary during the postovulatory phase?
- tertiary follicle collapses (basement membrane btwn granulosa and theca cells decompose)
- corpus hemorrhagicum forms after follicular rupture
- LH promotes mixing of theca + granulosa cells → corpus luteum
- CL disappears after ~1wk w/o hCG
229
what occurs in the uterus during the postovulatory phase?
- estrogens and progesterone (secreted by CL) promote thickening, vascularization, and secretion of glycogen in endometrium
- if no fertilization, CL collapses and hormone lvls drop, initiating new menstrual phase
230
what is the chorion?
an extraembryonic layer formed by a zygote that secretes human chorionic gonadotropin ~ 8 days after fertilization
231
why does hCG prevent degeneration of the corpus luteum?
corpus luteum's secretory activity is maintained, progesterone is maintained
- don't want to menstruate embryo out
232
why is the condom effective?
only method that prevents both pregnancy and transmission of sexually transmitted infections
233
how do hormonal methods work?
synthetic estrogens or progestins that exert negative feedback on the gonadotrophic cells, decreasing FSH and LH secretion
234
how do progestin-only contraceptives work?
they thicken cervical mucus, blocking sperm from entering uterus
235
what is abortion?
the premature removal or expulsion of the products of conception from the uterus
236
what are the two types of abortion?
- hormonal/medical abortions
- surgical abortions
237
when are hormonal/medical abortions given?
mifepristone approved for administration to pregnant individuals at <9wks
238
what do hormonal/medical abortions do?
blocks progesterone receptors on endometrial lining, permitting menstruation to proceed after implantation
239
when are vacuum aspiration abortions given?
vacuum aspiration uses a vacuum device to remove layers of the endometrium up to the 16th week
240
when are dilation and evacuation abortions given?
cervix must be dilated in pregnant individuals btwn 13-16 weeks
241
when are other surgical abortions given?
btwn 16-24 weeks, other methods may be used if it is an emergency
242
who may require abortions?
- women/couples who are unintentionally pregnant
- women whose lives are endangered by pregnancy (ectopic pregnancy)
- victims of sexual assault and other sexual crimes
- women/couples who choose to terminate due to results of fetal genetic testing (fetus may not survive)
243
Twenty-three-year-old Monica and her husband Bill are ready to start a family. They are both avid bicyclists and weight-lifters who carefully watch what they eat and pride themselves on their “buff” bodies. However, Monica is having difficulty becoming pregnant. Monica hasn’t had a menstrual period for some time but informs the doctor that is normal for her. After consulting with her physician, the doctor tells Monica that she needs to cut back on her exercise routine and “put on some weight” in order to get pregnant. Monica is outraged because she figures she will gain enough weight when she is pregnant! Explain to Monica what has happened to her and why weight gain could help her achieve her goal of pregnancy.
Monica’s excessive training has resulted in an abnormally low amount of body fat. A certain amount of body fat is needed in order to produce the hormones required for the ovarian cycle. Several hormones are involved. Her amenorrhea is due to a lack of gonadotropin-releasing hormone, which in turn reduces the release of LH and FSH. Her follicles with their enclosed ova fail to develop and ovulation will not occur. In addition, synthesis of estrogens and progesterone declines from the lack of hormonal feedback. Usually a gain of weight will allow normal hormonal feedback mechanisms to return.
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The term “progesterone” means “for gestation (or pregnancy).” Describe how progesterone helps prepare the female body for pregnancy and helps maintain pregnancy.
Along with estrogens, progesterone helps to prepare the endometrium for possible implantation of a zygote by promoting growth of the endometrium. The endometrial glands secrete glycogen, which will help sustain an embryo if one should implant. If implantation occurs, progesterone helps maintain the endometrium for the developing fetus. In addition, it helps prepare mammary glands to secrete milk. It inhibits the release of GnRH and LH, which stops a new ovarian cycle from occurring.
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After having borne five children, Mark’s wife, Isabella, insists that he have a vasectomy. Mark is afraid that he will “dry up” and won’t be able to perform sexually. How can you reassure him that his reproductive organs will function fine?
The ductus deferens is cut and tied in a vasectomy. This stops the release of sperm into the ejaculatory duct and urethra. Mark will still produce the secretions from his accessory male genital glands (prostate, seminal glands, bulbourethral glands) in his ejaculate. In addition, a vasectomy does not affect sexual performance; he will be able to achieve erection and ejaculation, as those events are nervous system responses.
