Sexual development and gonads Flashcards
(302 cards)
1
Q
What kind of glands are the gonads
A
Endocrine
2
Q
What makes sperm and testosterone in males
A
Testes
3
Q
What makes ova, estrogen, and progesterone in females
A
Ovaries
4
Q
What is sexual differentiation
A
Development of specific gonads, internal and external genitalia
5
Q
What is sexual differentiation a result of
A
Y-chromosome presence of absence
6
Q
How is sex characterized
A
Genetic
Gonadal
Phenotypic
7
Q
What is genetic sex differentiation
A
Presence of Y chromosome
8
Q
What is gonadal differentiation
A
Testes vs ovaries
9
Q
What is phenotypic sexual differentiation
A
Male or female appearance
10
Q
XX
A
Female
11
Q
XY
A
Male
12
Q
What decides what sex you are
A
SRY region of Y chromosome
13
Q
When is the transcription factor for the SRY region of Y chromosome activated
A
Week 7
14
Q
What does the activation of SRY region of Y chromosome initiate
A
Development of testes
15
Q
What happens if there is no Y or there is a mutation in SRY?
A
Ovary development begins at week 9
16
Q
What is the default sex
A
Female
17
Q
What is gonadal sex
A
What type of gonad develops in response to genetics
18
Q
What chromosomes develop ovaries
A
XX
19
Q
What do the germ cells of the ovaries do
A
Produce oogonia
20
Q
What do the theca cells of the ovaries do
A
Produce progesterone and testosterone
21
Q
What do the granulosa cells of the ovary do
A
Produce progesterone and estrogen from testosterone
22
Q
What do the germ cells of the testes do
A
Produce sperm
23
Q
What do the serotonin cells of the testes do
A
Produce anti-mullerian hormone
24
Q
What do the leydig cells of the testes do
A
Produce testosterone
25
What is phenotypic sex
What phenotype develops in response to gonadal sex (hormones)
26
What is the usually phenotypic sex of someone with XX
- internal-uterus, Fallopian tubes, upper vagina
| - external-clitoris, labia, lower vagina
27
What is the usually phenotypic sex of someone with XY
- internal- epididymis, vas deferens, seminal vesicles and ejaculatory ducts
- external-penis and scrotum
28
Consider a person with an XY genotype, internal testes and normal female genitalia, what is their gonadal sex
Male
29
What is the default setting for sex
Female
30
What do you need for activation into male development
SRY
31
What two sets of ducts are present during embryonic development
Wolffian and Mullerian
32
What do ovaries develop from at week 9
Undifferentiated gonads, wolffian ducts degenerate, Müllerian ducts develop into the internal genitalia
33
What hormones are needed for external genitalia development in females
Estrogen and progesterone
34
What does SRY cause
Development of testes from undifferentiated gonads around week 6
35
What ducts are present and what ducts are destroyed in male development (SRY)
Tastes secrete and-mullerian hormone that degrades the mullarian ducts
Wolffian ducts develop into the internal genitalia due to testosterone from developing testes
36
What causes the wolffian ducts to develop into the internal genitalia of males
Testosterone from developing testes
37
Select the answer that would best describe a person with an XY genotype with an SRY mutation that renders it non functional
Intact Müllerian ducts
38
How does hormonal regulation occur
Via the hypothalamic-pituitary-gonadal axis
39
What kind of feedback loop is the hypothalamic-pituitary-gonadal axis
Negative feedback
40
Where is GnRH from
Hypothalamus
41
Where is FSH and LH from
Anterior pituitary
42
What do the gonads secret
Sex steroids and inhibin/activin
43
How are levels of sex hormones regulated
Tightly
44
When is there a large spike of sex hormones
Developing fetus
45
What hormone starts in the developing fetus at week 4
GnRH
46
When do LH and FSH rise in the developing fetus
Week 10-12
47
When do hormonal levels drop
As brith approaches
| -stays low levels until puberty
48
After birth when do hormone levels rise again
Puberty
49
After birth, which is higher, FSH or LH
FSH
50
When do GnRH levels become cyclic
As puberty approaches
- both sexes have multiple daily spikes
- increase in frequency until puberty
- then fairly regular
51
After puberty what ar the spikes like in females
Larger monthly spikes
52
After puberty what are the hormon spikes like in males
Fairly stable levels
53
After puberty, which is high, LH or FSH
LH
54
What happens to GnRH at old age
Increases
- FSH>LH
- sex steroids decrease
- menopause/andropause
55
What initiates the final development of the testes
Rise in daily GnRH pulses
56
What all happens when there is a daily GnRH pulse that initiates the final development of the testes
- increased number of Leydig cells
- testes increase in seize
- accessory organs grow
- linear growth spurt and development of male secondary sex characteristics
57
What do the leydig cells produce
Testosterone
58
When the testes increase in size, what else increases
-more seminiferous tubules for sperm production
59
What initiates the final development of the ovaries in female puberty
Rise in daily GnRH
60
What happens during female puberty (daily rise in GnRH pulses that initiate final development of the ovaries)
- increases production of estrogens (estradiol)
- menarche occurs
- linear growth spurt and development of female secondary sex characteristics
61
What are some problems with SRY
Swyer syndrome
| 46,XX male
62
What is swyer syndrome
- 46, XY but SRY is non functional
- female external genitalia
- non-functional, streak gonads
- intact Müllerian ducts
63
What is 46 XX male
- phenotypically male
- possible small testes
- possible gynecomastia
- no mullerian organs
- sterile with no functioning sperm
64
What is klinefelters syndrome
- 47, XXY
- feminization of the male phenotype
- breast growth
- tall, sterile, poor coordination and low muscle mass
- broad hips
- slight learning disability
65
What is tuner syndrome
- 45, XO
- female missing an X chromosome
- short, with webbed neck, low sexy ears, and are infertile
- some learning disabilities and visual disabilities as well
66
Steroid synthesis pathway in adrenal
Used inboth adrenals and the gonads
67
What pathway is primarily used in gonads
Aldosterone to estrogen/testosterone
68
Congenital adrenal hyperplasia (CAH)
- adrenal glands have all the machinery to make androgens
- leads to excessive androgen production
- XX female will have ovaries but have ambiguous genitalia
- any defect in aldosterone or cortisol production can cause this
69
17a dehydrogenase deficiency in XY
-46, XY with underdeveloped or female genitalia
70
17a deficincy in XX
-46, XX range from normal but infertile to no menarche and underdeveloped female characteristics at puberty
71
17B hydroxysteroid dehydrogenase deficiency in XY
May have ambiguous genitalia or female external genitalia, but internal testes
72
17B hydroxysteroid dehydrogenase deficiency in XX
Females will be masculinized
73
5a reductase deficiency
- XX genotype with pseudo intersexuality
- underdeveloped male genitalia due to lack of DHT
- still be fertile after puberty due to other sources of DHT
Can't make final sex hormone
74
Androgen insensitivity syndrome
- mutation of testosterone receptors so that they cannot bind testosterone (normal/elevated levels of testosterone)
- genotypically XY, phenotypically female
75
What is androgen insensitivity syndrome
Mutation of testosterone receptors
76
What is the genotype and phenotype of androgen insensitivity syndrome
```
Genotypically XY
Phenotypically female
-normal female external genitalia and secondary sex characteristics
-short vagina, no uterus
-will have undescended testes
```
77
How is androgen insensitivity syndrome diagnosed
Failed menarche
78
A patient presents to the clinic complaining of loss of energy, irregular menstration and weight gain. She is diagnosed with Cushings disease due to a pituitary tumor. Which of the following physical findings might she present with
Excess body hair
79
What is the male gonad
Testes
80
What do testes do
Produce sperm and secretes testosterone
81
When do testes descend
Around birth
82
What temp does sperm develop best
1-2C below body temp
83
Why doesthe scrotum raise and lower testes
To keep temperature right for sperm production
84
What are the testes made of
- mostly seminiferous tubules (80%)
| - connective tissue (20%)
85
What are the 3 cell types in the seminiferous tubules
- sertoli cells
- spermatogonia
- spermocytes
86
What do Sertoli cells do
- blood teste barrier
- secrete fluid into tubule to transport spermatozoa
- secretes androgen binding protein to concentrate testosterone in the testes
87
What do the leydig cells do
In connective tissue outside the seminiferous tubules and secrete testosterone
88
Process in seminiferous tubules where the diploid spermatagonia cells divide into 4 haploid spermatid
Spermatogensis
89
What are the phases of spermatogensis
Mitotic phase
Meiotic phase
Spermiogenesis
90
Mitotic phase of spermatogensis
Spermatogonia divide to populate the testes with spermatocytes
91
What is the meiotic phase of spermatogensis
Spermatocytes divide to form spermatids
92
What is the spermiogenesis phase of spermatogenesis
Spermatids mature by losing cytoplasm and develop a flagella
93
Where are maturing sperm held until ejaculation
Epididymis
94
When do sperm become motel
After 18 hours
95
How long can sperm stay in suspended animation
For months
96
What happens to the sperm during ejaculation
Accessory glands add fluid to the sperm to form semen
97
What do the seminal vesicles add to the sperm
Citrate, fructose, prostaglandins, and fibrinogen
98
What do prostate glands add to sperm
Alkaline fluid that contains citrate, calcium, clotting enzymes and fibrinolysis
99
What is seems propelled by in ejaculation
Smooth muscle contractions
100
What happens once season is in a female reproduction tract
Sperm undergo capacitation to become fully active (5 hours)
101
What happens during capacitation to sperm
- takes 5 hours
- inhibitory factors present in semen are washed away
- full motility is achieved due to calciu, influx
- acrosome becoems more fragile due to removal of cholesterol
102
What does erection result from
PNS
103
How does the PNS stimulate erection
Release of NO relaxes vascular smooth muscle to increase blood flow, arterial flow is increased and venous flow is restricted
104
What does blood fill for erection
Corpus cavernosa and spongiosum
105
How is erection achieved
Due to increased pressure in the erectile tissue
106
What is the lubrication in males from (which nervous system)
PNS
107
What secretes mucus for lubrication in males
Bulbourethral and urethral glands
| -clears and lubricates urethra for semen
108
What part of the nervous system is responsible for emission and ejaculation
SNS
109
Male emission
Combines sperm and seminal fluid in the internal urethra
110
Male ejaculation
Expulsion of semen out of the penis by muscular contractions
111
Male resolution (loss of sexual excitement)
Occurs 1-2 minutes after ejaculation
112
Steroid hormones that have masculinization effects
Androgens
113
Where are androgens primarily produces
Leydig cells in testes
114
What do androgens produce in males
Testosterone, DHT, and androstenedione
115
Which are the most potent between testosterone, DHT, androstenedione
Testosterone and DHT
116
Testosterone production in fetus
Allow growth and differentiate of internal genitalia in response to hCG
117
Production of testosterone before puberty is in response to
GnRH
118
When does GnRH peak
In adulthood and slowly declines with age
119
What is testosterone responsible for
Secondary male sex characteristics
120
Produced in fetus to allow growth and differentiation of external genitalia
DHT
121
Production in response to GnRH beings during puberty
DHT
122
How is GnHR released in males
In a pulsatile manner every 1-3 hours
123
What hormones follow GnRH secretion in male hormone regulation
LH and FSH
124
What do the LH and FSH that follow GnRH in males do
- LH levels fluctuates more than FSH
- LH stimulates testosterone production
- FSH stimulates spermatogenesis and the production of inhibin
- need both for spermatogenesis
125
In male hormone regulation, what inhibits LH and GnRH release
Testosterone
| -negative feedback loop to both the pituitary and hypothalamus
126
In male hormone regulation, what inhibits FSH release
Inhibin from Sertoli cells
127
What does the ovary do
- produce ova (oogenesis)
| - produces and secretes E and P
128
How is the ovary connected to the uterus
Ligaments
129
What is the pathway from ovary to uterus
Fallopian tubes
130
What happens when ova is fertilized by sperm
Ova will I plan in the uterus and develop until birth (parturition)
131
Is there a mitotic or meiotic process to develop haploid ova?
Both
132
How many phases to develop haploid ova
3
133
Generation of the primary oocyte
- first phase
- mitotic phase
- stem cells develop into oogonium (7 mil)
- oogonium develop into primary oocytes (2mil)
134
What happens to primary oocytes around birth
Arrests in prophase I of meiosis
135
At the same time the primary oocytes arrests in prophase I, what else happens
Coating of granulosa cells (follicular) develop
136
What phase is their generation of the secondary oocyte?
Meiotic
137
When does generation of the secondary oocyte happen
Puberty
138
How many oocytes remain when secondary oocytes generate
0.5 mil
139
When you are at reproductive maturation, how many oocytes left
0.5 mil
140
How many oocytes each menstrual cycle
A few
141
What completes meiosis I
Generation of secondary oocyte and polar body which gets degenerated
142
When is the follicle fully developed
After meiosis I when there is a secondary oocyte and a polar body
143
Ovulation
- one of the developing secondary oocytes gains dominance (rest degenerate)
- ovulation occurs (500 over lifetime)
- if not fertilized secondary oocyte is shed with menses
144
When is the second round of meiosis in females complete?
IF fertilized
145
What occurs with the second round of meiosis
-2nd polar body is formed and degenerates
0mature ovum and sperm (both haploid) join to form zygote (diploid)
-follicle forms corpus Luteum
146
Which of the following differentiates permatogenesis from oogenesis
Mitosis during spermatogenesis continues after birth
147
Process of preparing the body for pregnancy
Ovarian (menstrual) cycle
148
When doe the menstrual cycle start
Every 28 days
149
How many phases to the menstrual cycle
4
150
What are there cyclic changes in in the menstrual cycle
FSH, LH, estrogen and progesterone
151
What do the hormone changes in the menstrual cycle do
Cause development of ovum, surrounding follicle and uterine lining
152
Day of menstrual cycle
Menstruation
- previous cycle ended, no fertiliztion
- uterine lining is shed de to drop in E and P levels
153
Follicular phase
Day 5
- drop in E/P removes negative feedback inhibiton of GnRH
- GnRH spikes more frequently, FSH/LH levels increase
- FSH cause development of ovarian follicles and secretion of E from granulosa cells
- high estrogen levels cause a positive feedback with GnRH
- GnRH spikes increase causing a LH spike wihich causes ovulation
154
Ovulatory phase
Day 14
- LH levels spike, causing ovulation
- follicle ruptures, releases ovum about 24 hours after spike
- always occurs 14 days prior to menses
155
Lateral phase
Days 14-28
- follicle becomes corpus luteum, secretes large amounts of progesterone
- P slows GnRH pulses, LH and FSH levels fall low
- if no fertilization, E and P levels fall, and menstruation will occur after day 28
- corpus luteum becomes corpus albicans
156
Uterine cycle
Uterus responds to high levels of E and P to prepare to receive fertilized embryo
157
Menstruation in the uterine cycle
Day 1
| -old lining is shed due to decrease in P and E levels
158
Proliferating phase of uterine cycle
Until ovulation
- increasing E from developing follicle increases the proliferation of endometrial cells, gland and blood vessels
- endometrium gets 6X thicker, becomes contractile and increases expression of P receptors
Builds thickness
159
Secretory phase of uterine cylce
Lateral phase
- high progesterone
- secretion of nutrient rich fluid
- further increases vascularity and growth
160
Premenstrual phase of the uterine cycle
End of luteal until menstruation occurs
- reduction in E and P levels cause loss of blood flow
- thickened endometrium becoems ischemic and is lost as menses
161
The transition between the proliferating phase and the secretory phase of the uterin cycle coincides with
Ovulation
162
What are the female sex hormones
E and P
163
What are the female sex hormones (E and P) produced by
Theca and granulosal cells
164
These cause the development of female secondary sex characteristics (growth of external and internal genitalia, breast tissue, and metabolism and fat deposition)
E and P
165
What do you need for testosterone
LH
166
What do you need for progesterone
LH and FSH
167
What's the difference between testosterone and estrogen
There's one more step for estrogen production which requires FSH
168
Maturation and maintenance of uterus, Fallopian tubes, cervix, and vagina
Estrogen
169
Responsible at puberty for hte development of female secondary sex characteristics
Estrogen
170
Requisite for development of breasts
Estrogen
171
Responsible for proliferation and development of ovarian granulosa cells
Estrogen
172
Up-regulatorion of E, P, and LH receptors
Estrogen
173
Negative and positive feedback effects on FSH and LH secretion
Estrogen
174
Maintainenance of pregnancy
Estrogen
175
Lowering of uterine threshold to contractile stimuli
Estrogen
176
Stimulation of prolactin secretion
Estrogen
177
Blocking the action of prolactin on the breast
Estrogen
178
Decreasing LDL cholesterol
Estrogen
179
Anti-osteoporosis
Estrogen
180
Why do menopausal women get osteoporosis
Because estrogen is an anti-osteoporosis thing and it gets lost at menopause
181
Maintanence of secretory activity of uterus during luteal phase
Progesterone
182
Development of the breasts
Progesterone
183
Maintains pregnancy
Progesterone
184
Raising uterine threshold to contractile stimuli during pregnancy
Progesterone
185
Is the female HPG axis positive or negative feedback
Both
186
When is the female HPG axis negative
During follicular and luteal phase
187
When is female HPG axis positive
For ovulation
188
What negatively regulates FSH?LH
Small amounts of estrogen and inhibin as well
189
Where is inhibin released from and what does it do
Released from corpus luteum and negatively regulates FSH and LH
190
What are high levels of inhibin during pregnancy an indicator for
Marker for Down's syndrome
191
What hormones has to be high in order for positive feedback in female
Estrogen
192
What causes high levels of estrogen for a positive feedback
- increased GnRH receptors on pituitary
| - leads to FSH and LH surge necessary for ovulation
193
What does activin do
Increases FSH and LH release, released from granulosa cells
194
What is the feedback hormone for follicular phase
Estradiol
195
What hormone is the feedback hormone for ovulation (midcycle)
Estradiol
196
What hormone is the feedback hormone for the luteal phase
Progesterone
197
What is the beginning of sexual maturity
Puberty
198
What is the first menses
Menarche
199
What is the end of reproductive years
Menopause
| -most primary follicles are gone
200
How many ova are present in the first and last few cycles of female
May not have any ova
- due to lower levels of LH
- usually shorter cycle, no corpus luteum and little progesterone
201
Due to loss of primary follicles
Menopause
202
What hormones increase in menopause
FSH and LH
- loss of feedback inhibition
- mostly FSH
203
What happens at menopause with los of estrogen
- hot flashes, mood swings, fatigue, anxiety, dry eye
- osteoporosis
- increased risk of CV events
204
What hormonal change is due to dry eye in females
Menopause, loss of estrogen
205
Lubrication in female sex act
PNS stimulation
| -bartholin glands secrete mucous into the introitus
206
Female climax
- perineal muscles contract to increase motility of the uterus and Fallopian tubes to aid sperm in finding egg
- cervix dilates
- oxytocin is released and increases uterine contractions
207
Female erection
- clitoris and introitus contains same elective tissue as one is, responds to PNS stimulation
- NO, Ach,vasoactive intestinal peptide (VIP)
208
Nervous impulses for female sex act
Sent up the sacral spinal cord through the pudendal nerve and sacral plexus
209
How long can sperm live in the female tract
5 days
210
How many days prior must sex occur for conception to occur
4-5 days before ovulation or shortly thereafter
211
How many days are females fertile each cycle
5 days
212
Rhythmic contraception
- if sex is avoided during this fertile window, conception can be avoided
- difficult because few cycles are regular
- 25% failure rate
213
Hormonal suppression as contraception
-lower E and P to keep in low level neg feedback to not get hte LH surge
214
Administration of what can inhibit LH surge and ovulation
Exogenous E and P
215
Most common form of sterility
Failure to ovulate
- abnormal hormone stimuli
- thickened ovarian capsule wont rupture
216
How do detect ovulation
Progesterone levels in urinalysis
- if no metabolites in late part of cycle, no ovulaton occurred
- measure body temp (o.5 degree spike)
217
Endometriosis
- developes outside of the uterus
- can cause scarring and fibrosis in pelvic cavity
- can encapsulate ova and not allow ova to enter Fallopian tubes
218
Salpingitis
- inflammation of the Fallopian tubes
| - fibrosis and scarring prevents ova transit
219
Causes of sterility
- failure to ovulate
- endometriosis
- salpingitis
- alteration in cervical mucus
220
What happens when sperm enters an egg
Ova finishes last round of meiosis and expels a polar body
221
How many chromosomes align during fertiliztion
23 male and 23 female align to generate normal 46 pairs
222
When the chromosomes line up during fertiliztion what happens
Mitosis occurs and diploid zygote is formed, zygote continues to divide as it moves toward uterus
223
What happens 5-7 days after fertiliztion
Blastocyst implants on uterine walls, transported down Fallopian tube by actions of cilia
224
Implantation
-trophoblast cells on blastocyst dig into endometrium which later forms the placenta
225
Early nutrition of fetus (blastocyst)
Gained by trophoblast digestion of endometrium and form glandular secretions. Can survive tis way for 8 weeks. Nut placenta helps by the send or the 2nd week
226
Develops as an exchange between fetal and maternal circulation and provides oxygen and fuel to fetus, removes wastes
Placenta
227
How does the placenta work
- highly permeable and exchange occurs via diffusion (simple and facilitated). Permeability increases with gestation, not permeable to cells
- forms high levels of hormones (HcG, E and P, HcG
228
What does HcG resemble
LH in structure
229
Where is HcG released
from trophoblast cells of the implanted blastocyst
230
What does the HcG do to corpus luteum
To continue to produce P and E
231
If no HcG in pregnancy
Menstruation will occur because if fall in progesterone levels
232
What hormone is required for pregnancy until week 12
HcG
233
What happens to HcG after week 12 in pregnancy
Placenta takes over after, if lost, spontaneous abortion will occur
234
What us estrogen produced by
Cooperation of mother and fetus
235
What does estrogen during pregnancy do to uterus
Expands it
236
What does estrogen o to breasts during pregnancy
Enlarges them and the duct allows structures as well
237
What relaxes the pelvic ligmaments during pregnancy
Estrogen
238
What is progesterone produced by in pregnancy
Placenta
239
What does progesterone do during pregnancy
Develops the decidual cells in endometrium (nourishment)
Inhibits contractions of uterus
Prepares breast tissue for lactation
240
Human chorionic somatomammotropin during pregnancy
- very highly secreted, general metabolic hormone
- aids in breast development for lactation
- has a weak GH-like effect
- decreases maternal insulin sensitivity and glucose utilization so the rectus has more glucose
241
What hormone could potentially cause gestational diabetes
Human chorionic somatomammotropin
242
Prolactin and pregnancy
Prepares breasts for lactation
243
Glucocorticoids and pregnancy
Help maintain high Amina acid in blood
244
What does aldosterone do in pregnancy
Fluid retention for increases blood volume
245
What does PTH do in pregnancy
Increased calcium resorption from bones
246
What could cause pregnancy induced hypertension
Aldosterone
247
What increases glucose levels during pregnancy
Human chorionic somatomammotropin
248
What is the weight gain needed for pregnancy
About 35 lbs
249
Too much weight during pregnancy
Makes pregnancy more difficult
250
What nutrition must you increase during pregnancy
-iron
-calcium
-protein
To meet the needs of the fetus
251
What if you don't get enough nutrients in your diet when you are pregnancy
Fetus will use maternal stores
252
Cardiac output during pregnancy
Increases 40%
253
Blood volume during pregnancy
Increases 1-2L
254
GFR during pregnancy
Increases 50%
255
Reabsorption in pregnancy
Increases bout 50%
You reabsorb just as much as you filter so only slight increase in urine volume
256
Why is there increased urination when pregnant
Due to growing fetus and displacement of bladder
| -GFR and resorption are matched and do not really contribute to urine volume
257
What is the term for birth of baby
Parturition
258
When does parturition occur
- generally 38 weeks after fertilization
| - 40 weeks after last menses
259
What expels the baby
Progressively stronger, rhythmic uterine contractions will expel the baby
260
What kind of feedback is childbirth
Positive
| -regulated by hormonal levels and uterine stretch
261
What are all of the positive feedback loops
- blood clotting
- ovulation
- brith
262
Estrogen/progesterone ratio during pregnancy
- progesterone inhibits contractions
| - estrogen increases contractions
263
Which is increased closer to birth, estrogen or progesterone
Estrogen
264
What does the increase in estrogen do during birth
- increases uterine contraction
| - inserted more gap junctions in the muscle layer (allows muscle to function as one cell)
265
Oxytocin is secreted by what during pregnancy
Placenta and maternal pituitary glands
266
What mechanism does oxytocin use during pregnancy
Gq coupled mechanism
267
What does oxytocin do during pregnancy
-induces contractions
268
When does oxytocin increase during pregnancy
As labor progresses
269
What increases the secretion of oxytocin
- labor progression
| - cervical stretch
270
What do we give someone to induce labor
Oxytocin
271
Fetal hormones
- prostaglandins: induce contractions
| - cortisol
272
Mechanical factors that increase the strength of contractions
Stretch of uterus
- property of smooth muscle
- stretch the uterus and it will contract harder
273
Cervical stretch
- stretch of the crevix elicits greater contractions by the uterus
- which cause a greater stretch of the cervix, etc
274
When do you usually have contractions
All throughout pregnancy
| -weak Braxton hicks contractions
275
When do contractions get stronger
Later in term. Possibly due to cervical stretch by child's head
276
What does cervical stretch induce
More contractions and releases oxytocin which generates more contractions
277
How do contractions occur
From the top of the uterus down to the bottom
278
Other than contractions, what else can help push the baby out
Abdominal muscles
279
Contractions after birth
- continues to contract
| - placenta will be torn off uterine wall and delivered about 30 minutes later
280
When does uterus return to normal size
After bout 4 weeks
281
How much blood gets lost when you deliver the placenta
About 350ml
282
What causes the bleeding to stop after getting rid of the placenta?
Further constriction of the uterus pinches off blood vessels and stops bleeding
283
When is it beneficial to give someone oxytocin?
AFTER birth to stop bleeding
-if too much is given to induce labor, you will reduce the sensitivity of the receptors and it will not have the same affect to stop the bleeding after birth
284
How are newborns usually fed
Breast milk
285
When do breasts develop
During puberty
| -duct systems and fat deposits
286
What happens to breast during pregnancy
- estrogens stimulate increase the growth and branching of the ductal systems
- prolactin, GH, insulin, and glucocorticoids also play a role
287
What is required for breast development
Progesterone
| -develops the secretory characteristics of the alveolar cells
288
What is required for lactation
Prolactin
289
What inhibits lactation
E and P
290
When does prolactin levels rise
Throughout pregnancy along with E and P
291
When do E and P drop
After birth
292
What does the hypothalamus do for lactation
- releases PIH
- essentially dopamine
- unique since hypothalamic usually stimulates other hormones
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What happens to mothers cycle while breast feeding
While nursing, the mothers menstrual cycle will cease
- both the neurological sensation of nursing and high levels of prolactin reduce GnRH secretion
- this will usually last for several months 3 months-2 years
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What is required for milk ejection (let down)
Oxytocin
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Milk production and ejection
Milk is constantly made, but will only be ejected in the presence of oxytocin
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What can cause release of oxytocin to eject milk
Suckling infant or just being near a baby. Crying baby or handling the baby can cause an increase in oxytocin
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How much milk is formed daily
1-1.5L
| More if multiple birth
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How many more calories a day is required for breast milk
Extra 700 calories a day
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What happens if there is not Anouilh maternal calcium
Will digest the maternal skalaton
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What is secreted into breast milk
Antibodies and WBCs
- IgA most abundant
- help protect against infection while immune system develops in infants
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What is the fat percentage of cows milk vs human milk
More fat in crowns milk
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Which has more lactose, cow or human milk
Human
