Chapter 26 Flashcards
1
Q
Zygote
A
fertilized egg
2
Q
Embryo
A
0-8 weeks of dvlpt.
3
Q
Fetus
A
8 weeks - birth
4
Q
sex organ 3 sets of structure
A
1 gonads
2 internal organs
3 external organs
5
Q
Gonads
A
organs that produce gametes TESTES (sperm) OVARIES (ova)
6
Q
Germ
A
undifferentiated gonads that will produce gametes
7
Q
Internal Genitalia
A
consists of accesory glands and ducts that connect gonads to external environment
8
Q
External Genitalia
A
all external reproductive structures
9
Q
Haploid
A
eggs + sperms are haploid with 22 chromosomes + 1 sex chromosome
10
Q
sex chromossomes
A
XX - fem XY - male XO - turner syndr fem YO - unable to survive XXY - male
11
Q
Barr Body
A
when a female develops ovaries, one of the X chromosomes becomes inactivated
12
Q
Bipotential
A
before sex organs have morphologically differentiated, they are called bipotential
-has outer cortex and inner medulla
13
Q
Bipotential differentiation
A
w/ signal, medulla turns into testis
w/o signal, cortex turns into ovarian tissue
14
Q
Bipotential Internal genitalias’ accessory ducts
A
Wolffian Ducts (embryonic kidney) Mullerian Ducts
15
Q
SRY gene
A
Sex-determining Region of the Y chromosome
sex determination depends on the absence or presence of the SRY gene
- presence > testis
- absence > ovaries
16
Q
Male Embryonic Development
A
1 SRY produces TESTIS-DETERMINING FACTOR (TDF)
2 TDF binds w DNA to produce multiple proteins
3 proteins cause GONAD MEDULLA to differentiate into TESTIS
4 TESTIS secrete 3 hormones:
(Sertoli Cells secrete Anti-Mullerian Hormones)
(Interstitial (Leydig) Cells secrete Testosterone + Dihydrotestosterone)
17
Q
Androgen hormones secreted by Testicular Interstitial Cells
A
testosterone + dihydrotestosterone
18
Q
Anti-Mullerian Hormone
A
secreted by Testicular Sertoli Cells + ovarian follicles’s granulosa cells
- causes embryonic Mullerian ducts to regress
- in women, acts as as a brake to keep to many follicles fr developing at one time
19
Q
TESTOSTERONE in male dvlpt.
A
- converts Wolffian ducts into epididymis, vas deferens, + seminal vesicles
- migration of testes from abdomen into the scrotum
20
Q
DHT in male dvlpt.
A
-differentiation of external genitalia
21
Q
Female Embryonic Dvlpt.
A
1 Cortext of bipotential gonad develops into ovarian tissue
2 Mullerian ducts develop into upper portion of vagina, uterus, + fallopian tubes
3 Wolffian ducts degenerate
4 external genitalia take on female characteristics
22
Q
MEIOSIS
A
cell division that forms gametes
23
Q
Spermatogonia
A
- germ cell w/2n or 46 chromosomes (23 pairs)
- during puberty, some undergoes Mitosis (makes spermatogonia), and others unergo Meosis (makes primary spermatocyte)
24
Q
Spermatogenesis
A
Mitosis: Spermatogonia>primary spermatocyte
Meiosis 1: spermatocyte>2 secondary spermatocyte
Meiosis 2: 2 spermatocyte> 4 spermatids
Maturation: 4 spermatid>4 sperm cell (w/1n)
- each primary spermatocyte creates 4 sperms
- takes about 64 days to complete
25
Spermatid
haploid which means 23 single chromosomes or "1n"
26
OOgonia
germ cell that completes mitosis + DNA replication by end of 5th month of fetal development
-results in primary oocytes (2n)
27
Primary Oocytes
At brth, each ovary contains about half a million Primary Oocytes
-no longer undergoes mitosis, no additional oocytes are formed
28
Oogenesis
Meiosis: Primary Oocyte> large SECONDARY OOCYTE + small FIRST POLAR BODY
(each has 1n. 1st polar body disintegrates)
-entry of sperm induces 2nd Meiosis
Meiosis 2/Ovulation: Secondary Oocyte>Ovum+2nd Polar Body
29
Sex Steroids/Hormones
Androgen,
Estrogen,
Progesterone
-fr hypothalamus + ant. pituirary
30
Testosterone
- secreted by testis + 5% fr adrenal cortx
| - in peripheral tissues, its converted into DHT (more potent derivative)
31
DHT
potent derivative of testosterone
| -results in physiological effects
32
Aromatase
- Enzyme produced in testis + ovaries
| - converts androgens to estrogens
33
Estogen + Progesterone
made in ovaries
34
Sex Hormone Pathway
1 Gpnadotropin-Releasing Horm (fr hypothal tp)
2 gonadotropins: FOLLICLE-STIM HORM + LUTENEIZING HORM (fr ant.pit)
3 FSH initiates ovulation; LH acts on endocrine cells to stim production of sex steroids
35
Sex Hormone Feedback Pathway
high levels of gonadotropins inhibit further release of GnRH, FSH, LH
-except high levels of Estrogen which can exert pos. or neg. feedback ( low levels have no effect)
36
Endrogen Feedback Pathway
high levels - either pos. or neg feedback
low levels - no feedback
moderate levels - neg. feedback
37
Gonadotropin-Releasing Hormone (GnRH)
- released fr hypothalamus to stim ant. pit to release FHS + LH
- absence of GnRH inhibits sexual amturation
- tonic release occurs in small pulses every 1-3 hours
38
GnRH Pulse Generator
- region in the hypothalamus that coordinates w coordinates the pulsation GnRH release
- contains neurons secreting KISSPEPTIN +other peptides that stim the pulse/release of GnRH
- if steady release, then children will fail to mature bc high levels cause donw-regulation of receptors making pituitary unable to respond
39
Cryptochidism
failure of one or both testes to descend
| -if left untreated, 80% descend later
40
Male accessory glands
1 Prostate Gland
2 Seminal Vesicles
3 Bulbourethral Gland
41
Prostate Gland
-fetal dvlpt is under control of Dihydrotestosterone
42
TESTES ANATOMY
- Scrotal Cavity
- Seminiferous Tubules
- Epididymis
- Vas Deferens
43
Seminiferous Tubules
- masses of coiled tubes in the testes which is 80% of testicular mass
- site of sperm production
- contains 2 types of cells :Sertoli + Spermatogonia
- leaves the testis by becoming joining the epididymis which becomes vas deferens
44
Epidedymis
- single duct that forms tightly coiled cord on the surface of testicular capsule
- becomes VAS DEFERENS as it extends away from the testis
45
Vas Deferens
originates fr. epidedymis of testis, passes into abdoment, and empties into urethra
46
Sertoli Cells
- in seminiferous tubules (of testis)
- extends fr basal lamina side to apical side for support and protection
- regulate sperm dvlpt. by providing sustenance + nourishment for developing spermatogonia
- junction forms BLOOD-TESTIS BARRIER
47
3 compartments of Testis
1 tubule lumen
2 basal compartment (on basolateral side of sertoli)
3 interstitial fluid (outside of basal lamina)
compartments are created by basal lamina + tight junctions of sertoli cells
48
Interstitial (Leydig) Cells
- located in the interstitial tissue between seminifurous tubules
- secrete testosterone; converts testosterone to estradiol sometimes
- active in the fetus to develope male characteristics, becomes inactive at birth, then reactivates during puberty
49
sperm production
- spermatogonia are clustered near basal ends of sertoli
- some undergo mitosis to become spermatocytes, some stay where they are to create more germ cells
- as spermatocyte differentiate into sperm, they move inwards but still surrounded by sertoli
- spermatids remain embedded on apical side of sertoli
- when sperm lose most of their cytoplasm, they are mobile and leave the apical membrane
50
Hormones of Spermatogenesis
- GnRH fr hypothalamus. targets release of LH +FSH
- LH + FSH fr ant.pit.
- LH targets Interstitial Cells (to produce testosterone for spermatogenesis)
- FSH targets Sertoli to synthesize paracrine moles needed for mitosis + spermatogenesis, production of androgen-binding protein, + inhibin
51
Seminiferous Secretion
sperm
52
Bulbourethral Secretion
mucus (as lubricant
53
Seminal Vesicles Secretion
nutrients (fructose, vit c), enzymes (clot semen in vagina, then liquify the clot), prostaglandis (smooth muscle contraction, aids in sperm transport)
54
Prostate Secretion
enzymes that clot semen in vagina and liquify clot.
| citric acide
55
Empididymis Secretion
Carnitine
56
Androgen's Primary Sex Characteristics
internal secual organs, external genitalia that distinguish male fr female
57
Androgen's Secondary Sex Characteristics
male body shape (inverted triangle), beard, body hair, muscle dvlpt, thickening of vocal chords, libido
58
Ovaries
- produces eggs + hormones
- thick outer cortex willed w ovarian follicles in various staged of dvlpt)
- small central medulla contains nerves + blood vessels
59
Stroma
inner connective framework on ovaries
60
Granulosa Cell
- single layer surrounds each primary oocyte
- increases in number at different stages until it dies via Atresia
- enclosed in basal lamina
61
Primordial Follicle
-precursor to primary follicle which has a single layer of granulosa cells
62
Atresia
- hormone regulated cell death
| - primordial cells usually undergo atresia and never develop
63
Primary Follicles
- slowly develops fr primordial follicles
| - oocyte enlargens +granulosa cells begin to divide (but remain a single layer in primary stage)
64
Secondary Follicles
- develops fr primary fol.
- has granulosa cell layer and THECA CELL LAYER
- granulosa begins to secrete fluid that collects in ANTRUM (central cavity)
65
Antral Fluid
found in central cavity of ovaries
| -contains hormones + enzymes needed for ovulation
66
Tertiary Follicles
-fr pool of tert. follicles, only a few survive to reach the final growth stages
67
Dominant Follice
- usually only 1 follicle develops to release its egg
| - fr secondary follicle to dominant follice takes about 3+ months
68
Ovarian Cycle Stages
1 Follicular Phase - follicular growth (10-20 days)
2 Ovulation - once 1+ follicles have ripened, ovary releases oocyte
3 Luteal Phase - transformation of ruptured follicle into CORPUS LUTEUM (secreted hormones that continue prep for pregnancy. if not pregnant after 2 weeks, then cease to function)
69
Uterine Cycle Stages
1 Menses - menstrual bleeding
2 Proliferative Phase - (latter part of follicular phase) endometrium adds a new layer of cells in anticipation of pregnancy
3 Secretory Phase - (after ovulation) hormones fr luteum convert thickened endothelium into secretory structures
70
Hormonal Control of Menstrual Cycle
-GnRH , FSH, LH, Estrogen (dominant in follicular phase), Progesteron, inhibin, AMH (fr ovary)
71
Early Follicular Phase
- begins @ first day of menstruation
- just before this cycle, there was an increase in FSH + LH release
- FSH causes tertiary follicles begin to mature
- AMH decrease follicle-sensitivity to FSH
- thecal cells synthesize androgens into estrogen (w enzyme aromatase)
- estrogen exerts neg feedback to decrease secretion of FSH LH
- estrogen exerts pos feedback on granulosa cells to produce more estrogen
- menstruation ends during early follicular phase
72
Mid-Late Follicular Phase
- by this point, only 1 follicle is still developing
- as follicular phase nears its end, estrogen secretion peaks, rising level of progesterone, LH surge, FSH increases lightly
- LH surge triggers chem signals for meiotic division
73
Ovulation
- occurs 16-24 hrs after LH peaks
- mature follicle secretes PROSTGLANDINS that contributes to wall rupturing + MATRIZ METALLOPROTEINASES that dissolve collagen + other components holding follicular cells together
- release of antral fluid + egg is swept into fallopian tube to be fertilized or to die
74
Early-Mid Luteal Phase
- thecal cells migrate into antral space to join granulosa cells
- LUTEINIZATION morphs the 2 cells into corpus luteum
- luteal cells accumulate lipid droplets +glycogen granules
- luteal cells begin to secrete progesterone, estrogen, + inhibin
- estrogen + progesterone shut off ant.pit
75
Late Luteal Phase + Menstruation
- corpus luteum has intrinsic lifespan of 12 days; if pregnancy doesnt occur, corpus luteum dies
- decrease in estrogen + progesterone, leads to increase in FSH LH
- remnants of corpus luteum becomes CORPUS ALBICANS
- 14 days after ovulation, endometrium begins to slough off its surface layer (menstruation)
76
Hormones Female Characteristic
Primary characteristics - affected by estrogen
| Secondary characteristics - Estrogen (breast + hips), Androgen (pubic + axillary hair, libido)
77
Erection Reflex
spinal reflex that is subject to control fr higher centers in the brain
- triggered by tactile + psychological stimuli
- inhibits vasocontrictive sympathetic input on penile arteriole
78
Maintaining an Erection
- increased parasymph nervous system produces Nitric Oxide
- N.O. dilates penile arteriole, allowing blood flow to open spaces in erectile tissue, which passively compresses the veins, + traps blood
79
Emission
mvmt of semen fr vas deferens into urethra
80
Tubal Ligation/Vasectomy
tying off/cutting fallopian tubes
or
vas deferens is tied or clipped
81
Parturition
the birth process
82
Capacitation
final maturation step which enables the sperm to swim rapidly and fertilize the egg
- involves changes in lipids and proteins of the sperm head membrane
- normally takes place in female reproductive tract
83
time length of viability of sperm and egg
sperm is viable for 5-6 days.
| egg can be fertilized for 12-24 hours after ovulation
84
Fertilization
-takes place in distal fallobian tube
1 ACROSOMAL RXN sperm penetrates Corona Radiata + Zona Pellucia
2 CORTICAL RXN first sperm in binds to receptors to prevent others fr penetrating
3 fused section of sperm + egg membrane opens + sperm nucleus sinks into cell's cytoplasm. signals cell to to complete final SECOND MEISOSIS.
4 zygote nucleus w 23 chrom fr mom + 23 chrom fr dad
85
Zona Pellucida
inner protective glycoprotein coat underneath corona radiata
86
Corona Radiata
loosely connected granulosa cells outside of egg
87
ACROSOMAL REACTION
-part of fertilization i which sperm secreted power enzymes thru its acrosome to break through the layers of the egg
88
CORTICAL RXN
membrane bound cortical granules in peripheral cytoplasm of the egg release their contents into space just outside of the egg membrane
-alters membrane + zona pellucida to prevent polyspermy
89
Polyspermy
more than one sperm fertilized the egg
90
GESTATION PERIOD
period in the womb/uterus.
| once egg is fertilized + becomes a zygote, it beings mitosis as it slowly moves along the fallopian tube to uterus.
91
Embryo Dvlpt.
1 dividing embryo takes 4-5 days to move fr fallopian to uterine cavity
2 embryo is a blastocyst when it reaches the uterus
92
Blastocyst
hollow ball of about 100 cells
- some of outer layer will become CHORION
- inner layer will become embryo + 3 other embryonic membranes
93
Chorion
extraembryonic membrane that will enclose the embryo and form the placenta
94
embryonic membranes
1 AMNION secretes amniotic fluid in which embryo will float in
2 ALLANTOIS becomes umbilical cord
3 YOLK SAC which degenerates early in dvlpt
95
implantation of blastocyte
- 7 days after fertilization
- blastocyte secretes enzymes that allow it to invade the endometrium
- endometrial cells grow out around the blastocyte until it is fully engulfed
96
Chorionic Villi
made of cells that will become placenta
| -forms fingerlike extensions that penetrate around endometrium to allow mothers blood to pool
97
Placenta Hormones
- prevents menstruation during pregnancy
- human chorionic gonadotropin, human chorionic somatomammotropin, estrogen (milk-ducts), progesterone (prevents contraction)
98
Human Chorionic Gonadotropin (hCG)
- keeps corpus luteum active during early pregnancy
- secreted by chorionic villi, binds to LH receptors
- stimulates testosterone production by developing testes
99
Human Chorionic Somatomammotropin (hCS)
- peptide hormone produced by placenta
- alters mom's glucose + fatty acid metabolism to support fetal growth
- 4% of women develop gestational diabetes mellitus
100
Gestational Diabetes Mellitus
elevated blood glucose levels caused by insulin resistance
- after birth, GDM returns to normal
- moms + bbs are at higher risk of developing type 2 diabetes later
101
Lactation
-estrogen contributes to dvlpt of milk secreting ducts
102
Labor
- begins parturition
- rhythmic contraction of uterus that push the fetus out
- possible trigger is Oxytocin
- possible trigger is fetus secreting corticotropin-releasing hormone
103
Pre-Labor
days prior- cervix soften; ligaments holding pelvic bones together loosen as enzymes destabilize collagen in connective tissue (maybe due to estrogen or relaxin)
104
Prostaglandins
- produced in uterus in response to oxytocin + CRH
| - effective at causing uterine muscle contractions
105
Mammary Gland
- 15-20 milk-secreting lobes that branch into lobules, then terminate into clusters of acini/alveoli
- contractile MYOEPITHELIUM surrounds the alveoli
- develops under estrogen, GH, + cortisol
106
estrogen + progesteron inhibit secretion of
milk
107
Prolactin-Inhibiting Hormone
fr hypothalamus; targets ant.pit
- during late staged of pregnancy, PIH falls, which causes prolactin to rise 10fold
- suckling inhibits PIH secretion
108
LET-DOWN REFLEX
ejection of milk fr glands requires Oxytocin fr post.pit.
