Hormonal Control in Males Hypothalamus GnRH FSH Anterior pituitary Sertoli cells Leydig cells...
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Transcript of Hormonal Control in Males Hypothalamus GnRH FSH Anterior pituitary Sertoli cells Leydig cells...
Hormonal Control in Males
Hypothalamus
GnRH
FSH
Anterior pituitary
Sertoli cells Leydig cells
Inhibin Spermatogenesis Testosterone
Testis
LH
Neg
ativ
e fe
edb
ack
Neg
ativ
e fe
edb
ack
– –
–
(a) Control by hypothalamus
Hypothalamus
GnRH
Anterior pituitary
1
Inhibited by combination ofestradiol and progesteroneStimulated by high levelsof estradiol
Inhibited by low levels of estradiol
2 FSH LH
Pituitary gonadotropinsin blood
(b)6
FSH
LH
FSH and LH stimulatefollicle to grow
LH surge triggersovulation
3
Ovarian cycle 8(c) 7
Growing follicle Maturingfollicle
Corpusluteum
Degeneratingcorpus luteum
Follicular phase Ovulation Luteal phase
Estradiol secretedby growing follicle inincreasing amounts
Progesterone andestradiol secretedby corpus luteum
4
Ovarian hormones in blood
Peak causesLH surge
(d)5
Estradiol Progesterone 910
Estradiol levelvery low
Progesterone and estra-diol promote thickeningof endometrium
Uterine (menstrual) cycle
Endometrium
(e)
Menstrual flow phase Proliferative phase Secretory phase
Day
s
0 5 10 14 20 25 28| | |
15| | | | |
–
–
+Hormonal Control in Females
Control by hypothalamus Inhibited by combination of estradiol and progesterone
Stimulated by high levelsof estradiol
Inhibited by low levels of estradiol
Hypothalamus
GnRH
Anterior pituitary
FSH LH
Pituitary gonadotropinsin blood
LH
FSH
FSH and LH stimulatefollicle to grow
LH surge triggersovulation
Ovarian cycle
Growing follicle Maturingfollicle
Corpusluteum
Degeneratingcorpus luteum
Follicular phase Ovulation Luteal phase
(a)
(b)
(c)
Da
ys
0 5 10 14 15 20 25 28| | | | | | | |
–
–
+
Horm
onal C
ontrol in
Fem
ales (E
xpan
ded
View
)
Ovarian hormones in blood
Peak causesLH surge
Estradiol level very low
Estradiol Progesterone
Ovulation Progesterone and estra-diol promote thickeningof endometrium
Uterine (menstrual) cycle
Endometrium
0 5 10 14 20 25 28| | | | | | | |
Da
ys
15
Menstrual flow phase Proliferative phase Secretory phase
(d)
(e)
Hormonal Control in Females (Expanded View)
Ovary
Uterus
Endometrium(a) From ovulation to implantation
(b) Implantation of blastocyst
Cleavage
Fertilization
Ovulation
Cleavage continues
The blastocystimplants
Trophoblast
Inner cell mass
Cavity
Blastocyst
Endo-metrium
1
2
3
4
5
Hormones During Pregnancy
Maternal Fetal Blood Flow
Placenta
Uterus
Umbilical cord
Chorionic villus,containing fetalcapillaries
Maternal bloodpools
Maternalarteries
Maternalveins
Maternalportionof placenta
Fetal arterioleFetal venuleUmbilical cord
Fetalportion ofplacenta(chorion)
Umbilicalarteries
Umbilicalvein
Placental Crossing
Fig. 46-17
(a) First Trimester (b) Second Trimester (c) Third Trimester
Fig. 46-17a
(a) First Trimester
Fig. 46-17b
(b) Second Trimester
Fig. 46-17c
(c) Third Trimester
Estradiol Oxytocin
fromovaries
Induces oxytocinreceptors on uterus
from fetusand mother’sposterior pituitary
Stimulates uterusto contract
Stimulates placenta to make
Prostaglandins
Stimulate morecontractions
of uterus
Po
siti
ve
fee
db
ac
k
+
+
3
2
1 Dilation of the cervix
Placenta
Umbilical cord
Uterus
Cervix
Expulsion: delivery of the infant
Uterus
Placenta(detaching)
Umbilicalcord
Delivery of the placenta
Birthing Process
Fig. 46-19-1
PlacentaUmbilical cord
Uterus
Cervix
Dilation of the cervix1
Fig. 46-19-2
Expulsion: delivery of the infant2
Fig. 46-19-3
Delivery of the placenta
Uterus
Placenta(detaching)
Umbilicalcord
3
Male Female
Method Event Event Method
Production ofsperm
Production ofprimary oocytes
Vasectomy Combination birth controlpill (or injection, patch, orvaginal ring)Sperm transport
down maleduct system
Oocytedevelopmentand ovulation
Abstinence
Condom
Coitusinterruptus(very highfailure rate)
Abstinence
Spermdepositedin vagina
Capture of theoocyte by the
oviduct
Tubal ligation
Female condom
Spermmovement
throughfemale
reproductivetract
Transportof oocyte in
oviduct
Spermicides;diaphragm;cervical cap;progestin alone(as minipill,implant,or injection)
Meeting of sperm and oocytein oviduct
Union of sperm and eggMorning-afterpill; intrauterinedevice (IUD)
Implantation of blastocyst in endometrium
Methods Of Birth Control
In-Vitro Fertilization
Ethics of In-Vitro Fertilization
• Advantages of IVF: there are as many reasons for this treatment as there are people seeking this treatment. – over comes infertility
– allow families for people who must be sterilised e.g.. radiography/chemo therapy cancer patients
• Disadvantages of IVF:– what happens to unwanted embryo's
– what happens to orphaned embryo's
– should infertility be by-passed