Human Reproduction

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Human Reproduction
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Today 1) Male and Female Reproductive
Systems 2) Sexual Cycles 3) Birth Control
Methods
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GnRH
Reproductive Systems Both Sexes
Hypothalamus
GnRH gonadotropin releasing hormone
Follicle stimulating hormone (FSH) Luteinizing
hormone (LH)
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Reproductive Systems Male
Pg 971
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Parts of the Male Reproductive System
Testes - male gonads - site of sperm production
and hormone release
Seminiferous tubules - tubes that make up testes
Leydigs cells - site of hormone release
Scrotum - sac for holding testes outside the body
- temperature regulation
Epididymis - tubules for collecting sperm from
the seminiferous tubules
Vas deferens - conducts sperm from epididymis
Accessory glands 1. Seminal vesicles -
contribute 60 to volume of semen 2. Prostate
gland - anticoagulant enzymes sperm
nutrients 3. Bulbourethral gland - secrete
alkaline mucus
Penis - contains erectile tissue (sinuses that
fill with blood) -places sperm as close as
possible to egg
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Reproductive Systems Female
Pg 970
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Parts of the Female Reproductive System
Ovaries - female gonads - site of egg production
and hormone release
Follicle - egg surrounded by follicle cells
Oviduct - tubes that connect ovary and uterus
Uterus (womb) - thick, muscular organ - site of
gestation of embryo
Endometrium - heavily vascularized inner lining
of the uterus
Cervix - neck of the uterus - opens into the
vagina
Vulva - collective term for external genitalia
Vestibule - recessed area containing the urethral
and vaginal openings
Vagina - site for copulation and birth canal
Labia minora - slender folds of skin at entrance
to vagina
Labia majora - thick, fat-filled ridges of skin
that protect the L. minora and vestibule
Clitoris - contains erectile tissue (sinuses that
fill with blood)
Bartholins glands - secrete mucous for
lubrication during intercourse
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Reproductive Systems Fetal - External Genitalia
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Reproductive Systems Fetal - Reproductive System
Bipotential gonad
Müllerian duct
Wolffian duct
Cloaca
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Reproductive Systems Fetal
Bipotential gonad
Müllerian duct
Wolffian duct
Müllerian duct becomes oviduct
Ovary
Cloaca
Wolffian duct degenerates
Vagina
FEMALE
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Reproductive Systems Fetal
Bipotential gonad
Müllerian duct
Wolffian duct
SRY protein
Müllerian duct becomes oviduct
Testis
Ovary
Cloaca
Wolffian duct degenerates
Wolffian duct Becomes vas deferens
Müllerian duct degenerates
Vagina
FEMALE
MALE
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Organ Equivalents
Male Bipotential Female
Glans penis Genital tubercle Clitoris
Shaft of penis Urethral folds groove Labia
minora
Shaft of penis Labioscrotal swelling Labia
majora scrotum
Regresses Gonad cortex Ovaries
Testes Gonad medulla Regresses
Epididymus, Wolffian duct Regresses Vas
deferens
Regress Müllerian duct Fallopian tube,
uterus, cervix upper vagina
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Male Sexual Cycle
FSH follicle stimulating horomone
Stimuli from brain
LH luteinizing horomone
GnRH (gonadotropin releasing hormone)
Negative feedback of testosterone
Leydig cells
LH
FSH
testosterone
Sertoli cells
Spermatogenesis
Primary and secondary sexual characteristics
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Female Reproductive Cycles
Ovarian - refers to egg maturation and
development in the ovary
Uterine ( Menstrual) - refers to changes in the
uterus
Estrous cycles - similar to uterine BUT 1)
associated with sexual receptivity 2)
endometrium is absorbed not shed
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Egg Development and Ovulation
Secondary oocyte (development resumes at puberty)
Primary oocyte (development arrested in fetus)
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Egg Development and Ovulation
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Egg Development and Ovulation
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Hormones and Menstrual Cycles
Estrogen
Inhibin
Ovarian Hormones
Progesterone
LH
Gonadotropic Hormones
FSH
Temperature
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Hormones and Menstrual Cycles
Hypothalamus releases GnRH
Anterior pituitary releases FSH and LH
Growth of follicles
Produce estrogen
LH stimulates formation of corpus luteum (c.l.)
c.l. secretes estrogen and progesterone
Spike in FSH/LH
Ovulation
Endometrium thickens
Embryo implants
Secretes hGCH
Further development
Degeneration of corpus luteum
Low estrogen levels
Contraction of arteries deprive endometrium of
blood
Menstruation
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Pregnancy Detection
Releases hCG (Human Chorionic Gonadotropin)
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Pregnancy Detection
Releases hCG (Human Chorionic Gonadotropin)
200 100 50 25 0
hCG Level (IU)
Detection level for home pregnancy kit
Detection level for blood test
0 4 8 12 16 20
Days Past Ovulation
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CONTRACEPTION

• prevent release of egg or sperm from gonads
• keep sperm and egg apart
• prevent implantation of embryo
• rhythm method

Effectiveness
Abstinence - 100
Sterilization - 100
The Pill - 99
Barrier methods - 90
Rhythm - 75
Morning After Pill - 75
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HOW DOES THE PILL WORK??
Combination of estrogen and progesterone inhibit
secretion GnRH
Hypothalamus releases GnRH
Growth of follicles
Anterior pituitary releases FSH and LH
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DONE!!!!