Human Reproduction and Development

Human Reproduction and Development

Human Gonads
* Primary sexual organs where genes are packaged into gametes
o Male - testes
o Female - ovaries
* Secrete sex hormones
o Regulate secondary sexual traits

Male Reproductive System
vas deferens
epididymis
testis
penis
seminal vesicle
prostate gland
bulbourethral gland
urethra
bladder
scrotum

Semen = Sperm + Secretions
* Secretions from epididymis aid sperm maturation
* Seminal vesicle secretes fructose and prostaglandins
* Prostate-gland secretions buffer pH in the acidic vagina
* Bulbourethral gland secretes mucus

Prostate Cancer
* Second leading cause of death in American men
* Detection

Testicular Cancer
* About 5,000 U.S. cases per year
* Can be detected by self exam

Spermatogenesis
* Spermatogonium (2n) divides by mitosis to form primary spermatocyte (2n)
* Meiosis produces haploid spermatids
* Spermatids mature to become sperm

Other Testicular Cells
* Sertoli cells
* Leydig cells

Male Hormonal Control
Hypothalamus
Anterior Pituitary
GnRH
LH
FSH
Sertoli Cells
Leydig Cells
Testes
Testosterone
Inhibin
Formation and Development of Sperm
Female Reproductive Organs
vagina
uterus
oviduct
ovary
vagina
clitoris
oviduct
ovary
uterus
Menstrual Cycle
* The fertile period for a human female occurs on a cyclic basis
* Menstrual cycle lasts about 28 days
* Follicular phase and luteal phase

Oocytes Arrested in Meiosis I
* Girl is born with primary oocytes already in ovaries
* Each oocyte has entered meiosis I and stopped
* Meiosis resumes, one oocyte at a time, with the first menstrual cycle

Menarche to Menopause
* First menstruation, or menarche, usually occurs between ages 10-16
* Menstrual cycles continue until menopause, in a woman’s late 40s or early 50s

Ovarian Cycle
secondary oocyte
antrum
primordial follicle
corpus luteum
first polar body
* Follicle grows and matures
* Ovulation occurs
* Corpus luteum forms
Female Hormonal Control
Hypothalamus
Anterior pituitary
GnRH
LH
FSH
Ovary
Estrogen
Progesterone,
estrogens
follicle growth,
oocyte maturation
Rising estrogen stimulates surge in LH
Corpus luteum
Cycle Overview
hypothalamus
anterior pituitary
FSH
LH
FSH
LH
estrogens
FOLLICULAR PHASE
LUTEAL PHASE
menstruation
ovulation
estrogens
progesterone
Fertilization
Pregnancy
Early Divisions
Blastocyst Forms
Implantation Begins
blastocoel
inner cell mass
trophoblast
Uterine cavity
Human Chorionic Gonadotropin (hCG)
Extraembryonic Membranes
yolk sac
chorionic cavity
chorionic villi
chorion
amniotic cavity
connecting stalk
Gastrulation - Day 15
Vertebrate Body Plan Emerges
The Placenta
Embryonic Period
Fetal Period
Fetal Nutrition
Teratogens
Birth (Labor)
Lactation
Stages of Human Development - Prenatal
* Zygote - Single cell
* Morula - Solid ball of cells
* Blastocyst - Ball with fluid-filled cavity
* Embryo - 2 weeks to 8 weeks
* Fetus - 9 weeks to birth
Stages of Human Development - Postnatal
* Newborn - First 2 weeks after birth
* Infant - 2 weeks to 15 months
* Child – To 10-12 years
* Pubescent - At puberty
* Adolescent - Puberty to maturation
* Adult
* Old age
Birth Control Options
Prevent fertilization
Prevent ovulation
Block implantation
AIDS
AIDS Test
Safer Sex
Bacterial STDs
Pelvic Inflammatory Disease (PID)
Viral STDs
Abortion

Human Reproduction and Development.ppt