Transcript SC.912.L16.13 Describe the

The Reproductive System
SC.912.L16.13 Describe the basic anatomy and
physiology of the human reproductive system.
Describe the process of human development from
fertilization to birth and major changes that
occur in each trimester of pregnancy.
The Male Reproductive System
The main function is to produce sperm, or male sex cells and
to deliver these cells to the ovary of the female for fertilization.
Anatomical path of sperm from formation to ejaculation
Testes , Epididymis, Vas deferens, Prostate, and Urethra
Structure of a Sperm
The Female Reproductive System
Function: 1. Produces and nourishes the egg cells that carry the female’s
genetic information.
2. It nourishes and protects the developing offspring if an egg
is fertilized.
Fertilization
Fertilization is the joining of a sperm and egg cell.
A zygote is a fertilized egg results from the fusion of the nuclei of two
gametes (egg and sperm)
Prenatal development (Embryonic and Fetal)
Zygote, Morula, Blastocyst, Grastula, Fetus
Structure made of 70-100 cells that forms early in mammalian
pregnancy. The inner cell mass creates the tissues of the body, while the
outer cell mass creates the placenta
Gastrulation and Neurulation
Gastrulation produces the three cell layers of the embryo. Ectoderm,
mesoderm and endoderm.
Neurulation which is the first step in the development of the nervous
system
First Trimester
 The zygote divides several times to form a
hallow ball called a blastula
 The blastula implants in the walls of the uterus.
 Cells continue dividing and form the gastrula.
 The placenta starts to secrete HCG (human
chorionic gonadotropin) so the embryo stays
attached to the uterus
 The major body structures develop in their basic
form during the first trimester.
Spina bifida is part of a group of birth defects called neural tube
defects. The neural tube is the embryonic structure that eventually
develops into the baby's brain and spinal cord and the tissues that
enclose them.
Normally, the neural tube forms early in the pregnancy and closes by
the 28th day after conception. In babies with spina bifida, a portion
of the neural tube fails to develop or close properly, causing
defects in the spinal cord and in the bones of the backbone.
Folic acid (Folate/Vitamin B9) can prevent this condition
Second trimester
 Grows larger and develops all structures it needs to
survive at birth.
 Fetus starts to move
 Forms lanugo hair on its body
 Sucks its thumb, swallows, hiccups
 The fetus has fully developed eyes and the lungs start to
develop
Third Trimester
 The brain develops rapidly.
 The fetus doubles its mass
 The fetus has regular breathing motions
 The central nervous systems and lungs complete
their development