Introduction
Trimester; three-month periods
The period of the egg; from fertilization to the end of the third week
The period of the embryo; beginning fourth week to the end of eight week
The period the fetus; from beginning of third month to birth.
Phases;
• Gametogenesis; formation of the gametes the egg and sperm. Meiosis is
involved → forming haploid cell
• Fertilization; joining of the gametes to form the zygote
• Cleavage; rapid cell divisions result first in formation of the morula then
formation of blastocyst. Mitosis is involved
• Gastrulation; rearrangement of cells in embryonic region of the blastocyst. 3
germ layers; ectoderm – mesoderm – endoderm to form embryonic disc
3 cardinal body axes are established
Dorsal-ventral
Cranial-caudal
Medial-lateral
• Formation of the tube-within-a-tube body plan; conversion of the embryonic
disc into a C-shaped embryonic body. Ectodermal tube (future skin) and inner
endodermal tube (gut tube), mesoderm between the tubes.
• Organogenesis; formation of organ rudiments and organ systems
Martini Chapter 28 man
Basic structures reproductive system
• Gonads; organs that produce gametes and hormones
• Ducts; receive and transport the gametes
• Accessory glands; secrete fluids into ducts
• Perineal structures = extragenitalia (geslachtdelene extern)
Female; 1 gamaete per month
Male; 0,5 billion sperm per day
Semen; sperm + secretion of accessory glands
The male reproduction system
• Gonad; testis
• Ducts; epididymis → ducts deference (vas
deference) → ejaculatory duct → membranous
urethra → spongy urethra
• Accessory glands; seminal vesicles
(zaadblaasje), prostate gland and bulbourethral
glands (Cowper)
• Extragenital; penis and scrotum