Unit 1 Flashcards
Ovum or preembryonic stage time
14 days
Embryotic stage lenght
Week 3 to 8 (6 weeks)
Fetus stage
Week 9 to 38 (29 weeks)
Three primary germ layers
Ectoderm, mesoderm, endoderm.
Ectoderm (upper layer)
Gives rise to the epidermis, the glands (anterior pituitary, cutaneous, and mammary), the nails and hair, the central and peripheral nervous systems, the lens of the eye, the tooth enamel, and the floor of the amniotic cavity
Mesoderm (middle layer)
Develops into the bones and teeth, the muscles (skeletal, smooth, and cardiac), the dermis and connective tissue, the cardiovascular system and spleen, and the urogenital system
Endoderm (lower layer)
Gives rise to the epithelium lining the respiratory and digestive tracts, and the glandular cells of associated organs, including the oropharynx, the liver and pancreas, the urethra, the bladder, and the vagina. The endoderm forms the roof of the yolk sac.
Decidua basalis
The portion of the endometrium directly under the blastocyst, where the chorionic villi tap into the maternal blood vessels. Maternal aspect of the placenta made up of uterine blood vessels, endometrial stroma, and glands. It is shed in lochial discharge after birth
teratogens
Substances or exposure that causes abnormal development.
hydramnios (polyhydramnios)
More than 1.5L of amniotic fluid. It can lead to gastrointestinal problems and malformations
oligohydramnios
Fetus with less than 300ml of amniotic fluid. Can lead to fetal renal problems
lecithin/sphingomyelin (L/S) ratio
determine the health or maturity of the fetus
Wharton’s jelly
Connective tissue that prevents compression of the blood vessels and ensures continued nourishment of the embryo or fetus
syncytium
is the functional layer of the placenta.
Four hormones produced by the placenta
hCG (human chorionic gonadotropin), hCS(human chorionic somatomammotropin), progesterone, estrogen (mostly estriol)
Pinocytosis
Mechanism used for transferring large molecules, such as albumin and gamma globulins, across the placental membrane
cephalocaudal
Pattern of supplying the highest levels of oxygen and nutrients to the head, neck, and arms enhances the development of the embryo/fetus.
Hematopoiesis
The formation of blood, occurs in the yolk sac beginning in the third week
omphalocele
A hernia in which abdominal organs protrude into the umbilical cord
nuchal cord
When the cord is wrapped around the fetal neck.
battledore placenta
A peripheral location of the placenta
fontanels
The areas where more than two bones meet
Dizygotic Twins
When two mature ova are produced in one ovarian cycle, both have the potential to be fertilized by separate sperm.
Identical, or monozygotic, twins
Develop from one fertilized ovum, which then divides
Congenital
The condition was present at birth
Gravida
A woman who is pregnated
Gravidity
Pregnancy
Nulligravida
A woman who has never been pregnant and is not currently pregnant.
Primigravida
A woman who is pregnant for the first time
Multigravida
A woman who has had two or more pregnancies.