Fetal development/Pregnancy Flashcards
Preembryonic stage
0-2 weeks after fertilization
3-4 weeks gestation
Embryonic stage
3-8 weeks after fertilization 5-10 weeks gestation MOST CRITICAL TIME rapid cell division major organs developing
Fetal stage
9-38 weeks after fertilization
11-40 weeks gestation
morula
16 cell ball of cells
ectoderm
forms the central nervous system, special senses, skin and glands
mesoderm
forms the skeletal, urinary, circulatory, and reproductive organs
endoderm
forms the respiratory system, liver, pancreas, and digestive system
hCG
preserves the corpus luteum and its progesterone production so that the endometrial lining of the uterus is maintained; this is the basis for pregnancy tests.
Human placental lactogen (hPL)
fetal and maternal metabolism, participates in the development of maternal breasts for lactation, and decreases maternal insulin sensitivity to increase its availability for fetal nutrition
Estrogen (estriol)
causes enlargement of a woman’s breast, uterus, and external genitalia; stimulates myometrial contractility
Progesterone (progestin)
maintains the endometrium, decreases the contractility of the uterus, stimulates maternal metabolism and breast development, provides nourishment for the early conceptus
relaxin
acts with progesterone to maintain pregnancy, causes relaxation of the pelvic ligaments, softens the cervix in preparation for birth
teratogens
substances that cause birth defects, such as alcohol and drugs
ductus venosus
shunts fetal blood from umbilical vein to the inferior vena cava
ductus arteriousus
shunts fetal blood from pulmonary artery to the aorta (bypassing the lungs)
foramen ovale
anatomic opening between the right and left atrium
autosomal dominant inherited disorders
one abnormal dominant gene
autosomal recessive inherited disorders
two abnormal genes
x-linked interited disorders
altered gene on the x chromosome
common in males
where does fertilization take place?
fallopian tube
Subjective (presumptive) signs
signs that the mother can perceive such as skipping a period, nausea, fatigue, breast tenderness, and urinary frequency.
LEAST reliable indicators
Objective (Probable) signs
those that can be detected on physical examination by a health care provider. Softening of the cervix, softening of the lower uterine segment, bluish-purple coloration of the vaginal mucosa and cervix
Hegar’s sign
softening of the lower uterine segment or isthmus
Goodell’s sign
softening of the cervix