Chapter 4 Flashcards
Describe male and female gonads and their functions.
Male gonads (sperm) are found in the testes, producing millions of immature sperm cells at birth and an unlimited supply. Female gonads (ova) are found in the ovaries, containing a finite number of ova at birth.
What are alternative fertilization methods?
Alternative fertilization methods include artificial insemination, in vitro fertilization (IVF), donor in vitro fertilization, surrogacy, and adoption.
How are abnormalities assessed during pregnancy?
Abnormalities during pregnancy are assessed through blood tests, ultrasounds, amniocentesis, chorionic villus sampling, and genetic screening, gene therapy, and gene counseling.
Describe the typical pregnancy duration and trimesters.
The typical pregnancy duration is 38 weeks (280 days). It is divided into three trimesters: 1st trimester (weeks 1-12) with the highest risk of miscarriage, 2nd trimester (weeks 13-24) with minimal sickness, and 3rd trimester (weeks 25-38) with rapid growth.
What happens during germination in prenatal development?
During germination, the egg is fertilized by sperm and becomes a zygote. It undergoes mitosis for about 5 days, forming a blastocyst that implants in the uterine lining.
What are the developmental stages in prenatal development?
The developmental stages are zygotic (weeks 1-2), embryotic (weeks 2-8), and fetal (weeks 9-38). These stages involve cell replication, blastocyst formation, and the development of internal organs and systems.
Describe the internal cells of the blastocyst.
The blastocyst contains the embryonic disk with three layers: ectoderm (skin, neurons, pigment cells), mesoderm (muscles, blood cells), and endoderm (lung, thyroid, pancreatic cells).
What is the cephalocaudal trend in prenatal development?
The cephalocaudal trend focuses on head development, with a smaller lower body and changing proportions over gestation.
Describe the amniotic sac and placenta’s functions.
The amniotic sac and fluid regulate the embryo’s temperature, cushion it, and prevent dehydration and adhesion. The placenta delivers food and oxygen to the embryo, filters waste, and prevents blood mixing.
What occurs during the fetal period (weeks 9-38)?
The fetal period involves rapid growth, early neurogenesis, the mother sensing fetal movement, age of viability (22-28 weeks), cerebral cortex emergence, and fetal reactions to stimuli.
What are some prenatal risk factors?
Prenatal risk factors include maternal malnutrition, obesity, age, chronic stress, and diseases like toxoplasmosis. Teratogens such as drugs, alcohol, and smoking, as well as environmental hazards like heavy metals and radiation, can also pose risks.
What are the stages of labor and birth?
Stage 1 involves practice contractions and dilation, Stage 2 is the delivery phase, and Stage 3 involves the expulsion of the placenta.
