Module 2 (Exam 1) ****2**** Flashcards
What are three unique structure associated with fetal circulation?
- Ductus Arteriosus
- Foramen Ovale
- Ductus Venosus
Ductus Arteriosus
Communication between the pulmonary artery and the aorta: Closes gradually within 10-96 hours after birth
Foramen Ovale
Communication between the atria of the heart; functionally closes in 1-2 hours after birth
Ductus Venosus
Shunts 1/3 of blood away from liver and into the vena cava
Follicular Phase
- Days ~1-13
- Graffian Follicle matures
- Ovum Matures
- FSH
- Estrogen (by follicles)
Ovulatory Phase
- ~Day 14
- Ovum is released
- LH
- Surge in Progersterone
Luteal Phase
- Corpus luteum develops
- If fertilization occurs, corpus luteum continues to release progesterone, estrogen until the placenta takes over this function
- Trophoblast secretees hCG that signals the corpus luteum to continue to secrete progesterone
- If no prgnancy, FSH and LH fall and corpus luteum stops productioon of estogen and progesterone = menstration
Uterine Cycle- Menstrual
- ~Days 1-6
- Shedding of the endometrium
Uterine Cycle - Proliferative
- ~Days 7-14
- Endometrium Develops
- Estrogen
Uterine Cycle - Secretory
- ~Days 15-26
- Endometrium enriches
- Progesterone
Uterine Cycle - Ischemic
- ~Days 27-28
- Endometrium becomes ischemic
Number of autosomes in the normal human genetic composition
22 pairs (non-sex chromosomes)
Number of sex chromosomes in the normal human genetic composition
1 pair (X or Y chromosomes)
Process of Fertilization and Implantation
- The ovum waits for sperm at the ampulla
- Entry of a spermatozoon
- Sperm head enters the cytoplasm of the ovum
- The ovum completes meiosis, 23 chromosomes remain
- Fusion of nuclei (ovum and sperm)
- Chromosomes from each gamete mingle and form 46
- Fertilizied ovum becomes a zygote
- Zygote divides until it is 12-16 cells, now it is a morula
- Outer cells of morula secrete fluid
- Fluid secreted around morula forms a blastocyst (sac of cells of to the side that will become the baby)
- The rest of the cells (outer layer) becomes tropoblast, which becomes the placenta and fetal membranes
- Blastocyst reaches 100 cells and enters the uterus
- After spending 2-4 days in uterus, the conceptus eordes through the decidua and “implants”
- Spotting may occur at this time
Umbilical Arteries
Carry de-oxygenated blood and waste from fetus to placenta. There are two of them
Major functions of the placenta
- Metabolic (sythesis of nutrients)
- Transfer (nourishment and waste removal, gas exchange, respiratory function of the placenta)
- Endocrine (hormonal production - progesterone, estrogen, human placental lactogen)
Intervillous Spaces
- Spaces where maternal blood is pored into for nutrience and gas exchance
- Gase transfers VIA simple diffusion
- 450-750mL ofblood/minute at term is spurted into these spaces
- Blood is breifly outside the maternal ciculatory system
- Blood washes over chorionic villi (which take up nutrience)
Amnion
- Inner fetal membrane
- Runs up the umbilical cord
- Joins the epithelium of the fetal abdominal skin
Chorion
- Maternal membrane (outer)
- Lies against the decidua
- Chorionic villi sprout from the chorion
Purposes of Amniotic Fluid
- Cushioning
- Thermoregulation
- Protection from pathogens
- Promotion of fetal growth and development
Umbilical Vein
One of them. Carries oxygen and nutrients from the placenta to the fetus.
Wharton’s Jelly
Cushions the umbilical cord
Most common cause of early heart murmurs
Patent ductus arteriosus (closes 10-96 hours after birth in most neonates, closes as oxygenation increases)
