Lecture 1 Conception & Fetal development Flashcards
During conception when sperm enters the egg what is produced?
Zygote
How long for zygote to be formed?
Hours
When the zygote divides it becomes an?
Embryo
Inner layer of the egg sperm must penetrate?
Zona pellucida
Outer layer of the egg
Corona radiata
Where does the embryo travel and implant?
Travels through the oviduct and implants at the endometrium
Physical signs of pregnancy?
No menstruation
Morning sickness
Breast enlargement
Increased urination
Dark areolas
Germinal, embryonic, and fetal stages of development
Germinal - Travels first two weeks
Embryonic - all organs are being created (VITAL STAGE)
Starts weeks 3-8
Fetal - Period of refinement (9th weeks until birth)
What produces hCG until the placenta takes over?
Corpus luteum
Purpose of the hormone hCG?
Keeps pregnancy going
Maintains the corpus luteum
Drops at 13 weeks
Purpose of estrogen?
Increases blood volume by 50%
Uterine contractility (Aids in labor)
Breast development
Purpose of progesterone?
COUNTERACTS estrogen
Relaxes
Maintains the endometrium
Breast development
What happens if progesterone drops too low?
Estrogen takes over and can cause uterine contractility at early point in pregnancy causing prematurity or miscarriage.
What is cleavage
Cell divides without growth
What is morphogenesis?
Shaping of embryo
What is differentiation?
Cells taking on specific structure and function. Each cell knows what organ it belongs to and its duties.
What is the morula?
Solid mass of cells results from cleavage
What is a blastocyte and embryonic disc?
Blastocyte is formed from morula and is a ball of cells
The embryonic disc is inner mass of cells within the blastocyte
What is the gastrula?
Three tissues of embryo
Ectoderm
Mesoderm
Endoderm
What is the neurula?
Nervous system the develops from the ectoderm
Germ Layer of Theory Ectoderm organs targeted?
Skin, epidermis, hair, nails, sweatglands
Nervous system - Brain, spinal cord, ganglia, Nerves
Eyes - Retina, lens, cornea of eye
Inner ear
Lining of nose mouth and anus
Tooth enamel
Germ Layer Theory -Mesoderm
All muscles
Dermis of skin
All connective tissue - Bone, cartilage, and blood
Blood vessel
Kidneys
Reproductive organs
Germ Layer of Theory - Endoderm
Lining of digestive tract, Gall bladder, urethra
Trachea, Bronchi, Lungs
Pancreas
Liver
Thyroid, parathyroid, thymus glands,
Bladder
What takes place during 7th and 8th week fetal development?
7 weeks - Feet, toes, legs
Blood vessels - heart beat this is when pulse helps feed rest of the body
8th week - Human appearnace all organs made no more tail
Materal portion of placenta?
Delivers O2 and nutrients through osmosis
Fetal portion of placenta?
Waste products
Role of arteries in the umbilical cord?
Arteries - Exchanges of gases and nutrients between maternal and fetal blood
Role of the vein in the umbilical cord?
Carries blood and oxygen away from the placenta to the fetus
What seperates the vein in the umbilical cord?
Wharton’s Jelly
Normal volume for amniotic fluid?
800-1200ml at term
Two types of outcomes for polyhydramnios
May be linked to cerebral palsy
Can always lead to premature labor - uterus can expand too much
Two types of outcomes for oligohydramnios?
Cord compression
Babys head drops
Oligohydramnios
Lower than average amniotic fluid
The babies kidneys aren’t working properly or the placenta
Nutrition, organ systems are affected
How to care for oligohydramnios?
Bed rest & less movements
increase fluid intakes to help produce more fluids
Polyhydramnios?
Too much amniotic fluid
Seen in GDM
If treated early can be reduced by removing some
