Babies Flashcards
2 functions of reproductive system
- Provide a way for fertilization to occur 2. Furnished environment that is conductive to the development of a fertilized ovum
Time frame for fertilization, why?
5 days Sperm lives for 3 days Egg lives for 2
What is capacitation
A process that allows sperm to release enzymes that allow access to the ovum
Three things that happen after sperm and egg unite
- pronuclei fuse 2. meiosis 2 3.egg swells to block sperm
How is sex determined in humans
X: female Y: male
How long does it take for the embryo to reach the uterus
(3-4 days)
What is a blastocyst
Fluid filled sphere of cells
Two parts of a blastocyst
Trophoblast-outer spear of cells (contribute to the formation of the placenta)
Inner cell mass- accumulation of cells that will become the embryo
When does the blastocyst implant in the endometrium
7 days after fertilization
What is necessary to maintain the endometrium and HOW
Estrogen and progesterone Maintain the endometrium in inhibit the secretion of FSH & LH which prevents the development of any follicles
What makes the corpus luteum stay? What is it like produced by?
Human Chorionic Gonadotropin HGC CHORION
When does the body no longer depend on the corpus luteum?
Second month
What does the placenta do 3
- Supply nutrients and remove waste from baby 2. Endocrine gland 3. Estrogen and progesterone
What feral blood vessels supply the placenta with blood?
umbelical artery
4 embryonic membranes
Amnion, yolk sac, Allantois, chorion
Amnion
-surrounds cavity between inner cell mass and trophoblasts - eventually will surround fetus - amniotic fluid protects embryo and maintains temp
Yolk Sac
- never grows serves nutritional function in humans - forms gut tube of the embryo
Allantois
- serves as a storage site for waste products - base of umbelical cord
Chorion
- formed from trophoblast and mesoderm - surrounds everything - helps make placenta
Endoderm forms:
Epithelial lining of glands of digestive and respiratory tract
Mesoderm forms:
All skeletal, most smooth and al cardiac muscle Connective tissue
Ectoderm
All nervous tissue Epidermis of skin
How long is gestation
280 days from first day of last period
Human Chronic Somatomammotropin HCS
-decreases mothers use of glucose to increase glucose of baby
How often do twins occur
1 in 85
Parturition
The process by which the fetus is expelled from the uterus
Why are babies usually born with their head facing downwards
Allows head to act as a wedge for the cervix and vagina
What is afterbirth? Why does it come out?
Contractions separates placenta from wall of uterus and expels it as afterbirth
When does uterus return to normal size
A few minutes after delivery
What 3 factors are associated with parturition
- Oxytocin 2. Prostaglandins 3. Oxytocin receptors
Outline the theory of how parturition works
- Oxytocin receptors increase because of estrogen
- Increasing sensitivity to oxytocin
- Oxytocin stimulates Prostaglandin
- Prostaglandin and oxytocin cause contractions
- Cervix pressure releases more oxytocin
What is lactation
Production of milk by mammary glands
What hormones stimulates the growth of the duct system in the breasts
Estrogen and progesterone makes boobies get big
Milk production hormone
Prolactin
Why is the majority of milk produced after delivery
Because of high levels of progesterone and estrogen during pregnany
What action by the infant stimulates milk production
Sucking of titty
How is the umbilical vein different from the other vessels in the fetus
only blood vessle with 100% O2 blood
What is another name for the umbilicus
Belly button Naval
What causes an infant to take its first breath
The decrease in O2 and increase in CO2
Foramen ovale
Fossa ovailis
Ductus arterious
Ligamentum arteriousum
Proximal portions of umbilical arteries
Superior vesicle arteries
Rest of umbilical arteries
Umbilical ligaments
Umbilical veins
Ligamentum Teres
Ductus venosus
Ligamentum venosum
flow of blood through fetus
Fetus > Umbilical Arteries > placenta >
Umbilical Vein
/ \
Ductous Venosus>IVC Liver > IVC
FROM THE IVC
IVC> RA > RV> pulmonary trunk > Ductus Arteriousus> Aorta> BOdy of Fetus
or
IVC> RA > RV> Foramen Ovale > LA> LV> aorta>BOdy of Fetus
Milk Let-Down Reflex
If one booby is sucked on, both release milk