Pregnancy and Birth

What occurs before the ovum is released from the ovarian follicle?

The nucleus divides by meiosis and becomes a secondary oocyte.

What does each paired chromosome lose during the maturation of the ovum?

One of its partners, which becomes incorporated into a polar body.

What process do ovums undergo after being ovulated?

They enter the fallopian tube.

What aids in the transportation of the ovum into the fallopian tube?

A slow fluid current.

What percentage of ova successfully move into the fallopian tubes?

Up to 98%.

How long does it take for sperm to travel to the ampulla of the fallopian tube after intercourse?

5-10 minutes.

What stimulates the contractions of the uterus and fallopian tubes?

Prostaglandins in male seminal fluid and oxytocin released by the anterior pituitary gland.

Out of half a billion sperm deposited, how many typically reach the ampulla?

Only a few thousand.

How many days does it take for the ovum to move from the fallopian tube to the uterus after fertilization?

3-5 days.

What structure forms over the surface of the blastocyst during implantation?

Trophoblast cells.

What do trophoblast cells produce to aid in implantation?

Proteolytic enzymes.

What does the placenta supply to the fetus after the 16th day of implantation?

Nourishment.

What is the term for the developing offspring during pregnancy?

Fetus.

How long does the initial development of the placenta occur compared to the fetus?

More rapidly.

At what length does the fetus measure at approximately 12 weeks?

About 10 cm.

What is the weight of the fetus at approximately 23 weeks?

1 pound.

When do most gross characteristics of all organs begin to develop?

Within 1 month after fertilization.

What happens to organ structures at 4 months of pregnancy?

They are grossly similar to those of the neonate.

During which week does the heart begin beating after fertilization?

4th week.

What type of red blood cells are formed around the 3rd week after fertilization?

Nucleated RBCs.

What is the primary metabolic energy source used by the fetus?

Glucose.

Which vitamins are crucial for the formation of RBCs in the fetus?

B vitamins.

What is the average weight gain during pregnancy?

25-35 pounds.

What is the average weight of the fetus at birth?

About 8 pounds.

What percentage increase does the basal metabolic rate in pregnant females experience?

About 15%.

What hormonal changes contribute to the desire for food during pregnancy?

Increased food removal from the fetus and hormonal changes.

What indicates health during the first year of an infant's life?

Birth weight.

What is the caloric requirement for newborns per kilogram of body weight?

Approximately 100 kcal.

What are the three macronutrient percentages in an infant's diet?

39% carbohydrates, 50-55% fats, 6% proteins.

What vitamin is crucial for the absorption of calcium in neonates?

Vitamin D.

What can insufficient iron intake in a mother lead to in an infant?

Severe anemia.

How long can infants rely on iron stores from their mother's diet?

Up to 6 months.

Which major tracts in the CNS are not myelinated until the end of the first year?

Certain major tracts.

What percentage of adult brain mass does an infant's brain represent at birth?

26%.

When do the fontanels and sutures of the skull allow for additional growth?

By the end of the 2nd year.

What is the primary problem associated with behavioral growth in infants?

Maturity of the nervous system.

What condition can result from poor liver function in newborns?

Jaundice.

What is the normal respiratory response for infants at birth?

Breathe within seconds and establish a normal rhythm within less than 1 minute.

What daily amount of water do infants need in the first 6 months?

0.7 liters.

What are the primary growth and nutritional needs of infants during their first year?

Rapid growth necessitating higher nutritional needs.

What can happen if maternal nutritional elements are insufficient during pregnancy?

Maternal defects can occur.

What is essential for the normal development of the fetal liver and coagulation factors?

Vitamin K.

What type of feed is recommended exclusively for infants in the first 4-6 months?

Human milk.

What happens to the uterus during the end of pregnancy?

It becomes more excitable and has rhythmic contractions.

What is the effect of progesterone on uterine contraction?

Inhibits uterine contraction.

What hormone specifically increases uterine contractions during labor?

Oxytocin.

What effect does the stretching of the uterine cervix have during labor?

Causes a neurogenic reflex that increases oxytocin secretion.

What can a child experience as a result of asphyxia during birth?

It stimulates the promptness to start breathing.

What condition can develop in an infant due to poor absorption of certain nutrients?

Hypoproteinemic edema.

What types of fats must infants obtain from their diet for neurological development?

Arachidonic acid and omega-3 fatty acids.