Prenatal Development

Question 1

Embryology:

Answer 1

The study of prenatal development

Question 2

Epigenesis:

Answer 2

The emergence of new structures and forms during the developmental process

Question 3

Reproduction

Answer 3

begins when egg is released from ovaries into the fallopian tube

Question 4

Conception:

Answer 4

union of gametes – the sperm (father sex cell) and egg (mother sex cell)

Question 5

What are the stages of the prenatal period?

Answer 5

Zygote – Embryo – Fetus

Question 6

What is a zygote? When does it occur, where, and what does it do?

Answer 6

• union of sperm and egg(½ mother’s genetic material and ½ father’s). Also known as fertilized egg.
• Timeline: conception until implantation (about 2 weeks)
• Location: traveling down the fallopian tube
• Activity: rapid cell division (perhaps twins..)

Question 7

What is an embryo? When does it occur, where, and what does it do?

Answer 7

• inner cell mass, after implementation
• Timeline: 3rd to 8th week
• Location: implantation in the uterine wall
• Activity: cell differentiation, primitive heart, Embryo folds into u-shaped groove. Top of groove fuses together  neural tube (later will be brain and spinal cord)

Question 8

When does it occur, where, and what does it do?

Answer 8

Timeline: 9th week on, considered a fetus
Location: uterus
Activity: Increasing behavior, sensory experience, start of learning, organs present, sex differences

Question 9

Cephalocaudal principle:

Answer 9

areas near the head develop at a more rapid pace than those farther away

Question 10

Critical period:

Answer 10

period of development in which certain structures or processes are particularly susceptible to interfering factors

Question 11

What is a teratogen? How does it affect the zygote, embryo, and fetus?

Answer 11

• environmental agents that may cause harm during prenatal development
• Zygote – likely won’t survive
• Embryo – damage to developing organs/limbs
• Fetus – more resilient, but may have higher rates of brain damage

Question 12

(teratogen) dose-response relationship

Answer 12

Amount and length of exposure matter

Question 13

What are three possible consequences of being exposed to this teratogen during prenatal development?

Answer 13

• subtle effects that result in developmental delays that are not obvious at birth
• sleeper effects—effects that are not visible until many years later

Question 14

Sensory Experiences:

• Touch
• Taste
• Smell
• Sight
• Hear (from at least 6mos of gestation)

Answer 14

• Grasping, sucking, rubbing, bumping walls of uterus
• Swallows amniotic fluid; Fetus has a sweet tooth
• Amniotic fluid has odor of what mom ate; During fetal breathing, amniotic fluid comes into contact with olfactory receptors
• Negligible
• Internally generated sounds (mom’s heartbeat, breathing, etc.); Externally generated sounds (mom’s voice and people talking to her); Fetus reacts by changes in heartbeat and movement

Question 15

Prenatal Learning

Answer 15

-Around 32 weeks the fetus shows signs of habituation
(measured by changes in a heartbeat)
-Around 37 weeks the fetus shows signs of long-term memory and learning

Question 16

After birth: Sensory experiences

Answer 16

Hearing: recognizes mom’s voice

Smell: Prefers own amniotic fluid

Taste: Recognizes carrot juice
exposed as a fetus, but not since
birth