Prenatal development Flashcards
Most major organ development occurs during which period?
Embryonic period
When does human development begin?
fertilization
Where does fertilization, or conception, occur?
Fallopian tube or uterine tube
What is the role of the stem cell?
form each of the cell types contained in the human body
Where does implantation occur, and when does it begin?
- Occurs in the uterine wall
- Begins 6 days after fertilization
What is the role of the placenta?
- Interface between maternal and embryonic circulatory system
- Delivers medication, hormones, oxygen, and nutrients to fetus
- Produces hormones and maintains body temp above mother’s
- Prevents embryo’s and mom’s blood from mixing
Which three layers are formed by the epiblast?
- ectoderm
- endoderm
- mesoderm
Ectoderm gives rise to which organ systems?
- brain
- spinal cord
- nerves
- skin
- nails
- hair
Endoderm gives rise to which organ systems?
- Lining of respiratory system
- Digestive tract
- liver
- pancreas
Mesoderm gives rise to which organ systems?
- heart
- kidneys
- bones
- cartilage
- muscles
- blood cells
What are the three sections of the brain formed by 3 weeks?
- forebrain
- midbrain
- hindbrain
Tubular Heart is formed by what age of the fetus?
3-4 weeks
Which is the first body system to achieve a functional state?
Circulatory system
What is the role of the amniotic fluid during pregnancy?
Provides protection embryo from injury
At what age are the cerebral hemispheres formed?
5 weeks 2 days
At what age is cartilage forming?
5.5 weeks
At what age do reflexive movements occur, and why is this important?
- Reflexive movements occur at 6 weeks and 6 days
- Necessary for normal neuromuscular development
At how many weeks is the diaphragm formed?
6 weeks
Brain waves are detectable as early as?
6 weeks 2 days
Ossification occurs where first?
Clavicle and upper and lower jaw
Startle response occurs as early as?
7 weeks 3 days
At how many weeks is coordination beginning development within a zero-gravity environment?
8 weeks
How many distinct anatomic structures are present at the end of the embryonic period?
4000 distinct anatomic structures
More than __ of the structures found in adults are present by the end of the embryonic period.
90%
The fetal period occurs from __ weeks until birth.
9
Light touch to the feet results in what?
Bend hip and knee and may curl toes
What process is occurring in most bones by 10 weeks?
Ossification
Response to ________ throughout most of the body (except top of head and back) is present at 12 weeks
light touch
Rooting reflex present at _____ to assist with feeding.
12 weeks
Sense of fetal movements call quickening occurs at how many weeks?
Between 14 and 18 weeks
What is the purpose of vernix?
Protects the skin from the irritating effects of anionic fluid
What is the “age of viability”? Why?
- 21-22 weeks
- survival outside the womb becomes possible for some fetuses due to the lungs ability to breath
Blink-startle response is present at what age?
24 weeks
Exposure to loud noises can result in what changes in the postnatal period?
- Adversely effects fetal health
- Prolonged increased heart rate
- Excessive fetal swallowing
- Abrupt behavior changes
- Hearing loss
Pupils respond to light at what age?
27 weeks
Somersaults in zero-gravity environment are occurring at what age?
6 months 3 weeks
Complex and coordinated movement patterns are frequently occurring, followed by periods of rest at what fetal age?
7 months 2 weeks
How is labor induced?
Release of large amounts of estrogen
