自用|醫(yī)學(xué)英語視聽說U1Ⅰvideo2 In the Womb

The fetus is 6 months old now, but has reached a major landmark. Though barely longer than her father’s hand,?it’s possible that she could survive?outside the cradle of?the womb. She still needs extensive care, but?24?weeks is currently regarded as the earliest that a baby can be born and still have a good chance of surviving. Exceptionally, a few babies live when born as young as 22 weeks. But any baby that is born prematurely faces an increased risk of brain damage, with nearly half of all babies born before 26 weeks developing disabilities or learning difficulties. The big problem is the lungs which are barely capable at this feeble age of taking enough oxygen into the blood stream to keep the baby alive.
The fetus may be completely surrounded by amniotic fluid,?but because sound travels through fluid about four times faster than it does in air, she has?plenty to hear. The first sounds the fetus heard as her ears started picking up vibrations at 13 weeks were the gurgles and rumbles made by the mother’s body. A succession of hiccups, burps, bubbles, sloshes and slurps will mark the passage of food, liquid and air in, out and through the maze of passages and tubes just inches from the baby’s ears.
At 26th weeks, the fetus measures 25 centimeters from head to bottom. She is growing fast and as she moves through the third trimester towards birth, the fetus will triple her weight and double her length. There will continue to be dramatic growth in the brain and nervous system. And soon the fetus will create her first memory. By week 26, it may just be possible to hear the fetal heartbeat by putting your ear against the mother’s abdomen.
At 28 weeks, the baby is over 2/3 of the way through her time in the womb and is gaining weight fast as she lays down a layer of fat under her skin. Her senses are buzzing and her cerebral cortex has matured enough to support consciousness. Over the next four weeks, her nervous?system will become as?advanced as a newborn baby’s. She is becoming aware of the world around her and for the first time, her brain is beginning to create memory.
?One of the things revealed by the 4-D scans is the fact that babies have REM—rapid-eye-movement sleep, a period of sleep where the eyes flicker around behind the eyelids. Later in life, we know this is an indication of dreaming. This gentle flicker of an eye could be a sign that the fetus, still?with a month to go before even being born, is already dreaming. Though with such little life experience, it’s hard to imagine what they dream about, playing with their feet perhaps or the gurgling of their mother’s stomach.
Having been cocooned for nine months, this little girl is now on her own. Her parents will feed her and keep her warm, but for the first time, her body must keep itself alive. She has gone from egg to embryo, to fetus, to trillions of cells of newborn baby. Her birth marks the beginning of her journey in the world, but she’s already traveled an incredible path during her nine-month odyssey in the womb. Protected by her mother and following her own unique genetic blueprint, she has grown a face, arms, eyes, legs. She has a brain and nervous system to control her body, stomach and intestines to digest food and a heart?to pump blood. She has learned to breathe, to hear, to feed, to remember and to tell her parents when she’s hungry, tired, happy or in pain, all before even being born. And now she is ready to face the world.