Cartões: Fetal Development Human Embryology | Quizlet

Plancenta

organ that nourishes the fetus

Zygote

the fertilized egg; it enters a 2-week period of rapid cell division and develops into an embryo

embryo

the developing human organism from about 2 weeks after fertilization through the second month.

fetus

The developing human organism from 9 weeks after conception to birth.

umbilical cord

a tube containing the blood vessels connecting the fetus and placenta

gestation

growth process from conception to birth

Days 8 - 9: implantation begins

The germinal stage ends when the blastocyst implants in the endometrium of the uterus

Week 4

A ball of cells called a blastocyst has officially become an embryo, roughly the size of a poppy seed. This is when organ development begins.

Week 5

The baby's heart begins to beat, generally at about twice the rate of an adult heart. The neural tube (brain, spinal cord and other neural tissue of the central nervous system) forms. The tiny "heart" tube will beat 110 times a minute by the end of the fifth week.

Week 6

Facial features begin to form, and little buds for the arms and legs start to develop. Blood cells are taking shape, and circulation will begin. Structures that'll become the ears, eyes and mouth take form. Your healthcare provider can probably detect a heartbeat on a vaginal ultrasound.

Week 7

Bones begin replacing soft cartilage and genitals begin to form. The embryo's head is large in proportion to the rest of its body. Some people think the embryo resembles a small tadpole or seahorse due to its prominent tail (which becomes legs) and large head.

Week 8

All of the major organs and body systems are developing. The fetus has web-like hands and feet. Eyes become visible and ears begin to form. The umbilical cord is fully developed and helps to transport oxygen and blood to the embryo.

Week 10

The embryo officially becomes a fetus. Organs like kidneys, intestines, brain, and liver are beginning to function, and fingernails and toenails are starting to form.

Week 12

Vocal cords form and the fetus's large head begins to grow proportionate to its body.

week 14 of development

The baby's kidneys are producing urine that's released into the amniotic fluid. The baby can make facial expressions and may begin sucking his or her thumb.

Week 16 of gestation

The baby's gender might be detectable at a mid-pregnancy ultrasound, which is generally done between 16 and 20 weeks into pregnancy.

Week 18 of gestation

The fetus is covered in lanugo, a peach fuzz-like hair. It helps keep the fetus warm and provides another layer of protection. The fetus may have a sleep-wake cycle, and loud noises may wake the fetus if it's asleep.

week 20 gestation

: The fetus's nails grow towards the end of its fingers. The area of the brain responsible for its five senses begins to develop.

Neurulation

The formation of the neural tube from overlying ectoderm cells.

What days of development does the neurulation form?

sixteen days after conception

When does brain development begin?

18 days after conception

What is the 1st stage of neurulation?

Formation of the neural plate.

What is the 2nd stage of neurulation?

The neural plate folds.

What is the 3rd stage of neurulation?

The forming of the neural tube.

What is the 4th stage of neurulation?

The closure of the the neural tube.