|
Sixth Week
|
Timing
|
Source |
| The upper and lower lips are forming. |
Early in 6th week after fertilization |
Moore, p 523 |
The tongue is developing.
|
Early in 6th week after fertilization |
Moore, p 523 |
| The eye is obvious, reflecting the
fact that the retinal pigment has formed. |
6th week after fertilization |
Moore, p 94 |
| The upper and lower eyelid primordia
appear. |
6th week of development. |
Larsen, p 259 |
| The primordia of the fingers, called
digital rays, start to develop. |
6th week after fertilization |
Moore, p 94 |
| Hiccups first occur. |
6th week after conception |
Roodenburg, p 32 |
| The ends of the limb buds become flattened
to form foot plates. |
6th week of development |
Sadler p 172 |
| The oral cavity is developing. |
6th week |
Sadler, p 376 |
| Spontaneous movements, such as twitching
of the trunk and limbs, have been reported. |
6th week after fertilization |
Moore, p 94 |
| The pelvis is developing. |
6th week |
Sadler, p 308 |
| Movement of the muscles is being controlled
by the nervous system. |
6th week after conception |
Rugh, p 34 |
| It is believed that the majority of
women do not realize they are pregnant during the
first six weeks after conception. |
6th week after conception |
Rugh, p 54 |
| In a study of 12 fetuses, the longest
median period of inactivity was 260 seconds. |
6th week after conception |
de Vries (1985), p 102 |
| The testes become identifiable. |
6th week |
O'Rahilly, p 210
|
| The ureter is developing. |
6th week |
Sadler, p 308 |
| Some salivary glands appear. |
About 6th week after fertilization |
Moore, p 236 |
| General movements first occur. |
6th -7th weeks after conception |
Roodenburg, p 31 |
| The fetus normally moves spontaneously. |
6th-8th weeks after conception |
de Vries (1982), p 318 |
| The heart is contracting at a rate
of 40 to 80 beats per minute, as measured with an
electrocardiogram. |
6th - 7th weeks after conception |
Rugh, p 53 |
| The salivary glands begin to develop |
6th - 7th weeks after fertilization |
England, p 90 |
| The uterus forms. |
6th - 7th weeks |
Larsen, p 175 |
| The vagina forms. |
6th - 7th weeks |
Larsen, p 175 |
| Startles first occur. |
6 - 7 1/2 weeks after conception |
Nijhuis/de Vries, p 5 |
| General movements first occur. |
6 1/2 - 7 1/2 weeks after conception |
Nijhuis/de Vries, p 5 |
| Hiccups first occur. |
6 1/2 - 8 1/2 weeks after conception |
Nijhuis/de Vries, p 5 |
| The aorta is developing. |
Day 36 of development |
Larsen, p 156 |
| Ear swelling is present. |
Day 36 after fertilization |
Sadler, front pages |
| The oral and nasal cavities are confluent. |
Day 36 after fertilization |
Moore, p 5 |
| All of the muscle blocks have appeared. |
Day 36 after conception |
Rugh, p 46 |
| The pancreas is developing. |
Approximately day 36 |
Sadler, p 281 |
| The thyroid is developing. |
Approximately day 36 |
Sadler, p 281 |
| Digital rays are present in the foot
plates. |
Days 36-42 of development |
Sadler, p 110 |
| Digital rays are present in the hand
plates. |
Days 36-42 of development |
Sadler, p 110 |
| The feet have become distinct. |
Day 37 of development |
Larsen, p 209 |
| Foot plates are formed on the lower
limb buds. |
Day 37 after fertilization |
Larsen, p xii |
| The legs have become distinct. |
Day 37 of development |
Larsen, p 209 |
| The thigh has become distinct. |
Day 37 of development |
Larsen, p 209 |
| Pigment can be seen in the retina. |
Days 37-40 after fertilization |
Moore, p 91 |
| The eye muscles begin to form. |
Day 38 after conception |
Rugh, p 47 |
| Finger rays are visible. |
Day 38 of development |
Larsen, p 209 |
| Finger rays are developing. |
Day 38 after fertilization |
Sadler, front pages |
| The upper and lower jaws begin to
fuse in the midline of the face. |
Day 38 after conception |
Rugh, p 47 |
| The nose is formed. |
Day 38 after fertilization |
Moore, p 5 |
| It is probable that the heartbeat
of the embryo is similar to an adult's heartbeat. |
Week 5 1/2 after conception |
Rugh, p 53 |
| The urinary bladder is developing. |
Day 39 after fertilization |
Sadler, front pages |
| The pancreas is developing. |
Day 39 after fertilization |
Sadler, front pages |
| The liver is developing. |
Day 39 after fertilization |
Sadler, front pages |
| The foundation of the sense of smell
is established when nerve fibers connect with the
olfactory lobe in the brain. |
Day 39 after conception |
Rugh, p 47 |
| The eyelids are developing. |
Day 40 after conception |
Moore, p 238 |
| The eyes become pigmented. |
Day 40 after conception |
Rugh, p 47 |
| The diaphragm forms. |
Day 40 after conception |
Rugh, p 47 |
| The forehead is developing. |
Day 40 after fertilization |
Moore, p 238 |
| The jaws are well-formed. |
Day 40 after conception |
Rugh, p 47 |
| The lower jaw is developing. |
Day 40 after fertilization |
Moore, p 238 |
| The kidneys are forming. |
Day 40 of development |
Larsen, p 156 |
| The nostrils are developing. |
Day 40 after fertilization |
Moore, p 238 |
| The teeth begin to form. |
Day 40 after conception |
Rugh, p 47 |
| Digital rays are clearly visible in
the hand plates. |
Days 41-43 after fertilization |
Moore, p 91 |
| The rudiments of the fingers become
evident. |
Day 42 after conception |
Rugh, p 47 |
| The earliest reflexes begin. |
Day 42 after conception |
Rugh, p 47 |
| The penis begins to form. |
Day 42 after conception |
Rugh, p 47 |
| The rudiments of the toes become evident. |
Day 42 after conception |
Rugh, p 47 |
| The eye is obvious. |
About day 42 after fertilization |
Moore, p 99 |
| The pigmented eye is developing. |
About 42 days after fertilization |
Moore, p 99 |
