Week 6

• formation of the nose
• further development of the brain
• straighter posture
• upper and lower jaws are recognizable
• the trachea (windpipe) is developed with two lung buds
• upper lip is formed
• palate is forming
• ears are developing
• arms and legs have lengthened with arms more developed than legs
• hands and feet have digits, but may still be webbed
• tail is receding
• heart is almost fully developed
• fetal circulation is more developed
• teratogens introduced during this period may cause:
  • profound heart or aorta abnormalities
  • cleft lip
  • absence of lower jaw