Medical science Fetal pregnancy anatomical model Developmental process Embryo 10-piece set laboratory hospital model

The 10 models are set to show the relationship between the development process of the fetus and the uterus in October pregnancy. The egg is called pregnant or fertilized within 2 weeks after fertilization; The 3-8 weeks after fertilization are called embryos; From the end of the 8th week, it is called fetus; 8 weeks; The embryo is about 3cm long and has begun to take on a human shape, with a particularly large head, recognizable eyes, ears, nose and mouth. The early heart formation and pulsation can be detected by ultrasound examination. At 12 weeks, the fetus is 7 ~ 9cm long and weighs about 20g. Exogenous orthogonia has occurred, there is weak activity in the limbs, and ossification centers have appeared in most bones. At 16 weeks, the fetus is about 10 to 17cm long and weighs 100 to 120g. It has red, smooth and transparent skin with a small amount of vellus hair. Further bone development, X-ray examination can see bone shadow, external straightener can distinguish male and female. Abdominal examination can hear fetal heart sound, pregnant women can feel fetal movement. At 20 weeks, the fetus is 18 ~ 27cm long, weighs 280 ~ 300g, the skin is dark red, the transparency is reduced, the body has fetal fat, the fetal head accounts for 1/3 of the body, there is hair growth, and the swallowing activity begins. 24 weeks fetal body length 28 ~ 34cm, weight 600 ~ 700g, subcutaneous fat began to deposit, skin wrinkles. At 28 weeks, the fetus is 35 ~ 38cm long and weighs 100 ~ 1200g. The whole body is thin, the skin is red, there is fetal fat on the finger (toe) nail does not reach the finger (toe) end. In women, the labia majora contains the labia minora and the clitoris, and in men, the testicles have descended to the scrotum. Due to less subcutaneous fat, facial wrinkles, like an old man. If born, they can cry, swallow, and move their limbs, but they are weak and require special care to survive. The 32-week fetus is 40cm long, weighs 1500 ~ 1700g, the skin is dark red, the facial hair has fallen off, and can survive after proper care. At 36 weeks, the fetus is 45 ~ 46cm long and weighs about 2500g. Subcutaneous fat, facial wrinkles disappear, finger (toe) nail has reached finger (toe tip). After birth, crowing and sucking have a good chance of survival. The fetus is mature at 40 weeks, with a length of about 50cm and a weight of about 3000 ~ 3300g. The skin is pink, the subcutaneous fat is well developed, most of the fetus has subsided, and the hair is 2 ~ 3cm long. The nail of the finger has passed over the tip of the finger. Active limb movement, loud crowing, strong sucking reflex. Fetal body length and weight gradually increase with the gestation month, in order to facilitate memory, the following formula is generally used to calculate: before 20 weeks of gestation length = the square of the number of gestation months (cm), after 20 weeks of gestation length = the number of gestation months ×5 (cm).