Developmental Biology 人的生长速率因发育阶段而异 Average growth after birth Male and female comparative growth rates Height Change (cm)180 in height 10 (cm/year) Girls 24681012141618 89101112131415161718 Age(years) Age (years) Fig. 14.4 Normal human growth comparative growth rates of boys and Left panel: an average growth curve girls. There is a growth spurt at puberty for a human male after birth. Right panel: in both sexes, which occurs earlier in girls
Developmental Biology 人的生长速率因发育阶段而异
Developmental Biology 人躯体的不同部分有不同的生长速率 adult Weeks of development Age in years Fig 14.5 Different parts of the human body grow at relatively large but, with time, other parts of the body grow much different rates At 9 weeks of development, the head is more than the head. After Gray, H: 1995
Developmental Biology 人躯体的不同部分有不同的生长速率
Developmental Biology 营养对生长的影响 胚胎在子宫中发育期间营养不良,一般会产 生较小、但各部分比例正常的个体。 出生后营养不良可影响某些器官的正常生长。 如断奶后营养不良的大鼠骨架生长正常,但 肝和肾会很小。 出生时个体较小的婴儿,长大后易患心血管 疾病和非胰岛素依赖性糖尿病
Developmental Biology 营养对生长的影响 ➢胚胎在子宫中发育期间营养不良，一般会产 生较小、但各部分比例正常的个体。 ➢出生后营养不良可影响某些器官的正常生长。 如断奶后营养不良的大鼠骨架生长正常，但 肝和肾会很小。 ➢出生时个体较小的婴儿，长大后易患心血管 疾病和非胰岛素依赖性糖尿病
Developmental Biology 生长受激素的调控 Hypothalamus Fig 14.6 Growth hormone production is under the control of the hy pothal- Growth hormone releasing hormone <7 Somatostatin amic hormones. Growth hormone is made in the pituitary gland and is secreted 计f Growth hormone- releasing hormone from the hypothalamus promotes growth hormone synthesis, while somatostatin Pituitary inhibits it. growth hormone controls its Growth hormone own release by negative feedback signals to the hypothalamus. Growth hormone causes the synthesis of the insulin-like growth factor IGF-1 and this promotes the production of growth hormone IGF-1 synthesis 缺失IGF-2基因的小鼠出生时的重量 仅为正常鼠的60%,表明IGF2是早 期胚胎生长所必需的。IGF-1主要在 出生后起作用 Cell multiplication
Developmental Biology 生长受激素的调控 缺失IGF-2基因的小鼠出生时的重量 仅为正常鼠的60%，表明IGF-2是早 期胚胎生长所必需的。IGF-1主要在 出生后起作用
Developmental binlnov 不同的器官具有不同的内在生长程序 Length 9 Humerus Humerus H Ulna C-Humerus Wrist Scapula 0 357911131517 Phalanx I Time after initial formation(days) Radius Fig. 14.7 Comparative growth of the Humerus cartilaginous elements in the embryonic chick wing. When first laid down, the cartilaginous elements of the humerus carpus uIna and wrist are the same size, but the Metacarpus Ulna humerus and ulna then grow much more Figure 9-22 Formation of the skeleton in the mammalian forelimb than the wrist element
Developmental Biology 不同的器官具有不同的内在生长程序