Newborn babies have a greater rate of heat loss and lower muscle mass for shiver
ID: 3473954 • Letter: N
Question
Newborn babies have a greater rate of heat loss and lower muscle mass for shivering. So that babies can maintain core body temperature they have higher levels of brown fat than adults. Brown fat responds to norepinephrine from the sympathetic nervous system by producing an uncoupling protein (UCP1). This UCP1 inserts itself into the inner mitochondrial membrane and allows H+ from the intermembrane space of the mitochondria to leak back into the matrix of the mitochondria. Explain what happens to ATP synthesis as a result and why this mechanism helps newborn babies maintain core body temperature.
Explanation / Answer
Thermoregulation is one of the most important parameters for a newborn, as compared to adults. Even Fetuses have higher metabolism , with more heat transfer taking place between the placenta and the uterus. After birth, the temperature of the newborn's body drops rapidly, in response to the external temperature. In order for survival, the neonate must have heat generation in its body, which is undertaken via nonshivering thermogenesis (NST), which is coupled to lypolysis in brown adipose tissue.The release of fatty acids stimulates the respiration of brown adipocytes and heat production.
By oxidizing fatty acids present in the mitochondria, the uncoupling of ATP synthesis takes place. This reaction also takes the aid of the uncoupling molecule.-uncoupling protein 1 (UCP1). The prodcution of heat starts at birth, and continues for several hours.
Leakages of free fatty acids are activated via cellular signals, which leads to increased rate of respiration, and leads to the release of more heat per unit time.