Descending tracts are the pathways by which motor
signals are pass through from the brain to lower motor neurones. Thus, all
the neurones within the descending motor system are classed as upper motor
neurones. The lower motor neurones then directly innervate muscles to produce
movement. Their cell bodies are found in the cerebral cortex or the brain stem,
with their axons remaining within the CNS.
Answer:
Testes and ovaries produce two types of hormones:
androgens (male sex hormones)
estrogens (female full hormones)
In each type of gland, both types of hormones are secreted only in different amounts: the ovaries secrete more estrogen than the androgen hormones, and the sperm inversely.
Explanation:
In testicular tissue, Leydig cells produce androgen hormones: androsterone and testosterone. The ovaries produce a group of estrogen hormones and progesterone. These hormones exert their effect at puberty when the glands are activated. At puberty, the pituitary gonadostimulins activate the sex glands, whose activity leads to the development of secondary sex characteristics (the appearance of first menstruation in girls, beards and mustaches in boys, etc.).
Answer:
The rocks may have different textures
Explanation:
If we have to igneous rocks, and they have the same minerals, that doesn't necessarily means that they will have the same name, thus being classified as the same rock. The reason for this is that the two igneous rocks may have a different texture. One of the rocks may have a foliated, while the other may have porphyritic, giving them different appearance despite the same minerals being in both of them. The reason why two igneous rocks with the same minerlas may appear different, is the process in which they have been formed, the quickness of the cooling, the temperature that they were exposed to, and the pressure they were exposed to.
