Hormones and Nerve Questions Essay Example | Topics and Well Written Essays - 3250 words

Hormones and Nerve Questions - Essay Example But it was proved that epinephrine alone could not cause this transformation to occur. It had to call on the help of a secondary messenger, cyclic AMP, for assistance. Cell membranes consist of lipid chains which makes them hydrophobic or water repelling in nature. Whereas hormones are proteins made of hydrophilic or water loving peptide chains, and they cannot readily pass through the cell membranes. This is where secondary messengers come in. they serve as a messenger between the hormones and the target cell. Secondary messengers are mostly small molecules causing a higher rate of diffusion through the cytoplasm of the cell and a faster rate of information transmission. Secondary messengers also help intensify the strength of a particular signal. Hormones in very small amounts can cause the release of thousands of secondary messengers. This means that the body can save up a lot of energy. It does not need to utilize all its nutritive resources such as proteins in the formation of h ormones, because only tiny quantities of these hormones are needed to get a response from the target cells. Therefore minimum amounts of energy are used by the body to communicate with various cells. Secondary messengers are present in the cytoplasm of cells, thereby controlling the rate of hormones and enzymes utilized by the cells. They could either cause an increase or decrease in the metabolic reactions of the cells. This means that tiny doses of hormones could cause immediate responses as the effects are amplified by the secondary messengers. Secondary messengers are also responsible for signal transduction torrents. Words: 310 NERVE QUESTION Write approximately 800 words on why it is important to understand the structure of nerve cells in order to appreciate their function. Please make sure you cover the generation of an action potential and the transmission of a nerve impulse. It is important to understand the structure of nerve cells, because it is because of their specific structure that they can carry out their important functions. A nerve is a bundle of neurons and a neuron is an individual nerve cell. There are three types of neurons: Sensory neurons Relay neurons Motor neurons These three neurons function together to transmit nerve impulses and each of them have a separate structure which facilitates the entire process. Sensory neuron endings are more concentrated in our sense organs like the retina of the eye, cochlea of the ear, etc. sensory neuron endings receive stimulus from the sense organs and then they pass the nerve impulse immediately to the dendrite which then passes them to the Dendron, which is a single fiber, and then these impulses are brought to the cell body which consists of a nucleus and cytoplasm. Finally these impulses pass through the axon and arrive at the synaptic knob which has several branches. These impulses are somewhat similar to electrical impulses. Sensory neurons are elongated cells consisting of sensory nerve endin gs at one end and synaptic knobs at the other. They are coated with a fatty layer known as the myelin sheath which acts as an electrical insulator so as not to get disturbed with other passing impulses. Gaps in the myelin sheath are known as the nodes of Ranvier, which help speed up the passage of nerve impulses. Relay neurons are smaller cells which act as a link