Synapses and Neurotransmitters

The Principal Nervous System

The principal nervous system consists of two regions, the brain and the spinal cord where it manages major tasks of the mind and body. The spinal cord is the communication pathway between the brain and the body thus if damaged, the communication between the other parts of the body and the brain is disrupted. The brain is the middle of human thoughts, the source of movement control and, the external surroundings interpreter. Similar to a central computer, the brain decodes data from the touch, taste, sound, smell, sight and, from internal body parts like intestines and stomach (Louveau, et al. 121).

Cells of the Central Nervous System

Synapses and Neurotransmitters

Information is passed between different neurons via synapses, minor cracks among the cells, with the assistance of neurotransmitters. In order to convey action possible information through a synapse, neurotransmitter particles are freed from a single neuron called a pre-synaptic neuron through the crack up to the subsequent neuron. This process keeps occurring until the information reaches its target. There are many links across neurons in the spinal cord that are only created in the course of development, using negative and positive signals to adjust them.(Louveau, et al. 12)

Motor Neurons, Sensory Neurons, and Negative Feedback System

A large group of axons move in the spinal cord where the longest ones move in the central nervous system. The motor cortex neurons, the section of the brain that manages controlled movement, direct their axons via the corticospinal region to link with the motor neurons inside the spinal cord. The motor spinal neurons extend from the spinal cord to the right muscles through the ventral root. The links manage voluntary movements like running and writing. Messages also travel in the opposite side causing unconscious movement since the sensory neurons give feedback through the dorsal root to the brain. A part of the sensory neurons is sent right under motor neurons before it gets to the brain, causing reflex movements, and the left sensory messages are sent back to the cortex(Louveau, et al. 121).

The Peripheral Nervous System

The PNS consists of every nervous tissue out of the central nervous system and it is joined with the central nervous system by nerves: it consists of two regions; the sensory region and the motor region. The peripheral sensory nervous neurons convey sensory messages to the central nervous system from every part of the body. The peripheral motor neurons are divided into somatic and automatic parts: They both transmit nerve impulses from the CNS to the body glands, as well as, muscles in every part of the body. These nerve impulses excite muscle contraction, and hormone secretion by glands (Louveau, et al. 178). Both the motor and sensory nerve cells convey information from the outside surroundings to the spine, but they are divided into front sensory root and back sensory root where each has a specific role.

The Circulatory System

Arteries

The main role of arteries is carrying blood away from the heart towards the other body parts. Arteries dense and thick walls shrink help to prevent blood from flowing through the body from the heart. During the general circulation, the blood that has oxygen is propelled into the thick artery (aorta)from the heart, then the blood vessel (aorta) coils up and spinal of the left ventricle then drops in the spinal cord anterior part towards the stomach. At the start of the aorta, 2 coronary arteries separate and branch into thinner vessels that offer nourishment and oxygen into the heart. On the other hand, pulmonary artery carries blood without oxygen, from the right ventricle; it separates into two branches towards the lungs where the blood collects oxygen (Marseille and Wolfgang 117).

Veins and, Capillaries

The veins contain valves which stop blood from flowing backward and, their main role is to transport blood to the heart from the body. The veins have three layers like the arteries but they are less flexible and thinner; the 2 biggest veins are inferior and superior venacava and they are positioned below and above the heart. A connection of tiny capillaries joins the veins and the arteries. The main function of the capillaries is to transport oxygen, as well as, nutrients to the cells. They also assist in eliminating waste materials like carbon dioxide from the body (Marseille and Wolfgang 98).

White and Red Blood Cells

The red blood cells basic role is to carry oxygen to the body cells from the lungs. RBCs similarly eliminate unwanted carbon II oxide from the body cells to the lungs where it can be exhaled. When they stop to operate properly, it is a sign that someone could be ill. White blood cells which are also known as leukocytes, perform immune responses in the body by identifying and neutralizing attackers like viruses and bacteria. Some WBCs engulf and break down pathogens, whereas others identify particular microorganisms and initiate immune mechanisms counter to them (Marseille and Wolfgang 132).

Work Cited

Louveau, Antoine, et al."Structural and functional features of central nervous system lymphatic                                vessels." Nature 523.7560 (2015): 337.

Marseille,Oliver, and Wolfgang Kerkhoffs. "Devices, methods and systems for establishing     supplementalblood flow in the circulatory system." U.S. Patent No. 9,572,917. 21 Feb.      2017.