EXPLORING BIOLOGY!

THE NERVOUS SYSTEM: THE BODY'S COMMAND CENTER

Have you encountered a situation that is a matter of life and death? Like if you are going fast and going to hit a car. You will probably reacted with an automatic response by running to the side of the road to avoid the accident.And you are probably wondering how you reacted fast and made a very quick reaction.

NEURONS

Well I learned that Neurons or Nerve cells are the one responsible for our quick responses and our natural actions. Because they are the one that sends the information through the nervous system in the form of nerve impulses. Neurons are unique because, unlike any other cells in the body, neurons don't reproduce. but don't worry we are born with neurons that is more than enough for a lifetime.

Figure 1
The Parts of a Neuron

The neurons have parts just like our body they have a purpose. The Cell body the largest part of the neuron holds the nucleus which controls all the activities of the cell. Dendrites are a threadlike structures that receives and carry information toward the cell body. axon a taillike fiber that extends from the cell body, carries messages away from the cell body. The myelin sheath covers the axon, which speeds up the travel of the nerve impulses. Axon terminal passes the message to the dendrites of other neurons.    

Figure 2
Types of Neurons

THE TYPES OF 

NEURONS

There are 3 types of neurons Sensory Neurons, Interneurons and Motor Neurons. The Sensory Neurons are also called afferent neurons and functions to receive initial stimuli from the sense organs, where most receptors are located. The next type is Interneurons are also called Connector Neurons or Association Neurons that is found in the spinal cord or in the brain and what they do is that they “read” impulses received from sensory neurons. Next in line is the Motor Neurons that is also called efferent neurons, transmit impulses from the brain and spinal cord to the effector cells, which may be the muscles, organs, or glands. So when a neuron receive a signal from the interneuron, they stimulate the effector cells to generate a reaction for the stimulus.    

                                                                                          Jacob Sy

THE NERVOUS SYSTEM AND ITS DIVISIONS

Now, as we all know, The Nervous System serves as the Body’s Command Center. Together with the Endocrine System, these body systems control and coordinate the activites of the body, ensuring the ability of the body functioning properly as a whole. As I studied the particular lesson tasked to me, I was able to obtain knowledge on the Divisions of the Nervous System as well as parts involved and how every part plays an important role in the body’s ability to respond to stimuli.

THE CENTRAL NERVOUS SYSTEM 
processes the information to the other parts of the body, and after proccessing the information, nerve impulses are sent to the motor neurons of the Peripheral Nervous System. The CNS consists of the brain and spinal cord, both vital parts of the NS in general. The parts are elaborated as follows:

The brain is very important and delicate, yet well-protected by a bone called the skull. Now, our control center is 85% the cerebrum-divided into the right half (artistic ability) and the left half (logical ability). With its cerebral cortex, learning, intelligence, and judgement are
possible! The 2nd lagest part, the cerebellum, coordinates muscle actions and balance. Now, this is the tricky part, as the last part contains so many regions! Here I go: The brain stem connects the spinal chord to the brain, and coordinates the survival function. The medulla oblongata controlling involuntary functions, the midbrain processing the visual and audio reflexes and the pons controlling respiratory functions comprises the brain stem. Other parts include the thalamus and hypothalamus. The spinal chord, based on what I’ve read, is a tubelike organ of neurons and blood vessels that is 1.8 cm wide. This serves as a link between the brain, and the whole body.

THE PERIPHERAL NERVOUS SYSTEM 
puzzled me at first, as it was quite complicated. But, from what I know, bundles of nerve fibers or axons conduct information to and from the central nervous system. The autonomic nervous system is the part of the nervous system concerned with the innervation of involuntary structures, such as the heart, smooth muscle, glands etc. It is distributed throughout the central and peripheral nervous systems. Ahh, so that’s what it does.

In conclusion, I’d say that the Nervous System plays and important role in our lives. Without it, we wouldn’t be living in the first place. Life itself is not possible without our Nervous System.

                                     Alyanna Ysabelle  Faustino

PREVENTION, DETECTION, AND TREATMENT OF DISEASES OF THE NERVOUS SYSTEM

Each system has different kinds of diseases. Some, a little more deadly and critical than others. Diseases regarding mental health are no exception as these may cause harm both physically and emotionally (including mentally.) Neurological disorders have been diagnosed and treated with some success for many years now. 

Disorders ranging from Alzheimer’s disease to Tourette’s Syndrome have been catalogued, identified, and treated. New disorders are diagnosed all the time, however, and sometimes it seems we may never be able to wipe out these diseases of the nervous system.

By far the most well known of the neurological disorders, at least in America, is a condition known as Alzheimer’s disease. It is infamous not only for it’s penchant for striking the elderly, but because we cannot fathom the cause or a working treatment. This disorder carries a certain mystique with it, because it has apparently been around since man could keep written records. 

In fact, Elaine Landau writes, “Shakespeare wrote about very old age as a time of “second childishness and mere oblivion,” suggesting that the symptoms of Alzheimer’s disease were known and recognized even then” The only thing we know of Alzheimer’s disease is that it attacks certain centers of the brain, namely the cerebral cortex, the basal forebrain, and the hippocampus. The cerebral cortex is usually the last thing to be effected, but the hippocampus and the nearby entorhinal cortex are the first victims, causing the classic memory loss associated with Alzheimer’s disease. Alzheimer’s disease often leads to other serious mental and social disorders, as the patient becomes less able to function, even in everyday conditions, and can even grow violent. 

                Another well known disease which effects the nervous system is 

ALS, or Lou Gehrig’s disease. This disease attacks the motor neurons in the peripheral 

nervous system, causing slow loss of control over the skeletal muscle system. The person’s brain is still active and alert, but the stimulus to move the muscles never reaches those muscles, due to the deterioration of the motor neurons in 
the anterior horn of the spinal cord.

 These are just a few cases of mental disorders and based from above, these aren't laughing matters and should be taken seriously. If not treated immediately it may result to a bigger complication which may be incurable if it reaches the severe stage.  In a nut shell, these diseases may not have any severe impact on the exterior portion of the body but it really affects the interior specifically the nervous system including the brain which is very dangerous since the brain is the control center the human body. deadly and critical than others. Diseases regarding mental health are no exception as these may cause harm both physically and emotionally (including mentally.) 

Mikaela Kate Andrel Kong

THE SENSE ORGANS AND THEIR FUNCTION

Senses are our ability to perceive stimuli. I learned that the sense organs — eyes, ears, tongue, skin, and nose — help to protect the body. The human sense organs contain receptors that relay information through sensory neurons to the appropriate places within the nervous system. This topic was quite familiar to me as it was discussed to me at elementary! The eye is the sense organ associated with sight, and it detects light that is converted to electro-chemical impulses in neurons. The ear is the sense organ associated with hearing, and the tongue has collections of nerve-like cells known as taste buds that connect to nerves going into the brain. The nose assists in distinguishing different smells, and the skin permits the sensations of cold, heat and touch. These senses are called special senses, localized to specific parts of the body. This topic was like a trip down memory lane, and I was happy to have studied about the senses in a much deeper level!

                                                                                  Daniel Elison Ordoyo

STIMULI AND RESPONSES IN PLANT

I learned that plants respond to stimuli either through growth or through movement without growth. This movement or growth toward or away from a stimulus is referred to as tropism. I also found out that tropism includes Gravitropism, that is, the growth in reponse to gravity, and Phototrpism which is the growth or movement in response to light. Plants also have Thigmotropism, the response to contact stimuli, and Heliotropism, the response to the suns’s direction. It is a great feeling to have learned so much about plants, from what I already know. I am glad that this lesson expanded my knowledge on plants. The number of tropisms made me come to a conclusion that, not just humans respond to stimuli, but also plants. Stimuli are everywhere!                                                                                              Aldrine Nicole Merto