Anatomy Of The Nervous System
If you think of the brain as a central computer that controls all bodily functions, then the nervous system is like a network that relays messages back and forth from the brain to different parts of the body. It does this via the spinal cord, which runs from the brain down through the back and contains threadlike nerves that branch out to every organ and body part.
When a message comes into the brain from anywhere in the body, the brain tells the body how to react. For example, if you accidentally touch a hot stove, the nerves in your skin shoot a message of pain to your brain. The brain then sends a message back telling the muscles in your hand to pull away. Luckily, this neurological relay race takes a lot less time than it just took to read about it.
Considering everything it does, the human brain is incredibly compact, weighing just 3 pounds. Its many folds and grooves, though, provide it with the additional surface area necessary for storing all of the bodys important information.
The spinal cord, on the other hand, is a long bundle of nerve tissue about 18 inches long and ¾ inch thick. It extends from the lower part of the brain down through spine. Along the way, various nerves branch out to the entire body. These make up the peripheral nervous system.
Things That Can Go Wrong With The Brain
Because the brain controls just about everything, when something goes wrong with it, its often serious and can affect many different parts of the body. Inherited diseases, brain disorders associated with mental illness, and head injuries can all affect the way the brain works and upset the daily activities of the rest of the body.
Problems that can affect the brain include:
Brain tumors. A brain tumor is an abnormal tissue growth in the brain. A tumor in the brain may grow slowly and produce few symptoms until it becomes large, or it can grow and spread rapidly, causing severe and quickly worsening symptoms. Brain tumors in children can be benign or malignant. Benign tumors usually grow in one place and may be curable through surgery if theyre located in a place where they can be removed without damaging the normal tissue near the tumor. A malignant tumor is cancerous and more likely to grow rapidly and spread.
Epilepsy. This condition is made up of a wide variety of seizure disorders. Partial seizures involve specific areas of the brain, and symptoms vary depending on the location of the seizure activity. Other seizures, called generalized seizures, involve a larger portion of the brain and usually cause uncontrolled movements of the entire body and loss of consciousness when they occur. Although the specific cause is unknown in many cases, epilepsy can be related to brain injury, tumors, or infections. The tendency to develop epilepsy may be inherited in families.
Which Part Of The Brain Keeps You Breathing
Breathing helps us to absorb oxygen from our atmosphere, and that oxygen plays a huge role in turning food into energy our body requires.
It also allows us to get rid of the carbon dioxide the respiration process generates.
The medulla oblongata is able to precisely detect the exact amount of oxygen and carbon dioxide within our system. Depending on this ratio, it signals the heart and the diaphragm with instructions on how to work.
The greater the level of strength we need to complete a task, the more oxygen we need. Therefore, both the respiratory and the cardiovascular system need to work harder to provide us with the amount of oxygen we need to produce energy and get rid of all the excess carbon dioxide.
For example, if were working out, were exerting ourselves more than usual. The medulla oblongata notices our bodys need for more oxygen .
So it makes us breathe more heavily to increase oxygen intake. In addition, our heart beats faster so the necessary oxygen can be distributed to the muscles with increased speed.
The increased intake of oxygen helps us deal with the greater generation of carbon dioxide more efficiently as well. Thus, the medulla oblongata keeps the respiratory process balanced: in with the oxygen, out with the carbon dioxide.
However, if the oxygen concentration is too great, the medulla oblongata signals the respiratory and the cardiovascular system to take it down a notch or two.
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The Autonomic Nervous System
The autonomic nervous system is responsible for controlling many physiological functions. It induces the force of contraction of the heart and its heart rate. In addition, it controls the peripheral resistance of blood vessels. The ANS has both sympathetic and parasympathetic divisions that work together to maintain balance.
The Lobes Of The Brain
Each hemisphere of the cerebrum is divided into four lobes: frontal, temporal, occipital and parietal. The frontal lobes are the largest sections of the brain and make up the front portion of the cerebrum. The frontal lobes are the main thought processing center and control reasoning, problem solving, decision making, language and personality traits.
The temporal lobes are found on the sides of the brain, just above the ears. This part of the brain is responsible for short-term memory, understanding speech and recognizing sounds. Together with the frontal lobes, they identify and process smells.
The back portion of the cerebrum are the occipital lobes, which control vision. Lying interior to the frontal, temporal and occipital lobes are the parietal lobes. The parietals are the sensory processing center of the brain and are responsible for spoken language and learning.
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Location And Basic Physiology
In vertebrate anatomy, the brainstem is the most inferior portion of the brain, adjoining and structurally continuous with the brain and spinal cord. The brainstem gives rise to cranial nerves 3 through 12 and provides the main motor and sensory innervation to the face and neck via the cranial nerves. Though small, it is an extremely important part of the brain, as the nerve connections of the motor and sensory systems from the main part of the brain that communicate with the peripheral nervous system pass through the brainstem. This includes the corticospinal tract , the posterior column-medial lemniscus pathway and the spinothalamic tract . The brain stem also plays an important role in the regulation of cardiac and respiratory function. It regulates the central nervous system and is pivotal in maintaining consciousness and regulating the sleep cycle.
The Cerebrum And Cerebral Cortex
The cerebrum is the largest portion of the brain. It is covered in a thick layer of gray tissue called the cerebral cortex. Interior to the gray matter of the cerebral cortex is the white matter portion of the cerebrum. The white color comes from the layer of insulation called myelin that is on the neurons in this part of the brain.
The cerebrum is divided into two hemispheres that are joined by a band of nerves which allow communication between the two halves. The left hemisphere controls the right side of the body and the right hemisphere controls the left side of the body.
What Is The Function Of Each Part Of The Heart
Chambers of the Heart The right atrium receives blood from the veins and pumps it to the right ventricle. The right ventricle receives blood from the right atrium and pumps it to the lungs, where it is loaded with oxygen. The left atrium receives oxygenated blood from the lungs and pumps it to the left ventricle.
Function Of The Medulla Oblongata
The medulla oblongata controls autonomic functions and connects the higher levels of the brain to the spinal cord. It is also responsible for regulating several basic functions of the autonomic nervous system, including:
- Respiration: chemoreceptors
- Reflex centers of vomiting, coughing, sneezing, and swallowing
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What Part Of The Brain Controls Fear
From a biological standpoint, fear is a very important emotion. It helps you respond appropriately to threatening situations that could harm you.
This response is generated by stimulation of the amygdala, followed by the hypothalamus. This is why some people with brain damage affecting their amygdala dont always respond appropriately to dangerous scenarios.
When the amygdala stimulates the hypothalamus, it initiates the fight-or-flight response. The hypothalamus sends signals to the adrenal glands to produce hormones, such as adrenaline and cortisol.
As these hormones enter the bloodstream, you might notice some physical changes, such as an increase in:
- heart rate
- blood sugar
In addition to initiating the fight-or-flight response, the amygdala also plays a role in fear learning. This refers to the process by which you develop an association between certain situations and feelings of fear.
What Parts Of The Brain Is Responsible For Respiration
Now that we have that covered, lets talk about the involvement of the brain in this process.
Your brain starts where the spinal cord enters the skull, and the first section that you encounter is called the Brain Stem. The brain stem contains the following structures:
- The medulla oblongata
- The Pons
- The Midbrain
The medulla oblongata is involved in regulating many of the bodily processes that are controlled automatically like blood pressure, heart rate and yes, you guessed it . . . RESPIRATION.
The way this works is relatively straightforward. The medulla oblongata basically detects carbon dioxide and Oxygen levels in the bloodstream and determines what changes need to happen in the body.
The reason I mentioned the heart is because the respiratory system is very much tied to the circulatory system.
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What Is The Gray Matter And White Matter
Gray and white matter are two different regions of the central nervous system. In the brain, gray matter refers to the darker, outer portion, while white matter describes the lighter, inner section underneath. In the spinal cord, this order is reversed: The white matter is on the outside, and the gray matter sits within.
Gray matter is primarily composed of neuron somas , and white matter is mostly made of axons wrapped in myelin . The different composition of neuron parts is why the two appear as separate shades on certain scans.
Each region serves a different role. Gray matter is primarily responsible for processing and interpreting information, while white matter transmits that information to other parts of the nervous system.
Is The Heart Organ Responsible For Feelings And Emotions
May 20, 2009 at 6:30 pm· Filed under Uncategorized
Almost all of us believe that heart organ is responsible for feeling and emotions. However, many researches prove that the feelings come from the brain only. The limbic cortex is the most important part of the brain that controls our emotions, feelings and physical reactions. Limbic Cortex is therefore referred to as the emotional brain.
The heart organ has been referred to as a source of love and virtue for many centuries. Heart is recognized as the source of intelligence by Hebrew, Christian, Hindu, Chinese and Islamic traditions. However, in the past few decades, we have been taught that the heart is just a ten-ounce muscle pumping blood and maintaining circulation. According to medical science, brain is the main part of the body, which rules all the other organs.
There is new scientific evidence that the heart organ is responsible for feelings and emotions. The heart uses neurological, biochemical and biophysical ways to send emotional and intuitive signals to our brain. The scientists are now discovering that the heart may be the actual intelligent force, which is behind the intuitive thoughts, feelings and emotions experienced by us.
You may notice that some people who experience emotional trauma and psychological stress may develop cardiac arrhythmia. This condition may even lead to sudden death. If someone with heart disease hears any bad news, he/she may indeed die.
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Neurocardiology: The Brain On The Heart
While the Laceys were conducting their research in psychophysiology, a small group of cardiologists joined forces with a group of neurophysiologists and neuroanatomists to explore areas of mutual interest. This represented the beginning of the new discipline now called neurocardiology. One of their early findings is that the heart has a complex neural network that is sufficiently extensive to be characterized as a brain on the heart . The heart-brain, as it is commonly called, or intrinsic cardiac nervous system, is an intricate network of complex ganglia, neurotransmitters, proteins and support cells, the same as those of the brain in the head. The heart-brains neural circuitry enables it to act independently of the cranial brain to learn, remember, make decisions and even feel and sense. Descending activity from the brain in the head via the sympathetic and parasympathetic branches of the ANS is integrated into the hearts intrinsic nervous system along with signals arising from sensory neurons in the heart that detect pressure, heart rate, heart rhythm and hormones.
Figure 1.2 Microscopic image of interconnected intrinsic cardiac ganglia in the human heart. The thin, light-blue structures are multiple axons that connect the ganglia.
Courtesy of Dr. J. Andrew Armour
Does Blood Flow Faster In Arteries Or Veins
Blood Flow Blood flows in the same direction as the decreasing pressure gradient: arteries to capillaries to veins. The rate, or velocity, of blood flow varies inversely with the total cross-sectional area of the blood vessels. As the total cross-sectional area of the vessels increases, the velocity of flow decreases.
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How Do I Control My Heart Rate And Nerves
Participating in relaxation methods such as deep breathing and progressive muscle relaxation can help reduce anxiety and heart rate. Deep breathing helps stimulate the vagus nerve, which causes activity in the nervous system and helps reduce the chemicals that cause the fight or flight response, says Isaacson.
What Happens During Exercise
When you are exercising, you are using your muscles in a significant way, and your body demands that you take in more Oxygen so that it can be delivered to your muscles.
Your circulatory and respiratory systems need to make sure that the Oxygen is getting to the muscles faster than when you are just chilling. Also, they need to make sure that the carbon dioxide that is produced is taken away efficiently.
In order for that process to happen efficiently, the medulla oblongata, after sensing what is happening, sends signals to the heart and the respiratory muscles .
You start breathing heavily to get that Oxygen in and carbon dioxide out. Your heart starts beating faster because not only does the Oxygen need to get into the body, but they need to be delivered to the muscles.
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Tissues Covering The Brain
Within the skull, the brain is covered by three layers of tissue called the meninges.
No computer has yet come close to matching the capabilities of the human brain. However, this sophistication comes with a price. The brain needs constant nourishment. It demands an extremely large amount and continuous flow of blood and oxygenabout 25% of the blood flow from the heart. The overall energy consumption of the brain does not change much over time, but certain areas of the brain, use more energy during periods of increased activity . A loss of blood flow to the brain for more than about 10 seconds can cause a loss of consciousness.
Lack of oxygen or abnormally low sugar levels in the blood can result in less energy for the brain and can seriously injure the brain within 4 minutes. However, the brain is defended by several mechanisms that can work to prevent these problems. For example, if blood flow to the brain decreases, the brain immediately signals the heart to beat faster and more forcefully, and thus to pump more blood. If the sugar level in the blood becomes too low, the brain signals the adrenal glands Overview of the Adrenal Glands The body has two adrenal glands, one near the top of each kidney. They are endocrine glands, which secrete hormones into the bloodstream. Each adrenal gland has two parts. Medulla: The inner… read more to release epinephrine , which stimulates the liver to release stored sugar.
Right Brain Left Brain
The cerebrum is divided into two halves: the right and left hemispheres They are joined by a bundle of fibers called the corpus callosum that transmits messages from one side to the other. Each hemisphere controls the opposite side of the body. If a stroke occurs on the right side of the brain, your left arm or leg may be weak or paralyzed.
Not all functions of the hemispheres are shared. In general, the left hemisphere controls speech, comprehension, arithmetic, and writing. The right hemisphere controls creativity, spatial ability, artistic, and musical skills. The left hemisphere is dominant in hand use and language in about 92% of people.
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What Is The Function Of The Ventricles
The right ventricle pumps the oxygen-poor blood to the lungs through the pulmonary valve. The left atrium receives oxygen-rich blood from the lungs and pumps it to the left ventricle through the mitral valve. The left ventricle pumps the oxygen-rich blood through the aortic valve out to the rest of the body.
What Part Of The Brain Is Affected When One Has A Stroke And Is Unable To Speak Or Write Quizlet
After suffering a stroke, a patient is unable to speak. He can understand what is said to him, and he can understand written messages, but he cannot express himself verbally. Which part of his brain has been affected by the stroke? the stroke has damaged the speech center, located in the frontal lobe.
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