The Autonomic Nervous System
The autonomic nervous system is part of the peripheral nervous system. One of its main roles is to regulate glands and organs without any effort from our conscious minds.The autonomic nervous system is made up of two parts: the sympathetic and the parasympathetic. These systems act on the body in opposite ways. Together, they coordinate a multitude of adjustments required for our changing personal needs as we move through our environment. For example, the size of our pupils is adjusted automatically to allow the correct amount of light into our eyes for optimum vision, our sweat glands are turned on when we get too hot and our salivary glands produce saliva when we eat food .
Things That Can Go Wrong With The Brain
Because the brain controls just about everything, when something goes wrong, 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.
Here are some of the problems that can affect the brain:
Brain tumors. A 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 a tumor can grow and spread rapidly, causing severe and quickly worsening symptoms.
Brain tumors can be benign or malignant. They 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.
Cerebral palsy. This condition is the result of a developmental defect or damage to the brain before or during a childs birth, or during the first few years of life. Cerebral palsy affects the motor areas of the brain. A person with cerebral palsy may have average intelligence or can have severe developmental delays or mental retardation.
Headaches. Of the many different types of headaches, some of the more common are:
Reviewed by: Yamini Durani, MDDate reviewed: October 2012
How The Nervous System Works
The basic functioning of the nervous system depends a lot on tiny cells called neurons. The brain has billions of them, and they have many specialized jobs. For example, sensory neurons take information from the eyes, ears, nose, tongue, and skin to the brain. Motor neurons carry messages away from the brain and back to the rest of the body.
All neurons relay information to each other through a complex electrochemical process, making connections that affect the way we think, learn, move, and behave.
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Divisions Of The Nervous System
In most animals, including humans, the nervous system consists of two parts: central and peripheral. The central nervous system is composed of the brain, spinal cord, and cerebellum. The peripheral nervous system consists of sensory neurons, motor neurons, and neurons that communicate either between subdivisions of the PNS or connect the PNS to the CNS
The Human Nervous System: The major organs and nerves of the human nervous system. The CNS is comprised of the brain, cerebellum and spinal cord. Remaining neurons, and associated cells, distributed throughout the body form the PNS.
The nervous system has three broad functions: sensory input, information processing, and motor output. In the PNS, sensory receptor neurons respond to physical stimuli in our environment, like touch or temperature, and send signals that inform the CNS of the state of the body and the external environment. This sensory information is then processed by the CNS, predominantly by the brain.
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.
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What Does The Brain Do
The brain controls what you think and feel, how you learn and remember, and the way you move and talk. But it also controls things you’re less aware of like the beating of your heart and the digestion of your food.
Think of the brain as a central computer that controls all the body’s functions. The rest of 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. It 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 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 happens in an instant.
How The Spinal Cord And Internal Organs Work Together
In addition to the control of voluntary movement, the central nervous system contains the sympathetic and parasympathetic pathways that control the “fight or flight” response to danger and regulation of bodily functions. These include hormone release, movement of food through the stomach and intestines, and the sensations from and muscular control to all internal organs.
This diagram illustrates these pathways and the level of the spinal cord projecting to each organ.
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Human Organs And Organ Systems
Achy Breaky Heart
You have probably heard this Billy Ray Cyrus song. Heartache, heartbreak…it all has to do with love. Did you ever wonder why the heart is associated with love? The heart was once thought to be the center of all thought processes, as well as the site of all emotions. This notion may have stemmed from very early anatomical dissections that found many nerves can be traced to the region of the heart. The fact that the heart may start racing when one is excited or otherwise emotionally aroused may have contributed to this idea as well. In fact, the heart is not the organ that controls thoughts or emotions. The organ that controls those functions is the brain. In this concept, youll be introduced to the heart, brain, and other major organs of the human body.
How Can I Keep My Nervous System Healthy
Just like other parts of your body, your brain needs sleep for rest and repair, so a good regular sleep schedule is key. A healthy balanced diet that features foods high in omega-3 fatty acids is important, too. Those include fatty fish like salmon, albacore tuna, mackerel, herring, and farmed trout.
Stress also can affect your nervous system, but you can do a few things to manage it:
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Male And Female Reproductive Systems
The reproductive system is the only body system that differs substantially between individuals. There is a range of Biological sex, but most books divide them into male and female. We will discuss the Biology of sex in detail in the reproductive and development chapters.
Feature: Human Biology in the News
Organ transplantation has been performed by surgeons for more than six decades, and youve no doubt heard of people receiving heart, lung, and kidney transplants. However, you may have never heard of a penis transplant. The first U.S. penis transplant was performed in May of 2016 at Massachusetts General Hospital in Boston. The 15-hour procedure involved a team of more than 50 physicians, surgeons, and nurses. The patient was a 64-year-old man who had lost his penis to cancer in 2012. The surgical milestone involved grafting microscopic blood vessels and nerves of the donor organ to those of the recipient. As with most transplant patients, this patient will have to take immunosuppressing drugs for the rest of his life so his immune system will not reject the organ. The transplant team said that their success with this transplant holds promise for patients with devastating genitourinary injuries and disease. They also hope their experiences will be helpful for gender reassignment surgery.
The Senses Of Hearing
The ear is the sense organ that collects and detects sound waves and plays a major role in the sense of balance and body position. The sensory receptors for both hearing and equilibrium are mechanoreceptors found in the inner ear; these receptors are hair cells that have stereocilia that are extremely sensitive to mechanical stimulations.
Anatomy of the Ear
The ear has three divisions: the outer ear, the middle ear, and the inner ear .
Figure;7. Anatomy of the human ear.
Outer Ear: Auricle, Ear Canal, Surface of Ear Drum
The outer ear is the most external portion of the ear. The outer ear includes the pinna , the ear canal, and the very most superficial layer of the ear drum . Although the word ear may properly refer to the pinna , this portion of the ear is not vital for hearing. The complicated design of the human outer ear does help capture sound, but the most important functional aspect of the human outer ear is the ear canal itself. This outer ear canal skin is applied to cartilage; the thinner skin of the deep canal lies on the bone of the skull. If the ear canal is not open, hearing will be dampened. Ear wax is produced by glands in the skin of the outer portion of the ear canal. Only the thicker cerumen-producing ear canal skin has hairs. The outer ear ends at the most superficial layer of the tympanic membrane. The tympanic membrane is commonly called the ear drum.
Middle Ear: Air Filled Cavity behind the Ear Drum, includes most of the Ear Drum, and Ear Bones
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What Happens To The Brain In Alzheimer’s Disease
The healthy human brain contains tens of billions of neuronsspecialized cells that process and transmit information via electrical and chemical signals. They send messages between different parts of the brain, and from the brain to the muscles and organs of the body. Alzheimers disease disrupts this communication among neurons, resulting in loss of function and cell death.
Why Cant The Central Nervous System Repair Itself After Injury
Many organs and tissues in the body can recover after injury without intervention. Unfortunately, some cells of the central nervous system are so specialized that they cannot divide and create new cells. As a result, recovery from a brain or spinal cord injury is much more difficult.
The complexity of the central nervous system makes the formation of the right connections between brain and spinal cord cells very difficult. It is a huge challenge for scientists to recreate the central nervous system that existed before the injury.
The Peripheral Nervous System
In addition to the central nervous system there is also a complex network of nerves that travel to every part of the body. This is called the;peripheral nervous system and it carries the signals necessary for the body to survive . Some of the signals carried by the PNS are related to voluntary actions. If you want to type a message to a friend, for instance, you make conscious choices about which letters go in what order and your brain sends the appropriate signals to your fingers to do the work. Other processes, by contrast, are not voluntary. Without your awareness your brain is also sending signals to your organs, your digestive system, and the muscles that are holding you up right now with instructions about what they should be doing. All of this occurs through the pathways of your peripheral nervous system.
Types Of Organs In A Human Body
Altogether there are seventy-eight main organs within the human body. These organs work in coordination to give rise to several organ systems. Among these 78 organs, five organs are considered vital for survival. These include the heart, brain, kidneys, liver and lungs. If any of these five organs stop functioning even for a few seconds death will result without any medical intervention. Therefore, it is always advised by the doctors to keep our system healthy, maintain a balanced diet, adequate sleep, regular physical activities and focus on healthy lifestyle changes.
Listed below are the tabular columns of 78 different types of organs of the human body.
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How Does The Brain Work
The brain sends and receives chemical and electrical signals throughout the body. Different signals control different processes, and your brain interprets each. Some make you feel tired, for example, while others make you feel pain.
Some messages are kept within the brain, while others are relayed through the spine and across the bodys vast network of nerves to distant extremities. To do this, the central nervous system relies on billions of neurons .
What Is An Organ
An organ is made up of the same type of tissues, which are well-organized to perform specific functions in all living things, including plants, animals, birds, insects, reptiles, mammals and humans.
Organs collectively form organ systems. These organs are macroscopic in structure. The brain, heart, lungs, liver, kidneys are a few examples of organs.
Human anatomy mainly deals with the study of the structure of the internal organs and physiology deals with the study of the functioning of the internal organs. The study of visceral organs is Splanchnology.
Read More: Human Body
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The Brainstem: Middle Of The Brain
The brainstem is located in front of the cerebellum. Think of the brainstem like a computer hard-drive. It is the bodys main control panel and is responsible for conveying messages between the brain and other parts of the body. The cerebrum, the cerebellum and the spinal cord are all connected to the brainstem. The brainstem has three main parts: the midbrain, the pons and the medulla oblongata.
The brain stem controls these vital body functions:
- Sensory relay
What Is The Central Nervous System
The central nervous system controls most functions of the body and mind. It consists of two parts: the brain and the spinal cord.
The brain is the center of our thoughts, the interpreter of our external environment, and the origin of control over body movement. Like a central computer, it interprets information from our eyes , ears , nose , tongue , and skin , as well as from internal organs such as the stomach.
The spinal cord is the highway for communication between the body and the brain. When the spinal cord is injured, the exchange of information between the brain and other parts of the body is disrupted.
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Neurons In Nervous Tissue Relay Rapid
All nervous tissue, from the brain to the spinal cord to the furthest nerve branch, includes cells called neurons. Neurons are charged cells: they conduct electrical signals to pass information through the body. A typical neuron consists of a cell body, dendrites, and an axon with an axon terminal. The dendrites receive signals from body tissues or other neurons and pass them into the cell body. If an outgoing signal is produced, it zips down the axon to the axon terminal and passes to the next neuron or target cell. This conductive capability sends information up and down nerve pathways and through the central nervous system at incredible speed. Some 100 billion neurons give the brain its awesome processing power.
General Functions Of The Cns
The central nervous system represents the largest part of the nervous system, including the brain and the spinal cord. Together with the peripheral nervous system , it has a fundamental role in the control of behavior.
When the central nervous system becomes damaged or peripheral nerves become trapped, a variety of impacts are possible. It can increase or decrease your internal organs functionality, it can even affect your facial expressions, i.e. make you frown a lot, your smile may become lop sided, your lungs can overwork, or underwork, lung capacity may increase or decrease, your bladder can fill, but you become unable to urinate, your bowels become lapsed and you are unable to completely clear them upon each bowel movement, the muscles in your arms, legs and torso can become weaker and more fatty, not from lack of use, but from the nerves that run from your spine into them being restricted from working properly, you can suffer headaches, earaches, sore throats, blocked sinuses. Even your ability to orgasm can be affected.
The CNS is conceived as a system devoted to information processing, where an appropriate motor output is computed as a response to a sensory input. Many threads of research suggest that motor activity exists well before the maturation of the sensory systems, and senses only influence behavior without dictating it. This has brought the conception of the CNS as an autonomous system.
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