Posts Tagged brain function

[WEB PAGE] Brain Anatomy and Function

 

The central nervous system (CNS) includes the brain and the spinal cord. The CNS is protected by bones and the meninges (the dura mater, arachnoid and pia mater). Cerebrospinal fluid cushions the CNS from damage. There are 86 main nerves branching off from the CNS – 12 pairs of cranial nerves that branch off from the brain and 31 pairs of spinal nerves that branch off from the spinal cord.

The brain, which is housed in and protected by the bones of the skull, makes up all parts of the central nervous system above the spinal cord. A human brain can weigh up to 3 pounds and is one of the largest organs of the body. Like the spinal cord, the brain is made of mainly gray matter and white matter arranged in distinct layers. The top of the brain appears as a soggy, pinkish-gray mass that looks like a walnut.

 

Contents

Parts of the Brain

The brain consists of the:

  • cerebrum
  • cerebellum
  • brain stem
  • diencephalon (thalamus and hypothalamus)
  • limbic system
  • reticular activating system

The brain can be divided into two major parts: the lower brain stem and the higher forebrain.

The brain stem sits above the spinal cord and has many connections between them. The brain stem, the most primitive part of the brain, is made up of the medulla, pons, cerebellum, midbrain, hypothalamus and thalamus. The cerebral cortex, limbic system and basal ganglia make up the forebrain. The forebrain deals with homeostasis, emotions and conscious actions.

The brain’s outer layer is only 1/4 inch thick but if flattened out would cover the size of an office desk. It has about 50 billion nerve cells. The cerebrum is the largest part of the brain and is part of the forebrain. It houses the nerve center that controls sensory, motor activities and intelligence. The outer layer, the cerebral cortex, is made of nerve fibers called gray matter. The inner layer is made of a different type of nerve fibers called white matter.

The basal ganglia is found in the white matter. The cerebrum is divided in to left and right hemispheres. The left half controls the right side of the body and the right half controls the left side of the body. A mass of nerve fibers known as the corpus callosum connects the two hemispheres and allows communication between the two. The surface of the cerebrum is made up of gyri and sulci.

A cortex is the outer layer of any organ. The cerebral cortex is the outer layer of the brain, called gray matter. It is where our conscious thoughts and actions take place. Many of the signals our brain receives from our senses are registered in the cerebral cortex. The visual cortex is in the lower back part of the brain and is where our brain registers what we see. The somatosensory cortex is a band that runs over the top of the brain is where our brain registers a touch on any part of our body.

The motor cortex is just in front of the somatosensory cortex and it sends out signals to muscles to make them move. The more nerve endings a part of the body has, the more of the sensory cortex it occupies. A big portion of the sensory cortex is taken up by our lips and face. Our hands take up almost as much as our face and our feet almost as much as our hands. This is because we move our hands and lips all the time and both are very sensitive.

The cerebellum, “little brain”, is the second largest region of the brain. It is located behind and below the cerebrum and at the back of the brain stem and attached to the midbrain. It has two hemispheres and an outer cortex of gray matter and an inner core of white matter. The cerebellum is involved in movement and coordination, walking, posture, reflexes, eye and head movement. It coordinates subconscious movements such as balance and coordinated movement. The cerebellum is constantly receiving updates about the body’s position and movement. It also sends instructions to our muscles that adjust our posture and keep our body moving smoothly.

The diencephalon is located between the cerebrum and midbrain. It consists of the thalamus and hypothalamus which lie deep in the cerebral hemispheres. Centers in the hypothalamus regulate our body temperature, blood sugar, hunger and hormones. The thalamus is involved with sensory signals sent to the higher forebrain, in particular the cerebral cortex. The thalamus also participates in motor control and regulating cortex excitement. Several pathways connect the brainstem to the lower motor centers in the spinal cord and the higher ones in the forebrain.

The brain is the control center of the body and contains billions of nerve cells. The brain stem lies just below the cerebrum and in front of the cerebellum. It continues from the cerebrum above and connects to the spinal cord below. The brain stem is made up of the midbrainpons and medulla oblongata. It carries out many vital functions of the body for maintenance and survival such as breathing, heartbeat, and blood pressure. It also controls vomiting, coughing, sneezing and swallowing. It is the body’s “autopilot.” It also provides pathways for nerve fibers between the higher and lower neural centers. It is also the origin for 10 of the 12 cranial nerves. The 12 cranial nerves enter the brain directly and are not connected to the spinal cord.

The midbrain is the reflex center for cranial nerves III and IV and is involved in eye reflexes and movements. The pons helps regular breathing. It connects the cerebellum with the cerebrum and links the midbrain to the medulla oblongata. The pons is the reflex center for cranial nerves V through VIII. The pons is involved in chewing, taste, saliva, hearing and equilibrium. The medulla oblongata joins the spinal cord at the foramen magnum. It influences heart, breathing and circulation. It’s the center for vomiting, coughing and hiccuping.

The medulla—the most primitive brain structure—controls our digestive, respiratory and circulatory systems. The ponsinteracts with the cerebellum, motor control and respiration. Other structures in the pons control sleep and excitement. The pons also relays information between the brain and the spinal cord.

The basal ganglia is found in the forebrain and consist of structures involved in motor processes. The basal ganglia works along with the motor areas of the cortex and cerebellum for planning and coordinating certain voluntary movements. The basal ganglia is made of gray matter.

The limbic system, or limbic lobe, is involved in the expression of intimate behaviors and emotions, hunger, aggression. The limbic system also screens all sensory messages to the cerebral cortex. It is located deep in the temporal lobe. The limbic system includes these structures: cingulate gyruscorpus callosummammillary bodyolfactory tractamygdala, and hippocampus. The hypothalamus affects body temperature, appetite, water balance, pituitary secretions, emotions, and autonomic functions including cycles of waking and sleeping.

Even though many functions of the brain are very localized to certain areas and parts of the brain, these parts work together as a whole—particularly in learning, memory, and consciousness.

Ventricles are fluid filled cavities in the brain; there are four of them. The ventricles connect with each other and produce cerebrospinal fluid which is a clear, shock-absorbing liquid that is constantly moving. The cerebrospinal fluid cushions the brain, distributes nutrients and collects wastes.

Blood Vessels in the Brain

The oxygen supply for the brain comes from 4 major arteries, two vertebral arteries and two carotid arteries. The two vertebral arteries supply blood to the back of the brain. The two carotid arteries branch and supply oxygen to the front and middle of the brain. The front and back arteries interconnect at the circle of Willis at the base of the brain. The circle of Willis ensures a continuous blood supply to the brain.

Mid-Sagittal Cross Section of Brain

Coronal brain view

Sectioning the Brain

Sectioning the brain

Left and Right Hemispheres

The forebrain consists of two almost symmetrical cerebral hemispheres made up of the cerebral cortex, the basal ganglia and the limbic system. The two hemispheres are divided by the longitudinal cerebral fissure and connected by a massive bundle of fibers called the corpus callosum. The surface of the two hemispheres is covered by a large, but thin layer of nerve cells called gray matter. Because of the area size of the gray matter, fitting it into the skull causes folds. The grooves in these folds are called sulci (singular sulcus), the ridges are called gyri (singular gyrus). The deeper grooves are called fissures. The cortex is a large mass of nerve fibers called white matter. These nerve fibers are highly developed and able to analyze both motor and sensory information.

The left and right hemispheres may look the same, but each side functions differently. Speech and language, reasoning and analysis, and certain communications are on the left side for most people. The left side of the brain sends and receives information to the right side of the body including the right hand. The right hemisphere is concerned with sensory input, auditory and visual awareness, creative abilities, and spatial-temporal awareness—that is what is happening around us moment by moment. The right brain controls the left side of the body.

Each of the cerebral hemispheres is divided into four lobes and are name for the cranial (skull) bones that lie over them:

  • The frontal lobe extends from the tip of the front of the hemisphere to the central sulcus. The back areas of the frontal lobe specialize in motor functions, including language and voluntary movement; the front areas are involved in learning, planning and other higher psychological processes like our personality and behavior.
  • The occipital lobe is at the back of the hemisphere and is involved in interpreting visual stimuli, that is, what we see.
  • The parietal lobes are at the top and outside areas between the occipital lobe and the frontal lobe and is involved in sensory functions of the skin including pain, temperature, and touch. It also interprets size, shape, distance, vibrations and texture. Other areas are also important in cognitive and intellectual processes.
  • The temporal lobe controls the hearing centers, language comprehension, storing and recalling memories and related areas including some speech centers. Other areas of the brain also affect memory. The front and bottom areas of the temporal lobe are involved in smell and functions of the limbic system.

Brain Injury: A guide for family and friends

• What is a Brain Injury?
• How Bad Is It?
• How the Brain Functions
• Common Problems During Early Recovery
• The Intensive Care Unit (ICU)
• Understanding Coma
• How Does an Injured Brain Heal?
• How You Can Help With Recovery
• Where Will the Journey Go From Here?
• How Will I Ever Get Through This?
• Where to Go for Help
• Books for Families Coping With Brain Injury

Via —->  Brain Anatomy | White Matter, Cerebellum, Cerebral Cortex, Medulla

, , ,

Leave a comment

[Factsheet] Understanding TBI: Part 2 – Brain injury impact on individuals functioning – Model Systems Knowledge Translation Center (MSKTC)

Father teaching child with blocks

Written by Thomas Novack, PhD and Tamara Bushnik, PhD in collaboration with the MSKTC

 

A traumatic brain injury interferes with the way the brain normally works. When nerve cells in the brain are damaged, they can no longer send information to each other in the normal way. This causes changes in the person’s behavior and abilities. The injury may cause different problems, depending upon which parts of the brain were damaged most.

There are three general types of problems that can happen after TBI: physical, cognitive and emotional/ behavioral problems. It is impossible to tell early on which specific problems a person will have after a TBI. Problems typically improve as the person recovers, but this may take weeks or months. With some severe injuries changes can take many years.

Structure and function of the brain

The brain is the control center for all human activity, including vital processes (breathing and moving) as well as thinking, judgment, and emotional reactions. Understanding how different parts of the brain work helps us understand how injury affects a person’s abilities and behaviors.

Left vs. Right Brain

  • The brain is divided into two halves (hemispheres). The left half controls movement and sensation in the right side of the body, and the right half controls movement and sensation in the left side. Thus, damage to the right side of the brain may cause movement problems or weakness on the body’s left side.
  • For most people, the left half of the brain is responsible for verbal and logical functions including language (listening, reading, speaking, and writing), thought and memory involving words.
  • The right half is responsible for nonverbal and intuitive functions such as putting bits of information together to make up an entire picture, recognizing oral and visual patterns and designs (music and art), and expressing and understanding emotions.

Brain Areas & Associated Functions

The brain is made up of six parts that can be injured in a head injury. The effect of a brain injury is partially determined by the location of the injury. Sometimes only a single area is affected, but in most cases of TBI multiple areas have been injured. When all areas of the brain are affected, the injury can be very severe.

Image of Brain with Lobe Information

Six parts Functions
Brain Stem
  • Breathing
  • Heart Rate
  • Swallowing
  • Reflexes for seeing and hearing
  • Controls sweating, blood pressure, digestion, temperature
  • Affects level of alertness
  • Ability to sleep
  • Sense of balance
Cerebellum
  • Coordination of voluntary movement
  • Balance and equilibrium
  • Some memory for reflex motor acts
Frontal Lobe
  • How we know what we are doing within our environment
  • How we initiate activity in response to our environment
  • Judgments we make about what occurs in our daily activities
  • Controls our emotional response
  • Controls our expressive language
  • Assigns meaning to the words we choose
  • Involves word associations
  • Memory for habits and motor activities
  • Flexibility of thought, planning and organizing
  • Understanding abstract concepts
  • Reasoning and problem solving
Parietal Lobe
  • Visual attention
  • Touch perception
  • Goal directed voluntary movements
  • Manipulation of objects
  • Integration of different senses
Occipital Lobes
  • Vision
Temporal Lobes
  • Hearing ability
  • Memory aquisition
  • Some visual perceptions such as face recognition and object identification
  • Categorization of objects
  • Understanding or processing verbal information
  • Emotion

Physical Problems

Most people with TBI are able to walk and use their hands within 6-12 months after injury. In most cases, the physical difficulties do not prevent a return to independent living, including work and driving.

In the long term the TBI may reduce coordination or produce weakness and problems with balance. For example, a person with TBI may have difficulty playing sports as well as they did before the injury. They also may not be able to maintain activity for very long due to fatigue.

Cognitive (Thinking) Problems

  • Individuals with a moderate-to-severe brain injury often have problems in basic cognitive (thinking) skills such as paying attention, concentrating, and remembering new information and events.
  • They may think slowly, speak slowly and solve problems slowly.
  • They may become confused easily when normal routines are changed or when things become too noisy or hectic around them.
  • They may stick to a task too long, being unable to switch to different task when having difficulties.
  • On the other hand, they may jump at the first solution they see without thinking it through.
  • They may have speech and language problems, such as trouble finding the right word or understanding others.
  • After brain injury, a person may have trouble with all the complex cognitive activities necessary to be independent and competent in our complex world. The brain processes large amounts of complex information all the time that allows us to function independently in our daily lives. This activity is called executive function because it means being the executive or being in charge of one’s own life.

Emotional/Behavioral Problems

Behavioral and emotional difficulties are common and can be the result of several causes:

  • First, the changes can come directly from damage to brain tissue. This is especially true for injuries to the frontal lobe, which controls emotion and behavior.
  • Second, cognitive problems may lead to emotional changes or make them worse. For example, a person who cannot pay attention well enough to follow a conversation may become very frustrated and upset in those situations.
  • Third, it is understandable for people with TBI to have strong emotional reactions to the major life changes that are caused by the injury. For example, loss of job and income, changes in family roles, and needing supervision for the first time in one’s adult life can cause frustration and depression.

Brain injury can bring on disturbing new behaviors or change a person’s personality. This is very distressing to both the person with the TBI and the family. These behaviors may include:

  • Restlessness
  • Acting more dependent on others
  • Emotional or mood swings
  • Lack of motivation
  • Irritability
  • Aggression
  • Lethargy
  • Acting inappropriately in different situations
  • Lack of self-awareness. Injured individuals may be unaware that they have changed or have problems. This can be due to the brain damage itself or to a denial of what’s really going on in order to avoid fully facing the seriousness of their condition.

Fortunately, with rehabilitation training, therapy and other supports, the person can learn to manage these emotional and behavioral problems.

Disclaimer

This information is not meant to replace the advice from a medical professional. You should consult your health care provider regarding specific medical concerns or treatment.

Source

Our health information content is based on research evidence whenever available and represents the consensus of expert opinion of the TBI Model Systems directors.

Our health information content is based on research evidence and/or professional consensus and has been reviewed and approved by an editorial team of experts from the TBI Model Systems.

Authorship

Understanding TBI was developed by Thomas Novack, PhD and Tamara Bushnik, PhD in collaboration with the Model System Knowledge Translation Center. Portions of this document were adapted from materials developed by the University of Alabama TBIMS, Baylor Institute for Rehabilitation, New York TBIMS, Mayo Clinic TBIMS, Moss TBIMS, and from Picking up the pieces after TBI: A guide for Family Members, by Angelle M. Sander, PhD, Baylor College of Medicine (2002).

via Understanding TBI: Part 2 – Brain injury impact on individuals functioning | Model Systems Knowledge Translation Center (MSKTC)

, , , , , , ,

Leave a comment

[WEB SITE] Brain Training: Improve Your Neuroplasticity in 9 Easy Steps

Can we improve our capacity for creativity, memory and analysis through brain training exercises? Do online brain training games really work? The simple answer to these questions is yes; we can improve the brain’s ability to function, and we can actually reshape the physical structure of our brains through neuroplasticity training exercises.

Happily in improving your brain’s ability to function, it is not necessary to pay for expensive online games, that ultimately add nothing to the quality of your life. These nine training tips are free to engage in, will improve your brain’s function, and entice you to live life to its fullest!

How We Can Increase Brain Function As We Age

A study of randomly chosen individuals age 57-71 showed improved brain function after just 12 hours of strategic brain training exercises. Using MRIs of the participants brains both before and after, researchers saw upwards of an 8% improvement in blood flow and other indices that indicate improved brain function.

Improved brain function included improved ability to strategize, remember and draw big-picture conclusions from lengthy texts of information.

Remarkably, in a follow up study using MRIs again on the participants, researchers found that the benefits derived from the single training session were still in place one year later. Enhanced synaptic plasticity means that we can think faster, listen better, respond to situations faster and concentrate with greater focus. Creativity is enhanced as well.

MRI of the Brain

By Nevit Dilmen (Own work)(http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons
By Nevit Dilmen (Own work)(http://creativecommons.org/licenses/by-sa/3.0)%5D, via Wikimedia Commons

[…]

more —> Brain Training: Improve Your Neuroplasticity in 9 Easy Steps | HealDove

, ,

Leave a comment

[WEB SITE] Neurorehabilitation & brain research group

 

The Neurorehabilitation and Brain Research Group is a multidisciplinary team focused on assessing and promoting the recovery of brain function after an injury and on examining the underlying mechanisms of different brain processes. The group involves researchers from i3B Institute and Labpsitec, and maintains close collaborations with other national and international entities

Areas

Source: Neurorehabilitation & brain research group

, , ,

Leave a comment

[WEB SITE] Center for BrainHealth Tool Provides Unique Insight for Those with Traumatic Brain Injury.

Tuesday, February 3, 2015

A new study reveals that individuals with traumatic brain injury (TBI) have significantly more difficulty with gist reasoning than traditional cognitive tests. Using a unique cognitive assessment developed by researchers at theCenter for BrainHealth at The University of Texas at Dallas, findings published Friday in the Journal of Clinical and Experimental Neuropsychology indicate that an individual’s ability to “get the gist or extract the essence of a message” after a TBI more strongly predicts his or her ability to effectively hold a job or maintain a household than previously revealed by traditional cognitive tests alone. The study also further validates the Center for BrainHealth’s gist reasoning assessment as an informative tool capable of estimating a broad range of daily life skills.

“Gist reasoning characterizes a meaningful complex cognitive capacity. Assessing how well one understands and expresses big ideas from information they are exposed, commonly known as an ability to “get the gist”, is window into real life functionality. I do not know of any other paper and pencil test that can tell us both,” explained Asha Vas, Ph.D., research scientist at the Center for BrainHealth and lead study author. “Although performance on traditional cognitive tests is informative, widely-used measures do not paint the full picture. Adults with TBI often fare average or above on these structured measures. All too often, adults with brain injury have been told that they ought to be fine; in reality, they are not doing and thinking like they used to prior to the injury and struggle managing everyday life responsibilities years after the injury. Gist reasoning could be a sensitive tool to connect some of those dots as to why they are having trouble with real-life functionality despite falling into the range of “normal” on other cognitive tests.”

Study participants included 70 adults ages 25-55: 30 suffered a TBI one year or longer prior to the study and 40 were healthy controls. The TBI group and matched controls were of similar socioeconomic status, educational backgrounds, and IQ. Researchers administered a series of standard cognitive assessments, including working memory, inhibition, and switching. Researchers also gave the gist reasoning assessment, which studies the number of gist-based ideas (not explicitly stated facts) participants are able to abstract from multiple complex texts. Daily life functionality in TBI participants was evaluated using a self-rated questionnaire that included topics such as problem solving at work, managing finances, organizing grocery lists at home, and social interactions.

Although the two groups had similar IQ, reading comprehension and speed of processing scores, nearly 70% of the TBI group scored lower on gist reasoning compared to controls. The TBI survivors’ decreased gist-reasoning performance showed a direct correlation with difficulties at work and at home. Interestingly the cumulative score of all standard cognitive tests only predicted daily function with 45% accuracy in individuals with TBI. Adding the gist reasoning measure boosted accuracy to 58%.

“TBI needs to be treated as a chronic condition. While acute recovery care is essential, long-term monitoring and effective interventions are necessary to mitigate persistent or later-emerging deficits and ensure maximum brain regeneration and cognitive performance,” said Sandra Chapman,Ph.D., founder and chief director at the Center for BrainHealth and Dee Wyly Distinguished University Professor in the School of Behavioral and Brain Sciences at UT Dallas. “We don’t want anyone who has survived a TBI to think that if gist reasoning and day-to-day life is challenging today that it will always be that way, because gist reasoning can be improved. In an earlier study conducted at the Center for BrainHealth, we found that individuals with TBI can improve gist reasoning. This is very promising outcome, because increased gist reasoning is associated with improved functionality and greater brain blood flow, a sign of increased brain health.”

The researchers theorize that gist reasoning impairments could reflect losses in flexible and innovative thinking and that losses in these areas hinder optimal daily life functioning, including job performance and social relationships. “Deficits of this nature may manifest in a lessened ability to problem solve in unexpected situations and understand others’ point of view,” Vas said.The Center is currently conducting multiple projects to study the effectiveness of high performance brain training strategies in individuals with TBI and other populations, to help improve brain function across the lifespan and enrich daily life.

This research was made possible by a Friends of BrainHealth Distinguished New Scientist Award.

Source: Center for BrainHealth

, , ,

Leave a comment

[VIDEO] Explaining Brain Smudging – YouTube

Published on Dec 4, 2014

An evidenced based multimedia approach to teaching neuroplasticity.

While many people have something of a mental picture of the external view of a brain, the internal workings are hard to imagine. Patients and other learners need something solid to grasp onto when trying to make sense of the very abstract idea of brain function.

A nail box (also called a pin-box) can be used to explain aspects of the brain and the therapeutic potential of interventions that target it. In terms of evidence based multimedia, the box is an external, animated model which allows a reasonably accurate, metaphorical, three dimensional model of neuroplasticity. It is particularly powerful because it can demonstrate the ‘elasticity’ of the brain – it’s ability to change, and also change back.

The nailbox is something you can touch, experience and “see” changes in. Demonstration of the brain’s working with a nailbox requires minimal scientific language and, via this simple mechanism, it’s possible to show complex aspects of neuroplasticity. This is my version of telling a person about smudging and changeability of the brain with a nailbox.

To find out more about the brain and pain visit http://www.noigroup.com

For Graded Motor Imagery brain training products visit http://www.noigroup.com/en/Category/BT and http://www.noigroup.com/Recognise

via Explaining Brain Smudging – YouTube.

, , ,

Leave a comment

%d bloggers like this: