Wednesday, August 17, 2022

What Tissue Is The Brain Made Of

Don't Miss

Fundamental Universal Properties Of Brain Tissue

Epilepsy Society Brain and Tissue Bank

We show that, across brain structures and species, the large variation in the average neuronal cell size, mn is strongly and uniformly correlated to the G/N ratio Ng/Nn, by an almost linear power law: Ng/Nn = 0.1370.922. The G/N ratio, however, is not strongly correlated with variation in average glial cell size, mg. The correlation between mn and Ng/Nn is consistent with our hypothesis that variations in the latter are a consequence of variations in the former, that is, that the glia/neuron ratio in any brain tissue or species is determined by the average cell mass of the neurons in that tissue . We propose that the relationship between the G/N ratio and average neuronal cell mass is a universal property of any brain tissue, achieved in a manner that will be developed further in the evo-devo model of brain tissue construction below.

What Are The 4 Lobes Of The Brain

Database Center for Life Sciences/Wikimedia Commons

The cerebrum’s left and right hemispheres are each divided into four lobes: the frontal, parietal, occipital and temporal lobes. The lobes generally handle different functions, but much like the hemispheres, the lobes don’t function alone. The lobes are separated from each other by depressions in the cortex known as sulcus and are protected by the skull with bones named after their corresponding lobes.

Cancer Research UK/Wikimedia Commons

The frontal lobe is located in the front of the brain, running from your forehead to your ears. It is responsible for problem-solving and planning, thought, behavior, speech, memory and movement. The frontal lobe is separated from the parietal lobe by the central sulcus and is protected by a singular frontal skull bone.

The parietal lobe picks up where the frontal lobe ends and goes until the mid-back part of the brain . It is responsible for processing information from the senses , as well as language interpretation and spatial perception. It is separated from the other lobes on all four sides: from the frontal lobe by central sulcus from the opposite hemisphere by the longitudinal fissure from the occipital lobe by parieto-occipital sulcus and from the temporal lobe below by a depression known as the lateral sulcus, or lateral fissure. Because each hemisphere has a parietal lobe, there are two parietal skull bonesone on the external side of each hemisphere.

About The Brain And Spinal Cord

Together, the brain and spinal cord form the central nervous system. This complex system is part of everything we do. It controls the things we choose to dolike walk and talkand the things our body does automaticallylike breathe and digest food. The central nervous system is also involved with our sensesseeing, hearing, touching, tasting, and smelling as well as our emotions, thoughts, and memory.

The brain is a soft, spongy mass of nerve cells and supportive tissue. It has three major parts: the cerebrum, the cerebellum, and the brain stem. The parts work together, but each has special functions.

The cerebrum, the largest part of the brain, fills most of the upper skull. It has two halves called the left and right cerebral hemispheres. The cerebrum uses information from our senses to tell us what’s going on around us and tells our body how to respond. The right hemisphere controls the muscles on the left side of the body, and the left hemisphere controls the muscles on the right side of the body. This part of the brain also controls speech and emotions as well as reading, thinking, and learning.

The cerebellum, under the cerebrum at the back of the brain, controls balance and complex actions like walking and talking.

The brain stem connects the brain with the spinal cord. It controls hunger and thirst and some of the most basic body functions, such as body temperature, blood pressure, and breathing.

Recommended Reading: What Does Bleeding In The Brain Mean

What Are The Four Nuclei Of The Cerebellum

As the three lobes take in information from the cerebrum, spinal cord and body, the cerebellum also has a way of sending out information. This is done through what are called nucleia bundle or neurons embedded deep in the cerebellum’s white matter.

Rounding out cerebellum’s composition are the four nuclei that pass information between the cerebrum and the body. These nuclei are: dentate, emboliform, globose, and fastcgi. They receive on the body and give information from the cerebellum through Purkinje cells and mossy fibers.

Life Sciences Database/Wikimedia Commons

The final section of the brain is a mass of tissue and nerves called the brain stem. Located underneath the cerebrum and cerebellum, the brain stem connects the brain to the spinal cord. All information that goes from the brain to the body , must pass through the brain stem to reach its destination. The brain stem accounts for the remaining 5% of the brain’s mass, and is , the oldest part of the brain. The brain stem is responsible for regulating the heart and lungs, communications between the brain and the peripheral nervous system , our sleep cycle, and coordinating reflexes.

The brain stem plugs the brain into the rest of the body through the spinal cord .

Structure Of Nervous Tissue

brain_tissue
  • It is made of nerve cells or neurons, all of which consists of an axon. Axons are long stem-like projections emerging out of the cell, responsible for communicating with other cells called the Target cells, thereby passing impulses
  • The main part is the cell body which contains the nucleus, cytoplasm and cell organelles. Extensions of the cell membrane are referred to as processes.
  • Dendrite is a highly branched processes, responsible for receiving information from other neurons and synapses . Information of other neurons is provided by dendrites to connect with its cell body.
  • Information in a neuron is unidirectional as it passes through neurons from dendrites, across the cell body down the axon.

Recommended Reading: Cebria Lawsuit

You May Like: What Happens If A Brain Bleed Goes Untreated

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 .

Ventricles And Cerebrospinal Fluid

Deep in the brain are four open areas with passageways between them. They also open into the central spinal canal and the area beneath arachnoid layer of the meninges.

The ventricles manufacture cerebrospinal fluid, or CSF, a watery fluid that circulates in and around the ventricles and the spinal cord, and between the meninges. CSF surrounds and cushions the spinal cord and brain, washes out waste and impurities, and delivers nutrients.

Read Also: Satiety Centre In Brain

The 3 Major Parts Of The Brain And What They Do

Mission control. Command center. Control tower. No, I’m not talking about space or your laptop hard drive, or even airport flight control. I’m talking about the human brainthe most complex and essential organ our bodies have. What is the brain structure? What part of the brain controls emotions?

Whether you’re studying it in class, preparing for an AP exam, or just curious about brain structure, in this article, you’ll learn about the main parts of brain anatomy and their functions and as well as get a general overview of the brain’s supporting cast.

The Cell Structure Of The Brain

Is Your Brain Really Made of FAT?

The brain is made up of two types of cells: neurons and glial cells, also known as neuroglia or glia. The neuron is responsible for sending and receiving nerve impulses or signals. Glial cells are non-neuronal cells that provide support and nutrition, maintain homeostasis, form myelin and facilitate signal transmission in the nervous system. In the human brain, glial cells outnumber neurons by about 50 to one. Glial cells are the most common cells found in primary brain tumors.

When a person is diagnosed with a brain tumor, a biopsy may be done, in which tissue is removed from the tumor for identification purposes by a pathologist. Pathologists identify the type of cells that are present in this brain tissue, and brain tumors are named based on this association. The type of brain tumor and cells involved impact patient prognosis and treatment.

Don’t Miss: Does Simvastatin Cause Memory Loss

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.

What Are The Main Parts Of The Brain Stem

The brain stem is made up of three parts: the midbrain, the pons and the medulla.

Life Sciences Database/Wikimedia Commons

The midbrain is located underneath the cerebral cortex, near the top of the brain stem. It connects the cerebrum to the brain stem. The midbrain helps process visual and auditory information, such as controlling the eyes and eyelids. It also plays a role in regulating our body temperature and motor movements.

Main Parts of the Midbrain

Life Sciences Database/Wikimedia Commons

Pons is the Latin word for “bridge.” The pons is responsible for connecting the brain stem to the cerebral cortex and the cerebrum to the cerebellum. It can be found right underneath the midbrain and above the medulla oblongata. Although it is the largest section of the brain stem, the pons is only about 2.5 centimeters long. The pons is responsible for assisting in motor functions, particularly for nerves in the face, ears, and eyes. It also plays a role in regulating the intensity and frequency of breathing. It has both gray and white matter, but it does share gray matter with the midbrain. The reticular formation of the pons’ gray matter plays a vital role in dreaming and REM sleep.

Life Sciences Database/Wikimedia Commons

The Cerebellar Peduncles

Recommended Reading: Shrinking Brain Tumors Naturally

White And Gray Matter

The CNS can be roughly divided into white and gray matter. As a very general rule, the brain consists of an outer cortex of gray matter and an inner area housing tracts of white matter.

Both types of tissue contain glial cells, which protect and support neurons. White matter mostly consists of axons and oligodendrocytes a type of glial cell whereas gray matter consists predominantly of neurons.

Also called neuroglia, glial cells are often called support cells for neurons. In the brain, they outnumber nerve cells 10 to 1.

Without glial cells, developing nerves often lose their way and struggle to form functioning synapses.

Glial cells are found in both the CNS and PNS but each system has different types. The following are brief descriptions of the CNS glial cell types:

Astrocytes: these cells have numerous projections and anchor neurons to their blood supply. They also regulate the local environment by removing excess ions and recycling neurotransmitters.

Oligodendrocytes: responsible for creating the myelin sheath this thin layer coats nerve cells, allowing them to send signals quickly and efficiently.

Ependymal cells: lining the spinal cord and the brains ventricles , these create and secrete cerebrospinal fluid and keep it circulating using their whip-like cilia.

Radial glia: act as scaffolding for new nerve cells during the creation of the embryos nervous system.

Structure And Function Of The Spine

TechPremier: Researchers Grow 3

The spine is made up of 26 bones divided into 5 sections. These bones surround and protect the spinal cord. This includes 24 vertebrae , the sacrum and the coccyx.

Cervical region These are 7 vertebrae at the top of the spine that run from the base of the skull to the lowest part of the neck.

Thoracic region These are 12 vertebrae that run from the shoulders to the middle of the back.

Lumbar region These are 5 vertebrae that run from the middle of the back to the hips.

Sacrum This is a large section of fused vertebrae at the base of the spine.

Coccyx This is a small, thin section of fused vertebrae at the end of the spine.

Between the vertebrae are the discs .

Disc A layer of cartilage found between the vertebrae. Discs cushion and protect the vertebrae and spinal cord.

Read Also: Compare And Contrast Heat Exhaustion And Heat Stroke Brainly

The Geography Of Thought

Each cerebral hemisphere can be divided into sections, or lobes, each of which specializes in different functions. To understand each lobe and its specialty we will take a tour of the cerebral hemispheres, starting with the two frontal lobes , which lie directly behind the forehead. When you plan a schedule, imagine the future, or use reasoned arguments, these two lobes do much of the work. One of the ways the frontal lobes seem to do these things is by acting as short-term storage sites, allowing one idea to be kept in mind while other ideas are considered. In the rearmost portion of each frontal lobe is a motor area , which helps control voluntary movement. A nearby place on the left frontal lobe called Brocas area allows thoughts to be transformed into words.

When you enjoy a good mealthe taste, aroma, and texture of the foodtwo sections behind the frontal lobes called the parietal lobes are at work. The forward parts of these lobes, just behind the motor areas, are the primary sensory areas . These areas receive information about temperature, taste, touch, and movement from the rest of the body. Reading and arithmetic are also functions in the repertoire of each parietal lobe.

As you look at the words and pictures on this page, two areas at the back of the brain are at work. These lobes, called the occipital lobes , process images from the eyes and link that information with images stored in memory. Damage to the occipital lobes can cause blindness.

Is Perception A Controlled Hallucination

A great mystery of the human brain is linked with consciousness and our perception of reality. The workings of consciousness have fascinated scientists and philosophers alike, and though we are slowly inching closer to an understanding of this phenomenon, much more still remains to be learned.

Anil Seth, a professor of cognitive and computational neuroscience from the University of Sussex in the U.K., who specializes in the study of consciousness, has suggested that this intriguing process is based on a sort of controlled hallucination, which our brains generate to make sense of the world.

Perception figuring out whats there has to be a process of informed guesswork in which the brain combines these sensory signals with its prior expectations of beliefs about the way the world is to form the best guess of what caused those signals.

Prof. Anil Seth

According to him, in delivering perceptions of things to our consciousness, our brains often make what you might call informed guesses, based on how it expects things to be.

This explains the uncanny effect of many optical illusions, including the now-notorious blue and black, or white and gold dress, when, depending on how we think the light in the picture is, we may see a different color combination.

Below, you can watch Prof. Seths 2017 TED talk. He explains how our brains make sense of the world around us and within us.

You May Like: Slow Brain Bleed In Elderly

Grey Matter In The Brain And Spinal Cord

Gray matter, named for its pinkish-gray color, is home to neural cell bodies, axon terminals, and dendrites, as well as all nerve synapses. This brain tissue is abundant in the cerebellum, cerebrum, and brain stem. It also forms a butterfly-shaped portion of the central spinal cord.

The back portion of this butterfly shape is known as the posterior, sometimes called the dorsal gray horn. This region passes sensory information via ascending nerve signals to the brain. The front part, which is sometimes called the ventral gray horn, sends descending nerve signals governing motor activities to your autonomic nerves. A problem with the dorsal gray horn may affect your brain’s ability to interpret sensory information, while issues with the ventral gray horn interfere with your body’s ability to receive motor information paralysis, tingling, and muscle weakness are often the products of damage to the ventral gray horn.

Constant Neuronal And Non

Histology of Brain tissue ( CNS ) :Shotgun Histology

Given that, by our definition, the mass of any brain structure can be considered to be composed of a neuronal component Mn = mnNn plus a glial component Mg = mgNg, then the mass of any brain structure can be said to consist of two fractions: a neuronal fraction fn = Mn/M, and a glial fraction fg = Mg/M.

When data from all structures and species are pooled, we find that the variation in structure mass spanning over four orders of magnitude, expressed as a function of the number of glial cells , is well-fitted by a power law that is approximately linear: M = kgNgg, with g = 1.078 ± 0.170 and kg = 1.673 ± 0.030 ng .1B). The common constant and the shared power law exponent suggest that characteristics related to glial cell size are shared across species, orders, and structures.

You May Like: Can Stress Cause A Brain Bleed

But Is Your Brain Actually A Muscle

As it turns out, your brain isn’t actually a muscle. It’s an organ one that actually plays a huge role in controlling muscles throughout your body.

Muscle is made up of muscle tissue, which is muscle cells grouped into elastic bundles that contract together to produce motion and/or force. You use your muscles to throw a ball for your dog and pick up your cat. And some of your muscles even work on their own, such as the ones that help move food through your digestive tract.

Your brain, on the other hand, is a three-pound organ made up of soft tissue called grey matter and white matter, which contain neurons and other cells that help maintain these neurons. Neurons are special cells that send and receive information throughout your body in the form of electrical and chemical signals.

Your brain controls and facilitates a lot of things, including your:

  • Movement
  • Emotion processing
  • Vital functions, such as respiration and heart rate

But, just because your brain isn’t a muscle, that doesn’t mean you shouldn’t train and flex it like one.

More articles

Popular Articles