Central Nervous System (CNS)

The central nervous system consists of the brain and spinal cord. Furthermore, the central nervous system controls thought, movement, and emotion, as well as breathing, heart rate, hormones, and body temperature.

In addition, CNS is known as “central”, because it combines information from the entire body. In addition, it coordinates activity across the whole organism.

What is the Central Nervous System (CNS)?

Specifically, the CNS consists of the brain and spinal cord.

Notably, the skull (the cranial cavity) protects the brain, and the spinal cord travels from the back of the brain, down the center of the spine, stopping in the lumbar region of the lower back.

Moreover, a protective triple-layered membrane called the meninges houses the brain and spinal cord.

Although the central nervous system has been thoroughly studied by anatomists and physiologists. It still holds many secrets; it controls our thoughts, movements, emotions, and desires. Additionally, it also controls our breathing, heart rate, the release of some hormones, body temperature, and much more.

Finally, some researchers consider the retina, optic nerve, olfactory nerves, and olfactory epithelium to be part of the CNS alongside the brain and spinal cord.

Function of the Brain

The brain is, in fact, the most complex organ in the human body. Moreover, the cerebral cortex which is the outermost part of the brain. It is the largest part by volume and contains an estimated 15–33 billion neurons. Each of which is connected to thousands of other neurons.

In total, around 100 billion neurons and  1,000 billion glial (support) cells make up the human brain. Interestingly, our brain uses around 20% of our body’s total energy.

Furthermore, the brain is the central control module of the body and coordinates activity. This includes, for example, physical motion, the secretion of hormones, the creation of memories, and the sensation of emotion.

To carry out these functions, some sections of the brain have dedicated roles. However, it is important to note that many higher functions. Such as reasoning, problem-solving, and creativity. Furthermore, the brain  involve different areas working together in networks.

The brain is roughly split into four lobes:

  • Firstly, the temporal lobe (green) is important for processing sensory input and assigning it emotional meaning. Additionally, the brain is also involved in laying down long-term memories. Furthermore, some areas of the brain also house aspects of language perception.
  • Secondly, the occipital lobe (purple) serves as the visual processing region of the brain, housing the visual cortex.
  • Thirdly, the parietal lobe (yellow) integrates sensory information, including touch, spatial awareness, and navigation. Touch stimulation from the skin is ultimately sent to the parietal lobe. It also plays a part in language processing.
  • Finally, the frontal lobe (pink) is positioned at the front of the brain. It contains the majority of dopamine-sensitive neurons. And plays a role in attention, reward, short-term memory, motivation, and planning.

Brain Regions

Next, we will look at some specific brain regions in a little more detail:

  • Basal ganglia: Firstly, it is involved in the control of voluntary motor movements, procedural learning, and decisions about which motor activities to carry out. Furthermore, diseases that affect this area include Parkinson’s disease and Huntington’s disease.
  • Cerebellum: In addition, it is mostly involved in precise motor control, but also in language and attention. If damage occurs to the cerebellum, consequently, disrupted motor control, known as ataxia, becomes the primary symptom.
  • Broca’s area: Moreover, this small area on the left side of the brain (sometimes on the right in left-handed individuals) is important in language processing. When damaged, an individual finds it difficult to speak; however, they can still understand speech. Notably, stuttering is sometimes associated with an underactive Broca’s area.
  • Corpus callosum: Additionally, it is a broad band of nerve fibers that join the left and right hemispheres. Indeed, it is the largest white matter structure in the brain and allows the two hemispheres to communicate. Interestingly, dyslexic children have smaller corpus callosums; conversely, left-handed people, ambidextrous people, and musicians typically have larger ones.

Additional regions

  • Medulla oblongata: Finally, extending below the skull, it is involved in involuntary functions, such as vomiting, breathing, sneezing, and maintaining the correct blood pressure.
  • Hypothalamus: Moreover, sitting just above the brain stem and roughly the size of an almond, the hypothalamus secretes a number of neurohormones and influences body temperature control, thirst, and hunger.
  • Thalamus: Furthermore, positioned in the center of the brain, the thalamus receives sensory and motor input and relays it to the rest of the cerebral cortex. It is involved in the regulation of consciousness, sleep, awareness, and alertness.
  • Amygdala: Finally, two almond-shaped nuclei deep within the temporal lobe. They are involved in decision-making, memory, and emotional responses; particularly negative emotions.

Spinal Cord

The spinal cord, running almost the full length of the back, carries information between the brain and body; however, it also carries out other tasks.

From the brainstem, where the spinal cord meets the brain, 31 spinal nerves enter the cord.

Along its length, it connects with the nerves of the peripheral nervous system (PNS) that run in from the skin, muscles, and joints.

Moreover, motor commands from the brain travel from the spine to the muscles, while sensory information travels from the sensory tissues, such as the skin, toward the spinal cord and finally up to the brain.

Furthermore, the spinal cord contains circuits that control certain reflexive responses, such as the involuntary movement your arm might make if your finger was to touch a flame.

In addition, the circuits within the spine can also generate more complex movements, such as walking. Even without input from the brain, the spinal nerves can coordinate all of the muscles necessary to walk. For instance, if the brain of a cat is separated from its spine so that its brain has no contact with its body, it will, consequently, start spontaneously walking when placed on a treadmill.

In addition, the brain is only required to stop and start the process, or make changes if, for instance, an object appears in your path.

Outer Cortex and Inner Medula

The CNS roughly divides into white and gray matter. In general, as a very general rule, the brain has an outer cortex of gray matter and an inner area housing tracts of white matter.

Moreover, both types of tissue contain glial cells, which protect and support neurons. Specifically, white matter mostly contains axons (nerve projections) and oligodendrocytes, a type of glial cell,  whereas gray matter predominantly contains neurons.

Central Glial Cells

Now, regarding central glial cells, also called neuroglia, glial cells are often called support cells for neurons. Interestingly, in the brain, they outnumber nerve cells 10 to 1.

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

Furthermore, glial cells are found in both the CNS and PNS, but each system has different types. In the following sections, the following are brief descriptions of the CNS glial cell types:

  • Firstly, astrocytes: these cells have numerous projections and anchor neurons to their blood supply. Additionally, they also regulate the local environment by removing excess ions and recycling neurotransmitters.
  • Secondly, oligodendrocytes: responsible for creating the myelin sheath,  this thin layer coats nerve cells, allowing them to send signals quickly and efficiently.
  • Next, ependymal cells: lining the spinal cord and the brain’s ventricles (fluid-filled spaces), these create and secrete cerebrospinal fluid (CSF) and keep it circulating using their whip-like cilia.
  • Lastly, radial glia: act as scaffolding for new nerve cells during the creation of the embryo’s nervous system.

Carnival Nerves

The cranial nerves consist of 12 pairs of nerves that arise directly from the brain and pass through holes in the skull rather than traveling along the spinal cord. Furthermore, these nerves collect and send information between the brain and parts of the body, mostly the neck and head.

Specifically, of these 12 pairs, the olfactory and optic nerves arise from the forebrain and constitute part of the central nervous system:

  • Firstly, olfactory nerves (cranial nerve I) transmit information about odors from the upper section of the nasal cavity to the olfactory bulbs on the base of the brain.
  • In addition, optic nerves (cranial nerve II) carry visual information from the retina to the primary visual nuclei of the brain. Moreover, each optic nerve contains around 1.7 million nerve fibers.

Central Nervous System (CNS) Diseases

Firstly, trauma: depending on the site of the injury, symptoms can vary widely from paralysis to mood disorders.

Secondly, infections: some micro-organisms and viruses can invade the CNS; these include fungi, such as cryptococcal meningitis; protozoa, including malaria; bacteria, as is the case with Hansen’s disease (leprosy), or viruses.

Additionally, degeneration: in some cases, the spinal cord or brain can degenerate. One example is Parkinson’s disease, which involves the gradual degeneration of dopamine-producing cells in the basal ganglia.

Moreover, structural defects: the most common examples are birth defects, including anencephaly, where parts of the skull, brain, and scalp are missing at birth.

Furthermore, tumors: both cancerous and noncancerous tumors can impact parts of the central nervous system. Both types can cause damage and yield an array of symptoms depending on where they develop.

In addition, autoimmune disorders: in some cases, an individual’s immune system can mount an attack on healthy cells. For instance, acute disseminated encephalomyelitis is characterized by an immune response against the brain and spinal cord, attacking myelin (the nerves’ insulation) and, therefore, destroying white matter.

Finally, stroke: a stroke is an interruption of blood supply to the brain. Consequently, resulting in lack of oxygen causes tissue to die in the affected area.

Biospecimens

biospecimens

Bay Biosciences is a global leader in providing researchers with high quality, clinical grade, fully characterized human tissue samples, bio-specimens, and human bio-fluid collections.

Moreover, human biospecimens are available including tumor tissue, serum, plasma and PBMC samples from most other therapeutic areas.

Furthermore, Bay Biosciences maintains and manages its own biorepository, the human tissue bank (biobank) consisting of thousands of diseased samples (specimens) and likewise normal healthy donors for controls. Additionally, available in all formats and types.

In fact, our biobank procures and stores fully consented, de-identified and institutional review boards (IRB) approved human tissue samples, human biofluids such as serum samples, plasma samples from various diseases and matched controls.

Also, all our human tissue collections, human biospecimens and human biofluids are provided with detailed, samples associated patient’s clinical data.

In fact, this critical patient’s clinical data includes information relating to their past and current disease, treatment history, lifestyle choices, biomarkers, and genetic information.

Additionally, researchers find the patient’s data associated with the human biospecimens extremely valuable and use it to help identify new effective treatments (drug discovery & development) in oncology, as well as in other therapeutic areas and diseases.

Bay Biosciences banks wide variety of human tissue samples and human biological samples, including fresh frozen human biospecimens cryogenically preserved at – 80°C.

For example fresh frozen tissue samples, tumor tissue samples, formalin-fixed paraffin-embedded (FFPE), tissue slides, with matching human bio-fluids, whole blood and blood-derived products such as human serum, human plasma and human PBMCs.

Bay Biosciences is a global leader in collecting and providing human tissue samples according to the specified requirements and customized, tailor-made collection protocols.

Please contact us anytime to discuss your special research projects and customized human tissue sample requirements.

Types of Biospecimens

Bay Biosciences provides human tissue samples (human specimens) and human biofluids from diseased and normal healthy donors which includes:

Moreover, we can also procure most human biospecimens and human biofluids, special collections and requests for human samples that are difficult to find. All our human tissue samples and human biofluids are procured through IRB-approved clinical protocols and procedures.

In addition to the standard processing protocols, Bay Biosciences can also provide human biofluids such as  human plasma, human serum, and human PBMCs bio-fluid samples using custom processing protocols; you buy donor-specific collections in higher volumes and specified sample aliquots from us.

Bay Biosciences also provides human biospecimens from normal healthy donors; volunteers, for controls and clinical research, Contact us Now.