The brain is a complex organ that controls thought, memory, emotion, touch, motor skills, vision, breathing, temperature, hunger and every process that regulates our body.
Together, the brain and spinal cord that extends from it make up the central nervous system, or CNS.
Neuron is an electrically excitable cell that communicates with other cells via specialized connections called synapses
.Most neurons receive signals via the dendrites and soma and send out signals down the axon. At the majority of synapses, signals cross from the axon of one neuron to a dendrite of another.
However, synapses can connect an axon to another axon or a dendrite to another dendrite.
In most cases, neurons are generated by neural stem cells during brain development and childhood.
Brain Positron Emission Tomography
Brain positron emission tomography is a form of positron emission tomography (PET) that is used to measure brain metabolism and the distribution of exogenous radiolabeled chemical agents throughout the brain.
PET measures emissions from radioactively labeled metabolically active chemicals that have been injected into the bloodstream.
The brainstem is the posterior stalk-like part of the brain that connects the cerebrum with the spinal cord.
It has the critical roles of regulating cardiac, and respiratory function, helping to control heart rate and breathing rate.
It also provides the main motor and sensory nerve supply to the face and neck via the cranial nerves.
Neuronal activity plays an essential role in shaping synaptic strength and connectivity at all stages of neuronal development and function.
A neuron reacts to changes in synaptic transmission by modulating gene expression programs, which in turn regulate important synaptic factors.
Magnetic Resonance of Brain
A special type of MRI is the functional MRI of the brain (fMRI). It produces images of blood flow to certain areas of the brain.
It can be used to examine the brain’s anatomy and determine which parts of the brain are handling critical functions.
One advantage of MRI of the brain over computed tomography of the head is better tissue contrast, and it has fewer artifacts than CT when viewing the brainstem. MRI is also superior for pituitary imaging.
Synapse is a structure that permits a neuron to pass an electrical or chemical signal to another neuron or to the target effector cell.
Synapses are essential to the transmission of nervous impulses from one neuron to another.
Neurons are specialized to pass signals to individual target cells, and synapses are the means by which they do so.
Neural pathway is the connection formed by axons that project from neurons to make synapses onto neurons in another location, to enable a signal to be sent from one region of the nervous system to another.
Neurons are connected by a single axon, or by a bundle of axons known as a nerve tract.
Shorter neural pathways are found within grey matter in the brain, whereas longer projections, made up of myelinated axons, constitute white matter.
Body Structure of Neuron
Neuron is composed of soma, dendrites, axon and axon terminal.
Soma is the body of the neuron. As it contains the nucleus, most protein synthesis occurs here.
Dendrites of a neuron are cellular extensions with many branches. This overall shape and structure is referred to metaphorically as a dendritic tree. This is where the majority of input to the neuron occurs.
Axon is a finer, cable-like projection that can extend tens, hundreds, or even tens of thousands of times the diameter of the soma in length. The axon primarily carries nerve signals away from the soma, and carries some types of information back to it.
Axon terminal is found at the end of the axon farthest from the soma and contains synapses. Synaptic boutons are specialized structures where neurotransmitter chemicals are released to communicate with target neurons.
Anatomy of the Brain
The brain is composed of the cerebrum, cerebellum, and brainstem.
Cerebrum: is the largest part of the brain and is composed of right and left hemispheres. It performs higher functions like interpreting touch, vision and hearing, as well as speech, reasoning, emotions, learning, and fine control of movement.
Cerebellum: is located under the cerebrum. Its function is to coordinate muscle movements, maintain posture, and balance.
Brainstem: acts as a relay center connecting the cerebrum and cerebellum to the spinal cord. It performs many automatic functions such as breathing, heart rate, body temperature, wake and sleep cycles, digestion, sneezing, coughing, vomiting, and swallowing.