Physiological Bases of Behavior
There are many physiological bases for behaviors. All
behaviors are produced and controlled by the brain. Different brain regions are
responsible for different behaviors. The brain, in turn, is affected by
genetics, nutrition, and myriad environmental factors.
The study of the physiological bases of behavior is biological or physiological
psychology. Most studies in this field relate to the function of
neurotransmitters and neurons.
In this chapter, we take a closer look at the communication
in the nervous system. The basic hardware of the nervous system is the nervous
tissue. Our nervous system is a living tissue composed of cells. There are two
types of cells in the nervous system: GLIA and NEURONS or NERVE CELL. First,
what is Neuron? It is the individual cells in the nervous system that receive,
integrate and transmit information. It is the basic unit of the nervous system.
Every neuron has different shapes, sizes and function. There are about
approximately trillion of neurons throughout the body which involved in the
control of body activities and behavior.
There are four parts of neuron; these are the cell
body/Soma, dendrites, axons, and myelin sheath. Cell body contains the nucleus
which provides nourishment and insulation. The function of Dendrites is to
receive signals from neighboring neurons and carry them back to the cell body,
while axons carries messages to the other neuron. Axons terminate in small
bulges called TERMINAL BUTTON that send messages to other neurons. Lastly,
Myelin sheaths are the fatty tissue and proteins surrounding the axons.
There are three kinds of neuron according to basic function;
Sensory (Afferent neurons), Motor (Efferent neurons) and
Association/Inter-neurons. Sensory neurons convey information from the body’s
sense organs to the brain and spinal cord. This is initiated by
receptors-specialized cells in the sense organs, muscles, skin and joints that
detect physical or chemical changes and convert these into impulses that pass
along the sensory neurons. Motor neurons carry impulses away from the brain and
spinal cord to the reacting organs, the muscles and glands. Lastly, the
Association Neurons connect the neurons together and combine the activities of
the sensory and motor neurons.
In the other hand, Glial cells are the non-neural cells that
surround the neurons and ensure that it can perform its function while holding
them in place.
There are 3 steps of how the neurons fire; the resting
state, the action potential and the Synapse: Sending the message to other
cells. Resting state is the state of neuron when not firing a neural impulse.
Action potential is the time when there is a release of the neural impulse
consisting of a reversal of the electrical charge within the axon. Lastly the
Synapse, in this situation, the neurons that send a signal across the gap is
called synaptic neuron and the neurons that receive the signals is called the
post-synaptic neuron.
Neurotransmitters are also known as the messenger. These are
the chemicals that carry messages across the synapse or cell body of a
receiving neuron. Neurotransmitter has five functions: these are the
acetylcholine, Norepinephrine, dopamine, Gamma amino. Acetylcholine is located
at brain, spinal cord, ANS, selected organs and release at neuromuscular
junctions. Norepinephrine is also located at brain, spinal cord and it’s
regulates physical logical arousal, learning, memory and emotion. Dopamine is
only located at brain and it’s linked to muscle activity, emotional arousal,
learning memory. Gamma Amino is also located at brain, spinal cord and it’s
involved in motor behavior and arousal.
The Peripheral nervous system can be divided into somatic
nervous system and autonomic nervous system. Somatic nervous system is made up
of nerves that connect to voluntary skeletal muscles and to sensory receptors.
These nerves are the cables that carry information from receptors in the skin,
muscles and joints to the central nervous system to the muscles. The Autonomic
nervous system is concerned with the parts of the body that keeps us alive- the
heart, blood vessels glands, and other organs that operate involuntarily
without our awareness.
The Central nervous system has two parts: the brain and the
spinal cord. The brain is the true core of the nervous system. It takes
information from senses processes it, makes decision and sends commands to the
rest of the body. The major parts of the brain is the Hindbrain (consist of
medulla, pons, cerebellum), Midbrain (located between hindbrain and forebrain)
and the Forebrain (largest part of the brain).
The Cerebral cortex consists of a mass of deeply folded,
rippled, convoluted tissue. It has four major sections called Lobes. The
Frontal lobe (lies at the front center of the cortex), the Parietal Lobe
(located at the top of the head function), Temporal Lobe (found in lower center
portion of the cortex), and the Occipital lobe (found at the back of the head).
The Limbic System or the old brains are found in the inner margin of the upper
brain which includes Thalamus (Inner chamber) and hypothalamus (below the inner
chamber).
For Conclusion, Our Brain is the most important parts of the body because it controls other organs and our mind. Brain is like a command center that commands to other organs to move or make their own job.