Brain Response of Behavior - Essay Example

?Communication Process of Neurons in the Brain, Common Neurotransmitters and Their Effects: What is a Neuron? Before we understand the communication process of neurons in the brain, it is very important for us to understand what a neuron itself is. A neuron can very simply be defined as a nervous system cell which is responsible for transmitting and receiving electrochemical information. (Huffman, 2008) Basic Parts of a Neuron: All neurons are different but most neurons share three features: 1. Dendrites 2. Cell body 3. Axon Dendrites: Dendrites resemble a leafless branch of a tree and act like an antenna for the neuron. They receive electrochemical information from other neurons and pass it on to the cell body. (Huffman, 2008) Cell Body: The cell body contains the cell nucleus and accepts incoming messages from dendrites. It passes the message on to the axon if it receives sufficient stimulation from the dendrites. (Huffman, 2008) Axon: Axon is like a long, tube-like structure and acts like a miniature cable which carries information and impulses away from the cell body. (Huffman, 2008) Communication Process of Neurons in the Brain: Communication between neurons is an intriguing process and one that very different from the process of communication within the neuron. Communication between neurons is transmitted chemically as opposed to electrically within the neuron. The transfer of information between the neurons occurs at the synapse which includes the tips of the axon (terminal buttons), the synaptic gap (very small space between the neurons) and the receiving neuron’s dendritic branches. The process starts with the release of a few thousand chemical molecules (neurotransmitters) into the synaptic gap by the sender neuron’s axon. These neurotransmitters then move towards the dendrites of the receiving neuron across the synaptic gap. This neurotransmitter then attaches itself to the receiving antenna of the neuron and delivers either an excitatory or an inhibitory message. (Huffman, 2008) Common Neurotransmitters and their effects1: Neurotransmitter Effects Endorphins Endorphins, effect-wise, are similar to opium based drugs such as Morphine. They promote pleasure and reduce pain. Serotonin Low-levels of Serotonin are associated with depression. They are known to suppress pain and regulate temperature. Other impacts include mood, appetite, sleep and sensory perception Dopamine Dopamine plays a role in addiction and the reward system. Excessive levels of Dopamine are associated with Parkinson’s disease while too little levels are associated with schizophrenia. Epinephrine (adrenaline) Epinephrine affects memory storage, metabolism and emotional arousal. It also majorly impacts the glucose necessary for energy release. Norepinephrine (noradrenaline) Norepinephrine impacts dreaming, waking from sleep, alertness, reactions to stress, learning and memory. High levels of Norepinephrine are associated with agitated, manic states while low levels are associated with depression. Major Regions of the Brain and Functions of Behavior They Control: The human brain can be divided into two major parts: 1. The lower level brain structures 2. The cerebral cortex It is important to note here that at the bottom of the brain “lower”, basic processes like breathing etc are performed and as we move towards the top “higher” more complex functions such as thinking etc are performed. Lower Level Brain Structures: The Hindbrain: The hindbrain controls and in some cases influences the automatic behaviors and survival responses of the human body. (Bailey, 2009) The hindbrain has three major parts: Medulla: The medulla is basically an extension of the spinal cord and is located near the base of the human brain. It contains many never fibers which pass through it carrying information to and from the brain. It also contains nerve fibers that control very important automatic bodily functions including respiration and heartbeat. (Bailey, 2009) (Huffman, 2008) Pons: Located right above the medulla, the pons plays a major role in dreaming, sleeping and waking, movement, and respiration. The pons contains many axons which cross from one side of the human brain to the other side. Cerebellum: Located behind the medulla and the pons and at the base of the human brain, the cerebellum is a very old structure in evolutionary terms. It coordinates balance and fine movement of the muscles. (Huffman, 2008) The Midbrain: Neural centers are contained in the midbrain which help the human body orient its eye and body movements to auditory and visual stimuli. These neural centers also help the human body control sleep and the arousal level. (Bailey, 2009) The Forebrain: The forebrain of the human brain contains extremely important structures including: The Thalamus: Located near the top of the brainstem, the Thalamus communicates sensory messages to the cerebral cortex. The thalamus receives information from almost all sensory systems of the human body and then directs that input to the suitable cortical areas of the brain. (Bailey, 2009) The Hypothalamus: Located right below the Thalamus, the Hypothalamus is very small in size but plays the role of a master control centre for emotions and basic drives such as aggression, hunger, sex etc. The hypothalamus is also responsible for regulating the human body’s internal environment. (Huffman, 2008) The Limbic System: The limbic system of the human brain is responsible for emotions, drives and memory. The major role of the limbic system, however, is that it produces and regulates fear and aggression. It also plays a very important role in the pleasure and reward system. (Huffman, 2008) The Cerebral Cortex: The cerebral cortex of the human brain has two, left and right, hemispheres. The left hemisphere controls the right side of the human body and the right hemisphere controls the left side. These two hemispheres are divided into 8 areas: Two Frontal Lobes: The frontal lobes receive and coordinate information from the other 6 lobes of the brain. They are also in charge of speech production, motor control, and higher functions including memory, emotions, and personality. (Huffman, 2008) Two Parietal Lobes: The parietal lobes of the human brain are responsible for interpretation of bodily sensations. (Huffman, 2008) Two Temporal Lobes: The major function of the temporal lobes is to assist in hearing, language comprehension, memory, and emotional control. (Huffman, 2008) Two Occipital Lobes: The major function of the occipital lobes is to help with vision and visual perception. (Huffman, 2008) The Sensory Process: As the baseball bat hits the ball and the ball flies through the air the eye of the catcher captures the scene (light) and focuses it on the receptors located at the back of the eyeball. These receptors turn the light energy into neural signal which will be interpreted by the brain later on. This light then goes into the cornea which is an outwardly curved (convex) shaped transparent tissue which helps focus this incoming light ray. Located right behind the cornea, the iris allows the pupil (the opening) of the eye to constrict or dilate in response to the intensity of the light. The light then goes to the lens, which adds to the focusing begun by the cornea. The lens of the eye is adjustable and it can change its shape to help us focus on close and distant objects. So when the ball hits the bat and is farther away from the catcher, the lens of the eye accommodates (the process of automatic adjustment of the human eye) by flattening and thinning in order to allow the catcher to see the ball hitting the bat and flying through the air. As the ball comes closer and closer to the catcher, the lens of the eye thickens and curves allowing him see the ball perfectly and to judge the catch. After passing through the cornea, the pupil and the lens the light ends up on the retina Located at the back of the eye, the retina helps the eye transmit neural information to the occipital lobes of the brain. The retina also contains special receptor cells known as rods and cones. Rods help us see in dim light and cones help us see in bright light. So as the ball flies through the air if there is any shadow in the background, such as that of a stand etc then the rods will take over, otherwise during the whole scenario the cones will help the catcher see the ball. The cones are mainly located toward the centre of the retina of the human eye. And this is how the sensory process takes place as the ball hits the bat, flies through the air and is caught by a catcher. Works Cited Bailey, R. (2009, January 15). Brain Basics. Retrieved August 13, 2011, from About.com: http://biology.about.com/od/anatomy/a/aa120704a.htm Huffman, K. (2008). Psychology in Action. John Wiley and Sons. Read More