Explore BrainMass

Human Nervous System

The Human Nervous System controls voluntary and involuntary actions using the central nervous system (CNS) and the peripheral nervous system (PNS). The central nervous system consists of the brain and the spinal cord and serves as the main control center. The peripheral nervous system consists of the associated nerve networks, whose function is to connect parts of the body with to CNS. The PNS is divided into the autonomic nervous system, which controls the involuntary activities like digestion and breathing, whilst the somatic nervous system controls voluntary actions by transmitting stimuli information to the CNS, and sending back response signals to muscles. The autonomic nervous system is further divided into the sympathetic, parasympathetic and enteric nervous system – sympathetic nervous system deals with fight-or-flight signals, parasympathetic maintains body conditions, and enteric nervous system oversees gastrointestinal functions. The divisions of the Nervous System are displayed in the diagram:


There are two types of nerves in the PNS, which are sensory and motor neurons. Sensory neurons carry information from receptors that detect stimuli in the surrounding environment to the motor neurons. The motor neurons are located in the spinal cord, it transfers signals from sensory neurons to the brain, and back to effector muscles to produce a response. Neurons communicate to each other by releasing neurotransmitters at axons, which travel through the synapse to bind to receptors on the dendrites of the adjacent neuron – this creates an action potential. There are two types of receptors, voltage-gated ion channels and second messenger systems. When the voltage of the post-synaptic membrane reaches the threshold, the voltage-gated ion channels open selectively allowing specific ions to enter. In second messenger systems, molecular alterations take place which increase or decrease the cell sensitivity to a certain stimuli.

A reflex arc is when a stimuli-associated signal is transported to the motor neuron in the spinal cord by the sensory neuron, it bypasses the brain and the motor neuron then sends a signal to effector muscles to respond. An example is when a hand responds to a heat source, and withdraws immediately.

Autonomic Nervous System Innervation

Please help me fill in the blank for first 2 questions and brief answer for 3rd. 1. During exercise, the heart rate will increase above 100 beats per minute. This is the result of higher centers of the brain activating the (Blank1) (Blank 2) in the (Blank 3) which will produce output from the (Blank 4) division to depolarize t

A case of Guillain-Barré syndrome

Israel was a third-year college Biology major when he noticed one day that both of his feet were tingling and painful. He figured it was probably from sitting cross-legged while studying for hours.The next morning, he woke up and was in pain throughout his body. He was in so much pain he felt he couldn't get out of bed, and he t

Neuromuscular Blocking Agents & Transmembrane Potential Gradient

1. A certain type of poison is a nicotinic receptor blocker. What affect would this poison have on the muscle action potential? 2. Some inhibitory postsynaptic potentials (IPSPs) are the result of Cl- entering the cell through a chloride channel. Other IPSPs are caused by the opening of K+ channels. How could movement of the

Mental Health and Green Space

Before you begin, please review this information about When to Cite Sources Other resources are available at and For tonight's meeting, the Springdale Community Coalition has asked

Pollution and Environmental Health

For this week's newspaper article, you decided to analyze the role of environmental health in your community. From your readings, your region's air quality reports, and independent research, write a 2- to 3-page paper that addresses the following: 1. What are the most pressing environmental hazards in your area (you can choose

week 12

Identify a drug, either natural or man-made, that affects the ANS; Identify the receptor affected by the drug; Describe that receptor's normal function; Describe how the drug affects that receptor's normal function on a molecular scale; Describe the physiological effect the drug has on the patient and what condition

Central Nervous System

1. Find a peer review study in which a subject has sustained an injury to a particular region of the CNS; 2. Describe the region of the CNS that was injured; 3. Describe what functions that region of the CNS is typically involved with; 4. Describe what symptoms the injured person displayed;

Parkinson's Disease - Neurotransmitters

Identify a genetic homeostatic imbalance (disease/disorder) of the nervous system involving neurotransmitters; Describe the symptoms of that disease; Describe how the neurotransmitter is involved in that disease; Name a drug used to treat the disease and how well it works; Describe the molecular mechanism behind how

Olfactory I Nerve

Choose a cranial nerve to discuss in detail and describe its function including the origination in the brain, the path it follows through the skull, its innervation (what body part it serves), and whether its function is sensory, motor, or both. Include unlabeled diagrams of the pathway from the brain through the opening(s)

Multiple Sclerosis MS

You will select and explore a behavioral condition or other CNS pathology. In the book, Neurobehavioral Anatomy on your ebrary bookshelf, you will find chapters that investigate various behavioral pathologies. I recommend beginning here to find your topic. Additional topics may include: Depression Post-traumatic stress

Anatomy and Physiology of Breast Cancer

I need an outline on the anatomy and physiology of breast cancer. It needs to contain these following areas: 1-Definition 2-Etiology 3-Pathophysiology 4-Complication 5-Symptom/signs 6-Investigation(lab or other tests) 7-Diagnosis 8-Treatment 9-Complication 10-Prognosis and prevention

Action Potential and Ion Regulation

Describe the events that must occur to generate an action potential. Indicate how the ionic gates are controlled, explain why the action potential is an all-or-none phenomenon.

Topics in Neuroanatomy

1) Describe the function of: A) a neurolemmocyte B) microglial cell 2) What role do the convolutions play in the brain? 3) What function does the optic nerve have? 4) The trigeminal nerve is larger than the trochlear nerve. how does this correlate with the function of both nerves?

Central Nervous System Injury

Result of injury to the central nervous system and how injury may be manifested in a patient with injury to the Temporal lobe of the brain, the parietal lobe, and the medulla oblongata would be affected.

Initiation and Propagation of an Action potential

Explain, in a sequential fashion, beginning with the motor neuron, the steps involved in the initiation and propagation of an action potential, including all neurotransmitters and ions involved in the process.

The Correlation Between Neurotransmitters and Drug Action

Based on neurotransmitters and drug action, explain how drugs use created altered states of consciousness. Other substances, such as caffeine and nicotine, also change our level of consciousness to some degree. Discuss at least three reasons individuals may seek substances such as nicotine and caffeine.

Sign and the magnitude of the change in the resting potential

In 1983, a young boy named Jimmy Tontlewicz fell through a hole in the ice on a lake in Minnesota. When the rescue team pulled him out of the water 20 min later, his body temperature had fallen from the normal 37 C to 29 C. Calculate the sign and the magnitude of the change in the resting potential of Jimmyâ??s neurons if the

Nervous System Questions

A) Functional Organization of Nervous Tissue 1. In hyperpolarization... 2. A stimulus either causes an action potential or it doesn't. This is called 3. The absolute refractory period assures 4. Neurotransmitters are released from the 5. When a neurotransmitter binds to its receptor and increases the permeability of

Urine Tests & Neurotransmitters

The urine tests can only test neurotransmitters in the body and not the brain. The brain is so compact and complex that it would be very difficult to completely test everything in the brain. QUESTION: 1. Please provide a chart of some kind stating the correct balance of neurotransmitters? There wouldn't be a way to exac

The Nervous System - Structure and Function

1.Provide a brief overview of the mechanisms behind a typical function of the nervous system. 2.Draw and label a diagram of a typical neuron. 3.Describe the mechanism by which an impulse moves down a neuron. 4.Explain in detail how the action potential in a neuron is able to cross the synapse between two neurons.

Neurotransmitters - Definition, effects and Treatment

Neurotransmitters play a vital role in both our minds and bodies; please respond to the following items: 1. Define neurotransmitters and describe their role in neurotransmission. Discuss how they are released, how they affect receiving neurons, and how they are removed from receptor sites. 2. Pick one neurotransmit

Chemical and Electrical synapses properties in the CNS.

A short comparison of chemical and electrical synapse properties in the Central Nervous System, including physical properties of each synapse type as well as reasons for requiring both types of synapse in the central nervous system (includes brain and spinal cord).

The Function of Neurotransmitters

Neurotransmitters play a vital role in both our minds and bodies. Considering this, please respond to the following items: - Describe neurotransmitters in terms of what they are, their general function within the body, and their impact on behavior. - Pick one neurotransmitter and discuss the effect it has on our bodies; part

Fiber tracts

Describe the functional problems that would be experienced by a person in which these fiber tracts have been cut: (a) lateral spinothalamic, (b) anterior and posterior spinocerebellar, (c) tectospinal.