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neuro.science

THE HYPOTHALAMUS AND THALAMUS

http://www.neuro.science/diencephalon.htm

The diencephalon (through brain or betweenbrain) includes the thalamus, hypothalamus, epithalamus, and subthalamus. It represents the highest part of the brain stem and is capped by the telencephalon (cerebral hemispheres). Except for the interthalamic adhesion, the diencephalon is divided by the cerebrospinal-fluid-filled third ventricle. It is bounded caudally by the midbrain and rostrally by the frontal lobes of the cerebrum. Please visit this site, where daily neurosurgical activities are going on.

neuro.science

RECEPTORS

http://www.neuro.science/receptors.htm

Nature has evolved a variety of morphological structures which function as receptors. The earliest studies of sensation led to the idea that each morphological receptor type was responsible for the transduction of a particular modality of sensation. This early hypothesis has been modified in light of evidence that receptors respond to more than one type of stimuli. CLASSIFICATION OF RECEPTORS BY ADEQUATE STIMULI. THE NATURE OF THE RECEPTOR POTENTIAL. It is thought that the receptor potential is produced ...

neuro.science

MEMBRANE POTENTIALS

http://www.neuro.science/membranepotentials.htm

Membrane Potentials and the Nerve Impulse. OVERVIEW OF NEURON ACTIVITY. Nervous systems are incredibly complex networks of nerve cells in which impulses traveling along one neuron initiate impulses in other neurons at chemically responsive junctures called synapses. Chemicals called neurotransmitters are released at these synapses in response to the arrival of impulses at the presynaptic terminals of the first neuron. BASIC ELECTRICITY AND THE NEURON. Current is carried in wires by electrons, but in biol...

neuro.science

AUTONOMIC NERVOUS SYSTEM

http://www.neuro.science/autonomicns.htm

Fortunately the body's vital functions are regulated automatically and require no conscious effort on our part. The autonomic nervous system (ANS) is to a large extent responsible for automatically and subconsciously regulating the cardiovascular, renal, gastrointestinal, thermoregulatory, and other systems, in order to enable the body to meet the continual and ever-changing stresses to which it is exposed. Fig-1: The sympathetic ganglia associated with spinal nerves T1 through L2 are connected to the ne...

neuro.science

MUSCLE TONE - SPINAL REFELXES

http://www.neuro.science/muscletone.htm

MUSCLE TONE - SPINAL REFELXES. MUSCLE TONE - SPINAL REFELXES. OVERVIEW OF MUSCLE TONE. The muscle tone exhibited by otherwise relaxed muscles is necessary for these muscles to produce effective movements. If muscles relaxed completely (no resting tone), they would overlengthen, and too much time would be required to take up slack when a contraction was called for. On the other hand, too much tone would not allow for sufficient rest and recovery. Innervation of the Spindles. The Myotatic (Stretch) Reflex.

neuro.science

THE SYNAPSE

http://www.neuro.science/synapse.htm

Impulse conduction in a single axon is fascinating to behold but, taken by itself, functionally limited. The full potential of the impulse is appreciated only by the functional changes it produces in a postsynaptic cell. Here we will examine the events which occur at these functional contacts known as synapses. There is strong evidence to implicate certain chemicals as neurotransmitters at synapses. Others, known as putative transmitters, are also suspected to act in this way, but the evidence suppor...

neuro.science

SKELETAL MUSCLE CONTRACTION AND THE MOTOR UNIT

http://www.neuro.science/motorunit.htm

SKELETAL MUSCLE CONTRACTION AND THE MOTOR UNIT. SKELETAL MUSCLE CONTRACTION AND THE MOTOR UNIT. Researchers have learned that muscle contraction cannot proceed in the absence of adenosine triphosphate (ATP) and Ca. A single skeletal muscle is composed of many thousands to millions of long, narrow contractile cells called muscle fibers (Fig-1). These fibers are clustered together in parallel bundles called fasciculi. Each muscle fiber is 10 to 80 µ. That are activated during muscle contraction. During con...

neuro.science

NEUROCHEMISTRY

http://www.neuro.science/neurochemistry.htm

The brain, like other organs of the body, requires an adequate vascular system in order to supply it with nutrients and oxygen and to remove metabolic wastes and carbon dioxide. Unlike most other organs, however, capillary exchange of these and other materials in the brain is complicated by the presence of a transport-limiting system, the. Cerebral Blood Flow and Oxygen Consumption. Our brain is a mystery and to understand it, you need to be a neurosurgeon, neuroanatomist and neurophysiologist.

neuro.science

SENSORY PATHWAYS

http://www.neuro.science/sensorypathways.htm

Ensory pathways include only those routes which conduct information to the conscious cortex of the brain. However, we will use the term in its more loosely and commonly applied context to include input from all receptors, whether their signals reach the conscious level or not. GENERAL SOMATIC AFFERENT (GSA) PATHWAYS FROM THE BODY. Fast and Slow Pain. Discriminating (Epicritic) Touch, Pressure, and Kinesthesia. Some of the subconscious proprioceptive input from the cervical region follows an alternate rou...