Divisions of the Nervous System

The nervous system has two main divisions: the central nervous system (CNS) and the peripheral nervous system (PNS) (Figure31). The CNS is the body’s control center, consisting of the brain and spinal cord. The brain is responsible for consciousness; its functions include perception, emotion, memory, thought, and language. The lower parts of the brain are also responsible for some unconscious functions, such as regulation of the endocrine (hormonal) and cardiovascular systems. The spinal cord is responsible for simple reflexes; it also serves as a pathway between the brain and the PNS.

The PNS is the body’s communication network; it includes the nerves and sense organs. Nerves are bundles of fibers that carry signals to and from the CNS. Motor nerves carry commands from the CNS to muscles and glands; sensory nerves carry input from sense organs (receptors) to the CNS. Different kinds of sensory receptors respond to differen..t

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Classifying Faces by Race: The Structure of Face Categories

Although face perception is usually studied from the standpoint of our amazing ability to differentiate a large number of faces, representations of face categories are also important. The process of categorizing individual faces has a number of implications both for general models of classification and for understanding face identification. The focus here is on the apparently paradoxical finding that participants are faster to classify faces they have difficulty recognizing. In the present case, this means that White participants classify Black or Asian faces faster than White faces (Levin, 1989; Valentine & Endo, 1992). In attempting to understand facilitated classification of cross-race faces (hereinafter referred to as the CR [cross-race] classification advantage), the present research considers explanations for the CR classification advantage as they relate to the basic structure of face categories, both in terms of discrimination between categories and in terms of their internal structure. Three explanations for the CR classification advantage are tested here. The first, stemming from Valentine's (1991) multidimensional space framework, places the advantage in

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Handbook of Drug Therapy in Psychiatry | Chapter 11 Movement Disorders and Neurologic Aspects of Psychotropic Drugs

Chapter. 11. Movement Disorders and Neurologic Aspects of Psychotropic Drugs

OVERVIEW

1. Acute dystonic reactions are common when starting antipsychotic chemotherapy - diphentydramine (Benadryl) 50 mg IV provides most rapid and safe relief within minutes. Alternatively, diphenhydramine may be given IM or benztropine may be given IV or IM ( 1-2 mg).

2. Parkinsonism is commonly seen, especially in the first few weeks of antipsychotic chemotherapy. There may be stiffness, reduced arm movement when walking, tremors, and sialorrhea. Prophylactic administration of an antiparkinsonian drug in low dosage 2 to 4 times daily may reduce the incidence and severity of acute extrapyramidal symptoms. These drugs should not be used prophylactically in the elderly or in patients with OBS. More potent antipsychotic agents with less anticholinergic potency are more likely to produce acute extrapyramidal (parkinsonian) effects. There is no evidence that neuroleptics with lower potential for producing acute EPS are less likely to produce the late-occurring neurologic syndrome known as tardive dyskinesia.

3. Akathisia is the most common acute EPS, and responds...

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Disposition of Toxic Drugs & Chemicals in Man | Primidone

Occurrence and Usage. Primidone (Mysoline), a desoxy derivative of phenobarbital, was synthesized in 1949 and first evaluated as an anticonvulsant in 1952. It is used frequently for the treatment of grand mal and temporal lobe seizures, in daily oral doses of 250-1500 mg. The drug is supplied as the free acid in tablets of 50 and 250 mg and as a 250 mg/5 mL suspension for oral administration.

Blood Concentrations. A single 250 mg oral dose of primidone given to 10 patients who were not receiving other anticonvulsants produced an average peak serum primidone concentration of 4.9 mg/L at 4 hours. Primidone concentrations declined with an average half-life of 15 hours (range, 9-22) in these patients, but patients receiving other anticonvulsant drugs exhibited primidone half-lives averaging 8 hours. The metabolites phenylethylmalonamide and phenobarbital were present at detectable levels within 24 or 48 hours, respectively, of the single primidone dose (Cloyd et al., 1981). After a 500 mg oral dose, one subject achieved a peak...

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Disposition of Toxic Drugs & Chemicals in Man | Phenobarbital

Occurrence and Usage. Phenobarbital is a barbiturate derivative that has been used as a daytime sedative and very extensively as an anticonvulsant since 1912. Phenobarbital is an excellent inducer of drug-metabolizing microsomal enzymes and its use often results in the lowering of plasma levels of other drugs. Its low oil/water partition coefficient relative to other barbiturates is the basis for its slow accumulation in brain tissue and its limited metabolism. The drug is available as either the free acid or the sodium salt in an elixir or as tablets of 15-65 mg for oral use or in a 65-130 mg/mL solution for intramuscular or intravenous injection. It is often found in combination with bronchodilators, vasodilators, analgesics, and anticholinergic agents. It is generally administered to epileptic patients in oral doses of 60-200 mg daily, often in combination with other anticonvulsant drugs.

Blood Concentrations. A single 30 mg oral dose given to 3 volunteers produced an average peak serum concentration of

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