SKELETAL 2 Flashcards
Is characterized by the loss of cholinergic neurons in the nucleus basalis of Meynert
Alzheimer’s disease
Is associated with a loss of dopaminergic neurons in the substantia nigra.
Parkinson’s disease
The most prevalent of Neurodegenerative Diseases
Alzheimer’s disease
2nd most prevalent neurodegenerative disorder
Parkinson’s disease
Is a progressive neurological disorder of muscle movement, characterized by tremors, muscular rigidity, bradykinesia (slowness in initiating and carrying out voluntary movements), and postural and gait abnormalities. Most cases involve people over the age of 65.
Parkinsonism
Parkinsonism is correlated with destruction of ___ in the substantia nigra with a consequent reduction of dopamine actions in the corpus striatum parts of the brain’s basal ganglia system that are involved in motor control. Genetic factors do not play a dominant role of this, although they may exert some influence on an individual’s susceptibility to the disease.
dopaminergic neurons
The substantia nigra, part of the extrapyramidal system, is the source of dopaminergic neurons that terminate in the striatum. The dopaminergic system appears to serve as a tonic, sustaining influence on motor activity rather than participating in specific movements.
Substantia nigra
Normally, it is connected to the substantia nigra by neurons that secrete the inhibitory transmitter GABA at their termini in the substantia nigra.
neostriatum
Cells of the substantia nigra send neurons back to the neostriatum, secreting the inhibitory transmitter ___ at their termini.
dopamine
Destruction of cells in the substantia nigra results in the degeneration of the nerve terminals responsible for secreting dopamine in the neostriatum.
Parkinson’s disease
Parkinsonian symptoms infrequently follow viral encephalitis or multiple small vascular lesions.
Secondary parkinsonism
Drugs whose major pharmacologic action is blockade of dopamine receptors in the brain, may also produce parkinsonian symptoms. These drugs should not be used in parkinsonian patients.
phenothiazines and haloperidol
Is a metabolic precursor of dopamine. It restores dopaminergic neurotransmission in the corpus striatum by enhancing the synthesis of dopamine in the surviving neurons of the substantia nigra. Uses in early disease.
Levodopa
Side effects of Levodopa in large doses.
- nausea,
- vomiting,
- cardiac arrhythmias, and
- hypotension
A dopa decarboxylase inhibitor that does not cross the blood-brain barrier. It diminishes the metabolism of levodopa in the gastrointestinal tract and peripheral tissues; thus, it increases the availability of levodopa to the CNS.
Carbidopa
Decreases the rigidity, tremors, and other symptoms of parkinsonism.
Levodopa
Large, neutral amino acids (for example, leucine and isoleucine) compete with it for absorption from the gut and for transport across the blood-brain barrier. Thus, it should be taken on an empty stomach, typically 45 minutes before a meal.
levodopa
Adverse effect of Levodopa and carbidopa in the peripheral.
- Anorexia
- nausea
- vomiting
- tachycardia
- ventricular systoles
- hypotension
- mydriasis
- blood dyscasias
- brownish saliva and urine
CNS eefects of Levodopa and carbidopa
- visual and auditory hallucinations
- dyskinesias
- overactivity of dopaine
- mood changes, depression, psychosis and anxiety in levodopa
increases the peripheral breakdown of levodopa and diminishes its effectiveness
Vitamin pyridoxine (B6)