Physiology/Psychopharmacology Flashcards
Aphasia (Broca’s, Wernicke’s, and Conduction)
Aphasia is impaired production and/or comprehension of language. Broca’s aphasia is caused by damage to Broca’s area and involves difficulty producing written or spoken language with little or no comprehension issues; it often includes anomia and impaired repetition. Wernicke’s aphasia is caused by damage to Wernicke’s area and involves an inability to comprehend written or spoken language along with the production of rapid, seemingly effortless speech that is lacking in content; it may include anomia, paraphasia, and impaired repetition. Conduction aphasia is caused by damage to the arcuate fasciculus and does not significantly affect comprehension but does result in anomia, paraphasia, and impaired repetition.
Autonomic Nervous System (ANS)/Sympathetic and Parasympathetic
The autonomic nervous system (ANS) is a division of the peripheral nervous system and is involved in the control of visceral functions (e.g., heart rate, blood pressure, respiration, digestion, and sweating). It consists of the sympathetic and parasympathetic branches: The sympathetic branch is involved in the mediation of flight or fight (emergency) reactions. Activation of the sympathetic branch produces increased heart rate, pupil dilation, increased blood sugar, and inhibition of the digestive processes. The autonomic nervous system (ANS) is the part of the peripheral nervous system that controls visceral functions (e.g., heart rate, blood pressure, respiration, digestion, and sweating). It consists of the sympathetic and parasympathetic branches. The sympathetic branch mediates flight or fight (emergency) reactions; activation produces increased heart rate, pupil dilation, increased blood sugar, and inhibition of the digestive processes. The parasympathetic branch regulates energy conservation and relaxation. Activation is associated with slowing of heart rate, lowered blood pressure, contraction of pupils, reduction of sweat gland output, and increased activity of the digestive system.
Basal Ganglia
The basal ganglia are subcortical structures (caudate nucleus, putamen, globus pallidus, and substantia nigra) that are involved in planning, organizing, and coordinating voluntary movements. Basal ganglia pathology has been linked to Huntington’s disease, Parkinson’s disease, Tourette’s Disorder, OCD, and ADHD.
Beta-Blockers (Propranolol)
Propranolol and other beta-blockers block or diminish the cardiovascular excitatory response to the hormones epinephrine and norepinephrine. They are used to treat cardiovascular disorders, glaucoma, and migraine headache and are also useful for reducing the physical symptoms of anxiety. Common side effects of propranolol include bradycardia, nausea, diarrhea, dizziness, decreased sexual ability, and trouble sleeping.
Brain Lateralization/Split-Brain Patients
Though the left and right hemispheres are both involved to some degree in most functions, they tend to specialize. This specialization is referred to as brain lateralization and was initially studied in split-brain patients, whose corpus callosums had been severed to control severe epilepsy. The left hemisphere dominates in verbal activities (spontaneous speaking and writing, word recognition, memory for words and numbers); analytical, logical thought; and positive emotional states. The right hemisphere dominates in visual-spatial activities such as facial recognition, spatial interpretation and memory for shapes, and in negative emotions.
Cerebellum And Ataxia
The cerebellum is a large structure on the dorsal aspect of the hindbrain. It is involved in the extrapyramidal control of motor activities (e.g., coordination, balance, posture). Damage can result in ataxia, which is characterized by slurred speech, severe tremors, and a loss of balance.
Cerebral Ventricles/Hydrocephalus
The ventricles are the four cavities of the brain that contain cerebrospinal fluid. Blockage of the ventricles and a resulting build-up of fluid can cause hydrocephalus.
Cerebrovascular Accident
Cerebrovascular accident (CVA) is also referred to as cerebral stroke and refers to brain damage that occurs when a blood clot or other obstruction or hemorrhage disrupts the flow of blood to the brain. Common symptoms include contralateral hemiplegia, hemianesthesia involving the face, arm, and leg, and contralateral visual field loss.
Contralateral Representation
For most sensory and motor functions, the cortex exhibits contralateral representation, which means that the left hemisphere controls the functions of the right side of the body and vice-versa.
Corpus Callosum
The right and left hemispheres are connected by several bundles of fibers, the largest of which is the corpus callosum. If the corpus callosum is severed, the two hemispheres operate essentially as separate, independent brains.
Depth Perception/Retinal Disparity
Depth perception depends on a combination of binocular and monocular cues. Retinal disparity is a binocular cue and refers to the fact that our two eyes see objects in the world from two different views; and the closer an object, the greater the disparity of the two images.
Dopamine Hypothesis
According to the dopamine hypothesis, Schizophrenia is due to overactivity at dopamine receptors either as the result of oversensivity of the receptors or excessive dopamine levels.
Effects Of Psychoactive Drugs
Terms used to describe the effects of the psychoactive drugs include the following: (1) Agonists produce effects similar to those produced by a neurotransmitter. (2) Inverse agonists produce an effect opposite the effect produced by a neurotransmitter or an agonist. (3) Partial agonists produce effects that are similar to (but less than) the effects produced by a neurotransmitter or an agonist. (4) Antagonists produce no activity in the cell on their own but, instead, reduce or block the effects of a neurotransmitter or agonist.
Emotion (Areas Of The Brain)
Areas of the brain that have been implicated in the regulation of emotion include the amygdala (which plays a role in the perception and expression of anger, fear, sadness, happiness, and other emotions and attaches emotion to memories), the hypothalamus (which is involved in the translation of emotions into physical responses), and the cerebral cortex. With regard to the latter, the left hemisphere governs happiness and other positive emotions, while the right hemisphere mediates sadness, fear, and other negative emotions.
Frontal Lobe, Broca’s Area, Prefrontal Cortex
The frontal lobe occupies the major portion of the cortex and includes the primary motor cortex, supplementary motor area, premotor cortex, Broca’s area, and prefrontal cortex. It is involved in initiative, planning ability, abstract thinking, and other executive functions; personality and mood; and motor functions. Damage to Broca’s area produces Broca’s (expressive) aphasia. Damage to the prefrontal cortex produces personality changes and deficits in higher-level cognitive abilities.
Gate-Control Theory of Pain
According to gate-control theory, there are mechanisms in the spinal cord that mediate (block) the perception of pain.
General Adaptation Syndrome
According to Selye, the human response to stress is mediated by adrenal-pituitary secretions (e.g., cortisol) and involves three stages: alarm reaction, resistance, and exhaustion. The model predicts that prolonged stress can result in illness or death.
Hippocampus
The hippocampus is a limbic system structure that is important for spatial and explicit memory and the consolidation of declarative memories.
Huntington’s Disease
Huntington’s disease is an inherited degenerative disease that is transmitted by a single autosomal dominant gene and involves emotional, cognitive, and motor symptoms. For many patients, emotional and cognitive symptoms appear first and include depression, apathy, anxiety, antisocial tendencies, and forgetfulness. Early motor symptoms include fidgeting, and clumsiness, which are followed by facial grimaces and “piano-playing” movements of the fingers. Huntington’s disease is believed to be due to a loss of GABA-secreting neurons and glutamate excitotoxicity in the basal ganglia, especially in the caudate nucleus, putamen, and globus pallidus.
Hyper- And Hypothyroidism
Hyperthyroidism is caused by hypersecretion of thyroxine by the thyroid gland and is characterized by a speeded-up metabolism, elevated body temperature, accelerated heart rate, increased appetite with weight loss, nervousness, and insomnia. Hypothyroidism is caused by hyposecretion of thyroxine and involves a slowed metabolism, slowed heart rate, lethargy, lowered body temperature, impaired concentration and memory, and depression.
Hypertension
There are two types of hypertension. Primary (essential) hypertension occurs when there is no known physiological cause. Secondary hypertension occurs when elevated blood pressure is related to a known disease. Primary hypertension accounts for about 85 to 90% of all cases; untreated, it can lead to cardiovascular disease. It is a major cause of heart failure, kidney failure, and stroke. The prevalence of hypertension is related to age, race, and gender. Older adults have higher rates than younger adults, and African Americans have higher rates than Whites. Rates are generally higher for men; however, for older adults and African Americans, rates are higher for women.
Hypoglycemia
Hypoglycemia (low blood glucose) is caused by excessive secretion of insulin by the pancreas and is characterized by hunger, dizziness, headaches, blurred vision, palpitations, anxiety, depression, and confusion.
Hypothalamus And Suprachiasmatic Nucleus
The hypothalamus consists of a cluster of nuclei that control the autonomic nervous system and endocrine glands, mediate basic drives, and regulate emotional expression. The suprachiasmatic nucleus (SCN), which is located in the hypothalamus, is involved in regulation of the body’s circadian rhythms.
Learning and Memory (Areas of the Brain)
Areas of the brain involved in learning and memory include: (1) The temporal lobes which encode, store, and retrieve of long-term declarative memories. (2) The hippocampus consolidates of long-term declarative memories (transferring information from short-term to long-term memory). (3) The amygdala plays a key role in fear conditioning, learning about rewards and punishments, and adding emotional significance to memories. (4) The prefrontal cortex is associated with short-term memory, episodic memory, and prospective memory. (5) The thalamus is involved in processing information and transferring it to the neocortex.
Learning And Memory (Neural Mechanisms)
Neural mechanisms that are believed to mediate long-term memory include long-term potentiation and protein/RNA synthesis. (1) Long-term potentiation (LTP) is a physiological process involving the modification of nerve synapses, especially at glutamate receptors in the hippocampus. (2) Inhibiting the synthesis of protein or RNA at the time of learning prevents the formation of long-term memories.