Physiology Chapter on Motor Neurons and Hormones

The brain monitors the amount of body fat and regulates it to maintain a stable level.

A hormone that signals to the brain about energy stores in the body, affecting hunger and satiety.

Signals sent to the brain to decrease or stop eating, including the feeling of fullness.

A condition characterized by a loss of appetite and a drastic decrease in food intake.

A complex eating disorder marked by cycles of overeating (binge) followed by attempts to purge the consumed food.

The release and regulation of pituitary hormones, which influence various bodily functions.

A region of the brain responsible for regulating several vital functions, including homeostasis.

A hormone that stimulates the release of thyroxine, a key hormone in regulating body temperature.

Drugs like benzodiazepines and barbiturates are often prescribed for epilepsy due to their ability to prolong the inhibitory effects of GABA, a neurotransmitter crucial for reducing neuronal excitability.

Non-REM sleep is characterized by a lack of complex dreams and minimal brain activity. It is a relatively quiet state compared to REM sleep.

Ultradian rhythms refer to the cyclical pattern of alternating between slow-wave sleep (approximately 75% of sleep time) and REM sleep (approximately 25% of sleep time).

During REM sleep, while the muscles controlling eye movements are very active, the rest of the body is essentially paralyzed. This is vital for preventing physical acting out of dreams.

REM sleep is called paradoxical sleep because brain activity patterns during REM resemble wakefulness, even though the body is largely paralyzed. This creates a disconnect between brain activity and physical behavior.

The Activation-Synthesis Hypothesis proposes that dreams are created by the brain's attempt to make sense of random neuronal activity originating in the pons during REM sleep, incorporating memories and associations from the cerebral cortex.

Sleep and wakefulness neurons are part of the diffuse modulatory neurotransmitter system, a network of neurons using different neurotransmitters to modulate widespread areas of the brain.

The Raphe nuclei (serotonin), the locus coeruleus (norepinephrine), and regions in the brainstem and forebrain (acetylcholine) are involved in regulating sleep and wakefulness transitions. Their specific neurotransmitters play crucial roles in maintaining and switching between these states.

A group of alpha motor neurons that control a single muscle.

The specialized sensory receptors located within muscles that provide information about muscle length and changes in muscle length.

The contraction of one set of muscles accompanied by the relaxation of its antagonist muscles.

A reflex that helps maintain balance by extending the opposite leg when the other leg is lifted in response to pain.

Neural circuits within the spinal cord that generate rhythmic patterns of muscle activity, like walking or breathing.

The Wada procedure is a test used to determine which hemisphere of the brain controls language. It involves temporarily anesthetizing one hemisphere at a time and observing the effects on speech and language abilities. The procedure is used in cases where surgery is being considered for epilepsy, or to understand the localization of language processing in the brain.

Aphasia, the loss of language function, can occur in deaf individuals, indicating that Broca's and Wernicke's areas are involved in broader language processing rather than just speech.

The non-dominant (usually right) hemisphere excels at tasks involving spatial processing and visual perception like drawing 3D figures.

Attention requires focusing on a specific aspect of sensory input out of the vast amount of information coming in from the environment.

The default mode network (DMN) is most active during passive, 'restful' states. Our brain remains active even during periods of rest, particularly in tasks requiring internal thinking like daydreaming, recalling memories, and planning.

The pulvinar nucleus, a structure in the thalamus, plays a role in attention. Lesions to the pulvinar result in slower responses to stimuli on the opposite side of the body, highlighting its involvement in directing attention.

Injection of bicuculline into the pulvinar nucleus has the opposite effect of a lesion, facilitating attention to the contralateral side.

Endogenous attention, also known as top-down attention, is goal-directed and involves consciously selecting what to focus on based on internal goals or intentions, like actively searching for a specific object or paying attention in class.

The release of hormones from the hypothalamus regulates many other endocrine glands, making it the 'master gland' in the endocrine system.

A steroid hormone produced by the adrenal glands during stress, mobilizing energy reserves and suppressing the immune system.

The part of the adrenal gland responsible for releasing adrenaline, a hormone crucial in the fight-or-flight response.

A network of neurons in the digestive system with its own independent processing abilities, monitoring the chemical conditions of the stomach and intestines.

A type of modulatory system using norepinephrine as its neurotransmitter. It originates in the locus coeruleus and speeds up information processing in the cerebral cortex.

A modulatory system that utilizes serotonin as its neurotransmitter, originating in the raphe nuclei and playing a key role in the sleep-wake cycle.

A modulatory system that uses dopamine as its neurotransmitter. It originates in the ventral tegmental area (VTA) and plays significant roles in reward and motivation.

A modulatory system that utilizes acetylcholine as its neurotransmitter and is present throughout the brain and in the parasympathetic autonomic nervous system.

The prefrontal cortex, FEF (frontal eye field), and Lateral intraparietal cortex (LIP) are all components of this network.

The Lateral intraparietal cortex (LIP) plays a crucial role in constructing a "priority map" that highlights salient (important) stimuli within our environment.

Electrical stimulation of neurons in the FEF (frontal eye field) leads to a decrease in the detection threshold for visual stimuli, making it easier to notice.

It refers to the minimal set of neuronal events that are necessary for conscious perception.

Binocular rivalry offers a powerful tool for studying consciousness, as it allows researchers to investigate brain activity associated with changes in perceived visual dominance.

General paresis of the insane, caused by syphilis, involves a progression from mania and cognitive deterioration to paralysis and ultimately death.

Anxiety disorders, a category of mental illnesses characterized by excessive worry and fear, are the most prevalent psychiatric disorders.

A panic attack involves a sudden surge of intense fear or discomfort, often accompanied by physical symptoms like palpitations, sweating, and increased heart rate.