Physiology Chapter on Motor Neurons and Hormones

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Questions and Answers

What is the primary reason for the swelling of ventral horns at the cervical and lumbar enlargements?

Increased production of neurotransmitters

A larger number of neurons is needed to innervate limb muscles (correct)

Development of additional synaptic connections

Higher metabolic activity in those regions

What is the collective term for the group of alpha motor neurons that innervate a single muscle?

Muscle spindle group

Motor neuron pool (correct)

Muscle fiber pool

Neural circuit

Which input sources to alpha motor neurons are primarily responsible for controlling voluntary movement?

Upper motor neurons in the motor cortex and brainstem (correct)

Proprioceptors

Muscle spindles

Local interneurons

Which type of motor neurons is responsible for maintaining the sensitivity of muscle spindles during muscle contraction?

Gamma motor neurons Signup and view all the answers

What is the function of reciprocal inhibition in muscle activity?

Contraction of one muscle set while the antagonist muscle relaxes Signup and view all the answers

What is the primary function of leptin in the body?

Regulates body mass and signals satiety Signup and view all the answers

What occurs when there is a drop in leptin levels?

Decrease in secretion of TSH and ACTH Signup and view all the answers

What is the role of the vagus nerve in the sensation of satiety?

Senses gastric distention and communicates with the NTS Signup and view all the answers

What characterizes the visceromotor response compared to the somatic motor response?

Visceromotor involves involuntary actions, somatic is voluntary Signup and view all the answers

Which hormone is primarily stimulated by TSH in relation to body temperature?

Thyroxine Signup and view all the answers

What psychological role does dopamine play in feeding behavior?

Links the sensory experience of food with emotional reward Signup and view all the answers

What is the physiological basis of gastric distention?

Stretching of the stomach wall during food intake Signup and view all the answers

What is the effect of high levels of ghrelin in the body?

Signals hunger when the stomach is empty Signup and view all the answers

What hormone is primarily involved in mobilizing energy systems during stress responses?

Cortisol Signup and view all the answers

Which neurotransmitter is primarily synthesized and released by the raphae nuclei?

Serotonin Signup and view all the answers

What results from enhanced transmission in the mesocorticolimbic dopamine system due to stimulant drugs?

Formation of addiction Signup and view all the answers

Which of the following systems contains about 500 million neurons and can operate independently?

Enteric nervous system Signup and view all the answers

What type of neurons in the sympathetic system primarily use norepinephrine?

Postganglionic fibers Signup and view all the answers

What is the main function of the locus coeruleus in the brain?

Enhances responsiveness to salient stimuli Signup and view all the answers

During which metabolic state do anabolism and catabolism become relevant?

Post absorptive state Signup and view all the answers

What is primarily stored in adipose tissue?

Triglycerides Signup and view all the answers

How do benzodiazepines and barbiturates work to suppress seizures?

By prolonging inhibitory actions of GABA Signup and view all the answers

What characterizes non-REM sleep?

It is marked by minimal brain activity and no complex dreams Signup and view all the answers

Which of the following statements is true about REM sleep?

It is known for having brain waves similar to those of an awake state Signup and view all the answers

What do circadian rhythms refer to?

Physiological functions that shift in accordance with light/dark cycles Signup and view all the answers

What best describes a free-running circadian rhythm?

A rhythm maintained in the absence of zeitgebers Signup and view all the answers

What is the role of the Raphae nuclei in wakefulness?

They release serotonin to modulate arousal states Signup and view all the answers

Why are chimpanzees limited in their ability to speak human languages?

Their vocal tract is not structured for human phonetics Signup and view all the answers

What was observed about the brain language areas in three-month-old infants?

They exhibited distinct patterns of neural activation related to early language learning Signup and view all the answers

What is a significant argument against the simplicity of language models in processing?

Most aphasia presents with both speech and comprehension deficits, indicating no linear pattern. Signup and view all the answers

During the Wada procedure, what is primarily assessed?

The hemispheric dominance for language and speech. Signup and view all the answers

What is the primary behavior exhibited by subjects with a split brain?

They behave as if they have two separate brains with distinct functions. Signup and view all the answers

Which hemisphere is typically dominant for language processing in most humans?

Left hemisphere is dominant. Signup and view all the answers

What typically occurs in brain activity when a person transitions from performing a task to resting?

Brain activity increases during rest. Signup and view all the answers

What is the consequence of pulvinar lesions in the visual field?

Slower response times to stimuli on the contralateral side. Signup and view all the answers

What is a characteristic of endogenous attention, also known as top-down attention?

Focused goal-directed behavior influenced by internal motives. Signup and view all the answers

What effect does an injection of bicuculline into the pulvinar nucleus have on attention?

It facilitates the shifting of attention to the contralateral side. Signup and view all the answers

Which of the following regions is not a part of the frontoparietal attention network?

Hypothalamus Signup and view all the answers

What helps explain how certain visual features grab one's attention?

Construction of priority map by LIP Signup and view all the answers

How does stimulation of neurons in FEF affect detection threshold?

Improves detection by lowering threshold Signup and view all the answers

What is meant by the neural correlates of consciousness (NCC)?

Minimal neuronal event sufficient for perception of consciousness Signup and view all the answers

What characterizes agoraphobia?

Anxiety about difficulty escaping a situation Signup and view all the answers

Which class of drugs is most commonly used in the treatment of acute anxiety?

Benzodiazepines Signup and view all the answers

What are some of the symptoms of major depression?

Intense feelings of worthlessness and guilt Signup and view all the answers

What is the effect of lithium on the nervous system?

Prevents normal turnover of PIP2 in the neuron Signup and view all the answers

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Study Notes

Chapter Summaries

There are several chapters, with each focusing on different aspects of the brain.
Different sections of the brain and their roles in memory, emotions, and cognition are covered.
The neurobiological mechanisms underlying behaviour, emotion, and memory are outlined
Various disorders, pathologies, and clinical cases are used to illustrate concepts.
The brain activity and underlying neural mechanisms are explained.

Memory and Learning

Memory consolidation is a process that converts short-term memories into long-term memories.
The hippocampus plays a crucial role in declarative memory consolidation.
Procedural memory is linked to the striatum.
Working memory is a type of memory that allows us to hold information briefly in our minds.
Retrograde amnesia is the inability to remember events that occurred before a certain traumatic event.
Different types of memory and learning are described, along with the neural systems involved.

Language and Cognition

Language deficits, such as aphasia, can result from damage to specific brain regions.
Broca's area and Wernicke's area are critical for language production and comprehension.
The Wernicke-Geschwind model describes the neural pathways involved in language processing.
Language processing is described in relation to different brain areas.

Emotions

The amygdala is a brain region associated with emotional processing and aggression.
The hypothalamus plays a key role in controlling the physiological responses associated with emotions.
Different emotional responses and brain areas linked to them are examined.

Sleep

Sleep stages and sleep cycles are covered.
The neural correlates of sleep are outlined, explaining how specific brain areas are active during different sleep phases.

Brain Structures and Function

The brain's structure, and different parts and their functions, are explained.
Neural pathways and neurotransmitters are discussed in terms of how they function and interact to have an effect in the brain.
Various brain disorders are examined, highlighting specific symptoms; their causal mechanisms are often implied.

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Description

This quiz examines key concepts in physiology, focusing on the functions of alpha motor neurons, the role of hormones like leptin and ghrelin, and the mechanisms of satiety and voluntary movement. Test your understanding of how these elements interact to regulate body functions and behavior.