Some Anatomy on Postoperative Pain

Nociception is the neural processing of injurious stimuli in response to tissue damage ( 2023). Nociception starts at the sensory receptors; however, the perception does not start until the brain gets the signal. There are several of these nociceptive pathways that lead to the brain. Most axons  (which are nerve fibers that conduct electrical impulses) that carry nociceptive information to the brain from the spinal cord project to the thalamus. Their final processing takes place in the primary somatosensory cortex. There is one nociceptive pathway that projects directly to the hypothalamus in the forebrain. This area modulates the cardiovascular and neuroendocrine functions of the autonomic nervous system. This pathway is responsible for stimulating the sympathetic branch of the visceral sensory system, which gives you a fight-or-flight response (2023). 

Afferent neural pathways mediate the sensation of pain. Acute post-surgical pain has three categories

• nociceptive
• occurs in response to stimuli such as direct intraoperative tissue injury (Horn & Kramer 2022).
• inflammatory
• This pain occurs when the nociceptive fibers become sensitized which is in response to the release of inflammatory mediators such as cytokines and can last hours to days.
• neuropathic
• This pain is more chronic and it results from injury to neuronal structures.

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Postoperative pain is characterized as somatic or visceral.

• Somatic pain is the type of pain you feel in your skin, muscles, joints, and bones. 1 It can feel like a gnawing, aching, cramping or sharp.
• Visceral pain comes from your organs 

The goal for pain management aims to target the afferent pain pathways by different mechanisms such as antagonizing pain receptor activity or blocking the production of proinflammatory mediators

• Approximately 75 percent of patients who undergo surgery experience acute postoperative pain, which is often medium-high in severity (Horn & Kramer, 2022).
• Less than half of patients undergoing surgery report adequate postoperative pain relief.

"Inadequate postoperative pain control may lead to adverse physiologic effects among patients in the immediate postoperative period and places them at increased risk of developing chronic pain associated with the procedure (Horn & Kramer, 2022).

• Severe persistent postoperative pain affects 2 to 10 percent of adults.

References

 Horn, R., & Kramer, J. (2022, September 19). Postoperative Pain Control. PubMed; StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK544298/

(2023). Vitalsource.com. https://bookshelf.vitalsource.com/reader/books/9781938168093/pageid/377

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Causal Factors for Eating Disorders

 There is no single cause of eating disorders. They are likely caused by a complex interaction of genetic and environmental factors. Genetic factors: Eating disorders may be partly caused by genes. People who have a family history of eating disorders are more likely to develop them themselves.

Environmental factors

 Eating disorders may also be partly caused by environmental factors. These include cultural pressures to be thin, exposure to dieting and weight loss programs, and traumatic life events.

 

Specific environmental factors (Hooley et al., 2019):

1. Cultural pressure to be thin
2. Exposure to dieting and weight loss programs
3. Traumatic life events
4. Family history of eating disorders
5. History of other mental health conditions, such as anxiety or depression

 The diathesis–stress model helps explain how genetic and environmental factors interact to cause eating disorders.

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The diathesis-stress model (Hooley et al, 2019):

•  Genes make some people more susceptible to environmental pressures, which can then lead to the development of problematic eating attitudes and behaviors.
• the diathesis -  people who are genetically predisposed to a certain condition 
• When the above meets the right stressor, an eating disorder can develop
• This model is only a theory.

Genetics

• Family studies: Family studies have shown that people with eating disorders are more likely to have relatives with eating disorders or other mental health conditions.
• Twin studies: Twin studies have shown that eating disorders are more likely to be shared by identical twins than fraternal twins. This suggests that genes play a role in the development of eating disorders.

Genome-wide association studies:

•   Genome-wide association studies have identified several genes that are associated with eating disorders. These genes are involved in a variety of biological processes, including
•  metabolism
•  mood regulation
•  development.
• These genes alone do not guarantee an eating disorder will develop.

Brain abnormalities 

 

Hypothalamus:

     The hypothalamus is a part of the brain that plays an important role in regulating eating behavior. Animal studies have shown that lesions to the hypothalamus can lead to overeating or undereating.

 Frontal and temporal cortex:

 The frontal and temporal cortex are also involved in eating behavior. Damage to these areas has been linked to the development of anorexia nervosa and bulimia nervosa.

Network of brain areas:

 Animal research suggests that a network of brain areas, including the hypothalamus, the frontal cortex, and the amygdala, may be involved in the development of eating disorders.

Set point

• Set point theory is a theory that suggests that our bodies have a natural weight range that they try to maintain.
• Hunger is one way that our bodies try to maintain our set point. When we lose weight, our hunger increases in an attempt to get us back to our set point.
• Influenced by a variety of factors, including genetics, metabolism, and environment.

Serotonin

• 
   Serotonin is a neurotransmitter that has been implicated in obsessionality, mood disorders, and impulsivity. It also modulates appetite and feeding behavior.
• Many patients with eating disorders respond well to treatment with antidepressants (which target serotonin), leading some researchers to conclude that eating disorders involve a disruption in the serotonergic system.
• Serotonin is made from an essential amino acid called tryptophan, which can only be obtained from food.

5-HIAA

Product of serotonin metabolism(5 HIAA, n.d.). 

• People with anorexia nervosa have low levels
• People with bulimia nervosa have normal levels.

Serotonin overactivity

It has been suggested that people with may use dieting as a way to regulate this by decreasing the amount of tryptophan available to make serotonin (Hooley et al, 2019).

•  Neurotransmitters like serotonin do not work in isolation and changes in the serotonin system will have implications for other neurotransmitter systems too

 

Reward Sensitivity

• A new direction in eating disorders research centers on the brain pathways and neurotransmitters (such as dopamine) that are involved in reward processing.
• Patients with anorexia nervosa show more activity in brain reward areas when they view pictures of thin rather than healthy models, while controls show the opposite pattern
  
• Reward and punishment systems get contaminated; normally rewarding stimuli such as food become aversive, and stimuli associated with self-starvation become valued.

References

 5 HIAA. (n.d.). TheFreeDictionary.com. Retrieved August 27, 2023, from https://medical-dictionary.thefreedictionary.com/5+HIAA

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Psychology: The Prism of Human Behavior

 A Prism of Human Understanding

 The human mind is a complex and fascinating thing. It is capable of great love, creativity, and compassion, but it can also be the source of great pain, suffering, and confusion. Psychology is the study of the human mind and behavior, and it offers a lens through which we can better understand ourselves and others.

Just as a prism can split white light into a rainbow of colors, psychology can help us to see the many different facets of human experience. It can help us to understand our thoughts, feelings, and behaviors, and it can help us to make sense of the world around us.

There are many different approaches to psychology, each with its own unique perspective on the human mind. Some psychologists focus on the biological basis of behavior, while others focus on the social and cultural factors that influence our thoughts and feelings. Still others focus on the individual's unique experiences and personal history.

The Prism of Human Behavior

 Just as a prism refracts light into a spectrum of colors, psychology can be seen as a prism that refracts human behavior into its many different facets. By understanding the different factors that influence human behavior, psychologists can help us to understand ourselves and others better.

The Refraction of Light and Mental Disorders

Just as a prism refracts light into a spectrum of colors, mental disorders can refract our thoughts, feelings, and behaviors into a variety of different expressions. By understanding the different factors that contribute to mental disorders, we can better understand how they can shape our experiences.

Some of the factors that can contribute to mental disorders include:

• Genetics: Some mental disorders, such as schizophrenia and bipolar disorder, have a strong genetic component. This means that if you have a family history of a mental disorder, you are more likely to develop it yourself.
• Environment: Our environment can also play a role in the development of mental disorders. For example, childhood trauma can increase the risk of developing anxiety and depression.
• Brain chemistry: Mental disorders can also be caused by imbalances in brain chemistry. For example, people with depression often have low levels of serotonin, a neurotransmitter that plays a role in mood regulation.
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  Lifestyle: Our lifestyle choices can also contribute to the development of mental disorders. For example, smoking and excessive alcohol use can increase the risk of developing mood disorders.
  

When these factors come together, they can create a "prism" that refracts our thoughts, feelings, and behaviors into a variety of different expressions. For example, someone with depression may experience sadness, hopelessness, and fatigue. They may also withdraw from social activities and have difficulty concentrating. Someone with anxiety may experience excessive worry, fear, and restlessness. They may also have difficulty sleeping and concentrating.

By understanding the different factors that contribute to mental disorders, we can better understand how they can shape our experiences. This knowledge can help us to identify the signs and symptoms of mental disorders, seek professional help, and develop effective treatment plans.