Digestive system study guide

Digestive Disorders Guided Notes 1 Review the anatomy and physiology of the gastrointestinal system. The gastrointestinal (GI) tract encompasses the mouth, esophagus, stomach, small and large intestines, and accessory organs: liver, pancreas, and gallbladder (Ogobuiro et al., 2023). Digestion starts in the mouth with mechanical and chemical breakdown, progresses in the stomach through acid and enzymes, and finishes in the small intestine, where nutrients are absorbed. The large intestine reabsorbs water, forming feces. Liver bile and pancreatic enzymes aid digestion; dysfunction causes disorders like gastroesophageal reflux disease (GERD) or irritable bowel syndrome (IBS). 2 What are the common signs and symptoms of digestive disorders? Changes in bowel patterns, such as constipation or diarrhea and abdominal pain, which can range from cramping to severe or mild feelings, are common signs of digestive problems (Cohen, 2022). Dysphagia indicates trouble swallowing, but nausea and vomiting may be signs of infections or blockages. Jaundice indicates liver or bile duct issues, whereas heartburn indicates GERD. Unintentional weight reduction can lead to cancer or malabsorption issues. Serious symptoms, such as blood in the stool or continuous vomiting, require emergency care. 3 What are the different characteristics of diarrhea? Diarrhea can be characteristic depending on its source and duration. Food poisoning and infections with bacteria or viruses cause acute diarrhea in less than two weeks (Cohen, 2022). If diarrhea lasts more than four weeks, it may mean that you have celiac disease, IBD, or IBS. Permanent secretory diarrhea, such as cholera, carries on in the fasted state, but cases of osmotic diarrhea due to lactose intolerance cease. In Crohn's disease and colitis, blood or mucus is characteristic of inflammatory diarrhea. Chronic conditions usually require stool testing, blood work, and a colonoscopy to be diagnosed. 4 What are some causes of constipation? The two causes of constipation are dehydration and poor dietary choices, which restrict stool movement (Bellini et al., 2021). Sitting down still makes it worse, as does ignoring bowel movements and illnesses such as diabetes, hypothyroidism, and neurologic problems slowing digestion. Anatomical factors include pelvic floor dysfunction or tumors, medications such as opioids, antacids, or antidepressants, or other factors. Treatment includes laxatives, exercise, hydration, and fiber. 5 How can digestive disorders lead to malnutrition? Malnutrition can occur from multiple gastrointestinal disruptions, including Crohn's mucosal injury or celiac disease (Montoro-Huguet et al., 2021). While decreased nutritional uptake in short bowel syndrome limits nutritional absorption, they suffer from enzyme shortages, like in pancreatitis or lactose intolerance, that impair digestion. Motility problems like gastroparesis and chronic inflammation from IBD make the alimentary canal more difficult to intake. Osteoporosis, iron or B12 deficiency, and weight loss result from this. 6 Cleft lip/palate Describe It Pathophysiology of It Risk Factors Signs and Symptoms Congenital anomalies are when the upper lip, palate, or both fail to fuse properly during fetal development, resulting in an opening or split. This occurs between 4 and 12 weeks of gestation for the lip and the 6th to 9th weeks for the palate, affecting roughly 1 in 700 births worldwide. The condition can present unilaterally (one side) or bilaterally (both sides) and ranges from a small notch in the lip to a complete separation extending into the nose and roof of the mouth (Babai & Irving, 2023). Cleft occurs when facial tissues, like maxillary and medial nasal prominences, fail to migrate and fuse properly due to disrupted cellular signaling and growth factors (Babai & Irving, 2023). Genetic, environmental, or multifactorial interference can halt this process, leading to incomplete closure. This affects facial structure and function, resulting in a cleft that alters appearance and may complicate breathing, eating, or speech development. Cleft risk rises with genetic predisposition, especially if a parent or sibling is affected, and environmental factors like maternal smoking, alcohol, or anticonvulsants during early pregnancy. The likelihood is also increased by maternal diabetes and obesity, as well as folate deficiency. Some syndromes like the Pierre Robin sequence or Trisomy 13 may also be linked to clefts and contribute to the influence of inherited traits and external triggers on the development of disrupted facial tissue. A cleft presents as a visible split in the lip or palate, varying from mild notches to severe gaps. Feeding challenges arise from poor suction, leading to nasal regurgitation or choking. Eustachian tube dysfunction increases ear infections and hearing loss risks. Without treatment, speech delays or nasal tones emerge. Dental issues, such as missing or crooked teeth, are frequent. Early intervention surgery, speech therapy, and nutritional guidance significantly enhance long-term outcomes. 7 Thrush Describe It Pathophysiology of It Risk Factors Signs and Symptoms Specific Lab Values Thrush, a fungal infection from Candida albicans, a yeast naturally in the mouth, arises when it overgrows due to immune suppression or microbial imbalance. Common in infants, older adults, and immunocompromised people, it creates white patches on the tongue, cheeks, or throat. Typically, mild, untreated thrush may spread or recur, necessitating antifungal treatment to control the overgrowth and restore balance. Candida albicans, a normal oral flora, over-proliferates when immune defenses weaken or bacterial competition decreases. It adheres to mucosal surfaces, forming pseudohyphae that invade epithelial layers, triggering inflammation. Biofilm formation enhances its resistance to treatment. In severe cases, it may disseminate systemically, particularly in immunocompromised patients, disrupting tissue integrity and causing localized or widespread infection. Toxicity strongly increased with weakened immunity (HIV, cancer, diabetes, steroid or antibiotic use, infancy or old age, dry mouth (xerostomia), smoking, poor oral hygiene). Those who wear dentures retain moisture. Growth of Candida is further enhanced by its susceptibility to chemotherapy, radiation, and malnutrition, which compromise immune responses and mucosal barriers and leave this fungus unchecked. Thrush presents as white, creamy patches on the tongue, inner cheeks, or throat, often scraped off to reveal red, raw tissue. Symptoms include soreness, burning, or a cottony mouth sensation. Difficulty swallowing, altered taste, and cracking at mouth corners may occur. In infants, it may cause fussiness and feeding issues; severe cases signal underlying immune compromise. Diagnosis rarely relies on lab values but may involve a Candida culture or microscopy showing pseudohyphae. Elevated white blood cell count (leukocytosis) or C-reactive protein indicates inflammation in systemic cases. Blood glucose may be high in people with diabetes. Immunocompromised patients might show low CD4 counts (<200/µL in HIV) or neutropenia (<500/µL), reflecting susceptibility to infection (Nesamari, 2023). 8 Type I herpes simplex Describe It Pathophysiology of It Risk Factors Signs and Symptoms Specific Lab Values Type I herpes simplex (HSV-1) is a viral infection caused by the herpes simplex virus, primarily affecting the mouth and face. It manifests as cold sores or fever blisters, often recurring due to viral latency in the nerve ganglia. Typically acquired through direct contact, it is highly contagious and widespread, with most infections occurring in childhood. HSV-1 enters through mucosal surfaces or skin breaks, replicating in epithelial cells and causing cell lysis and vesicles. It then ascends sensory neurons to the trigeminal ganglion, establishing latency. Stress, illness, or UV exposure triggers reactivation, with the virus traveling back to the skin, producing recurrent lesions. Immune responses limit but do not eliminate the infection. Close contact with infected individuals (kissing, sharing utensils), early chi...