Exam 1 Flashcards
What are the 6 classes of nutrients?
Carbohydrates (O)
Proteins (O)
Fat (O)
Water (I)
Vitamins (O)
Minerals (I)
Type 1 Diabetes Mellitus
Condition in which the body can no longer produce insulin due to the destruction of pancreatic beta cells. Glut-4 receptors are no longer signalled to take up blood glucose. In turn, blood glucose levels increase.
Hyperglycemia also results in increased fatty acid metabolism, which increases Acetyl CoA production and therefore, oxaloacetate is limited, so the TCA cycle does not turn. This causes Acetyl CoA to form ketone bodies which will eventually lead to diabetic ketoacidosis.
Why can a type 1 diabetic no longer produce insulin?
Pancreatic Beta cells have been destroyed by bodies own immune cells.
Hyperglycemia in a type 1 diabetic also results in ____________ due to excess Acetyl CoA forming ketone bodies.
Diabetic Ketoacidosis
Phenylketonuria (PKU)
A genetic condition in which the enzyme phenylalanine hydroxylase is defective. This results in the termination of phenylalanine forming tyrosine.
What are the symptoms of long-term phenylalanine buildup in the body?
High levels of phenylalanine are toxic to the brain. If left untreated, it can result in disabilities, seizures, mental disorders, and more.
How is PKU treated?
PKU cannot be treated because it is an inherited genetic disorder. Treatment is avoiding foods that contain the chemical phenylalanine. Foods include artificial sugars, fish, eggs, chicken, and more.
Anemia
An issue in which the body does not have enough red blood cells to oxygenate all tissue needs properly.
What are the common symptoms of anemia?
Extreme fatigue and poor appetite
What can be the possible causes of anemia?
In terms of nutrients, it is typically due to deficiencies in key vitamins and minerals like iron, folate, B6, and B12.
Nutrigenetics
The concept that our inherited genetic characteristics influence the body’s response to specific nutrients.
Nutrigenomics
The idea that the nutrients we consume can affect gene expression.
What is an example of nutrigenomics?
Saturated fatty acids bind to TLR4 receptors on cells. This induces a cell signalling cascade that increases the transcription of inflammatory-related genes. On the other hand, EPA and DHA reduce inflammation by blocking this cell signalling pathway.
What is the difference between testing for single-gene disorders and direct-to-consumer panel testing?
Single-gene disorders are done in a medical setting that provides counselling and data regarding your results. DTC panel testing only looks for mutations in the form of SNPs, and it is not done in a medical setting.
What are the issues with DTC panel testing?
Many SNP associations are not known or well-understood leading to confusion based on possible results.
Catabolism
Breakdown of nutrients.
Anabolism
Building of larger molecules from smaller ones.
What are the primary components of the GIT?
Mouth, pharynx, esophagus, stomach, small intestine, large intestine, rectum, and anus.
What are the accessory organs of the GIT?
Teeth, tongue, salivary glands, pancreas, liver, and gallbladder.
What type of muscle are sphincters made out of?
Circular smooth muscle
What are the 4 layers of the GIT from inside to outside?
- Mucosa
- Submucosa
- Muscularis externa
- Serosa
What are the 3 layers of the mucosa lining the lumen?
- Epithelium- lines the lumen
- Lamina propria- made of connective tissues and filled with small blood and lymph vessels
- Muscularis mucosa- a thin layer of smooth muscle that acts as a protective barrier covered in mucus
What does the submucosa layer contan?
Connective tissue called the neural network called the submucosal plexus.
What does the muscularis externa layer contain?
Contains circular and longitudinal smooth muscles used in peristalsis.
What does the outer layer of the Serosa in the GIT contain?
The serosa is a thin layer of connective tissue covered by single squamous epithelium.
What regulates the swallowing reflex?
The swallowing center in the medulla of the brain.
What is in saliva?
Water and salts that dissolves food.
Mucus made of glycoproteins calls mucins to protect and lubricate mouth and throat.
Enzymes including alpha-amylase and lingual lipase.
Antibacterial and antiviral components for dental health.
What is the function of alpha-amylase enzyme in saliva?
Breaks alpha 1,4 glycocidic bonds in starch
What is the function of the lingual lipase enzyme in saliva?
Hydrolyzes triglycerides
What is anosmia?
Complete inability to detect odors
What is hypoanosmia?
Inability to detect odors
What is ageusia?
Total lost of taste
What is hypoageusia?
Decreased ability to taste
What is peristalsis?
Progressive wavelike motion that moves bolus through esophagus into stomach. Takes around 10 seconds and is initiated by the bolus moving through the upper esophageal sphincter.
The upper esophageal sphincter seperates the _________ from the ________.
Pharynx; esophagus
The lower esophageal sphincter seperates the _________ from the __________.
Esophagus; stomach
Sphincters are made of ______ ________ muscle.
Cirular smooth
How do we treat heartburn?
Antacids and proton pump inhibitors
Which portion of the stomach is the site of major production of gastric juices?
Upper 3/4 of stomach called the body
What are in gastric juices?
Water, electrolytes, HCL, enzymes, mucus, and intrinsic factor
What is the role of hydrochloric acid in gastric juice?
HCL acttivates the zymogen pepsinogen to pepsin. It denatures that 2nd and 3rd protein structures preparing for hydrolysis. Releases nutrients from organic complexes and is a bacterocide.
What is the function of the gastric juice enzyme pepsin?
Pepsin breaks down proteins into smaller peptides through hydrolysis of the peptide bond.
Why do we have mucus in gastric juices?
They hold glycoproteins and they lubricate and protect the gastric mucosa which prevents ulcers.
Once the bolus enters the pharynx, swallowing is primarily an __________ process
involuntary
Which layer of the GIT protects against oxidative damage?
Muscularis Mucosa
What enzymes is present in saliva?
Alpha-amylase and lingual lipase
Gastrin ________ and secretin _________ gastric motility.
Increases; decreases
Which is not an example of mechanical digestion?
Enzyme secretion from the pancreas
The pH of chyme leaving the pyloric sphincter is approximately?
2
What sphincter is impaired in a person experiencing heartburn?
Lower esophageal
What is the function of pepsin?
Produces large peptide fragments, some free amino acids
The majority of nutrients are absorbed within ________ of entering the ________.
30 minutes; duodenum
Which of the following lowers LES pressure?
Smoking and alcohol
What controls gastric emptying and gastric motility?
When food is swallowed, the proximal portion of the stomach relaxes to accommodate the ingested food. The pacemaker of the stomach is located between the fundus and the body of the stomach and determines the frequency of contraction and rate at which chyme enters the distal stomach.
What is the migrating motility complex?
Series of contractions that moves chyme distally through GIT in wavelike motions every 90-230 minutes between meals. Sweeps prevent bacterial overgrowth.
What is the rate at which chyme is released from the stomach into the duodenum?
1 teaspoon every 30 seconds
What is stomach emptying primarily controlled by?
Milling/grinding action of stomach
What are some specific nutrients that slow gastric emptying?
Fiber, free amino acids, and fat (most potent inhibitor of gastric emptying)
How long after a meal does gastric emptying typically take place?
2-6 hours after meal
What is dumping syndrome?
When the stomach contents empty too quickly into the duodenum of the small intestine. Symptoms include diarrhea, nausea, and lightheadedness after a meal. It is caused by a defect in the pyloric sphincter. It can be improved by eating small meals, lying down after meals, and eating more protein, fat, and fiber.
What is gastritis?
Inflammation of the stomach lining. Symptoms include gnawing or burning ache and pain in the upper abdomen. It can be caused by damage to the stomach lining, gastric acid irritation that causes vulnerability to H pylori, regular use of NSAIDs, alcohol, age, and stress.
Enzymatic digestion of protein begins in the stomach through the activity of _______ that cleaves ________ bonds.
Pepsin; peptide
What is the longest portion of the GIT?
The ileum at 5-9 feet long