Pancreatic Islets: Insulin, Glucagon, and Somatostatin
Pancreatic Endocrine Islets
Pancreatic endocrine islets, or islets of Langerhans, constitute approximately 1% of the pancreatic mass. They are innervated by the autonomic nervous system (ANS), feature intercellular communication, and possess a fine vascular network. Key hormones produced include insulin (β cells), glucagon (α cells), and somatostatin (δ cells).
Insulin Synthesis
Insulin synthesis begins with the ribosomal transcription of pre-proinsulin from mRNA. In the endoplasmic reticulum, pre-
Read MoreUnderstanding Protein Structure, Function, and Classification
Protein Functions
- Structural: All cellular and extracellular structures contain proteins.
- Catalytic: Enzymes are proteins that accelerate a diverse range of (bio)chemical reactions.
- Transport: Gases (hemoglobin, myoglobin); mineral cations (transferrin (Fe++)/ceruloplasmin (Cu++)); organic anions and lipids (retinol binding protein, transcortin, albumin).
- Regulatory: Hormones (TSH, LH, FSH, GH, etc.); growth factors; cytokines.
- Defense: Antibodies, lectins, complement, blood clotting factors.
- Motor functions:
Fiber’s Impact on Colorectal Cancer and Diabetes
Beneficial Effects of Fiber on Colorectal Cancer
Populations that consume more fiber have a lower incidence of colorectal cancers. Diets low in fat and high in fiber (cereals, fruits, and vegetables) reduce the risk of this type of cancer.
Fiber, Food, and Diabetes
Glycemic Index (GI): A measure of the ability of foods to increase blood glucose levels after meals.
Daily Intake: Aim for an insoluble/soluble fiber ratio of 3:1.
- Breakfast: Cereal, fruit, jam.
- Lunch and Dinner: Increase vegetable intake with
Essential Minerals: Functions, Sources, and Health Impact
Essential Minerals: Functions, Sources, and Health
Calcium
Functions: Provides consistency in bones and teeth, regulates hormone release, and is involved in blood clotting. Osteoporosis is the process of bone decalcification. Recommendations: Engage in regular physical activity, consume a diet rich in manganese and vitamins B and D, control the intake of sugar and unsaturated fats, and moderate caffeine and alcohol consumption. Sources: Primarily dairy products, and in smaller amounts, fish, eggs,
Read MoreCalculate Calories: Protein, Fat, and Carbs
Calculate Calories from Fat, Protein, and Carbohydrates
How to determine nutritional values:
- Determine total fat, protein, or carbohydrate content: Divide the specific number of total fat calories by the total number of calories in that serving, as indicated on the nutrient label.
- Determine the percentage of carbohydrates, fats, or proteins in the total amount of food ingested: For example, if you ate 2000 calories and 800 of those calories were from carbohydrates, then 800 divided by 2000 times 100
Understanding Macronutrients and Micronutrients
Carbohydrates: Importance and Impact
Carbohydrates Importance:
- Energy Production: Carbohydrates are the primary, most readily available, and most economical source of energy for the body.
- Macronutrient Sparing Effect: Consuming at least 100g of carbohydrates per day prevents protein catabolism and excessive lipolysis (ketogenesis).
- Structural Function: Carbohydrates participate in the structure of essential molecules like ATP, DNA, RNA, NADP, CoA, connective tissue, and nerve tissue.
- Regulation of Bowel