Clinical Nutrition Exam 2

Body Regulation & Hydration

Body Temperature Regulation
- The hypothalamus in your brain controls body temperature.
- It sends signals to:
  - Shiver: To make heat when you're cold.
  - Sweat: To release heat when you're hot.
Effects of Alcohol Consumption:
- Drinking too much alcohol can lead to:
  - Liver Damage: Your liver works hard to process alcohol, and too much can overwhelm it.
  - Brain Damage: Alcohol slows down your nervous system.
Consequences of Dehydration:
- When you're dehydrated, cells lose water to the blood, which causes:
  - Less blood volume.
  - Weakness and poor cell function.
Electrolytes Definition:
- Electrolytes are substances that dissolve in water and separate into electrically charged particles (ions).

Sodium, Water Balance, & Cellular Function

Sodium-Potassium Pump Function:
- This pump uses energy (ATP) to move ions across cell membranes:
  - It pushes 3 \text{ Na}^+ \text{ (sodium ions)} out of the cell.
  - It pulls 2 \text{ K}^+ \text{ (potassium ions)} into the cell.
  - This creates an electrical difference (electrochemical gradient) and balances ions inside and outside the cell.
  - Chloride Ions (Cl⁻): These ions follow to balance the electrical charge.
Hyponatremia Definition:
- This condition means you have too little sodium in your blood. It happens when there's too much water compared to salt.
Dietary Sources of Sodium:
- Most of the sodium we eat comes from processed foods.
Osmosis Definition:
- Osmosis is when water moves across a thin, permeable barrier (like a cell membrane).

Diet & Nutrients

DASH Diet Nutrients:
- The DASH diet increases your intake of:
  - Magnesium
  - Potassium
  - Calcium
Functions of Water:
- Water does many important things for your body, such as:
  - Keeping your body temperature steady.
  - Acting as a main solvent for many substances.
  - Lubricating your joints and tissues.
  - Being the environment where chemical reactions happen.
  - Moving nutrients and waste products around your body.
Vitamin C Sources:
- Vitamin C from whole foods (like fruits and vegetables) is absorbed better because of useful plant compounds called phytochemicals.

Oxidative Stress & Atherosclerosis

Oxidative Stress Definition:
- This happens when there's an imbalance between harmful unstable molecules (free radicals/reactive oxygen species, ROS) and protective substances (antioxidants), leading to cell damage.
Atherosclerosis Definition:
- This is a condition where plaque builds up in your arteries, caused by:
  - Damage to the artery walls.
  - LDL ("bad") cholesterol rushing into these damaged areas, which leads to immune cells (macrophages) dying and forming foam cells.
  - This damage gets worse when ROS oxidize LDL, making arteries hard and blocked.
Antioxidant Nutrients:
- Key antioxidants include:
  - Vitamin C
  - Vitamin E
  - Vitamin A
  - Beta-carotene
  - Carotenoids
  - Various phytochemicals
  - Minerals like Zinc, Copper, Selenium, Magnesium

Vitamins & Immune Function

Vitamin C and the Common Cold:
- Vitamin C can help make a common cold shorter, but it doesn't prevent or cure it.
Importance of Folate:
- Folate is vital for cell growth and how your body uses energy. It's especially important during pregnancy to prevent birth defects.
Effects of B12 Deficiency:
- A lack of Vitamin B12 leads to macrocytic anemia, specifically pernicious anemia. This occurs because the body lacks intrinsic factor, which is needed to absorb B12 (cobalamin).

Bone Health

Bone Mineral Density (BMD):
- This measures how many minerals are in your bones. It's checked using DEXA scans.
- The result is compared to a healthy 30-year-old's bone density using a T-score.
Populations at Risk for Osteoporosis:
- Groups most likely to get osteoporosis include:
  - Women after menopause.
  - Older people.
  - People who don't get enough nutrients.
  - Individuals prone to diabetes.
Nutrients Involved in Bone Remodeling:
- Essential nutrients for healthy bones include:
  - Calcium
  - Phosphorus
  - Magnesium
  - Fluoride
  - Vitamin D
  - Vitamin K
  - Collagen
  - Iron
Importance of Phosphorus for Bones:
- Phosphorus is crucial for making bone tissue hard and strong.
Compounds Inhibiting Calcium Absorption:
- Oxalates and phytates:
  - These compounds found in plants can bind to calcium, making it harder for your body to absorb.
Weight-Bearing Exercises Include:
- Exercises like running, weight lifting, and walking.
- Activities that put stress on your bones are effective (swimming or biking are not weight-bearing).
Osteoblast Function:
- Osteoblasts are cells that build new bone tissue.
Wolff’s Law Explanation:
- This law states that bones get stronger and adapt based on the stress put on them. So, working out with weight-bearing exercises makes your bones stronger.
Vitamin D and Calcium Homeostasis:
- Function of Vitamin D:
  - When blood calcium levels are low, Vitamin D tells bones to release calcium and signals kidneys to reabsorb it.
Foods High in Vitamin D:
- You can get Vitamin D from:
  - Salmon
  - Cheese
  - Mushrooms (especially if exposed to UV light)
  - Fortified foods (foods with added Vitamin D)
  - Sunlight exposure (best from April to October, 10 AM to 2 PM).
Foods High in Vitamin A:
- Sources include:
  - Liver
  - Spinach
  - Dairy products
  - Cantaloupe

Macronutrients & Metabolism

Catabolic Pathway Definition:
- A process in the body that breaks down big molecules into smaller ones (for example, glycolysis breaks down sugar).
Anabolic Pathway Definition:
- A process in the body that builds bigger molecules from smaller ones (for example, making proteins from amino acids).
Role of B Vitamins:
- B vitamins act as helper molecules (coenzymes) vital for many body processes and enzyme functions.
Functions of Iron:
- Iron has important jobs, such as:
  - Carrying oxygen in your red blood cells (hemoglobin).
  - Helping with metabolism, making DNA, and supporting bone health.
Interaction Between Vitamin C and Iron:
- Vitamin C helps your body absorb iron better, especially non-heme iron (iron from plant foods).

Blood & Nutrients

Components of Blood:
- Blood is made of:
  - Plasma (the liquid part)
  - Platelets (for clotting)
  - Red blood cells (carry oxygen)
  - White blood cells (fight infection)
Blood Transport Functions:
- Blood carries oxygen, nutrients, and waste products all around your body.
Vitamin K Function:
- Vitamin K helps your blood clot by creating clotting factors.
- It also helps calcium attach to your bones.
Causes of Iron Deficiency Anemia:
- This type of anemia happens when you don't get or absorb enough iron. This leads to smaller, less effective red blood cells with less hemoglobin.

Sports Nutrition & Scientific Sources

When Sports Drinks Are Preferred Over Water:
- Sports drinks are better than water during long workouts, like endurance running, when you lose a lot of electrolytes through sweat.
Peer-Reviewed Journal Articles vs. Original Articles:
- Peer-Reviewed Article: These are checked by other experts for scientific quality and accuracy, making them reliable.
- Original Article: This presents new research results, but it might not have been checked by other experts before being published.

BONUS / Additional Content

Rickets:
- A condition in children where bones become soft due to a lack of vitamin D.
Osteomalacia:
- A similar condition in adults where mature bones soften, causing bone pain and weakness.