Nutrition and Deficiencies Overview

Study Notes

Balanced Diet

A balanced diet includes all food groups in the correct proportions.
Essential food groups include carbohydrates, proteins, lipids, vitamins, minerals, dietary fiber, and water.

Scurvy

Scurvy is a severe vitamin C deficiency.
It develops from a lack of vitamin C for more than three months.
Symptoms include anemia, exhaustion, spontaneous bleeding, limb pain, swelling, gum ulcerations, and tooth loss.
Historically, scurvy was common among sailors during long voyages due to limited access to fresh produce.
Treatment involves vitamin C supplements (oral or intravenous).

Rickets

Rickets is a childhood condition affecting bone development.
Symptoms include bone pain, stunted growth, and soft, weak bones (potentially leading to deformities).
It results from a severe vitamin D deficiency.
Vitamin D is crucial for calcium absorption.
Calcium is vital for healthy bones and teeth.
Vitamin D sources include sunlight exposure and some foods (fish, eggs, butter).
Treatment involves increasing calcium and vitamin D intake through diet or supplements.

Digestive System

The digestive system digests food and absorbs nutrients.
The alimentary canal includes structures food travels through: mouth, esophagus, stomach, small intestine (duodenum and ileum), large intestine (colon, rectum, anus).
Accessory organs (salivary glands, pancreas, liver, gall bladder) support digestion but are not part of the food pathway.
Digestive processes: ingestion, mechanical digestion (physical breakdown), chemical digestion (breaking down molecules), absorption, egestion.

Physical Digestion

Physical digestion breaks down food into smaller pieces without changing their chemical composition.
This increases the surface area for digestive enzymes.
Examples include chewing, stomach churning, and bile emulsification.

Types of Teeth

Human teeth have varying shapes for different functions.
Incisors: biting and cutting.
Canines: tearing and holding.
Premolars and molars: chewing and grinding.

Chemical Digestion

Chemical digestion breaks down large insoluble molecules into small soluble ones.
Enzymes like amylase are required (e.g., starch to simple sugars).
Small soluble molecules are absorbed into the blood.

Bile

The liver produces bile, which is stored in the gall bladder.
Bile is alkaline to neutralize stomach acid.
Bile emulsifies fats, increasing their surface area for faster lipase action.

Small Intestine Adaptations

The ileum's long, folded structure and villi maximize surface area for nutrient absorption.
Villi have microvilli for further increased surface area.
One-cell thick villus walls and a rich blood supply allow quick absorption.
Lacteals transport fatty acids and glycerol.

Transport in Plants

Plants' transport systems include xylem and phloem.
Xylem transports water and minerals from roots to leaves.
Phloem transports food (sucrose, amino acids) from leaves to other parts.
These vessels are in vascular bundles throughout the plant.

Xylem Function and Adaptations

Xylem transports water and dissolved minerals.
Xylem cells are joined end-to-end, forming continuous tubes.
Xylem cells are dead, losing their contents for efficient water flow.
Thickened lignin walls provide structural support.

Description

Explore the key concepts of a balanced diet, as well as the implications of nutrient deficiencies such as scurvy and rickets. Understand the importance of essential vitamins and minerals for overall health and development. This quiz covers essential dietary components and associated health conditions.