1. Body Basics
Chapter 03

2. Why Learn about Chemistry When Studying Nutrition?
Organization
Atoms → molecules → compounds → cells → tissues → organs → organ systems
Atoms
Ion
Electrolyte

3. Levels of Organization in the Body

4. Why Learn about Chemistry When Studying Nutrition?
Element
Pure substance of only one type of atom
20 are essential to human health
6 elements account of 99% of body weight
Molecule
Two or more atoms are joined together
Chemical bonds
Macromolecules
Molecular formula

5. Understanding Molecular Formulas

6. How are Cells, Tissues, Organs, & Organ Systems Related?
Cytoplasm
Organelles
Transport mechanisms
Passive mechanisms
Osmosis
Simple diffusion
Facilitated diffusion
Active mechanisms

7. Passive Transport Mechanisms

8. Carrier-Mediated Active Transport

9. A Typical Cell

10. How are Cells, Tissues, Organs, & Organ Systems Related?
Types of tissue
Epithelial
Skin and inner lining of organs
Connective
Supports, connects, and anchors
Muscle tissue
Skeletal and smooth muscle
Neural tissue

11. How are Cells, Tissues, Organs, & Organ Systems Related?
Organs and organ systems
More than 40 organs
Eleven organ systems
Communication systems
Nervous system
Endocrine system
Chemical messengers
Homeostasis

12. Organ Systems and Related Major Functions

13. What Happens during Digestion?
Digestive system
Hollow tube from mouth to anus
Lumen
Organs
Transit time
24 to 72 hours
Accessory organs
Functions
Digestion, absorption, elimination

14. Organs of the Digestive System

15. What Happens during Digestion?
Neural and hormonal signals
Peristalsis
Wave-like muscular contraction
Sphincters
One-way valves
Mucosa
Enzymes
Hormones

16. Peristalsis

17. Sphincters Regulate the Flow of Food

18. What Happens during Digestion?
Cephalic phase of digestion
Before food enters the mouth
Mouth
Physical digestion
Grinding action of teeth
Chemical digestion
Saliva

19. What Happens during Digestion?
Esophagus
Swallowing is in two phases
Bolus pushed back to pharynx
Voluntary
Bolus enters the esophagus
Involuntary
Peristalsis propels food toward the stomach
Gastroesophageal sphincter
Gastroesophageal reflux disease (GERD)

20. Voluntary and Involuntary Phases of Swallowing

21. Gastroesophageal Reflux Disease (GERD)

22. What Happens during Digestion?
Stomach
Functions
Mixing food with gastric secretions
Temporary food storage
Ulcers
Gastrin
Chyme
Gastric emptying
Pyloric sphincter

23. What Happens during Digestion?
Small intestine
Primary site of chemical digestion & nutrient absorption
Duodenum
Secretions from gallbladder & pancreas
Surface area
Villi
Specialized epithelial cells
Microvilli

24. Overview of the Small Intestine & Accessory Organs

25. Absorptive Surface of the Small Intestine

26. What Happens during Digestion?
Pancreas
Protects small intestine from acid
Gallbladder
Storage reservoir for bile
Dispersion of large fat globules
Gallstones
Cause
Risk factors

27. The Pancreas Has an Important Role in Nutrient Digestion

28. Nutrient Absorption: What Happens after Digestion?
Transfer of nutrient from lumen
Blood or lymph
Bioavailability
Influential factors
One nutrient influencing another nutrient

29. Nutrient Absorption and Circulation

30. Nutrient Absorption: What Happens after Digestion?
Large intestine
Sphincter between small and large intestine
Prevent backward flow into small intestine
Prevent premature flow into the colon
Absorption of water and electrolytes

31. Overview of the Large Intestine

32. Nutrient Absorption: What Happens after Digestion?
Large intestine
Ideal environment for bacterial growth
Microbiota
Probiotic versus prebiotic foods
Sphincter between rectum & anal canal
Feces
Intestinal disorders
Irritable bowel syndrome (IBS)
Inflammatory bowel disease

33. How Does the Body Circulate Nutrients & Excrete Waste Products?
Cardiovascular system
Water-soluble nutrients
Circulate directly to liver
Lymphatic system
Lacteal
Fat-soluble nutrients
Excretion of wastes
Excretory organs

34. What Is Metabolism? Metabolism
Sum of chemical processes within a cell to maintain life
Energy metabolism
Transform stored energy in nutrients into ATP

35. What Is Metabolism? Metabolic pathways Enzymes Catabolic pathways
Assistance of vitamins and minerals
Catabolic pathways
Breakdown of molecules to release energy
Anabolic pathways
Use of energy to construct pathways

36. What Is Metabolism? Metabolic pathways Catabolic pathways
Anaerobic
Limited energy generation
Aerobic
Anabolic pathways
Example