Unit 2 DB: Nutrition Labels

Body Basics

The human body is composed of many organ systems which all work together to promote healthy functioning of the body.

1) integumentary - skin, hair, skin glands: protection, secretion

2) skeletal - 206 bones: movement, protection, mineral storage

3) muscular - over 600 muscles: movement, heat production, glycogen storage

4) nervous - brain, spinal cord, nerves: communication, control, respond to stimuli

5) endocrine - pituitary gland, thyroid gland, pancreas: communication, control (hormones control growth, metabolism, homeostasis)

6) cardiovascular (circulatory) - heart, blood, blood vessels: transport materials through body (oxygen, nutrients, carbon dioxide)

7) lymphatic - lymph nodes, lymph vessels (fight disease)

8) digestive - stomach, intestines, esophagus (break down nutrients for absorption)

9) respiratory - lungs, trachea, bronchi (gas exchange: oxygen and carbon dioxide)

10) urinary - kidneys, bladder, urethra (excrete nitrogenous waste)

11) reproductive - sex organs (male and female functions)

Organ Systems

Each system performs specific functions, but all organ systems depend on one another. For example, the digestive system breaks down the food we eat, but the circulatory system transports the nutrients to cells throughout the body for energy.

The Digestive System The human digestive system is responsible for the breakdown of food, the absorption of nutrients, and the elimination of waste. Ingested food passes through the digestive tract, or alimentary canal, in this sequence:

1. mouth (oral cavity) 2. pharynx (throat) 3. esophagus (food tube) 4. stomach - protein digestion begins here; hydrochloric acid has pH of 1 5. small intestine (duodenum, jejunum, ileum) - most digestion + absorption 6. large intestine (ascending colon, transverse colon, descending colon)

* The appendix is a vestigial structure with no apparent function in modern humans. 7. rectum 8. anus

Trace the path of a bolus (ball) of food through the digestive tract.

eliminating

Accessory organs aid in the process of digestion, but are not part of the alimentary canal. Food does not travel directly through them:

1. salivary glands - produce saliva to aid in carbohydrate digestion 2. liver - produces bile to aid in fat digestion; also stores glycogen (a

polysaccharide, or complex carbohydrate, containing glucose sugar units) 3. gallbladder - stores bile and releases it when needed 4. pancreas - secretes digestive juices; also produces hormones to maintain

sugar balance (insulin lowers blood sugar; glucagon raises blood sugar)

LIVER: consists of several lobes

GALLBLADDER: tiny greenish sac under the liver

PANCREAS: hides behind the stomach