Body Basics Chapter 4

Transcription

1 Body Basics Chapter 4 1 Chapter 4- Body Basics (Nutrition)

2 Chapter Learning Outcomes 1. Define key basic chemistry terms, including atom, element, ion, chemical bond, solution, solvent, solute, acid, base, and enzyme. 2. Explain the basic function of an enzyme. 3. Define cell, tissue, organ, and organ system. 4. List the organ systems, identify major organs or tissues in each system, and describe primary functions of each system. 5. Discuss the overall processes of nutrient digestion, absorption, transport, and waste elimination. 6. Identify some common gastrointestinal problems and discuss preventive measures and treatments for these conditions. Chapter 4- Body Basics (Nutrition) 2

3 Chemistry and Physiology Chemistry Study of composition and characteristics of matter Human physiology Study of how the human body functions Principles of chemistry and human physiology form the foundation for the scientific study of nutrition. Chapter 4- Body Basics (Nutrition) 3

4 Basic Chemistry Concepts Chemicals make up food and other aspects of the environment. Humans are complex collections of chemicals, mostly organized into cells. Chapter 4- Body Basics (Nutrition) 4

5 From Atoms to Compounds Matter is made of atoms that contain: ATOM Protons Positivelycharged particles in the nucleus Electrons Negatively-charged particles that surround the nucleus in a cloud Matter is comprised of atoms that contain particles, including protons and electrons. The nucleus of this hydrogen atom contains one positively-charged proton. Chapter 4- Body Basics (Nutrition) 5

6 More than 100 types of atoms exist, and each is an element. Elements: cannot be separated into simpler substances are the building blocks of matter Minerals such as calcium, iron, and zinc are elements that are essential nutrients. What Are Elements? Chapter 4- Body Basics (Nutrition) 6

7 Molecules Molecule - matter that forms when 2 or more atoms interact and are held together (such as H 2 0 or C 6 H 12 O 6 ) Compound- molecule that contains 2 or more different elements Chemical bond- attraction that holds atoms together to form a molecule Chapter 4- Body Basics (Nutrition) 7

8 Types of Chemical Bonds Some atoms form single bonds such as hydrogen. Carbon atoms may form single, double, or triple bonds Chapter 4- Body Basics (Nutrition) 8

9 Solutions Solution Evenly distributed mixture of 2 or more compounds (Kool-aid) The 2 compounds in a solution are: Solvent - the primary component Thing doing the dissolving (water*) Solute - lesser component that is dissolved in the solvent Thing getting dissolved (sugar) Solubility- describes how easily a substance (solute) will dissolve in a substance (Solvent) Highly soluble- sugar in water Insoluble- oil in water Chapter 4- Body Basics (Nutrition) 9

10 Ions: electrically-charged atom or group of atoms Electrically-charged atom or group of atoms Form when the atom or group of atoms gains or loses 1 or more electrons Negative charge - gain of an electron Positive charge - loss of an electron Chapter 4- Body Basics (Nutrition) 10

11 What Are Acids and Bases? Acids Donate hydrogen ions in solution Bases Accept hydrogen ions in solution ph Measure of acidity or alkalinity of a solution Your body must maintain and acid-base balance (homeostasis) to maintain your health! To maintain this it must use buffers (chemicals that can pick up excess H+ or release H+ when there isn t enough in the blood). Chapter 4- Body Basics (Nutrition) 11

12 What Is a Chemical Reaction? Chemical Reactionprocess that changes atomic arrangement of molecules Digestion- process by which molecules in food are mechanically and chemically broken down Metabolism- chemical reactions occurring in living cells Chapter 4- Body Basics (Nutrition) 12

13 Metabolism: the sum of all chemical reactions occurring in living cells. Catabolism break down molecules Anabolism build up molecules Metabolism Chapter 4- Body Basics (Nutrition) 13

14 What Is a Salt? A salt forms when an acid reacts with a base. Chapter 4- Body Basics (Nutrition) 14

15 Enzymes Enzyme Protein that speeds up the rate of a chemical reaction but is not altered during the process Names of most enzymes end in ase sucrase lactase lipase protease Chapter 4- Body Basics (Nutrition) 15

16 Basic Physiology Concepts Anatomy Study of cells and other body structures Physiology Study of how cells and body structures function Chapter 4- Body Basics (Nutrition) 16

17 The Cell Cell Smallest functional structure in a living organism A human has ~ 100 trillion cells. Organelles Structures within cells that perform specialized functions Organelles include: nucleus, mitochondria, and ribosomes Chapter 4- Body Basics (Nutrition) 17

18 What Are Tissues? Tissues Collection of similar cells that perform specialized functions 1. Epithelial tissue - Cells that form linings and coverings (skin, inner intestine) 2. Connective tissue - Cells that hold together, protect, and support organs (e.g., bone, fat, and blood) 3. Muscle tissue- moves 4. Nervous tissue- carries electrical signals Chapter 4- Body Basics (Nutrition) 18

19 From Cells to Systems Organ: Collection of tissues that perform a specific function System: Collection of organs that work together to perform a major function Chapter 4- Body Basics (Nutrition) 19

20 The Organ Systems of the Human Body 1. Cardiovascular System 2. Respiratory System 3. Lymphatic System 4. Urinary System 5. Muscular System 6. Skeletal System 7. Nervous System 8. Endocrine System 9. Integumentary System 10. Reproductive System 11. Digestive System Chapter 4- Body Basics (Nutrition) 20

21 Cardiovascular System Organs: Heart Blood Vessels Functions Transport Immune Response Temperature regulation 21 Chapter 4- Body Basics (Nutrition)

22 Respiratory Organs: System Lungs Respiratory Passages Functions: Oxygen & carbon dioxide exchange Helps regulate the bloods ph Chapter 4- Body Basics (Nutrition) 22

23 Lymphatic System Organs Thymus Spleen Tonsils Lymph Vessels Lymph Nodes Functions Clean Blood and Lymph Fight Disease Aids in Fat absorption Chapter 4- Body Basics (Nutrition) 23

24 Urinary System Organs Kidney Ureter Bladder Urethra Function Removes waste from blood Regulates ph, Water levels, and ion levels in the blood Chapter 4- Body Basics (Nutrition) 24

25 Muscular System Organs Skeletal Muscle Function Produces body movements Maintains posture Produces heat Chapter 4- Body Basics (Nutrition) 25

26 Skeletal System Organs Bones Cartilage Tendons Ligaments Functions Protection Support Body movements Mineral Storage Fat Storage Blood cell production Chapter 4- Body Basics (Nutrition) 26

27 Nervous System Organs Brain Spinal Cord Nerves Sensors Functions Major regulatory system Controls mental activities Controls movement Controls movement Controls physiologic processes Chapter 4- Body Basics (Nutrition) 27

28 Organs Endocrine System Endocrine glands like the thyroid, adrenal gland, ovaries, testis, pancreas Functions Influences metabolism, growth and reproduction as well as many other processes. Chapter 4- Body Basics (Nutrition) 28

29 Integumentary Organs Skin Hair System Nails Functions Protection Temperature regulation Vitamin D Production Reducing water loss Chapter 4- Body Basics (Nutrition) 29

30 Reproductive System Organs Male Testis Tubes Penis Female Breasts Ovaries Uterus Vagina Function Male Organ of copulation Produce Sperm Produce male hormones Female Organ of copulation Produce ova Produce female hormones House fetus Feed Baby once born Chapter 4- Body Basics (Nutrition) 30

31 Digestive System Organs Mouth Esophagus Stomach Small Intestine Liver Pancreas Gallbladder Large Intestine Rectum Anus Functions: Mechanical digestion Chemical Digestion Absorption Elimination Chapter 4- Body Basics (Nutrition) 31

32 Digestion and Absorption GI Tract Muscular tube that extends from mouth to anus Bioavailability Extent to which digestive tract absorbs nutrients and how well the body uses them Chapter 4- Body Basics (Nutrition) 32

33 Digestion begins in the mouth. Mechanical digestion Biting and grinding actions break and mash food into smaller pieces. Chemical digestion Saliva mixes and lubricates food. Salivary amylase and lipase begin breakdown of starch and fat, respectively. Mouth Chapter 4- Body Basics (Nutrition) 33

34 Taste Buds Taste and Smell of Foods Specialized sensory structures on the tongue and in the lining of mouth and throat Five Tastes: Sweet, sour, salty, bitter, and umami Smell Chemicals in food become airborne and stimulate nasal passages, contributing to sense of taste Chapter 4- Body Basics (Nutrition) 34

35 Esophagus Esophagus Hallow muscular tube connecting pharynx to stomach Epiglottis Flap that folds down over trachea (windpipe) when you swallow Chapter 4- Body Basics (Nutrition) 35

36 What Happens When You Swallow? Chapter 4- Body Basics (Nutrition) 36

37 Muscular contractions that move small amounts of food and beverages through intestinal tract in a milkingtype motion Peristalsis Chapter 4- Body Basics (Nutrition) 37

38 The Stomach and Duodenum *Gastroesophageal sphincter is the go between from the esophagus to the stomach and helps regulate food passage between them. Stomach is lined with cells that secrete lots of mucus so that when food does enter and *hydrochloric acid (HCl) is secreted (along with other enzymes) the stomach s lining will not be damaged. Food entering the stomach stimulates the muscular walls to begin contracting mixing the HCl and enzymes with food beginning both chemical and mechanical digestion This mixture is called Chyme The pyloric sphincter is responsible for regulating the emptying of the stomach into the beginning of the small intestine (Duodenum) Depending on the meals content the stomach can take 3 to 4 hours to empty Chapter 4- Body Basics (Nutrition) 38

39 Small Intestine Small hollow tube extending from the stomach to the large intestine (~ 9-15ft long) Lumen-Hole in the tube SI- secretes ~ 1 ½ qts of watery fluid into the lumen/day Lubricates to help chyme move thru SI SI also produces mucus Protect tissue as chyme moves Chapter 4- Body Basics (Nutrition) 39

40 3 sections 1. Duodenum 10 long Entrance into the SI where chyme mixes with basic secretions from the Gallbladder and Pancreas These secretions neutralize the acid and aid in the function of intestinal enzymes 2. Jejunum ft long Most digestion and absorption occur here 3. Ileum 5-9 ft long Digestion and absorption Small Intestine Chapter 4- Body Basics (Nutrition) 40

41 Peristalsis Milking action Segmentation Movement thru the SI Contraction and relaxation of muscular rings in the SI to mix chyme with secretions. TIME? ~ 3-5 hours to go from beginning of SI to end Chapter 4- Body Basics (Nutrition) 41

42 Accessory Organs of the SI Liver, Gallbladder, & pancreas Liver processes and stores many nutrients Makes cholesterol and bile Gallbladder stores bile that aids in fat digestion Pancreas produces and secretes many digestive enzymes and bicarbonate ions Chapter 4- Body Basics (Nutrition) 42

43 Absorbing Nutrients Villi Tiny projections that line the small intestine Absorptive cells Remove nutrients from chyme and transfer them into intestinal blood or lymph Hepatic Portal Vein* Next Slide Lacteal Fats do not like going to water and have to be surrounded by a transporter thus they can only fit into the lacteal and not the capillary Chapter 4- Body Basics (Nutrition) 43

44 Things that are absorbed in the intestines can t just go directly into the blood they are transferred to the liver to be checked. Once this is done it may be changed, destroyed, stored, or allowed to have access to the blood stream. This is to prevent bad from getting thru and having access to the entire body Hepatic Portal Vein Chapter 4- Body Basics (Nutrition) 44

45 1. Colon Large Intestine 2 Major sections 2. Rectum Without villi in the LI there is no carbohydrates, fat, or protein absorption mainly it is water and mineral absorption that occur As water is absorbed a semisolid material is prod d called Feces. Made-up of large amounts of water and bacteria Rectum lower part of large intestine where feces are stored until muscular contractions move it into the anal canal then out the body thru the anus External Anal Sphinctervoluntarily controlled muscle that allows us to decide when we release feces Chapter 4- Body Basics (Nutrition) 45

46 Cystic Fibrosis and Inflammatory Bowel Disease Cystic fibrosis An inherited, incurable disease Thick sticky mucus blocks passageways Mucus blocks pancreatic ducts, interfering with nutrient digestion, especially fat Inflammatory bowel disease Group of diseases that cause inflammation and swelling of the intestines Includes Crohn s disease & ulcerative colitis Chapter 4- Body Basics (Nutrition) 46

47 Microbes in Your Digestive Tract The large intestine contains vast numbers of various types of bacteria, that can: 1. metabolize undigested food material 2. make vitamin K and biotin 3. produce gas Bacteria eventually excreted in feces. Chapter 4- Body Basics (Nutrition) 47

48 Your Adaptable Digestive Tract Humans are omnivores Meaning we can digest and absorb nutrients from plants, animals, fungi and bacteria Human digestive tract: Can handle combinations of foods such as mixtures of animal & plant foods Can digest foods and absorb nutrients from wide variety of sources, including: Plants Animals Fungi Bacteria Chapter 4- Body Basics (Nutrition) 48