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

Body Basics

Chapter 41

Chapter 4- Body Basics (Nutrition)

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.

2Chapter 4- Body Basics (Nutrition)

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.


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

From Atoms to Compounds

• Matter is made of atoms that contain:

• Protons — Positively-charged 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.


ATOM

What Are Elements?

• 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.


Molecules • Molecule - matter that

forms when 2 or more atoms interact and are held together (such as H20 or C6H12O6)

• Compound- molecule that contains 2 or more different elements

• Chemical bond- attraction that holds atoms together to form a molecule


Types of Chemical Bonds Some atoms form single bonds such as hydrogen.

Carbon atoms may form single, double, or triple bonds


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

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


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! 7.35-7.45– 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).


What Is a Chemical Reaction? • Chemical Reaction-

process 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


Metabolism• Metabolism: the sum of

all chemical reactions occurring in living cells.

– Catabolism – break down molecules

– Anabolism – build up molecules


What Is a Salt?A salt forms when an acid reacts with a base.


Enzymes Enzyme – Protein that speeds up the rate of achemical reaction but is not altered during theprocess

Names of most enzymes end in “ase” sucrase lactase lipase protease


Basic Physiology Concepts

• Anatomy – Study of cells and

other body structures

• Physiology – Study of how cells

and body structures function


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


What Are Tissues?

• Tissues – Collection of similar cells that perform specialized functions1. 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- moves4. Nervous tissue- carries

electrical signals


From Cells to SystemsOrgan: Collection of tissues that perform a

specific function

System: Collection of organs that work together to perform a major function


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


Cardiovascular System

• Organs:– Heart– Blood Vessels

• Functions– Transport– Immune Response– Temperature regulation

Chapter 4- Body Basics (Nutrition)

21

Respiratory System

• Organs:– Lungs– Respiratory Passages

• Functions:– Oxygen & carbon dioxide

exchange– Helps regulate the bloods

pH


Lymphatic System

• Organs– Thymus– Spleen– Tonsils– Lymph Vessels– Lymph Nodes

• Functions– Clean Blood and Lymph– Fight Disease– Aids in Fat absorption


Urinary System• Organs

– Kidney– Ureter– Bladder– Urethra

• Function– Removes waste from blood– Regulates pH, Water

levels, and ion levels in the blood


Muscular System

• Organs– Skeletal Muscle

• Function– Produces body movements– Maintains posture– Produces heat


Skeletal System• Organs

– Bones– Cartilage– Tendons– Ligaments

• Functions– Protection– Support– Body movements– Mineral Storage– Fat Storage– Blood cell production


Nervous System• Organs

– Brain– Spinal Cord– Nerves– Sensors

• Functions– Major regulatory system– Controls mental activities– Controls movement– Controls movement– Controls physiologic

processes


Endocrine System

• Organs– Endocrine glands like

the thyroid, adrenal gland, ovaries, testis, pancreas

• Functions– Influences metabolism,

growth and reproduction as well as many other processes.


Integumentary System

• Organs– Skin– Hair – Nails

• Functions– Protection– Temperature

regulation– Vitamin D Production– Reducing water loss


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

Digestive System

• Organs– Mouth– Esophagus– Stomach– Small Intestine

• Liver• Pancreas• Gallbladder

– Large Intestine– Rectum– Anus


• Functions:– Mechanical

digestion– Chemical

Digestion– Absorption– Elimination

Digestion and

AbsorptionGI Tract

Muscular tube that extends from mouth to anus

BioavailabilityExtent to which digestive tract absorbs nutrients and how well the body uses them


Mouth• 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.


Taste and Smell of FoodsTaste Buds

– 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


Esophagus

• Esophagus – Hallow muscular tube connecting pharynx to stomach

• Epiglottis – Flap that folds down over trachea (windpipe) when you swallow


What Happens When You Swallow?


Peristalsis

• Muscular contractions that move small amounts of food and beverages through intestinal tract in a milking-type motion


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

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


Small Intestine• 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• 3-5.5 ft long• Most digestion and

absorption occur here3. Ileum

• 5-9 ft long• Digestion and absorption


Movement thru the SI• Peristalsis

– Milking action

• Segmentation– 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


Accessory Organs of the SILiver, 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


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


Hepatic Portal Vein• 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


Large Intestine2 Major sections1. Colon

• 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

2. Rectum

• 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 Sphincter- voluntarily controlled muscle that allows us to decide when we release feces


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


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.


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


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

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