Nutrition Unit 2

Question 1

Body Cells (Definition)

Answer 1

The smallest unit in which independent life can exist. Need energy, oxygen, and nutrients to remain healthy and do work.

Question 2

Regulators in the Body

Answer 2

• Genes
• Proteins
• Co-enzymes

Question 3

Genes

Answer 3

• Units of a cell’s inheritance that act as a code or recipe
  for the making of protein to do the body’s work. Proteins
  of a cell determine a cell’s structure and the functions it
  can perform.
• Genes are segments of a cell’s DNA (deoxcyribomucleic
  acid). Chromosomes are composed of the DNA and
  protein.
• Each cell contains all genes but different ones are active
  in different cells.

Question 4

Proteins

Answer 4

• Enzyme: Facilitates/speeds up a chemical reaction
  without itself being altered in the process. Many in the
  body.
• Hormones: Chemical messengers that control the
  activity of other organs. Produced by glands (specialized
  cells).

Question 5

Co-Enzymes

Answer 5

• Non-Protein, organic molecule that works with the
  enzyme to promote the enzyme’s activity (aids the
  action of the enzyme).
• Many have B vitamins as part of their structure.

Question 6

Organization of the Body

Answer 6

Cells-Tissue- Organs- Systems- Whole Body

Question 7

Body Fluids and the Cardiovascular System

Answer 7

• Blood
• Extracellular Fluid
• Intracellular Fluid
• Lymph

Question 8

Blood

Answer 8

• Fluid of the cardiovascular system composed of water,
  red and white blood cells, platelets, nutrients, oxygen
  and other constituents.
• Blood travels in:

Arteries: Blood vessels that carry oxygen from the heart to the tissues.
Veins: Blood vessels that carry CO2 and other wastes from the tissues back to the heart.
Capillaries: Minute, weblike blood vessels that connect arteries to veins and permit transfer of materials (CO2, O2, nutrients, and fluid) between blood and tissues.

Question 9

Extracellular Fluid

Answer 9

• Fluid outside the cells that bathes the cells and

transports materials to and from the cells.

Question 10

Intracellular Fluid

Answer 10

• Fluid within the cell that provides the medium for cellular reactions and helps the cell to hold its shape.

Question 11

Lymph (Fluid)

Answer 11

• Excess tissue fluid not reabsorbed by blood capillaries.
• Lymphatic capillaries take up excess tissue fluid and
  return it to the blood stream.

Question 12

Cardiovascular System

Answer 12

• Organ system composed of the heart and blood
  vessels. Its function is to transport nutrient-rich,
  oxygenated blood to the tissues and pick up CO2 and
  other waste products, carrying them to points of
  disposal.
• Blood Flow Diagram (see page 75 of text):

Lungs: O2 picked up by the blood, CO2 released. Blood returns to the heart and is pumped to other parts of the body.
Liver: Filters toxins from the blood and accepts blood from the digestive system, altering the absorbed materials to make them better suited for use by other tissues (“Gatekeeper of the blood). Blood then returns to the heart.
Intestines: After food is broken down in the intestines, nutrients are picked up by the blood vessels in the intestines and transported to the liver. Large fats picked up by intestinal lymphatic vessels which then transport them to the blood.
Kidneys: Cleanses the blood of wastes. Blood then returns to the heart.

Question 13

Lungs

Answer 13

O2 picked up by the blood, CO2 released. Blood returns to the heart and is pumped to other parts of the body.

Question 14

Liver

Answer 14

Filters toxins from the blood and accepts blood from the digestive system, altering the absorbed materials to make them better suited for use by other tissues (“Gatekeeper of the blood). Blood then returns to the heart.

Question 15

Intestines

Answer 15

After food is broken down in the intestines, nutrients are picked up by the blood vessels in the intestines and transported to the liver. Large fats picked up by intestinal lymphatic vessels which then transport them to the blood.

Question 16

Kidneys

Answer 16

Cleanses the blood of wastes. Blood then returns to the heart.

Question 17

The Hormonal (Endocrine) System, Nervous System, and Hunger Relations

Answer 17

See next cards

Question 18

Homeostasis

Answer 18

The relatively constant, self-correcting internal environment of a living organism.
To maintain homeostasis, cells in the body must communicate with each other.
Each cell communicates with its neighbor or by releasing chemicals into the extracellular fluid.
Communication over long distances, however, is coordinated by the endocrine and nervous systems.
The nervous system joins the hormonal system to regulate body processes through communication among all organs.

Question 19

Hormonal (Endocrine System)

Answer 19

• System of cells, tissues, and organs used for life
  processes (growth, development, reproduction,
  regulation) that require long-term (leisurely)
  communication.
• Uses hormones as the chemical messengers.

Examples:
Pancreas- monitors blood sugar levels. If blood sugar is high, insulin is released which helps glucose to enter cells. If blood sugar is low, glucagon is released which stimulates the liver to release its stored glucose into the bloodstream. Insulin and glucagon are examples of hormones.

Question 20

Nervous System

Answer 20

• Organ System consisting of the brain, spinal cord, and
  nerves that coordinate the other organ systems of the
  body. The nervous system is our rapid method of
  communication.
• Uses neurotransmitters as the chemical messengers.

Question 21

Hunger Regulation ( a joint effort by the hormonal and nervous systems)

Answer 21

• The sensation of hunger and fullness are perceived by
  the cortex, the brain’s thinking, outer layer. We have the
  ability to override these signals and choose not to eat
  or ignore that we are full.
• Deep inside the brain is the hypothalamus which
  monitors many body conditions (including the availability
  of nutrients) and communicates with the cortex and
  other parts of the body.
• Internal signals come to the hypothalamus from the
  digestive tract by way of hormones and the nervous
  system. Fat tissue produces a hormone that informs the
  brain about the degree of body fatness that helps to
  regulate appetite. The sight and smell of food can also
  increase or decrease appetite.

Question 22

Immune System

Answer 22

• Enables the body to resist diseases.
• Protects the body against antigens: foreign substances
  that stimulate the immune system. Antigens can be a
  pathogen (bacterium, virus), part of a foreign cell, toxin
  or cancer cell.

Question 23

Parts of the Immune System

Answer 23

• Barrier to Entry
• White Blood Cells
• Lymphoid Organs

Question 24

Barriers to Entry

Answer 24

• Skin and mucous membranes lining the respiratory,
  digestive, and urinary tracts.
  -Oil glands on the skin- chemicals weaken or kill bacteria.
• Hydrochloric Acid in the stomach inhibits/ kills bacteria.
• Helpful bacteria in the intestines inhibit growth of
  pathogens (disease-causing agents).

Question 25

White Blood Cells

Answer 25

• Phagocytes: Ingest and destroy antigens, old cells, and
  cell debris by the process of phagocytosis (cell eating).
• T Cells: Destroy cells infected by bacteria or viruses and
  destroys cancer cells and tissue transplants. HIV-
  attacks/destroys helper T Cells.
• B Cells: Produce antibodies in response to antigen.
  Antibodies: proteins designed to combine with and
  inactive specific antigens.

Question 26

Lymphoid Organs

Answer 26

• Lymph Nodes: Clean the lymph.
• Tonsils: 3 sets of tonsils.
• Spleen: Cleanses the blood. Removes debris and worn
  out/ damaged cells.
• Thymus: Along the trachea. Site where T Cells mature.
• Red Bone Marrow: Produces white blood cells, red
  blood cells, and platelets.

Question 27

Digestive System/ Gastrointestinal System (GI)

Answer 27

See following cards

Question 28

Functions of the Digestive/GI System

Answer 28

1. Ingestion of food
   2.Breakdown of food into smaller particles by mechanical
   processing, movement of food, and chemical digestion.
2. Absorption of nutrients into the cells lining the
   digestive tract.
3. Elimination of undigested/ unabsorbed substances.

Question 29

Digestive Enzymes Function

Answer 29

Digestive enzymes function at a particular pH: measure of acidity on a point scale.

pH below 7- acid
pH of 7- neutral
pH above 7- basic

Acids: Compounds that release hydrogen (H+) in a watery solution.
Bases: Compounds that either accepts hydrogens from solutions or releases hydroxide (OH) particles.

Question 30

Parts of the Digestive Tract

Answer 30

1. Mouth
2. Swallowing and epiglottis
3. Esophagus
4. Stomach (gastric)
5. Small Intestines
6. Large Intestines (Colon)

Question 31

Parts of the Digestive Tract: Mouth

Answer 31

• Mechanical processing: Teeth chew (masticate) food into
  small pieces; tongue manipulates food into a bolus (ball
  of food), mixes it with saliva.
• Chemical digestion: Breakdown of starch is begun by
  enzyme salivary amylase in saliva. Saliva is produced by
  the salivary glands.

Question 32

Parts of the Digestive Tract: Swallowing and Epiglottis

Answer 32

The epiglottis is a flap-like structure of cartilage that covers the opening of the larynx during swallowing so food doesn’t go down the trachea.

Question 33

Parts of the Digestive Tract: Esophagus

Answer 33

• Passes food to the stomach by peristalsis: wavelike,
  muscular contractions of the esophagus, stomach, and
  intestines that push contents along.
• Lower esophageal sphincter. A sphincter is a circular
  muscle surrounding a body opening. It contracts to
  close the opening.

Question 34

Parts of the Digestive Tract: Stomach (Gastric)

Answer 34

• Has deep folds for expansion (rugae)
• Mechanical processing: Mixes and churns food into a
  thick, soupy, acidic liquid: chyme.
• Chemical digestion (Gastric Juice)
• Absorption: Absorbs aspirin, alcohol, some drugs.
• Pyloric Sphincter: Circular muscle at the lower end of
  the stomach that regulates the flow of chyme into the
  small intestine.

Question 35

Gastric Juice Contains

Answer 35

• Pepsin enzyme that digests protein and gastric lipase
  that digests some lipids (fats).
• HCI: activates pepsin, kills bacteria, denatures protein.
• Mucus: lubrication and protection. Stomach protected
  by a bicarbonate-rich mucus layer excreted from goblet
  cells.

Question 36

Small Intestines

Answer 36

1. Mechanical Processing and propulsion: Mixes contents with digestive juices and moves contents along.
2. Chemical Digestion:
   -Villi: Finger-like projections of the cells that line the
   intestinal tract for increased absorptive surface area.
   House blood capillaries and lymphatic capillaries
   (lacteals). The products of protein and CHO
   digestion, and most vitamin and minerals are
   absorbed directly into the blood stream while the
   products of fat digestion (large fats) are absorbed
   into the lacteals. The lacteals eventually carry them
   to the blood steam.
   - Microvilli: Tiny hair, hairlike projections on each cell of
   every villus that can trap nutrients and
   transport them into the cells. Called the “Brush
   Boarder”. Houses intestinal enzymes.
   Increases absorptive surface.
   - Most digestion and absorption occurs in the small
   intestine.
   - With an under supply of energy and nutrients, the
   absorptive surface of the small intestine shrinks
   (atrophy).

Question 37

Large Intestine (Colon)

Answer 37

Functions:
Absorption of water, electrolytes, and bile salts; secretion of mucus; compaction of intestinal contents; and storage of feces.
Feces: Waste material remaining after digestion and absorption are complete; eventually excreted.
Fiber: Some digested by bacteria in the colon. Most fiber unabsorbed. Fiber provides bulk against which the muscles of the colon can work.
Cecum: Blind end (pouch) of the large intestine that has the appendix (has lymphoid tissue to fight infection).
Rectum and Anal Canal: Last 20 cm of digestive tract. Stores feces prior to elimination.
Anus: Hold rectum closed. Opens to allow elimination.

Question 38

Accessory Organs

Answer 38

1. Pancreas
   - Secretes pancreatic juice into the upper small intestine.
   Pancreatic juice contains enzymes (to digest CHO, FAT,
   PRO) and sodium bicarbonate (neutralizes the stomach
   acid so enzymes can work).
   - Secretes the hormones insulin and glucagon into the
   blood to keep sugar (glucose) within normal limits.
2. Liver
   - Accepts blood from the digestive system and alters the
   absorbed materials to make them better suited for use
   by other tissues.
   - Produces bile: A substance made from cholesterol and Bilirubin that emulsifies fat.
3. Gallbladder
   - Stores bile until needed.
   - When fatty foods enter the small intestine, bile is
   released.

Question 39

Emulsifier:

Answer 39

A compound that breaks fat into tiny droplets so that enzymes can get to it. It can do this because it has a water-loving end and a fat-loving end.

Question 40

Hormonal Control of Digestion

Answer 40

1. Several hormones are released from the GI tract in
   response to food.
2. Hormones either increase or decrease digestive juices,
   bile, and peristalsis.

Question 41

The Excretory System

Answer 41

Kidneys:
- Filters blood, adjusting the blood’s composition in
response to the body’s need, disposes wastes, removes
toxins, and regulates fluid volume.
- Nephrons: the working units of the kidneys, consisting
of inter-meshed blood vessels and tubules. Concentrate
wastes as urine.
Bladder:
Sac that holds urine until the time of elimination.

Question 42

Storage Systems

Answer 42

Liver
Adipose
Bone
Muscle

Provides cells with a constant flow of needed nutrients between meals. All body systems need a constant supply of nutrients and are impaired by an under supply or over supply.

Question 43

Storage Systems: Liver

Answer 43

1. Converts excess energy- containing nutrients into
   glycogen and fat. Glycogen: Storage form of
   carbohydrates in animals and humans.
2. Glycogen stored in the liver is for short-term use to
   help maintain blood glucose levels between meals. The
   fat is shipped out in packages to be picked up by body
   cells for energy use or for storage.
3. Stores fat-soluble vitamins (A, D, E, K), iron and B12.

Question 44

Storage Systems: Adipose Tissue

Answer 44

1. Fat tissue consisting of fat-storing cells and blood
   vessels to nourish them.
2. Meets long-term energy needs. Supplies energy for days and weeks when no food is eaten.

Question 45

Storage Systems: Bone

Answer 45

1. Stores calcium and other minerals like phosphorus,
   fluoride, and sodium.
2. The mineral reserves help to maintain normal
   concentrations in body fluids.

Question 46

Storage Systems: Muscle

Answer 46

Stores glycogen as a reserve for its own use.