Unit 13 - Digestive System

Vitamin A

Helps form a light-sensitive chemical in the eyes; aids epithelial cell growth

Vitamin D

Aids calcium and phosphorus absorption in the intestine, prevents loss of these elements in the urine; needed for bone growth

Vitamin E

Inhibits the breakdown of cell membranes; necessary for red blood cell, DNA, and RNA formation; is an antioxidant that neutralizes free radicals

Vitamin K

Plays a major role in blood clotting

Thiamine (B1)

(CE) works in multiple body sys, needed for biochemical rxns - like ATP generating ones, and synthesis of acetylcholine (used by nervous sys cells)

Riboflavin (B2)

(CE) works in multiple body sys; needed for cellular rxns in eyes, skin, intestinal epithelia, and blood cells.

Niacin (B3)

(CE) that works in multiple body sys; needed for breakdown of fats and for skin cell metabolism

B6

(CE) that works in multiple body sys, needed for chemical reactions that involve amino acids

B12

Plays a role in red blood cell formation and in chemical rxns involving nucleic acids

Folate (Folic Acid B9)

Needed for chem rxns involving amino acids and nucleic acids

Pantothenic acid (B5)

(CE) that works in multiple body sys; used in creation of several hormones; needed for biochemical processing of carbohydrates, lipids, and amino acids

Ascorbic Acid (C)

promotes protein synthesis, including collagen formation; and antioxidant that neutralizes free radicals (highly reactive chemicals that could otherwise cause damage)

Calcium (Ca)

Helps form/maintain healthy bones and teeth; decreases the risk of certain cancers; plays a role in regulation of blood pressure and immune system function

Fluoride (F)

Supports the deposition of calcium and phosphorus in bones and teeth

Iodine (I)

A component of thyroid hormones that controls the regulation of body temperature, BMR, growth, and reproduction

Iron (Fe)

part of hemoglobin and myoglobin, which transport oxygen in the body; component of many enzymes; essential for brain growth/function

Phosphorus (Ph)

An essential component of ATP; helps form/maintain healthy bones; helps activate/deactivate enzymes; a component of DNA and RNA

Potassium (K)

plays a role in muscle contractions and the transmission of nerve impulses; helps regulate blood pressure

Sodium (Na)

Helps regulate water distribution and blood pressure; involved in nerve transmission and muscle function; aids in absorption of some nutrients

List the minerals

Calcium, Fluoride, Iodine, iron, phosphorus, sodium, and potassium

List the fat-soluble Vitamins

Vitamins A, D, E, and K

List the Water-soluble vitamins

Niacin (B3), Riboflavin (B2), Thiamine (B1), B6, B12, Folate (B9), Pantothenic acid (B5), and Ascorbic Acid (C)

Calorie (kilocalorie)

Unit food scientists use to measure potential energy in foods; amount of heat required to raise the temperature of 1kg of H2O by 1 degree celsius

Basal Metabolic Rate (BMR)

amount of energy required to sustain a person’s metabolism for 1 day if at rest

Energy

capacity of a physical system to do work

Nutrients

substances the body needs for energy, growth, and maintenance

Macronutrients

substances like carbs, proteins, and fats that the body needs in relatively large quantities

Micronutrients

vitamin and minerals that are essential to the body in small amounts

Carbohydrate examples

sugars and starches such as fructose, sucrose, glucose, bread, and pasta

How many calories in 1 gram of carbohydrates?

about 4 calories

How much of daily caloric intake should be from carbohydrates?

1/4

Amino Acids

make up proteins

Essential amino acids

must be part of diet as body doe snot produce them in sufficient amounts or at all

Nonessential amino acids

body makes them in sufficient amounts

How much of daily caloric intake should be from protiens?

1/4

How many calories does one gram of protein supply?

4 calories

Examples of proteins

legumes and grains like beans, peas, rice, corn, and wheat

Fats (lipids)

substances in foods that include oils and solid fats

Saturated fatty acids come from…

animal products, palm oil, and coconut oil; usually solid at room temp

Unsaturated fatty acids come from…

plant sources; are usually liquid at room temp

Three divisions of unsaturated fatty acids

Monosaturated, polysaturated, and trans-unsaturated fats

Sources of monosat fats

canola and olive oils

sources of polysat fat

corn and soybean oils

Sources of Trans fats

artificially produced

how many calories are in one gram of fat?

about 9 calories

Hoe many calories should be from fat daily?

less than 25-35% of total daily calories

Vitamins

organic chemicals needed by the body for normal function

Fat-soluble (water insoluble) vitamins are stored…

in the body and in excess can be toxic

water-soluble vitamins are stored…

not in the body and excess is expelled in urine, most are coenzymes

Coenzymes

molecules that aid in the actions of enzymes

Vitamin Deficiency

long-term lack of a particular vitamin in one’s diet, may result in health issues

Minerals

elements that the body needs in relatively small amounts but are essential, body need different amounts of each

The Alimentary Canal is also called…

the gastrointestinal (GI) tract

Alimentary canal

the tube that runs through the body beginning with the mouth and ending with the anus

Ingestion

getting food into body, involves the mouth, lips, teeth, and tongue

Propulsion

initiated by swallowing at the pharynx and peristalsis

Mechanical breakdown

reduces food into smaller pieces and increases the surface area of the food

Chemical Breakdown

enzymes in the lumen and on the walls of the GI tract that break large food molecules into smaller molecules (Digestion)

Absorption

digested food particles moved into blood from the lumen of the small intestine

Defecation

the expulsion of the food that was not absorbed (via the anus)

Mucosa (mucus membrane)

has an innermost layer of epithelial tissue whose surface is covered by mucus secreted by cells or glands

* has a slightly deeper layer of areolar connective tissue containing blood/lymph vessels, nerves, and some mucus secreting glands

Submucosa

lies below the mucosa and is a layer of irregular, dense connective tissue containing blood vessels, lymph vessels, and nerves

Muscularis Externa

surrounds the submucosal layer can be divided into 2 layers of smooth muscle visceral (closer to lumen) with fibers that contract in a circular manner around lumen and parietal with fibers that contract in a longitudinal manner around canal. These layers help with mechanical breakdown via peristalsis

Serosa

the outermost layer, is a serous membrane, is called peritoneum in the abdominopelvic cavity

* Visceral peritoneum - wraps around the organs and forms the outer layer of those organs
* Parietal peritoneum - lines the body wall

Mesentery

connects the visceral and parietal peritoneum, helps to hold abdominopelvic organs, especially the small intestine in place

Peritoneal cavity

the empty space between the visceral and parietal peritoneum is filled with watery fluid

Retroperitoneal

Organs that are not surrounded by visceral peritoneum and lie against the dorsal wall of the abdominopelvic cavity

Lumen

central opening of the alimentary canal into the stomach

Peristalsis

the symmetrical contraction of muscles that moves food along the remainder of the GI tract

Gums (gingiva)

a soft tissue that covers the necks of the teeth and the maxilla (upper jaw) and mandible (lower jaw)

Incisors

4 front teeth on top/bottom of mouth used for cutting

Canine

lateral and posterior to the incisors and are used for cutting

Molars

grind and crush, 2 sets of premolars or bicuspids, 2 sets of molars, 1 set of wisdom teeth

Parotid glands

largest salivary gland, located below skin in front of ears

Submandibular

located on the medial side of the lower back part of the mandible

Sublingual

under each side of the tongue

Saliva

protects mouth from bacteria, initiates chem breakdown of food, moistens and lubricates food, made of water, enzymes - salivary amylase and lingual lipase

Esophagus

a muscular tube that connects the pharynx to the stomach, reaches the stomach just below the diaphragm

Glottis

opening to larynx and trachea, located in laryngopharynx

Epiglottis

fold of tissue that directs food to esophagus during swallowing, located within laryngopharynx

Stomach

reservoir where food is broken down mechanically and chemically

Regions of the stomach

* Cardia - region closest to esophagus “near the heart”
* Fundus - upper
* Body - middle
* Pyloric - lower part

What are the three muscle layers of the stomach?

the extra muscle layer (oblique muscle layer), longitudinal and circular layers. Oblique is below the others.