Chapter 3

Question 1

Which of our senses influence eating?

Answer 1

Sight, smells, taste, texture, sound

Question 2

Distinguish between appetite, satiety, anorexia and hunger.

Answer 2

Appetite- psychological desire to consume specific foods Anorexia-absence of appetite Hunger-physiologic sensation that prompts us to eat

Question 3

Identify the region of the brain and body that is responsible for regulating hunger and thirst.

Answer 3

Hypothalamus

Question 4

What is a hormone?

Answer 4

a regulatory substance produced in an organism and transported in tissue fluids such as blood or sap to stimulate specific cells or tissues into action.

Question 5

What is an enzyme?

Answer 5

a substance produced by a living organism that acts as a catalyst to bring about a specific biochemical reaction.

Question 6

How do the different macronutrients affect hunger & satiety?

Answer 6

x

Question 7

What are the parts of a Cell?

Answer 7

x

Question 8

Describe the structure of the human body from the atom to each of the systems.

Answer 8

Atoms

Molecules

Calls

Tissues

Organs

Organ systems,

Organisms

Question 9

What are the 3 digestive processes associated with food in the human body?

Answer 9

Digestion

Absorbtion

Elimination

Question 10

What are the functions of saliva?

Answer 10

The digestive functions of saliva include moistening food, and helping to create a food bolus, so it can be swallowed easily. Saliva contains the enzyme amylase that breaks some starches down into maltose and dextrin. Thus, digestion of food occurs within the mouth, even before food reaches the stomach.

Question 11

Identify the parts of the gastrointestinal tract, including all major and accessory organs.

Answer 11

The organs of the digestive system are classified into two parts:

1. Gastrointestinal organs: stomach, small and large intestines, esophagus…basically organs that run the food from point of ingestion to defecation.
2. Accessory organs: organs such as the gallbladder and the pancreas. These organs generally help with chemical digestion by secreting enzymes to catalyse the breakdown of food.

Question 12

Describe the role of each of the following in digestion: Mouth

Answer 12

Cephalic phase-Brain thinks about and prepares the digestive organs for the consumption of food

Chewing

Saliva

Question 13

Describe the role of each of the following in digestion: Esophagus

Answer 13

Propels food into the stomach

Bolus- chewed moistened mass

Question 14

Describe the role of each of the following in digestion: Stomach

Answer 14

The stomach is a muscular, hollow, dilated part of the digestion system which functions as an important organ of the digestive tract in some animals, including vertebrates, echinoderms, insects (mid-gut), and molluscs. It is involved in the second phase of digestion, following mastication (chewing).

The stomach is located between the esophagus and the small intestine. It secretes protein-digesting enzymes called proteases and strong acids to aid in food digestion, (sent to it via esophageal peristalsis) through smooth muscular contortions (called segmentation) before sending partially digested food (chyme) to the small intestines.

Question 15

Describe the role of each of the following in digestion: Small Intestine

Answer 15

is the part of the gastrointestinal tract following the stomach and followed by the large intestine, and is where much of the digestion and absorption of food takes place. The small intestine is composed of a duodenum, jejunum, and ileum. It receives bile juice and pancreatic juice through the hepatopancreatic duct, controlled by Sphincter of oddi. The primary function of the small intestine is the absorption of nutrients and minerals found in food

Question 16

Describe the role of each of the following in digestion: Liver

Answer 16

The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion.

This gland plays a major role in metabolism and has a number of functions in the body, including glycogen storage, decomposition of red blood cells, plasma protein synthesis, hormone production, and detoxification. It lies below the diaphragm in the abdominal-pelvic region of the abdomen. It produces bile, an alkaline compound which aids in digestion via the emulsification of lipids. The liver’s highly specialized tissues regulate a wide variety of high-volume biochemical reactions, including the synthesis and breakdown of small and complex molecules, many of which are necessary for normal vital functions.

Question 17

Describe the role of each of the following in digestion: Gall bladder

Answer 17

is a small organ where bile is stored, before it is released into the small intestine. Humans can live normal lives without a gallbladder.

Question 18

Describe the role of each of the following in digestion: Bile

Answer 18

dark green to yellowish brown fluid, produced by the liver of most vertebrates, that aids the digestion of lipids in the small intestine. In many species, bile is stored in the gallbladder and, when the organism eats, is discharged into the duodenum.

Question 19

Describe the role of each of the following in digestion: Pancreas

Answer 19

glandular organ in the digestive system and endocrine system of vertebrates. It is an endocrine gland producing several important hormones, including insulin, glucagon, somatostatin, and pancreatic polypeptide which circulate in the blood. The pancreas is also a digestive organ, secreting pancreatic juice containing digestive enzymes that assist digestion and absorption of nutrients in the small intestine. These enzymes help to further break down the carbohydrates, proteins, and lipids in the chyme.

Question 20

Describe the role of each of the following in digestion: Large intestine

Answer 20

is the last part of the digestive system in vertebrate animals. Its function is to absorb water from the remaining indigestible food matter, and then to pass useless waste material from the body

Question 21

Describe the role of each of the following in digestion: Hormones

Answer 21

Stomach: Pepsin is an enzyme used to partially hydrolyze protein. Pepsin is released in an inactive form PEPSINOGEN. The pepsinogen reacts with HCl to form pepsin.
The hormone GASTRIN is secreted by the stomach cells to regulate the production of gastric juices.

Small Intestine: It is divided into 3 sections ( Duodenum, Jejunum, and ileum). Accessory Organs ( Pancreas, Liver, and Gall Bladder), add digestive enzymes, juices and hormones into the small intestine. As the acid chyme enters the duodenum (first 25 cm of the small intestine) a hormone called SECRETIN is released from the intestinal walls to siginal the pancreas to release a bicarbonate solution which neutralizes the acid.
The hormone CHOLECYSTOKININ (CCK), is released from the intestinal cells causing the gall bladder to release bile. It also causes the pancreas to release its digestive enzymes. The hormone ENTEROGESTRONE is also secreted to slow down peristalsis. Protein Digestion: Trypsin and Chymotrypsin are enzymes that break bonds next to specific amino acids. Carboxypeptidase splits off one amino acid at a time.
This enzyme works on the end with the free carboxyl group. Aminopeptidase works in the opposite direction. All the above enzymes are secreted in an inactive form. They are activated by the hormone ENTEROKINASE. Fat Digestion: Bile emulsifies fat. This creates a larger surface area for the enzyme lipase to digest it. Carbohydrate Digestion: Disaccharide digestion is under the control of the enzymes maltase, lactase, sucrase.

Question 22

Describe the role of each of the following in digestion: Peristalsis

Answer 22

contraction and relaxation of muscles which propagates in a wave down a muscular tube, in an anterograde fashion. Peristalsis is often found in the contraction of smooth muscle tissue to propel food/chyme through a digestive tract, such as the human gastrointestinal tract. It is wave contraction of longitudinal and circular muscles preceded by wave relaxation of these muscles.

Question 23

Describe the role of each of the following in digestion: gastro-esophageal sphincter and pyloric sphincter

Answer 23

gastroesophageal sphincter - a ring of smooth muscle fibers connecting the esophagus and stomach.

pyloric sphincter - A ring of smooth muscle fibers around the opening of the stomach into the duodenum.

Question 24

Describe the role of each of the following in digestion: Mucus and Hydrochloric acid

Answer 24

Mucus - is a slippery secretion produced by, and covering, mucous membranes.

HCl breaks down fats, and emulsifies food

Question 25

Describe the role of each of the following in digestion: Chyme

Answer 25

is the semifluid mass of partly digested food expelled by the stomach into the duodenum.

Question 26

Describe the role of bicarbonate in the small intestine.

Answer 26

Bicarbonate’s main role is to help neutralize the very acidic contents coming out of the stomach and into the small intestine. This serves a protective role to help protect the lining of the small intestine from being eaten away aswell as a functional one – the digestive enzymes at work in the small intestine operate better at a higher pH (less acidic).

Question 27

What does lymph do relative to food digestion?

Answer 27

Pics up most fats, fat-soluble vitamins, and fluids that have excaped from the cardiovascular system, and transport them to the lymph. The lymph filters and destroys harmful microbs

Question 28

Identify the two pancreatic hormones responsible for maintaining blood glucose levels.

Answer 28

insulin will lower your sugar, glucagon will raise it.

Question 29

Where does most digestion and absorption take place?

Answer 29

The greatest amount of digestion occurs in the upper portion of the small intestine called the duodenum. The small intestine is also where about 95% of nutrients are absorbed.

Question 30

What are Heartburn and gastro-esophageal reflux disease (GERD)

Answer 30

Heartburn (GER)- a painful sensation that occurs over the sternum when HCl back up into the lower esophagus GERD-a more painful type of GER that occurs more than 2x per week

Question 31

What causes ulcers?

Answer 31

The bacteria H. pylori,

Question 32

Describe Food allergies vs intolerances?

Answer 32

Allergy - Inflamitory reaction caused by an immune system hypersensitivity Intolerance-gastrointestinal discomfort caused by certain foods that is not a result of an immune systems reaction

Question 33

What is Celiac disease?

Answer 33

a disease in which the small intestine is hypersensitive to gluten, leading to difficulty in digesting food. Autoimune