Term
| __________ are organisms that must obtain their energy and nourishment from the organic molecules manufactured by other organisms. |
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Definition
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Term
| __________ are substances in food that are used as energy sources to power the systems of the body, as ingredients to make compounds for metabolic processes, and as building blocks in the growth and repair of tissues. |
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Definition
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Term
| Obtaining nutrients is of such vital importance that both individual organisms and ecosystems are structured around the central theme of __________, the process of taking in and using food. |
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Definition
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Term
| __________ has been an important force in human evolution. |
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Definition
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Term
| __________, or poor nutritional status, results from dietary intake that is either below or above required needs. |
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Definition
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Term
| __________ is the selection, acquisition, and ingestion of food. |
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Definition
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Term
| __________ is the process of taking food into the digestive cavity. |
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Definition
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Term
| The process of breaking down food is called __________. |
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Definition
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Term
| A hyena cannot incorporate the proteins and other organic compounds from an elephant carcass directly into its own cells; it must __________ digest its food and then __________ digest it by enzyme __________. |
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Definition
1) Mechanically
2) Chemically
3) Hydrolysis |
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Term
| During __________, complex organic compounds are degraded into smaller molecular components. |
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Definition
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Term
| Amino acids and other nutrients pass through the lining of the digestive tract and into the blood by __________. |
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Definition
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Term
| Food that is not digested and absorbed is discharged from the body, a process called __________ or __________. |
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Definition
1) Egestion
2) Elimination |
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Term
| Animals that feed directly on producers are __________, or primary consumers. |
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Definition
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Term
Most of what an __________ eats is not efficiently digested and is eliminated from the body, almost unchanged, as waste.
Because of this, __________ must eat large quantities of food to obtain the nourishment they need. |
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Definition
1) Herbivores
2) Herbivores |
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Term
| Animals cannot digest the __________ of plant cell walls, and many adaptations have evolved for extracting nutrients from the plant material they eat. |
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Definition
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Term
| __________ (cattle, sheep, deer, giraffes) are hooved animals with a stomach divided into four chambers. |
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Definition
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Term
| In Ruminants, symbiotic bacteria and protists living in the first __________ chambers digest __________, splitting some of it into sugars, which are then used by the host and the bacteria themselves. |
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Definition
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Term
| In ruminants, __________ produce fatty acids during their metabolism, some of which are absorbed by the animal and serve as an important energy source. |
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Definition
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Term
In __________, food that is not sufficiently chewed clumps together, forming a __________.
This is then regurgitated into the mouth, where it is mixed with saliva, chewed again, and reswallowed to be further digested. |
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Definition
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Term
| Herbivores are sometimes eaten by flesh-eating __________, which may also eat one another. |
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Definition
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Term
| Many carnivores (__________ and higher-level consumers) are __________, adapted for capturing and killing prey. |
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Definition
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Term
Carnivorous mammals have well-developed __________ teeth for stabbing their prey during combat.
Meat is more easily digested then __________ food, and carnivore digestive tracts are (longer/shorter) than those of herbivores. |
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Definition
1) Canine
2) Plant
3) Shorter |
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Term
| __________, such as pigs, humans, and some fishes, consume both plants and animals. |
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Definition
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Term
| Many omnivores are __________ __________ that removed suspended food particles from the water they inhabit. |
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Definition
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Term
Sponges, the simplest invertebrates, obtain food by __________ (think suspension feeders) microscopic organisms from the surrounding water.
Individual cells phagocytose the food particles, and digestion is __________ within food vacuoles. |
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Definition
1) Filtering
2) Intracellular |
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Term
| Digestion within a __________ is more efficient than __________ digestion because digestive enzymes can be released into one confined space, so less surface area is required. |
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Definition
1) Cavity
2) Intracellular |
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Term
| Cnidarians (such as hydras and jellyfish) and flatworms have a __________ __________, a central digestive cavity with a single opening. |
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Definition
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Term
__________ capture small aquatic animals with the help of their stinging cells and tentacles.
The mouth opens into the __________ __________ where cells secrete enzymes that break down proteins in addition to the help of food vacuoles.
Body contractions promote __________ of undigested food particles through the mouth. |
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Definition
1) Cnidarians
2) Gastrovascular cavity
3) Egestion |
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Term
Free-living __________ begin to digest their prey even before ingesting it.
They extend their __________ out through their mouth and secrete digestive enzymes onto their prey.
After it is ingested, the food enters the branched __________ __________, where enzymes continue to digest it.
Undigested wastes are __________ through the mouth. |
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Definition
1) Flatworms
2) Pharynx
3) Gastrovascular cavity
4) Egested |
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Term
| Most invertebrates have a __________-__________-__________-__________ body plan |
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Definition
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Term
| The mixing and propulsive movements of the digestive tract are referred to as __________. |
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Definition
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Term
| The propulsive activity characteristic of most regions of the digestive tract is __________, waves of muscular contraction that push the food in one direction. |
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Definition
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Term
| What three organs are considered accessory glands that secrete digestive juices into the digestive tract? |
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Definition
1) Liver
2) Pancreas
3) Salivary glands (in terrestrial organisms) |
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Term
| The wall of the vertebrate digestive tract has __________ layers. |
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Definition
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Term
The __________ is a layer of epithelial tissue and underlying connective tissue that lines the __________ (inner space) of the digestive tract.
In the __________ and __________, it is greatly folded to increase the secreting and absorbing surface. |
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Definition
1) Mucosa
2) Lumen
3) Stomach
4) Intestine |
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Term
Surrounding the mucosa (first, or inner layer of the digestive tract) is the __________, a connective tissue layer rich in blood vessels, lymphatic vessels, and nerves.
A __________ __________ consisting of two sublayers of smooth muscle surrounds the submucosa.
-In the inner sublayer, the muscle fibers are arranged (circularly/longitudinally) around the digestive tube.
-In the outer sublayer, the the muscle fibers are arranged (circularly/longitudinally). |
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Definition
1) Submucosa
2) Muscle layer
3) Circularly
4) Longitudinally |
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Term
Below the level of the diaphragm, the outer connect tissue coat (third layer of the digestive system) is called the __________ __________, or muscularis.
By various folds it is connected to the __________ __________, or serosa, a sheet of connective tissue that lines the walls of the abdominal and pelvic cavities.
The visceral and parietal peritonea enclose part of the coelom called the __________ __________. |
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Definition
1) Visceral peritoneum
2) Parietal peritoneum
3) Peritoneal cavity |
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Term
| Inflammation of the peritoneum, called __________, can be very serious, because infection can spread along the peritoneum to most of the abdominal organs. |
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Definition
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Term
| __________ __________ begins as you bite, grind, and chew the food with your teeth. |
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Definition
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Term
The chisel shaped __________ are used for biting, whereas the long, pointed __________ are adapted for tearing food.
The flattened surfaces of the __________ and __________ are specialized for crushing and grinding.
Each tooth is covered by __________, the hardest substance in the body.
Most of the tooth consists of __________, which resembles bone in composition and hardness.
Beneath the dentin is the __________ __________, a soft connective tissue containing blood vessels, lymph vessels, and nerves. |
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Definition
1) Incisors
2) Canines
3) Premolars
4) Molars
5) Enamel
6) Dentin
7) Pulp cavity |
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Term
Three pairs of __________ __________ secrete about a liter of saliva into the mouth cavity each day.
Saliva contains an enzyme, __________ __________, which begins the chemical digestion of starch into sugar. |
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Definition
1) Salivary glands
2) Salivary amylase |
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Term
| After being chewed and fashioned into a lump called a __________, the bite of food is swallowed - moved through the __________ into the __________. |
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Definition
1) Bolus
2) Pharynx
3) Esophagus |
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Term
The __________, or throat, is a muscular tube that serves as the hallway of both the respiratory and the digestive system.
During swallowing, a small flap of tissue, the __________, closes the opening to the airway. |
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Definition
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Term
Waves of __________ sweep the bolus through the pharynx and esophagus towards the __________.
(Circular/longitudinal) muscle fibers in the wall of the esophagus contact around the top of the bolus and push it downward.
Almost at the same time, (circular/longitudinal) muscles around the bottom of the bolus and below it contract, which shorten the tube. |
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Definition
1) Peristalsis
2) Stomach
3) Circular
4) Longitudinal |
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Term
| When the body is in an upright position, __________ helps move food through the __________; however, it is not essential. |
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Definition
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Term
| The entrance to the large, muscular __________ is normally closed by a ring of muscle at the lower end of the esophagus. |
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Definition
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Term
When a peristaltic wave passes down the __________, the muscle relaxes and the bolus enters the stomach.
When empty, the __________ is collapsed and shaped almost like a hot dog.
Folds of the stomach wall, called __________, give the inner lining of a wrinkled appearance. |
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Definition
1) Esophagus
2) Stomach
3) Rugae |
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Term
The __________ is lined with a simple, columnar epithelium that secretes large amounts of mucus.
Tiny pits mark the entrances to the millions of __________ __________, which extend deep into the walls. |
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Definition
1) Stomach
2) Gastric glands |
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Term
| Parietal cells in the gastric glands secrete __________ __________ and __________ __________, a substance needed for adequate absorption of vitamin B12. |
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Definition
1) Hydrochloric acid
2) Intrinsic factor |
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Term
Chief cells in the gastric glands secrete __________, an inactive enzyme precursor.
When it comes in contact with the acidic gastric juice in the __________, it is converted to __________, the main digestive enzyme of the stomach. |
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Definition
1) Pepsinogen
2) Stomach
3) Pepsin |
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Term
Several protective mechanisms prevent the __________ __________ from digesting the wall of the stomach.
-Cells of the gastric __________ secrete an alkaline mucus that coats the stomach wall and neutralizes the acidity of the __________ __________ along the lining.
-__________ cells of the lining fit tightly together, preventing __________ __________ from leaking between them and into the tissue beneath. |
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Definition
1) Gastric juice
2) Mucosa
3) Gastric juice
4) Epithelial
5) Gastric juice |
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Term
Sometimes, protective mechanisms malfunction and part of the stomach lining is digested, leaving an open sore, or __________ __________.
They often occur in the __________ (area in small intestine) and sometimes in the lower part of the __________. |
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Definition
1) Peptic ulcer
2) Duodenum
3) Esophagus |
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Term
| The bacterium __________ __________ has been implicated as a causative factor in ulcers, as it infects the mucus-secreting cells of the __________ lining, decreasing the protective mucus, which can lead to peptic ulcers or cancer. |
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Definition
1) Helicobacter pylori
2) Stomach |
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Term
| During the 3 to 4 hours food is in the stomach, the stomach churns and (mechanically/chemically) degrades the food so that it assumes the consistency of a thick soup; this partially digested food is called __________. |
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Definition
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Term
| Over a period of several hours, peristaltic waves release chyme in spurts through the stomach exit, the __________, and into the __________ __________. |
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Definition
1) Pylorus
2) Small intestine |
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Term
| Digestion of food is completed in the __________ __________, and nutrients are absorbed through its wall. |
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Definition
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Term
| What are the three regions of the small intestine (in order)? |
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Definition
1) Duodenum
2) Jejunum
3) Ileum |
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Term
| Most (mechanical/chemical) digestion takes place in the __________, the first portion of the small intestine, and not in the __________. |
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Definition
1) Chemical
2) Duodenum
3) Stomach |
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Term
Bile from the __________ and enzymes from the __________ (major digestive organ) are released into the duodenum and act on the chyme.
Enzymes produced by __________ (type of skin cell)cells lining the duodenum then catalyze the final steps in the digestion of the major nutrients. |
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Definition
1) Liver
2) Pancreas
3) Epithelial |
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Term
| The lining of the small intestine appears velvety because of its millions of tiny finger-like projections, the intestinal __________. |
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Definition
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Term
| The __________ __________ is the only organ in the digestive system to have villi. |
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Definition
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Term
| __________ increase the surface area of the small intestine for digestion and absorption of nutrients. |
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Definition
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Term
| The surface of the small intestine is further expanded by __________, projections of the plasma membrane of simple columnar epithelial cells of the villi. |
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Definition
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Term
Folds in the wall of the intestine, the villi, and microvilli together increase the __________ __________ (type of measurement) of the small intestine by about __________ times.
If we could unfold and spread the lining of the small intestine of an adult human, its surface would approximate the size of a (tennis/basketball) court. |
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Definition
1) Surface area
2) 600
3) Tennis |
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Term
| The __________, the largest internal organ and also one of the most complex organs in the body, lies in the upper-right part of the abdomen just under the __________. |
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Definition
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Term
| The liver secretes __________, which (mechanically/chemically) digests fats by a detergent-like action. |
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Definition
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Term
Bile consists of water, bile salts, bile pigments, cholesterol, salts, and __________ (a phospholipid).
Bile contains no digestive __________, and is unable to digest food (chemically/mechanically).
The pear-shaped __________ stores and concentrates bile and releases it into the __________ (part of the small intestine) as needed. |
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Definition
1) Lecithin
2) Enzymes
3) Mechanically
4) Gallbladder
5) Duodenum |
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Term
A single liver cell can carry on more than 500 separate, specialized metabolic activities! These are the primary functions of the liver:
1. Secretes __________ that mechanically digests fats.
2. Helps maintain __________ by removing or adding nutrients to the blood.
3. Converts excess glucose to __________ and stores it.
4. Converts excess __________ __________ to fatty acids and urea.
5. Stores __________ and certain vitamins.
6. Detoxifies __________ and other drugs and poisons. |
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Definition
1) Bile
2) Homeostasis
3) Glycogen
4) Amino acids
5) Iron
6) Alcohol |
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Term
| The __________ is an elongated gland that secretes both digestive enzymes and hormones that help regulate the level of glucose in the blood. |
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Definition
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Term
Cells that line the pancreatic ducts secrete an alkaline solution rich in __________ ions.
-This pancreatic juice neutralizes the stomach acid in the __________.
-Provides the optimal __________ for the action of the pancreatic enzymes. |
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Definition
1) Bicarbonate
2) Duodenum
3) pH |
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Term
Pancreatic Enzymes
-__________ and __________, which digest polypeptides to dipeptides;
-__________ __________ which degrades fats;
-__________ __________ which breaks down almost all types of complex carbohydrates, except __________ (insoluble in humans), to disaccharides; and
-__________ and __________, which split the nucleic acids ribonucleic acid (RNA) and deoxyribonucleic acid (DNA) to free nucleotides. |
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Definition
1) Trypsin
2) Chymotrypsin
3) Pancreatic lipase
4) Pancreatic amylase
5) Cellulose
6) Ribonuclease
7) Deoxyribonuclease |
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Term
| Chyme moves through the digestive tract by __________, mixing contractions, and motions of the __________. |
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Definition
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Term
__________ are large glucose units which are connected by __________ __________ linking carbon 4 (or 6) of one glucose molecule with carbon 1 of the adjacent glucose molecule.
Their bonds are hydrolyzed by __________ that digest polysaccharides to the disaccharide maltose. |
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Definition
1) Polysaccharides
2) Glycosidic bonds
2) Amylases |
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Term
| Although amylase can split the __________-glycosidic linkages present in starch and glycogen, it cannot split the __________-glycosidic linkages present in cellulose. |
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Definition
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Term
Amylase cannot split the bond between the two glucose units of __________.
Enzymes produced by the cells lining the __________ __________ break down disaccharides such as this into monosaccharides, primarily through the use of __________, an enzyme which splits maltose into two glucose molecules. |
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Definition
1) Maltose
2) Small intestine
3) Maltase |
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Term
Trypsin, secreted in an inactive form by the __________, is activated by an enzyme called __________.
Trypsin then activates __________ and __________, as well as additional trypsin. |
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Definition
1) Pancreas
2) Enterokinase
3) Chymotrypsin
4) Caboxypeptidase |
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Term
__________ removes amino acids with free terminal carboxyl groups from the end of polypeptide chains.
__________ released by the duodenum then split the small peptides to amino acids. |
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Definition
1) Carboxypeptidase
2) Dipeptidases |
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Term
__________ are usually ingested as large masses of triacylglycerols.
They are digested mainly within the duodenum by __________ __________.
Since lipase's substrates are not water soluble, bile salts use __________ to break large masses of fat into smaller droplets.
-(Increases/decreases) the surface area of fat exposed to the action of pancreatic lipase.
-(Increases/decreases) the rate of lipid digestion. |
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Definition
1) Lipids
2) Pancreatic lipase
3) Emulsification
4) Increases
5) Increases |
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Term
| Salivary gland secretion is controlled entirely by the __________ system, but secretion of other digestive juices is regulated by both nerves and hormones. |
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Definition
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Term
| The wall of the digestive tract contains dense networks of neurons which together form the __________ __________ system, a system which continues to regulate many motor and secretory activities of the digestive system even if __________ and __________ nerves to these organs are cut. |
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Definition
1) Enteric Nervous
2) Parasympathetic
3) Sympathetic |
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Term
| The hormones gastrin, secretin, cholecystokinin (CCK), and glucose-dependent insulinotropic peptide (GIP) are polypeptides secreted by __________ cells in the __________ (stomach layer) of certain regions of the digestive tract. |
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Definition
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Term
| What are five four substances that are readily absorbed through the stomach wall? |
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Definition
1) Water
2) Simple sugars
3) Salts
4) Alcohol
5) Certain drugs |
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Term
| Absorption of nutrients is primarily the job of the intestinal __________. |
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Definition
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Term
| Inside each villus is a network of capillaries and a central lymph vessel, called a __________. |
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Definition
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Term
| __________ is a hormone secreted by the stomach that stimulates the gastric glands to secrete pepsinogen. |
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Definition
|
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Term
| __________ is a hormone secreted by the duodenum that signals secretion of sodium bicarbonate and bile. |
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Definition
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Term
| __________ is a hormone secreted by the duodenum that stimulates the release of digestive enzymes and the emptying of bile. |
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Definition
|
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Term
| __________ is a hormone secreted by the duodenum that stimulates insulin secretion. |
|
Definition
| 1) Glucose-dependent insulinotropic peptide (GIP) |
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Term
Absorption of glucose and amino acids is coupled with (active/passive) transport of __________ (element).
Fructose is absorbed by __________ __________ (type of transport). |
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Definition
1) Active
2) Sodium
3) Facilitated diffusion |
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Term
| Amino acids and glucose are transported directly to the liver by the __________ __________ __________. |
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Definition
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Term
After free fatty acids and monoacylglycerols enter an __________ cell in the intestinal lining, they are reassembled as triacylglycerols in the __________ __________ __________ (organelle).
The triacylglycerols, along with the absorbed cholesterol and phospholipids, are packaged into protein-covered fat droplets, called __________. |
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Definition
1) Epithelial
2) Smooth endoplasmic reticulum
3) Chylomicrons |
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Term
| After they are released into the interstitial fluid, chylomicrons enter the __________ (lymph vessel) of the villus. |
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Definition
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