Chapter 5: Digestion, Absorption, and Metabolism Flashcards
Summarize the process of macronutrient digestion.
Which phrase describes the process of a bolus formation in the upper gastrointestinal (GI) tract?
A mass that forms as food and is broken into smaller pieces and mixed with saliva in the mouth
What is the purpose of the villi in the small intestine?
To increase the surface area for absorption
Which statements describe the processes involved in swallowing?
-Muscles at the base of the tongue help move food from the mouth to the esophagus
-The epiglottis covers the opening of the trachea, preventing food from being aspirated into the lungs
What is the initial site of protein chemical digestion?
Stomach
What is the function of bile in the lower gastrointestinal tract?
Emulsification of fats
Which statement explains why newborn infants are given an injection of vitamin K at birth?
Bacteria have not populated the large intestine of a newborn.
Which statements correctly describe the principles of water absorption in the body?
-Absorption of water is closely associated with the absorption of sodium
-The small intestine is responsible for absorbing most of the water in the body
-Most of the water remaining when chyme enters the large intestine is absorbed in the first half of the colon
Which statements correctly describe facilitated diffusion?
-It is a passive transport method
-It requires the aid of a protein in the membrane
-It involves movement from a higher nutrient concentration to a lower concentration
Which statement describes the absorption of fat into the lymphatic system?
Chylomicrons leave the basement membrane of the enterocyte and enter the lacteals
Which statements correctly describe the function of the hepatic portal vein in portal circulation?
-It bypasses the general venous circulation
-It provides the liver with nutrient-rich blood from digested food
-It allows the liver to perform many vital metabolic functions such as transforming nutrients into substances that can be readily utilized in the body
Order the steps that are required for the absorption and transport of dietary fat.
-Fats enter the small intestine
-Micelles are formed to aid in lipid absorption
-Chylomicrons are formed in the enterocytes
-Chylomicrons enter the lacteals
-Chylomicrons enter the lymphatic circulation
-Fats enter the venous system to be transported to the liver
Which statement correctly describes the transport of fat-soluble nutrients?
Lipids are absorbed through lacteals in the villi walls and released directly into the lymphatic system
Which examples describe anabolic processes?
-Acetyl-CoA is used to make fats
-Amino acids become polypeptides
-Formation of glycogen from glucose molecules
Which statements describe the process of glycogenesis?
-It is an anabolic pathway that is stimulated by insulin
-It is the process by which a polysaccharide is built from a monosaccharide
Which statement differentiates gluconeogenesis from glycogenesis?
Gluconeogenesis uses noncarbohydrate sources, whereas glycogenesis uses glucose molecules
Place the stages of the catabolic pathway in the correct order.
-Blood glucose levels rise
-Insulin is released
-Glycolysis results in the formation of pyruvate
-The TCA cycle results in the formation of ATP and NADH
-The electron transport chain generates ATP and water
Which statements are true regarding the TCA cycle?
-It takes place in the mitochondria of the cell
-It results in carbon dioxide production and adenosine triphosphate (ATP) formation
-It is a process during which nicotinamide adenine dinucleotide (NAD) is converted to reduced nicotinamide adenine dinucleotide (NADH)
Which statements describe the process of catabolism?
-Catabolism produces energy in the form of adenosine triphosphate (ATP)
-Catabolism is the energy-releasing process of metabolism that involves breaking down molecules in the body
-The final steps of catabolism involve the transfer of electrons from high-energy molecules to drive the generation of energy
Which gastrointestinal secretion lubricates and protects the tissues that line the GI tract and helps moisten the food mass?
Mucus
Which term refers to the movement of intestinal muscles that slowly pushes the food mass forward, sometimes with long, sweeping waves over the entire length of the intestine?
Peristaltic waves
In response to a low pH in the duodenum, which hormone stimulates the pancreatic release of bicarbonate to increase the pH to an alkaline environment?
Secretin
A deficiency of which substance causes an intolerance to milk and dairy products?
Lactase
Nutrients that do no need the help of a specific protein channel to move across a mucosal cell wall are transferred by which process?
Simple diffusion
When digestion is complete, to which product are carbohydrates reduced in order to be absorbed into the body?
Galactose
Where does intestinal gas form in the GI tract?
Colon
In what part of the GI tract is chyme formed?
Antrum
Which type of transport occurs when particles move across their concentration gradient?
Active transport
Which description defines glycogenesis, a metabolic function of the liver?
Breaking down stored glycogen into individual glucose units
Which small intestinal movement results in the progress chopping off a food mass into soft lumps, mixing it with GI secretions?
Segmentation rings
What is the function of the mucous glands that line to esophagus?
Moving food towards the stomach
Where does the breakdown of fat begin, and which enzyme is involved in the breakdown?
Mouth, lipase
Fatty materials have to pass through the lymph before entering the bloodstream for which reason?
They are not water soluble
In which section of the GI tract does the absorption of water take place?
Colon
Which network of nerves, extending from the esophagus to the anus, is located in the GI wall?
Intramural nerve plexus
In which absorption process in the small intestine does the cell engulf large molecules in order to absorb them?
Pinocytosis
Which genetic disease causes complications for patients despite rigorous treatment?
Galactosemia
Which genetic disease affects approximately 1 in every 30,000-60,000 live births and can cause fatal brain and liver damage if not treated?
Galactosemia
Which condition is a food allergy that can affect the normal functioning of the GI tract?
Celiac disease
An allergy to the protein gluten
