Week 5: The Gastrointestinal System Flashcards

1
Q

The process of _______ occurs when the muscles of the pharynx contract.

a) propulsion

b) mechanical breakdown

c) digestion

d) ingestion

A

a) propulsion

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2
Q

Swallowing and peristalsis are examples of this digestive process.

a) defaecation

b) chemical digestion

c) absorption

d) propulsion

A

d) propulsion

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3
Q

This is the process of eliminating indigestible substances from the body.

a) defaecation

b) absorption

c) digestion

d) mechanical breakdown

A

a) defaecation

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4
Q

There are six major processes of the digestive system beginning with __________.

A

There are six major processes of the digestive system beginning with ingestion.

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5
Q

As the foodstuff enters the mouth, __________ begins through the acts of chewing.

A

As the foodstuff enters the mouth, mechanical breakdown begins through the acts of chewing.

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6
Q

As the foodstuff enters the mouth, mechanical breakdown begins through the acts of chewing. Then the process of ________ sends the foodstuff through the digestive tract.

A

As the foodstuff enters the mouth, mechanical breakdown begins through the acts of chewing. Then the process of propulsion sends the foodstuff through the digestive tract.

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7
Q

In the stomach, further mechanical breakdown is performed by the oblique muscles called ___________.

A

In the stomach, further mechanical breakdown is performed by the oblique muscles called churning.

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8
Q

Further mechanical breakdown occurs in the _____________ by segmentation.

A

Further mechanical breakdown occurs in the small intestine by segmentation.

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9
Q

____________ is the process that mainly occurs in the small intestine.

A

Absorption is the process that mainly occurs in the small intestine.

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10
Q

As the indigestible foodstuff is propelled through the __________, further absorption of water and vitamins occurs and eventually the process of ___________ ends the digestive process.

A

As the indigestible foodstuff is propelled through the large intestine, further absorption of water and vitamins occurs and eventually the process of defaecation ends the digestive process.

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11
Q

T/F: There are three layers of the digestive tract.

A

False
There are actually four layers of the digestive tract: mucosa, submucosa, muscularis externa and serosa

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12
Q

Which of the following processes occur in the stomach?

a) mechanical breakdown, propulsion, chemical digestion and absorption
b) ingestion, mechanical breakdown, propulsion and defecation
c) mechanical breakdown, chemical digestion, absorption and defecation
d) mechanical breakdown, propulsion, chemical digestion and defecation

A

a) mechanical breakdown, propulsion, chemical digestion and absorption

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13
Q

Which of the following is considered an accessory organ of digestion?

a)appendix

b) gall bladder

c) rectum

d) stomach

A

b) gall bladder

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14
Q

Which of the following is considered an accessory organ of digestion?

a) liver

b) oesophagus

c) small intestine

d) ascending colon

A

a) liver

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15
Q

Which of the following is considered an accessory organ of digestion?

a) pharynx

b) pancreas

c) caecum

d) transverse colon

A

b) pancreas

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16
Q

The pancreas produces ____________ that contains __________, these then breakdown all classes of foodstuff.

A

The pancreas produces pancreatic juice that contains enzymes, these then breakdown all classes of foodstuff.

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17
Q

The pancreas also produces the hormones __________ and __________ that are involved in metabolism

A

The pancreas also produces the hormones insulin and glucagon that are involved in metabolism

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18
Q

The __________ produces ____________ that aids in the digestion of fats. The accessory organ that stores the bile is the ____________
.

A

The liver produces bile that aids in the digestion of fats. The accessory organ that stores the bile is the gallbladder

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19
Q

Cellular respiration

a) is the process of producing ATP.

b) is the process of producing glucagon.

c) occurs only in neurons.

d) is the process of synthesising proteins.

A

a) is the process of producing ATP.

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20
Q

The catabolic state is

a) also known as the post-absorptive state.

b) also known as the “fed” state.

c) is the state when nutrients are stored for later use.

A

a) also known as the post-absorptive state.

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21
Q

Which of the following is not a fate of amino acids

a) stored as fat.

b) used to produce ATP.

c) used to make bile.

A

c) used to make bile.

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22
Q

Glycogenesis

a) is the process of forming new glucose from noncarbohydrate molecules.

b) occurs when blood glucose levels decrease.

c) is the production of glycogen.

A

c) is the production of glycogen.

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23
Q

Gluconeogenesis

a) is the process of forming glycogen.

b) involves glycogenolysis.

c) is the process of forming new glucose from noncarbohydrate molecules.

A

c) is the process of forming new glucose from noncarbohydrate molecules.

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24
Q

Define

Digestive tract

A

A continuous, hollow, muscular tube extending from the mouth to the rectum, involved in the digestion and movement of food. Also known as the gastrointestinal tract or the alimentary canal.

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24
Q

Define

Digestive system

A

The system in the body responsible for the breakdown and absorption of food, consisting of the digestive tract and accessory organs.

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25
Q

Define

Accessory organs

A

Organs that assist in digestion but are not part of the digestive tract itself, including the teeth, tongue, salivary glands, gallbladder, liver, and pancreas.

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26
Q

Define

Small intestine

A

The portion of the digestive tract where most digestion and nutrient absorption occur, consisting of the duodenum, jejunum, and ileum.

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27
Q

Define

Large intestine

A

The section of the digestive tract that absorbs water and electrolytes from indigestible food matter, and forms and expels feces. It includes the cecum, colon, and rectum.

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28
Q

Define

Rectum

A

The final section of the large intestine that stores feces until they are expelled from the body through the anus.

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29
Q

Define

Bolus

A

A soft, rounded mass of chewed food mixed with saliva, ready to be swallowed.

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30
Q

Define

Peristalsis

A

A series of rhythmic, wave-like contractions of smooth muscle that move food through the digestive tract.

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31
Q

Define

Mechanical breakdown

A

Also known as mechanical digestion; the physical process of breaking food into smaller pieces to increase surface area for chemical digestion.

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32
Q

Define

Segmentation

A

A type of mechanical breakdown in the small intestine, involving rhythmic constrictions that mix and move food back and forth to enhance digestion and absorption.

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33
Q

Define

Chemical digestion

A

The process by which enzymes break down complex food molecules into simpler forms that can be absorbed by the body.

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34
Q

Define

Glycogen

A

A polysaccharide that serves as the main storage form of glucose in animal tissues.

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35
Q

Define

Amylases

A

Enzymes that break down carbohydrates into simpler sugars.

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36
Q

Define

Brush border enzymes

A

Enzymes located on the surface of the small intestine’s epithelial cells that further break down carbohydrates, proteins, and nucleic acids.

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37
Q

Define

Pepsin

A

An enzyme in the stomach that begins the digestion of proteins into smaller peptides.

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38
Q

Define

Proteases

A

Enzymes that break down proteins into amino acids.

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39
Q

Define

Emulsification

A

The process by which bile salts break down large fat globules into smaller droplets, increasing the surface area for fat digestion.

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40
Q

Define

Lipases

A

Enzymes that break down triglycerides into fatty acids and glycerol.

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41
Q

Define

Nucleases

A

Enzymes that break down nucleic acids into nucleotides.

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42
Q

Define

Mucosa

A

The innermost layer of the digestive tract, a moist membrane that lines the lumen and is involved in secreting mucus, digestive enzymes, and hormones, and absorbing nutrients.

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43
Q

Define

Submucosa

A

The layer of tissue external to the mucosa, containing elastic tissues that allow the digestive tract to stretch and recoil.

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44
Q

Define

Muscularis Externa

A

The layer surrounding the submucosa, composed of smooth muscle cells responsible for peristalsis, segmentation, and forming sphincters to direct the movement of food.

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45
Q

Define

Serosa

A

The outermost layer of the digestive tract, providing support to the digestive organ and anchoring it to surrounding structures.

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46
Q

Define

Deglutition

A

The process of swallowing, where food is pushed to the back of the mouth with the tongue and then involuntarily propelled into the pharynx.

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47
Q

Define

Pyloric Sphincter

A

A ring of muscle at the end of the stomach that controls the release of stomach contents into the duodenum of the small intestine.

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48
Q

Define

Rugae

A

Large folds in the lining of the stomach that allow it to expand when full and increase its surface area for digestion.

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49
Q

Define

Chyme

A

A semi-liquid mixture of partially digested food and gastric juices that is gradually released from the stomach into the duodenum.

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50
Q

Define

Goblet Cells

A

Cells in the stomach mucosa that produce mucus, forming a protective layer to shield the stomach lining from acidic gastric contents and digestive enzymes.

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51
Q

Define

Gastric Pits

A

Deep indentations in the stomach mucosa that lead to gastric glands, which secrete various substances necessary for digestion.

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52
Q

Define

Parietal Cells

A

Cells in the gastric glands that produce hydrochloric acid (HCl), which creates an acidic environment necessary for activating digestive enzymes and digesting food.

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53
Q

Define

Chief Cells

A

Cells in the gastric glands that produce pepsinogen, an inactive precursor of the enzyme pepsin, which is activated by HCl to aid in protein digestion.

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54
Q

Define

Peptic Ulcers

A

Sores that develop on the lining of the stomach when the mucus barrier is breached, allowing stomach acid and pepsin to damage the stomach wall.

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55
Q

Define

Duodenum

A

The first segment of the small intestine, a C-shaped tube that receives bile and pancreatic secretions, and is involved in both mechanical and chemical digestion.

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56
Q

Define

Hepatopancreatic Sphincter

A

A smooth muscle valve that controls the release of bile and pancreatic secretions into the duodenum.

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57
Q

Define

Jejunum

A

The middle segment of the small intestine, primarily involved in nutrient absorption and digestion.

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58
Q

Define

Ileum

A

The final segment of the small intestine, ending at the large intestine, where the absorption of nutrients continues.

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59
Q

Define

Circular Folds

A

Deep, permanent folds in the submucosa and mucosa layers of the small intestine that increase surface area and slow the movement of chyme for enhanced nutrient absorption.

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60
Q

Define

Villi

A

Finger-like projections of the mucosa in the small intestine that increase surface area for nutrient absorption, containing capillaries and lacteals to transport absorbed nutrients.

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61
Q

Define

Microvilli

A

Tiny, densely packed projections on the surface of absorptive cells in the small intestine, forming the “brush border,” which contains enzymes for the final stages of digestion.

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62
Q

Define

Brush Border

A

The fuzzy appearance of the microvilli on the surface of absorptive cells, equipped with enzymes that complete the chemical digestion of carbohydrates, proteins, and nucleic acids.

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63
Q

Define

Enterocytes

A

Cells found in the intestinal crypts that secrete alkaline intestinal juice to neutralize acids and add water to the chyme, aiding in nutrient absorption.

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64
Q

Define

Intestinal Crypts

A

Indentations in the mucosa between the villi that contain enterocytes and stem cells responsible for secreting intestinal juices and renewing the epithelial lining.

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65
Q

Define

Lacteal

A

A lymphatic capillary located in the core of the villi that absorbs and transports lipids and other nutrients to the liver.

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66
Q

Define

Ileocecal Valve

A

A valve located between the ileum of the small intestine and the cecum of the large intestine, preventing the backflow of waste into the small intestine.

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67
Q

Define

Cecum

A

A pouch-like structure that forms the beginning of the large intestine, located beneath the ileocecal valve.

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68
Q

Define

Vermiform Appendix

A

A small, tube-like appendage connected to the cecum, containing lymphoid tissue and involved in immune functions.

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69
Q

Define

Colon

A

The longest part of the large intestine, divided into the ascending colon, transverse colon, descending colon, and sigmoid colon.

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70
Q

Define

Ascending Colon

A

The portion of the colon that extends upwards from the cecum to the transverse colon.

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71
Q

Define

Transverse Colon

A

The section of the colon that runs horizontally across the abdomen from the ascending colon to the descending colon.

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72
Q

Define

Descending Colon

A

The segment of the colon that descends from the transverse colon to the sigmoid colon.

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73
Q

Define

Sigmoid Colon

A

The S-shaped segment of the colon that connects the descending colon to the rectum.

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74
Q

Define

Teniae Coli

A

Three bands of longitudinal muscle along the colon that contract to form haustra and move waste through the large intestine.

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75
Q

Define

Haustra

A

Pouch-like sacs formed by the contraction of the teniae coli in the large intestine.

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76
Q

Define

Internal Sphincter

A

An involuntary muscle located at the anus, controlled by parasympathetic motor neurons, that maintains closure of the anal canal.

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77
Q

Define

External Sphincter

A

A voluntary muscle located at the anus, controlled by somatic motor neurons, that can be consciously relaxed to allow defecation.

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78
Q

Define

Mass Movements

A

Powerful, long contractions in the colon that propel contents toward the rectum and are typically triggered by eating.

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79
Q

Define

Hepatic Artery

A

A blood vessel that supplies oxygenated blood from the systemic circulation to the liver, constituting approximately 20% of the liver’s blood supply.

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80
Q

Define

Hepatic Portal Vein

A

A blood vessel that supplies nutrient-rich blood from the digestive tract to the liver, constituting approximately 80% of the liver’s blood supply.

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81
Q

Define

Hepatic Portal System

A

The system of veins that carries blood from the digestive organs to the liver for processing.

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82
Q

Define

Liver Lobules

A

The structural and functional units of the liver, each composed of hepatocytes arranged around a central vein, and connected by the portal triad.

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83
Q

Define

Portal Triad

A

A collection of three vessels at each corner of a liver lobule: an arterial branch of the hepatic artery, a venous branch of the hepatic portal vein, and a bile duct.

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84
Q

Define

Bile Duct

A

A vessel in the portal triad that collects bile produced by hepatocytes and transports it to the gallbladder.

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85
Q

Define

Liver Sinusoids

A

Specialized capillaries in the liver with large fenestrations that allow the exchange of large molecules and filtering of blood.

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86
Q

Define

Central Vein

A

The vein at the center of each liver lobule that collects filtered blood and drains it into the hepatic vein.

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87
Q

Define

Hepatic Vein

A

The vein that carries blood from the liver to the inferior vena cava, returning it to the systemic circulation.

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88
Q

Define

Bile Canaliculi

A

Small channels between hepatocytes that collect bile produced by the liver cells and transport it to the bile duct.

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89
Q

Define

Albumin

A

A plasma protein synthesized by the liver that maintains osmotic pressure, essential for proper fluid distribution between the extracellular fluid (ECF) and intracellular fluid (ICF).

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90
Q

Define

First-pass Metabolism

A

The process by which the liver metabolizes drugs and hormones into more water-soluble forms for excretion, occurring after substances are absorbed from the digestive tract.

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91
Q

Define

Fat-Soluble Vitamins

A

Vitamins A, D, E, K, and B12, which are stored in the liver.

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92
Q

Define

Bile

A

A yellow-green alkaline solution produced by the liver that aids in digestion by emulsifying fats, making them easier for digestive enzymes to break down.

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93
Q

DefineEndocrine Tissue

A

The part of the pancreas that secretes hormones, including insulin and glucagon, to regulate blood glucose levels.

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94
Q

Define

Exocrine Tissue

A

The part of the pancreas that produces pancreatic juice, which contains bicarbonate ions and digestive enzymes.

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95
Q

Define

Pancreatic Juice

A

A fluid produced by the pancreas that contains bicarbonate ions to neutralize acidic chyme and enzymes to digest food.

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96
Q

Define

Anabolism

A

A type of metabolic reaction that builds larger molecules from smaller ones, such as protein synthesis.

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97
Q

Define

Catabolism

A

A type of metabolic reaction that breaks down complex structures into simpler ones, such as breaking down glycogen into glucose.

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98
Q

Define

Anabolic (or Absorptive) State

A

A metabolic state occurring during and up to four hours after eating, when the digestive tract provides nutrients that are used for energy and stored for later use.

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99
Q

Define

Catabolic (or Post-absorptive) State

A

A metabolic state occurring more than four hours after eating, when the digestive tract is empty and the body breaks down stored nutrients to provide energy.

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100
Q

Define

Glucose Sparing

A

A process where other cells in the body use fuels other than glucose to make ATP, preserving glucose for neurons.

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101
Q

Define

Cellular Respiration

A

A biochemical process that extracts energy from nutrients by breaking down chemical bonds in glucose to produce ATP.

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102
Q

Define

Glycolysis

A

The first step in cellular respiration, where glucose is broken down into pyruvate, producing ATP and NADH.

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103
Q

Define

Glycogenesis

A

The process of converting excess glucose into glycogen for storage in the liver and skeletal muscles.

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104
Q

Define

Lipogenesis

A

The process of converting excess glucose or amino acids into triglycerides for storage in adipose tissue.

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105
Q

Define

Glycogenolysis

A

The process of breaking down glycogen into glucose to maintain blood glucose levels during fasting.

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106
Q

Define

Gluconeogenesis

A

The creation of new glucose from non-carbohydrate sources, such as glycerol and amino acids, when glycogen stores are depleted.

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107
Q

Define

Lipolysis

A

The breakdown of triglycerides in adipose tissue into glycerol and fatty acids, which can be used to produce glucose through gluconeogenesis.

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108
Q

What is

The system in the body responsible for the breakdown and absorption of food, consisting of the digestive tract and accessory organs.

A

Digestive system

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109
Q

What is

A continuous, hollow, muscular tube extending from the mouth to the rectum, involved in the digestion and movement of food. Also known as the gastrointestinal tract or the alimentary canal.

A

Digestive tract

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110
Q

What is

Organs that assist in digestion but are not part of the digestive tract itself, including the teeth, tongue, salivary glands, gallbladder, liver, and pancreas.

A

Accessory organs

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111
Q

What is

The portion of the digestive tract where most digestion and nutrient absorption occur, consisting of the duodenum, jejunum, and ileum.

A

Small intestine

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112
Q

What is

The section of the digestive tract that absorbs water and electrolytes from indigestible food matter, and forms and expels feces. It includes the cecum, colon, and rectum.

A

Large intestine

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113
Q

What is

The final section of the large intestine that stores feces until they are expelled from the body through the anus.

A

Rectum

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114
Q

What is

A soft, rounded mass of chewed food mixed with saliva, ready to be swallowed.

A

Bolus

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115
Q

What is

A series of rhythmic, wave-like contractions of smooth muscle that move food through the digestive tract.

A

Peristalsis

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116
Q

What is

Also known as mechanical digestion; the physical process of breaking food into smaller pieces to increase surface area for chemical digestion.

A

Mechanical breakdown

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117
Q

What is

A type of mechanical breakdown in the small intestine, involving rhythmic constrictions that mix and move food back and forth to enhance digestion and absorption.

A

Segmentation

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118
Q

What is

The process by which enzymes break down complex food molecules into simpler forms that can be absorbed by the body.

A

Chemical digestion

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119
Q

What is

A polysaccharide that serves as the main storage form of glucose in animal tissues.

A

Glycogen

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120
Q

What isEnzymes that break down carbohydrates into simpler sugars.

A

Amylases

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121
Q

What is

Enzymes located on the surface of the small intestine’s epithelial cells that further break down carbohydrates, proteins, and nucleic acids.

A

Brush border enzymes

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122
Q

What is

An enzyme in the stomach that begins the digestion of proteins into smaller peptides.

A

Pepsin

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123
Q

What is

Enzymes that break down proteins into amino acids.

A

Proteases

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124
Q

What is

The process by which bile salts break down large fat globules into smaller droplets, increasing the surface area for fat digestion.

A

Emulsification

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125
Q

What is

Enzymes that break down triglycerides into fatty acids and glycerol.

A

Lipases

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126
Q

What is

Enzymes that break down nucleic acids into nucleotides.

A

Nucleases

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127
Q

What is

The innermost layer of the digestive tract, a moist membrane that lines the lumen and is involved in secreting mucus, digestive enzymes, and hormones, and absorbing nutrients.

A

Mucosa

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128
Q

What is

The layer of tissue external to the mucosa, containing elastic tissues that allow the digestive tract to stretch and recoil.

A

Submucosa

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129
Q

What is

The layer surrounding the submucosa, composed of smooth muscle cells responsible for peristalsis, segmentation, and forming sphincters to direct the movement of food.

A

Muscularis Externa

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130
Q

What is

The outermost layer of the digestive tract, providing support to the digestive organ and anchoring it to surrounding structures.

A

Serosa

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131
Q

What is

The process of swallowing, where food is pushed to the back of the mouth with the tongue and then involuntarily propelled into the pharynx.

A

Deglutition

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132
Q

What is

A ring of muscle at the end of the stomach that controls the release of stomach contents into the duodenum of the small intestine.

A

Pyloric Sphincter

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133
Q

What is

Large folds in the lining of the stomach that allow it to expand when full and increase its surface area for digestion.

A

Rugae

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134
Q

What is

A semi-liquid mixture of partially digested food and gastric juices that is gradually released from the stomach into the duodenum.

A

Chyme

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135
Q

What is

Cells in the stomach mucosa that produce mucus, forming a protective layer to shield the stomach lining from acidic gastric contents and digestive enzymes.

A

Goblet Cells

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136
Q

What is

Deep indentations in the stomach mucosa that lead to gastric glands, which secrete various substances necessary for digestion.

A

Gastric Pits

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137
Q

What is

Cells in the gastric glands that produce hydrochloric acid (HCl), which creates an acidic environment necessary for activating digestive enzymes and digesting food.

A

Parietal Cells

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138
Q

What is

Cells in the gastric glands that produce pepsinogen, an inactive precursor of the enzyme pepsin, which is activated by HCl to aid in protein digestion.

A

Chief Cells

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139
Q

What is

Sores that develop on the lining of the stomach when the mucus barrier is breached, allowing stomach acid and pepsin to damage the stomach wall.

A

Peptic Ulcers

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140
Q

What is

The first segment of the small intestine, a C-shaped tube that receives bile and pancreatic secretions, and is involved in both mechanical and chemical digestion.

A

Duodenum

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141
Q

What is

A smooth muscle valve that controls the release of bile and pancreatic secretions into the duodenum.

A

Hepatopancreatic Sphincter

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142
Q

What is

The middle segment of the small intestine, primarily involved in nutrient absorption and digestion.

A

Jejunum

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143
Q

What is

The final segment of the small intestine, ending at the large intestine, where the absorption of nutrients continues.

A

Ileum

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144
Q

What is

Deep, permanent folds in the submucosa and mucosa layers of the small intestine that increase surface area and slow the movement of chyme for enhanced nutrient absorption.

A

Circular Folds

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145
Q

What is

Finger-like projections of the mucosa in the small intestine that increase surface area for nutrient absorption, containing capillaries and lacteals to transport absorbed nutrients.

A

Villi

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146
Q

What is

Tiny, densely packed projections on the surface of absorptive cells in the small intestine, forming the “brush border,” which contains enzymes for the final stages of digestion.

A

Microvilli

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147
Q

What is

The fuzzy appearance of the microvilli on the surface of absorptive cells, equipped with enzymes that complete the chemical digestion of carbohydrates, proteins, and nucleic acids.

A

Brush Border

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148
Q

What is

Cells found in the intestinal crypts that secrete alkaline intestinal juice to neutralize acids and add water to the chyme, aiding in nutrient absorption.

A

Enterocytes

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149
Q

What is

Indentations in the mucosa between the villi that contain enterocytes and stem cells responsible for secreting intestinal juices and renewing the epithelial lining.

A

Intestinal Crypts

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150
Q

What is

A lymphatic capillary located in the core of the villi that absorbs and transports lipids and other nutrients to the liver.

A

Lacteal

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151
Q

What is

A valve located between the ileum of the small intestine and the cecum of the large intestine, preventing the backflow of waste into the small intestine.

A

Ileocecal Valve

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152
Q

What is

A pouch-like structure that forms the beginning of the large intestine, located beneath the ileocecal valve.

A

Cecum

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153
Q

What is

A small, tube-like appendage connected to the cecum, containing lymphoid tissue and involved in immune functions.

A

Vermiform Appendix

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154
Q

What is

The longest part of the large intestine, divided into the ascending colon, transverse colon, descending colon, and sigmoid colon.

A

Colon

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155
Q

What is

The portion of the colon that extends upwards from the cecum to the transverse colon.

A

Ascending Colon

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156
Q

What is

The section of the colon that runs horizontally across the abdomen from the ascending colon to the descending colon.

A

Transverse Colon

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157
Q

What is

The segment of the colon that descends from the transverse colon to the sigmoid colon.

A

Descending Colon

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158
Q

What is

The S-shaped segment of the colon that connects the descending colon to the rectum.

A

Sigmoid Colon

159
Q

What is

Three bands of longitudinal muscle along the colon that contract to form haustra and move waste through the large intestine.

A

Teniae Coli

160
Q

What is

Pouch-like sacs formed by the contraction of the teniae coli in the large intestine.

A

Haustra

161
Q

What is

An involuntary muscle located at the anus, controlled by parasympathetic motor neurons, that maintains closure of the anal canal.

A

Internal Sphincter

162
Q

What is

A voluntary muscle located at the anus, controlled by somatic motor neurons, that can be consciously relaxed to allow defecation.

A

External Sphincter

163
Q

What is

Powerful, long contractions in the colon that propel contents toward the rectum and are typically triggered by eating.

A

Mass Movements

164
Q

What is

A blood vessel that supplies oxygenated blood from the systemic circulation to the liver, constituting approximately 20% of the liver’s blood supply.

A

Hepatic Artery

165
Q

What is

A blood vessel that supplies nutrient-rich blood from the digestive tract to the liver, constituting approximately 80% of the liver’s blood supply.

A

Hepatic Portal Vein

166
Q

What is

The system of veins that carries blood from the digestive organs to the liver for processing.

A

Hepatic Portal System

167
Q

What is

The structural and functional units of the liver, each composed of hepatocytes arranged around a central vein, and connected by the portal triad.

A

Liver Lobules

168
Q

What is

A collection of three vessels at each corner of a liver lobule: an arterial branch of the hepatic artery, a venous branch of the hepatic portal vein, and a bile duct.

A

Portal Triad

169
Q

What is

A vessel in the portal triad that collects bile produced by hepatocytes and transports it to the gallbladder.

A

Bile Duct

170
Q

What isSpecialized capillaries in the liver with large fenestrations that allow the exchange of large molecules and filtering of blood.

A

Liver Sinusoids

171
Q

What is

The vein at the center of each liver lobule that collects filtered blood and drains it into the hepatic vein.

A

Central Vein

172
Q

What is

The vein that carries blood from the liver to the inferior vena cava, returning it to the systemic circulation.

A

Hepatic Vein

173
Q

What is

Small channels between hepatocytes that collect bile produced by the liver cells and transport it to the bile duct.

A

Bile Canaliculi

174
Q

What is

A plasma protein synthesized by the liver that maintains osmotic pressure, essential for proper fluid distribution between the extracellular fluid (ECF) and intracellular fluid (ICF).

A

Albumin

175
Q

What is

The process by which the liver metabolizes drugs and hormones into more water-soluble forms for excretion, occurring after substances are absorbed from the digestive tract.

A

First-pass Metabolism

176
Q

What is

Vitamins A, D, E, K, and B12, which are stored in the liver.

A

Fat-Soluble Vitamins

177
Q

What is

A yellow-green alkaline solution produced by the liver that aids in digestion by emulsifying fats, making them easier for digestive enzymes to break down.

A

Bile

178
Q

What is

The part of the pancreas that secretes hormones, including insulin and glucagon, to regulate blood glucose levels.

A

Endocrine Tissue

179
Q

What is

The part of the pancreas that produces pancreatic juice, which contains bicarbonate ions and digestive enzymes.

A

Exocrine Tissue

180
Q

What is

A fluid produced by the pancreas that contains bicarbonate ions to neutralize acidic chyme and enzymes to digest food.

A

Pancreatic Juice

181
Q

What is

A type of metabolic reaction that builds larger molecules from smaller ones, such as protein synthesis.

A

Anabolism

182
Q

What is

A type of metabolic reaction that breaks down complex structures into simpler ones, such as breaking down glycogen into glucose.

A

Catabolism

183
Q

What is

A metabolic state occurring during and up to four hours after eating, when the digestive tract provides nutrients that are used for energy and stored for later use.

A

Anabolic (or Absorptive) State

184
Q

What is

A metabolic state occurring more than four hours after eating, when the digestive tract is empty and the body breaks down stored nutrients to provide energy.

A

Catabolic (or Post-absorptive) State

185
Q

What is

A process where other cells in the body use fuels other than glucose to make ATP, preserving glucose for neurons.

A

Glucose Sparing

186
Q

What is

A biochemical process that extracts energy from nutrients by breaking down chemical bonds in glucose to produce ATP.

A

Cellular Respiration

187
Q

What is

The first step in cellular respiration, where glucose is broken down into pyruvate, producing ATP and NADH.

A

Glycolysis

188
Q

What is

The process of converting excess glucose into glycogen for storage in the liver and skeletal muscles.

A

Glycogenesis

189
Q

What is

The process of converting excess glucose or amino acids into triglycerides for storage in adipose tissue.

A

Lipogenesis

190
Q

What is

The process of breaking down glycogen into glucose to maintain blood glucose levels during fasting.

A

Glycogenolysis

191
Q

What is

The creation of new glucose from non-carbohydrate sources, such as glycerol and amino acids, when glycogen stores are depleted.

A

Gluconeogenesis

192
Q

What is

The breakdown of triglycerides in adipose tissue into glycerol and fatty acids, which can be used to produce glucose through gluconeogenesis.

A

Lipolysis

193
Q

What are the other names for the digestive tract?

A

Gastrointestinal tract and alimentary canal.

194
Q

What is the digestive system composed of?

A

The digestive tract and its accessory organs.

195
Q

How long is the digestive tract approximately?

A

About 9 meters.

196
Q

What are the two ends of the digestive tract open to?

A

The mouth and the anus.

197
Q

What are the main components of the digestive tract?

A

Mouth, pharynx, esophagus, stomach, small intestine, large intestine, and rectum.

198
Q

Which organs are considered accessory organs in digestion?

A

Teeth, tongue, salivary glands, gallbladder, liver, and pancreas.

199
Q

What is the role of accessory organs?

A

They assist in digestion but are not part of the digestive tract.

200
Q

What is the first major process of the digestive system?

A

Ingestion

201
Q

How can food or water be introduced into the digestive system aside from eating?

A

Via a nasogastric tube or a tube placed directly through the abdominal wall.

202
Q

What is a bolus?

A

A soft ball of food mixed with saliva that is swallowed.

203
Q

What is the second digestive process?

A

Propulsion

204
Q

What is peristalsis?

A

The rhythmic contraction of smooth muscles around the food bolus to move it through the digestive tract.

205
Q

What two types of muscle contractions are involved in propulsion?

A

Circular and longitudinal muscle contractions.

206
Q

How does the nervous system affect peristalsis?

A

The parasympathetic nervous system increases motility, while the sympathetic nervous system decreases it.

207
Q

Where does mechanical breakdown occur?

A

In the mouth, stomach, and small intestine.

208
Q

What happens during mechanical breakdown in the mouth?

A

Food is chewed and mixed with saliva to form a bolus.

209
Q

What is chyme?

A

A liquefied substance formed in the stomach after food is mixed with gastric juices.

210
Q

What is segmentation?

A

The rhythmic local constriction of circular muscles in the small intestine to mix food and digestive juices.

211
Q

What does chemical digestion involve?

A

Breaking down complex foods into their component building blocks using enzymes.

212
Q

What is cellulose, and why is it important?

A

A type of polysaccharide that is indigestible but provides dietary fiber, important for healthy bowels.

213
Q

Which enzymes are necessary for breaking down carbohydrates into monosaccharides?

A

Amylases and brush border enzymes.

214
Q

What are the monomers into which proteins must be broken down for absorption?

A

Amino acids.

215
Q

Which enzymes are involved in protein digestion?

A

Pepsin, proteases, and brush border enzymes.

216
Q

What are triglycerides, and why do they require emulsification?

A

The most abundant fats in the diet, requiring emulsification because they are insoluble in water and form fat globules.

217
Q

What is emulsification?

A

The process of breaking down fat globules into smaller droplets to increase surface area for digestion.

218
Q

What enzymes break down triglycerides into their monomers?

A

Lipases

219
Q

How are nucleic acids digested?

A

By nucleases and brush border enzymes in the small intestine, breaking them down into a base, phosphate ion, and sugar.

220
Q

Where does absorption primarily occur?

A

In the small intestine.

221
Q

What needs to happen to monomers in the lumen of the digestive tract for them to enter the body?

A

They need to move into the bloodstream or the lymphatic system.

222
Q

How much food, drink, and secretions do we consume daily?

A

Between 9 and 10 liters.

223
Q

Where does a small amount of absorption occur aside from the small intestine?

A

In the stomach and large intestine.

224
Q

What substances can be absorbed in the stomach?

A

Lipid-soluble substances, particularly alcohol.

225
Q

What is absorbed in the large intestine?

A

A small amount of water, electrolytes, and some vitamins.

226
Q

What is the final digestive process?

A

Defecation

227
Q

Which digestive processes are managed by single organs?

A

Ingestion by the mouth and defecation by the large intestine.

228
Q

Do most digestive processes require cooperation of several organs?

A

Yes, most processes require cooperation of several organs and occur gradually as food moves along the digestive tract.

229
Q

What is the innermost layer of the digestive tract called?

A

Mucosa

230
Q

What is the main function of the mucosa?

A

To secrete mucus, digestive enzymes, and hormones, and to absorb nutrients.

231
Q

What is the role of the submucosa?

A

It contains elastic tissues that allow for stretch and recoil.

232
Q

Which layer of the digestive tract is responsible for peristalsis and segmentation?

A

Muscularis externa.

233
Q

What does the serosa do?

A

Supports the digestive organ and anchors it to surrounding structures.

234
Q

What additional structures are found in the digestive tract besides the four basic layers?

A

Blood vessels, parasympathetic and sympathetic nerves, lymphatic vessels, and lymphoid tissue.

235
Q

How is the mucosal layer modified in the mouth?

A

It is lined with multiple layers of epithelial cells for durability and protection.

236
Q

What are the major salivary glands in the mouth?

A

Parotid, sublingual, and submandibular glands.

237
Q

What are the functions of saliva?

A

Moistens the food and mouth, lubricates the oral cavity, facilitates taste, and begins the chemical digestion of carbohydrates.

238
Q

Which enzyme in saliva starts the digestion of carbohydrates?

A

Amylase.

239
Q

What antimicrobial proteins are found in saliva?

A

IgA, lysozymes, and defensins.

240
Q

How does the parasympathetic nervous system affect saliva secretion?

A

It increases saliva secretion.

241
Q

What happens to saliva production during strong sympathetic activation?

A

It can lead to thick mucus or a dry mouth.

242
Q

What are the four digestive processes involved in the mouth?

A

Ingestion, mastication (chewing), digestion, and propulsion.

243
Q

What is mastication?

A

The mechanical breakdown of food through chewing.

244
Q

What is a bolus?

A

A soft ball of food mixed with saliva formed in the mouth.

245
Q

How does saliva help with taste?

A

It dissolves foods to facilitate taste.

246
Q

What is the role of the pharynx in digestion?

A

To receive food pushed from the mouth and serve as a passageway to the esophagus.

247
Q

What is the role of the esophagus in digestion?

A

To serve as a muscular tube that propels food from the pharynx to the stomach.

248
Q

What is the role of the pyloric sphincter in the stomach?

A

The pyloric sphincter controls the emptying of the stomach and regulates the release of chyme into the small intestine.

249
Q

What is the typical volume range of the stomach when empty and when full?

A

When empty, the stomach’s volume is about 50 milliliters, and when full, it can expand to hold up to four liters.

250
Q

How does the muscularis externa of the stomach differ from other parts of the digestive tract?

A

The muscularis externa of the stomach has an additional oblique layer of smooth muscle, in addition to the circular and longitudinal layers, which helps to pummel and mix food.

251
Q

What are rugae, and when are they present in the stomach?

A

Rugae are large folds in the stomach lining that are present when the stomach is empty and collapse inward.

252
Q

What are the three main types of specialized cells found in the gastric pits and glands?

A

The three main types are parietal cells, chief cells, and goblet cells.

253
Q

What is the function of parietal cells in the stomach?

A

Parietal cells produce hydrochloric acid (HCl), which creates an acidic environment necessary for pepsin activity and digestion, denatures proteins, and helps kill bacteria.

254
Q

What is pepsinogen, and how is it activated in the stomach?

A

Pepsinogen is an inactive form of the enzyme pepsin produced by chief cells. It is converted into active pepsin in the presence of hydrochloric acid.

255
Q

What role do goblet cells play in the stomach?

A

Goblet cells produce mucus that forms a protective barrier on the stomach lining, preventing damage from stomach acid and enzymes.

256
Q

What happens if the mucus barrier in the stomach is breached?

A

Breaching the mucus barrier can result in gastric ulcers, as stomach acid and pepsin may begin to digest the stomach wall itself.

257
Q

How does the stomach contribute to the mechanical breakdown of food?

A

The stomach mixes food with gastric juice through its muscular contractions, forming a liquefied substance called chyme.

258
Q

Which enzyme is responsible for the initial chemical digestion of proteins in the stomach?

A

The enzyme pepsin is responsible for the initial chemical digestion of proteins in the stomach.

259
Q

Can the stomach absorb any nutrients or substances?

A

The stomach absorbs some fat-soluble substances, such as alcohol, aspirin, and certain drugs, but absorption is a minor role compared to the small intestine.

260
Q

What is chyme, and how is it formed in the stomach?

A

Chyme is a liquefied food mixture formed in the stomach by the mechanical breakdown of food and mixing with gastric juice.

261
Q

How does the stomach aid in the propulsion of food?

A

The stomach propels food into the small intestine by churning and mixing the contents, which helps to push the food forward.

262
Q

What is the primary function of the small intestine?

A

The small intestine is the body’s major digestive organ and the site where almost all absorption occurs.

263
Q

What are the three divisions of the small intestine?

A

The three divisions are the duodenum, jejunum, and ileum.

264
Q

What is the function of the pyloric sphincter?

A

The pyloric sphincter controls the emptying of the stomach into the duodenum.

265
Q

What is the role of the hepatopancreatic sphincter?

A

The hepatopancreatic sphincter controls the release of bile and pancreatic secretions into the duodenum.

266
Q

What are circular folds in the small intestine?

A

Circular folds are deep, permanent folds of the submucosa and mucosa that force the chyme to spiral around, slowing its movement for better nutrient absorption.

267
Q

How tall are the circular folds?

A

The circular folds are about 1 centimeter tall.

268
Q

What are villi?

A

Villi are finger-like projections of the mucosa that absorb nutrients and electrolytes from the food and fluids consumed.

269
Q

What is found in the core of the villi?

A

The core of the villi contains capillary beds and a lymphatic capillary called a lacteal.

270
Q

What is the function of goblet cells in the villi?

A

Goblet cells produce mucus to ease the passage of food.

271
Q

What are intestinal crypts?

A

Intestinal crypts are indentations in the mucosa between the villi that contain cells secreting alkaline intestinal juice and stem cells.

272
Q

What do enterocytes in the intestinal crypts secrete?

A

Enterocytes secrete alkaline intestinal juice to neutralize acids and add water to the chyme.

273
Q

What are microvilli?

A

Microvilli are very small, densely packed projections on the surface of absorptive cells, giving a “brush border” appearance.

274
Q

What is the function of the brush border enzymes?

A

Brush border enzymes complete the chemical digestion of carbohydrates, proteins, and nucleic acids.

275
Q

What digestive process moves chyme through the small intestine?

A

Peristalsis moves the chyme through the small intestine.

276
Q

What is segmentation in the small intestine?

A

Segmentation, or intestinal churning, is the process where smooth muscle squeezes food back and forth to break it down and mix it with digestive juices.

277
Q

What happens to nutrients, electrolytes, and water by the end of the small intestine?

A

Virtually all nutrients, electrolytes, and water have been absorbed by the end of the small intestine.

277
Q

Where does the large intestine begin?

A

The large intestine begins at the ileocecal valve.

278
Q

What is the function of the ileocecal valve?

A

The ileocecal valve prevents waste from moving back into the small intestine.

279
Q

What is the cecum?

A

The cecum is a pouch that lies beneath the ileocecal valve.

280
Q

What is the role of the vermiform appendix?

A

The vermiform appendix contains lymphoid tissue and plays a role in the immune system.

281
Q

What are the divisions of the colon?

A

The colon is divided into the ascending colon, transverse colon, descending colon, and sigmoid colon.

282
Q

What are teniae coli?

A

Teniae coli are three bands of muscle along the walls of the colon that contract and form pocket-like sacs called haustra.

283
Q

What are haustra?

A

Haustra are small pocket-like sacs formed by the contraction of teniae coli.

284
Q

What is the rectum?

A

The rectum is an expandable organ that allows for the temporary storage of feces.

285
Q

What triggers the defecation reflex?

A

The presence of feces in the rectum triggers the defecation reflex.

286
Q

What are the internal and external anal sphincters?

A

The internal anal sphincter is involuntary and innervated by parasympathetic motor neurons, while the external anal sphincter is voluntary and composed of skeletal muscle, innervated by somatic motor neurons.

287
Q

What is the primary function of the large intestine?

A

The primary function of the large intestine is to propel waste toward the anus and eliminate it from the body.

288
Q

What are haustral contractions?

A

Haustral contractions are slow, short-lived contractions that move food into the next haustral segment and mix the waste.

289
Q

What are mass movements or mass peristalsis?

A

Mass movements are long, powerful contractile waves that push contents through the colon and into the rectum.

290
Q

What is the composition of semi-solid feces?

A

Semi-solid feces consist of food residue, mucus, sloughed-off epithelial cells, bacteria, and enough water for smooth passage.

291
Q

What effect does fiber have on colon contractions and stool?

A

Fiber increases the effectiveness of colon contractions and softens the stool by retaining water.

292
Q

How is defecation controlled?

A

Defecation is controlled by the contraction of the rectal wall, relaxation of the internal anal sphincter, and voluntary relaxation of the external anal sphincter.

293
Q

What role do enteric bacteria play in the large intestine?

A

Enteric bacteria produce vitamins like B and K, ferment indigestible carbohydrates into fatty acids, and produce gas.

294
Q

Does the large intestine perform chemical digestion?

A

No, chemical digestion is not a function of the large intestine; it is performed primarily in the small intestine by enzymes produced by the body.

295
Q

What is the largest gland in the body?

A

The liver is the largest gland in the body.

296
Q

Where is the liver located?

A

The liver is located beneath the diaphragm and lies almost entirely within the rib cage.

297
Q

What organ rests on the inferior surface of the right lobe of the liver?

A

The gallbladder rests on the inferior surface of the right lobe of the liver.

298
Q

What is the dual blood supply of the liver?

A

The liver receives blood from the hepatic artery (20%) and the hepatic portal vein (80%).

299
Q

What is the function of the hepatic artery?

A

The hepatic artery delivers oxygenated blood from the systemic circulation to the liver.

300
Q

What is the function of the hepatic portal vein?

A

The hepatic portal vein supplies nutrient-rich blood from the digestive tract to the liver.

301
Q

How is blood processed in the liver?

A

Blood delivered to the liver is filtered and processed by hepatocytes before returning to the systemic circulation.

302
Q

What are liver lobules?

A

Liver lobules are structural and functional units of the liver, each about the size of a sesame seed.

303
Q

What cells surround the central vein in a liver lobule?

A

Hepatocytes surround the central vein in a liver lobule.

304
Q

What is the portal triad in a liver lobule?

A

The portal triad consists of an arterial branch from the hepatic artery, a venous branch from the hepatic portal vein, and a bile duct.

305
Q

What are liver sinusoids?

A

Liver sinusoids are capillaries with large fenestrations that allow large molecules to enter or exit the vessel.

306
Q

What is the function of the bile duct in the portal triad?

A

The bile duct collects bile produced by hepatocytes and carries it to the gallbladder.

307
Q

How does blood flow through the liver lobule?

A

Blood flows from the hepatic artery and hepatic portal vein into the sinusoids, then to the central vein, and finally to the hepatic vein and systemic circulation.

308
Q

What is the role of hepatocytes in the liver?

A

Hepatocytes filter blood, remove or add substances, and produce bile.

309
Q

What are bile canaliculi?

A

Bile canaliculi are small canals that collect bile produced by hepatocytes.

310
Q

How does bile flow in the liver lobule?

A

Bile flows from the hepatocytes through the bile canaliculi to the bile duct in the portal triad.

311
Q

What is the function of macrophages in the liver sinusoids?

A

Macrophages in the liver sinusoids remove debris such as old red blood cells, cellular debris, and bacteria.

312
Q

Where does filtered blood from the liver lobules eventually return to?

A

Filtered blood from the liver lobules returns to the systemic circulation via the hepatic vein and inferior vena cava.

313
Q

What is the only digestive function of the liver?

A

The liver produces bile.

314
Q

What is the role of albumin produced by the liver?

A

Albumin maintains osmotic pressure, which is necessary for the proper distribution of body fluids between the extracellular fluid (ECF) and intracellular fluid (ICF).

315
Q

What is the liver’s role in detoxification?

A

The liver detoxifies harmful chemicals, including alcohol and drugs, by converting them into less harmful materials that can be excreted.

316
Q

What is first-pass metabolism?

A

First-pass metabolism is the process where the liver metabolizes drugs and hormones, transforming them into more water-soluble forms for excretion.

317
Q

How does the liver handle excess glucose?

A

The liver stores excess glucose in the form of glycogen.

318
Q

What metabolic processes occur in the liver involving amino acids?

A

The liver uses amino acids to synthesize proteins or produce ATP for energy.

319
Q

How does the liver store vitamins and minerals?

A

The liver stores fat-soluble vitamins (A, D, E, K, and B12) and minerals like iron.

320
Q

What is the role of bile in digestion?

A

Bile emulsifies fats, breaking them into smaller droplets to increase the surface area for digestive enzymes to act on.

321
Q

Where is bile stored before being released into the duodenum?

A

Bile is stored in the gallbladder.

322
Q

How often can bile recirculate during the digestion of a single meal?

A

Bile can recirculate up to five times during the digestion of a single meal.

323
Q

What is the primary function of the gallbladder?

A

The gallbladder stores and concentrates bile until it is needed for digestion.

324
Q

What are the two main parts of the pancreas?

A

The two main parts of the pancreas are the endocrine tissue and the exocrine tissue.

325
Q

What hormones are secreted by the endocrine tissue of the pancreas?

A

The endocrine tissue secretes hormones such as insulin and glucagon to regulate blood glucose levels.

326
Q

What does the exocrine tissue of the pancreas produce?

A

The exocrine tissue produces pancreatic juice, which contains bicarbonate ions and digestive enzymes.

327
Q

What is the function of bicarbonate ions in pancreatic juice?

A

Bicarbonate ions help neutralize the acidic chyme entering the duodenum from the stomach.

328
Q

What are the four classes of enzymes produced by the pancreas and their functions?

A

Pancreatic amylase: Breaks down carbohydrates.
Pancreatic proteases: Digest proteins.
Pancreatic lipases: Break down triglycerides into fatty acids and glycerol.
Pancreatic nucleases: Break down nucleic acids.

329
Q

What can result from a failure of the pancreas to secrete or deliver digestive enzymes?

A

It can impair digestion and lead to malnutrition.

330
Q

What is metabolism?

A

Metabolism is the sum total of all the chemical reactions that occur within the body.

331
Q

What does anabolism involve?

A

Anabolism involves reactions that build larger molecules from smaller ones, such as protein synthesis.

332
Q

What is catabolism?

A

Catabolism involves processes that break down complex structures into simpler ones, such as breaking down glycogen into glucose.

333
Q

Can products from anabolic reactions be used in catabolic reactions?

A

Yes, products made during anabolic reactions can be broken down in catabolic reactions and then rebuilt as needed.

334
Q

What is metabolic rate?

A

Metabolic rate is the energy the body uses to drive metabolism.

335
Q

What is basal metabolic rate (BMR)?

A

Basal metabolic rate (BMR) is the energy required for essential activities like breathing and maintaining resting levels of organ functions.

336
Q

What is the anabolic (or absorptive) state?

A

The anabolic state occurs during and up to four hours after eating when the digestive tract provides a large amount of nutrients, which are used to supply stable fuel for all body cells and convert excess nutrients into storage forms.

337
Q

What is the catabolic (or post-absorptive) state?

A

The catabolic state occurs when the digestive tract is empty, more than four hours after eating, and the body uses stored nutrients from the anabolic state to provide energy and nutrients.

338
Q

What is the main function of the body during the anabolic state?

A

The main function is to supply energy to all body cells for activities such as active transport, muscle contraction, and chemical reactions.

339
Q

What is ATP, and why is it important?

A

ATP (adenosine triphosphate) is a universal energy source that stores energy from food and releases it when needed by body cells.

340
Q

Which cells rely entirely on glucose to supply ATP?

A

Neurons and red blood cells rely entirely on glucose to supply ATP.

341
Q

What is glucose sparing?

A

Glucose sparing is the process that allows other cells to use fuels other than glucose to make ATP, preserving glucose for neurons.

342
Q

What biochemical process produces ATP from glucose?

A

Cellular respiration produces ATP by breaking down chemical bonds in glucose.

343
Q

Where does cellular respiration occur?

A

Cellular respiration occurs in the mitochondria.

344
Q

What are the three main processes involved in cellular respiration?

A

The three main processes are glycolysis, the tricarboxylic acid cycle (Krebs cycle or citric acid cycle), and the electron transport chain.

345
Q

Can foods other than carbohydrates be used to produce ATP?

A

Yes, other foods such as fats, alcohol, and amino acids can also be used to produce ATP either directly or by being converted into other molecules used in cellular respiration.

346
Q

What happens to amino acids during metabolism?

A

Amino acids can be used to produce ATP, and their metabolism results in the production of urea, which is excreted in urine.

347
Q

What occurs during the anabolic or absorptive state?

A

During the anabolic state, which occurs during and up to 4 hours after eating, there is an abundant supply of nutrients in the blood. Body cells use glucose to create ATP and, if glucose is utilized, other food sources and amino acids can be used for protein synthesis.

348
Q

What happens to excess nutrients during the anabolic state?

A

Excess nutrients consumed during the anabolic state must be stored for use during the catabolic state, as there is a limit to how much ATP can be stored.

349
Q

What is glycogenesis?

A

Glycogenesis is the process of converting excess glucose into glycogen, which is then stored in the skeletal muscles and liver.

350
Q

What happens to excess glucose after glycogenesis?

A

Any excess glucose remaining after glycogenesis is converted into triglycerides through a process called lipogenesis and stored in adipose tissue.

351
Q

What is lipogenesis?

A

Lipogenesis is the process of creating lipids (triglycerides) from excess glucose and amino acids, which are then stored in adipose tissue.

352
Q

How are amino acids managed during the anabolic state?

A

Amino acids are used for protein synthesis in body cells. Any excess amino acids are converted to triglycerides through lipogenesis and stored in adipose tissue.

353
Q

What happens to triglycerides in the anabolic state?

A

Triglycerides are broken down into glycerol and fatty acids, which are used to produce ATP. Any excess glycerol and fatty acids are recombined to form triglycerides and stored in adipose tissue through lipogenesis.

354
Q

What is the role of insulin during the absorptive state?

A

Insulin regulates blood glucose levels by prompting body cells to take up glucose and amino acids after a meal. It is released by the beta cells of the pancreas in response to increased blood glucose levels.

355
Q

Do brain and liver cells require insulin to take up glucose?

A

No, brain and liver cells take up glucose regardless of the presence of insulin.

356
Q

What is the fate of glucose when ATP storage is full?

A

When ATP storage is full, excess glucose is converted into glycogen through glycogenesis and then stored in the liver and skeletal muscles. Any remaining glucose is converted into triglycerides through lipogenesis.

357
Q

What is the primary storage form of glucose in the body?

A

The primary storage form of glucose in the body is glycogen, stored in the liver and skeletal muscles.

358
Q

How are triglycerides used for energy during the anabolic state?

A

Triglycerides are broken down into glycerol and fatty acids, which are used to produce ATP. Any excess components are recombined into triglycerides and stored in adipose tissue.

359
Q

What happens to amino acids if glucose is insufficient during the anabolic state?

A

If glucose is insufficient, amino acids may be used to produce ATP. Any remaining excess amino acids are converted into triglycerides through lipogenesis and stored in adipose tissue.

360
Q

What is the catabolic or post-absorptive state?

A

It is the metabolic state that begins more than 4 hours after eating, where larger molecules stored during the anabolic state are broken down into smaller ones.

361
Q

What are the primary metabolic processes during the catabolic state?

A

Catabolic reactions, where stored molecules are broken down into smaller molecules to maintain blood glucose levels.

362
Q

Why is it important to maintain blood glucose levels between 4.0 and 6.0 millimoles per liter?

A

To ensure adequate glucose for neurons and to maintain homeostasis.

363
Q

What happens if blood glucose levels drop below 4.0 millimoles per liter?

A

It results in hypoglycemia, which can make the extracellular fluid hypotonic and affect neurons.

364
Q

What happens if blood glucose levels rise above 6.0 millimoles per liter?

A

It results in hyperglycemia, which makes the extracellular fluid hypertonic and can also affect neurons.

365
Q

What is glycogenolysis?

A

The process of breaking down glycogen stored in the liver and skeletal muscles to release glucose into the bloodstream.

366
Q

What is gluconeogenesis?

A

The production of new glucose from non-carbohydrate sources when glycogen stores are exhausted.

367
Q

What role does lipolysis play in the catabolic state?

A

Lipolysis breaks down triglycerides into glycerol and fatty acids, with glycerol used for gluconeogenesis to produce glucose.

368
Q

What is glucose sparing?

A

The process where fatty acids produced during lipolysis are used by all body cells except neurons to produce ATP, conserving glucose for neurons.

369
Q

Which hormone dominates during the catabolic state?

A

Glucagon.

370
Q

What stimulates the release of glucagon?

A

Decreased plasma glucose levels and the sympathetic nervous system through adrenaline.

371
Q

How does glucagon help maintain blood glucose levels?

A

By stimulating glycogenolysis and gluconeogenesis, increasing plasma glucose levels.

372
Q

What happens to proteins during periods of starvation?

A

Proteins are broken down into amino acids, which are converted into glucose through gluconeogenesis.

373
Q

What is the main source of glucose production once glycogen stores are depleted?

A

Gluconeogenesis from glycerol and amino acids.

374
Q

What is the main difference between the anabolic and catabolic states?

A

The anabolic state involves building and storing nutrients, while the catabolic state involves breaking down stored nutrients to maintain glucose levels.

375
Q

How is glucose utilization different for neurons compared to other cells during the catabolic state?

A

Neurons rely entirely on glucose for ATP, while other cells can use fatty acids for energy, preserving glucose for neurons.

376
Q

Which of the following is not one of the six major processes of the digestive system?

A) Ingestion
B) Propulsion
C) Filtration
D) Digestion

A

C) Filtration

377
Q

What is the primary function of the digestive process known as absorption?

A) Breaking down food into smaller molecules
B) Transporting nutrients into the bloodstream
C) Ingesting food into the mouth
D) Eliminating waste products

A

B) Transporting nutrients into the bloodstream

378
Q

Which organ is responsible for the majority of nutrient absorption in the digestive system?

A) Stomach
B) Liver
C) Small intestine
D) Large intestine

A

C) Small intestine

379
Q

Which organ produces bile that aids in the digestion of fats?

A) Pancreas
B) Gallbladder
C) Liver
D) Small intestine

A

C) Liver

380
Q

What is the primary role of the gallbladder in digestion?

A) Produces digestive enzymes
B) Stores and concentrates bile
C) Absorbs nutrients
D) Filters blood

A

B) Stores and concentrates bile

381
Q

Which enzyme is produced by the pancreas to break down carbohydrates?

A) Pancreatic protease
B) Pancreatic amylase
C) Pancreatic lipase
D) Pancreatic nuclease

A

B) Pancreatic amylase

382
Q

What is the function of pancreatic lipase?

A) Breaks down carbohydrates
B) Breaks down proteins
C) Breaks down fats
D) Breaks down nucleic acids

A

C) Breaks down fats

383
Q

During the absorptive (anabolic) state, excess glucose is converted into which substance for storage?

A) Protein
B) Triglycerides
C) Amino acids
D) Urea

A

B) Triglycerides

384
Q

In the post-absorptive (catabolic) state, what process releases glucose into the bloodstream from glycogen stores?

A) Glycogenesis
B) Glycogenolysis
C) Gluconeogenesis
D) Lipolysis

A

B) Glycogenolysis

384
Q

Which metabolic process is responsible for the production of new glucose from non-carbohydrate sources during the post-absorptive state?

A) Glycogenesis
B) Gluconeogenesis
C) Glycogenolysis
D) Lipolysis

A

B) Gluconeogenesis

385
Q

Which hormone primarily regulates blood glucose levels during the post-absorptive state?

A) Insulin
B) Glucagon
C) Adrenaline
D) Cortisol

A

B) Glucagon

386
Q

What is the role of insulin in the absorptive state?

A) Stimulates glycogenolysis
B) Promotes the uptake of glucose and amino acids into cells
C) Stimulates gluconeogenesis
D) Inhibits the release of glucose from the liver

A

B) Promotes the uptake of glucose and amino acids into cells

387
Q

Which of the following is NOT a function of the liver?

A) Producing bile
B) Synthesizing plasma proteins
C) Storing glycogen
D) Digesting proteins

A

D) Digesting proteins

388
Q

What is the primary function of the large intestine in the digestive system?

A) Nutrient absorption
B) Digestion of fats
C) Water absorption and formation of feces
D) Protein synthesis

A

C) Water absorption and formation of feces

389
Q

How does the pancreas contribute to neutralizing stomach acid?

A) By producing bile
B) By secreting pancreatic juice with bicarbonate ions
C) By releasing insulin
D) By breaking down proteins

A

B) By secreting pancreatic juice with bicarbonate ions

390
Q

Which digestive organ stores and concentrates bile before it is released into the duodenum?

A) Liver
B) Small intestine
C) Gallbladder
D) Pancreas

A

C) Gallbladder

391
Q

What is the role of glucose sparing during the post-absorptive state?

A) Allows neurons to use glucose while other cells use fatty acids
B) Converts fatty acids into glucose
C) Stores excess glucose as triglycerides
D) Increases the production of ATP in neurons

A

A) Allows neurons to use glucose while other cells use fatty acids

392
Q

What is the primary source of energy for body cells other than neurons during the post-absorptive state?

A) Amino acids
B) Triglycerides
C) Glucose
D) Urea

A

B) Triglycerides

393
Q

During the absorptive state, what happens to amino acids that are not used for protein synthesis or ATP production?

A) They are excreted in urine
B) They are converted into glucose
C) They are converted into triglycerides and stored
D) They are used to produce bile

A

C) They are converted into triglycerides and stored