The Digestive System And Metabolism 14 Flashcards
(237 cards)
1
Q
Ingestion
A
Taking in food
2
Q
Digestion
A
Breaking food into nutrient molecules
3
Q
Absorption
A
Movement of nutrients into bloodstream
4
Q
Defecation
A
Getting rid of indigestible waste
5
Q
Groups of digestive organs
A
1.Alimentary canal
2. Accessory digestive organs
6
Q
Alimentary canal GI tract
A
Continuous hollow tube that helps ingest, digest, absorb, defecate (mouth to anus )
7
Q
Accessory digestive organs
A
Assist in digestion in various ways
Teeth, tongue and other big digestive organs (liver pancreas, gallbladder)
8
Q
Organs of alimentary canal
A
Mouth
Pharynx
Esophagus
Stomach
Small intestine
Large intestine
Anus
9
Q
Mouth (oral cavity) lined with
A
Mucous membrane lined cavity
10
Q
Lips (labia)
A
Protect anterior opening
11
Q
Cheeks
A
Form the lateral walls
12
Q
Hard palate
A
Forms anterior roof
13
Q
Soft palate
A
Forms posterior roof
14
Q
Uvula
A
Fleshy projection of soft palate
15
Q
Vestibule
A
Space between lips externally and teeth and gums internally
16
Q
Oral cavity proper
A
Area contained by teeth
17
Q
Tongue attached by
A
Attached at hyoid bone and styloid processes of skull
Attached by lingual frenulum to floor of mouth
18
Q
Palatine tonsils
A
@ posterior end of oral cavity
19
Q
Lingual tonsil
A
At base of tongue
20
Q
Gingivae
A
Gums
21
Q
Functions of mouth
A
1.Mastication
2. Mixes chewed food with saliva
3.tongue initiates swallowing
4. Tastebuds on tongue allow for taste
22
Q
Pharynx function in eating
A
Passage for food, fluid, air
23
Q
Food passes to from the mouth posteriorly to the
A
Oropharynx
Laryngopharynx
24
Q
Location of Laryngopharynx
A
Under oropharynx
Continuous with esophagus
25
Food is propelled to esophagus by two layers of skeletal muscle in pharynx
Longitudinal outer layer
Circular inner layer
26
What propels food?
Peristalsis
Alternating contractions of muscle layers
27
Anatomy of esophagus
10 inches long
Runs from pharynx to stomach through diaphragm
28
Physiology of esophagus
1. Uses peristalsis to take food to stomach
2.passageway for food only. (Resp system branches off after pharynx(
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Layers of tissue that make alimentary canal organs (innermost to outermost)
1. Mucosa
2. Submucousa
3. Muscularis externa
4.serosa
30
Lines cavity aka lumen
Innermost, moist membrane
Mucosa
31
Mucosa made of
1.Surface epithelium that's mostly simple columnar
Esophagus made of stratified squamous
2. Small amount of connective tissue (lamina propria)
3. Scanty smooth muscle layer
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Submucousa
1. Under mucosa
2. Soft, connective tissue w/ blood vessels, nerve endings, mucosa Associated Lymphoid tissues, lymphatic vessels
33
Muscularis externa
Smooth muscle
Inner circular layer, outer longitudinal layer
34
Serosa
Outermost layer of wall; contains fluid producing cells
35
Visceral peritoneum of serosa
Innermost layer continuous with outermost layer
36
Parietal peritoneum of serosa
Outermost layer that lines the abdominopelvic cavity by way of the mesentery
37
Alimentary Wall canals have 2 intrinsic nerve plexuses
Submucosal nerve plexus
My enteric nerve plexus
38
Function of alimentary canal nerve plexuses
Regulate mobility and secretory activity of GI tract organs
39
Submucosal nerve plexus
Controls glandular secretions
Electrolyte and water transport
Blood flow
40
Myenteric nerve plexus
Peristaltic movement of bowels
41
C-shaped organ on left side of abdominal cavity
Stomach
42
Food enters the stomach from
Cardioesophageal sphincter from the esophagus
43
Food from stomach empties into the small intestine from
Pyloric sphincter (valve)
44
Regions of the stomach
1. Cardial
2.Fundus
3.Body
4.Pylorus
45
Cardia (cardial)
Near heart
Surrounds the cardioesophageal sphincter
46
Fundus
Expanded portion lateral to cardiac region
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Body
Mid portion
48
Greater curvature of stomach Body
Convex lateral surface
49
Lesser curvature of stomach Body
Concave medial surface
50
Pylorus
Funnel shaped terminal end of stomach
Empties into duodenum
51
Stomach can stretch and hold what capacity of food when full?
4L (1 gal)
52
Rugae
Internal folds of mucosa present when stomach is empty
53
Lesser omentum
Double layer of peritoneum
Extends from liver to lesser curvature of stomach
54
Greater omentum
1.Another extension of peritoneum
2.Covers abdominal organs
3.Fat insulates, cushions and protects abdominal organs
55
What kind of cells make stomach mucosa
Simple columnar epithelium made of mucous cells
56
Describe mucus produced by mucous cells?
Bicarbonate-rich alkaline mucous
57
The stomach mucosa is dotted by
Gastric pits leading to gastric glands that secrete gastric juices
58
Intrinsic factor
Needed for vitamin B-12 absorbtion for small intestine
59
What secretes intrinsic factor?
Gastric pits
60
Chief cells
Make protein digesting enzymes
Secrete pepsinogen
61
Pepsinogens
Protein digesting enzymes
62
Parietal cells
Make HCL acid that activates enzymes
63
Mucous neck cells
Make thin acidic mucus (different from mucus made by mucous cells of the mucosa)
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Enteroendocrine cells
Produce local hormones such as gastrin
65
Pepsinogen is known as inactive form, becomes active when
Comes in contact with HCL made by parietal cells
66
Pepsin is active form of
Pepsinogen
67
Functions of stomach
1.Temporary storage tank for food
2. Site of food breakdown
3. Chemical breakdown of protein begins
4. Delivers chyme to small intestine
68
Chyme
Processed food
69
Body's major digestive organ
Small instestine
70
Longest portion of alimentary tube + length
Small instestine
2-4m, or 7-13 ft in living person
71
Small intestine function
Site of nutrient absorption in the blood
72
Small intestine extends from
Pyloric sphincter to ileocecal valve
73
Small instestine is suspended from
Posterior abdominal wall by the mesentery
74
Subdivisions of small intestine
Duodenum
Jejunum
Ileum
75
Chemical digestion begins in the
Small intestine
76
Steps of chemical digestion
1. Enzymes from intestinal cells and pancreas carried to duodenum by pancreatic ducts
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Bile, formed by liver enters the ______ via the ____ _______
Duodenum
Bile duct
78
Location where main pancreatic duct and bile ducts join
Hepatopancreatic ampulla
79
Purpose of structural modifications in small intestine
Increase surface area for food absorption
Decrease in number towards end of small intestine
80
Vili
Fingerlike projections formed by the mucosa
81
House a capillary bed and lacteal
Villi
82
Microvilli
Tiny projections of the plasma membrane
(Brush border enzymes)
83
Circular folds
Plicae circulares
Deep folds of mucosa and submucosa
84
Peyer's patches
Collections of lymphatic tissues in small intestine
85
In which layer are peyer's patches located?
Submucousa
86
Increase in number towards end of the small intestine (more in ileum)
Peyer's patches
87
Why do we need more peyer's patches towards the end of the small intestine?
Remaining food residue contains much bacteria
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Lacteal
Lymphatic vessel that carries fat from intestines
89
Why is the large intestine called the large intestine?
Larger in diameter, but it's shorter in length at 1.5 m
90
Large intestine extends from
Ileocecal valve to the anus
91
Subdivisions of large intestine
Cecum
Appendix
Colon
Rectum
Anal canal
92
Saclike first part of large intestine?
Cecum
93
Hangs from cecum
Appendix
94
Appendix
Accumulation of lymphoid tissue that sometimes becomes inflamed
95
Appendicitis
Inflamed Lymphoid tissu e
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Ascending colon
Travels up right side of abdomen and makes turn at right colic (hepatic) flexure
97
Transverse colon
Across abdominal cavity turns at left colic (splenic) flexure
98
Descending colon
Travels down left side
99
Sigmoid colon
S shaped region
Enters pelvis
100
What parts of large intestine are in the pelvis?
Sigmoid colon
Rectum
Anal canal
101
Anal canal ends at the
Anus
102
Anus
Opening of large intestine
103
External anal sphincter
Formed by skeletal muscle, voluntary
104
Internal anal sphincter
Formed by smooth muscle and is involuntary
105
Anal sphincters are normally closed except during
Defecation
106
Large instestine delivers indigestible food residues to the body's
Exterior
107
Produce alkaline mucus to lubricate passage of feces
Goblet cells
108
Muscularis externa is reduced to 3 bands of muscle known as
Teniae coli
109
What do the teniae coli do?
Cause wall to pucker into haustra (pocket-like sacs)
110
Accessory digestive organs
Teeth
Salivary glands
Pancreas
Liver
Gallbladder
111
Deciduous teeth
Baby teeth
112
A baby has __ teeth by age 2
20
113
First teeth to appear are the
Lower central incisors
114
Permanent teeth replace deciduous teeth between ages
6-12
115
A full set is ____ teeth (with the wisdom teeth)
32
116
Incisors
Cutting
117
Canines (eye teeth)
Tearing or piercing
118
Premolars (bicuspids)
Grinding
119
Molars
Grinding
120
Two major regions of a tooth
Crown and root
121
Crown
Exposed part of tooth above gingiva (gum)
122
Enamel
Covers the crown
123
Dentin
Deep to enamel, makes bulk of tooth, surrounds pulp cavity
124
Pulp cavity
Contains connective tissue, blood vessels and nerve fibers (pulp)
125
Root canal
Where pulp cavity extends into the root
126
Hardest part of teeth and within body
Enamel
127
Root-cement
Covers outer surface
Attaches tooth to periodontal membrane (ligament)
128
Root- Periodontal membrane
holds tooth in place in the bony jaw
129
Connector between crown and root
Neck
130
Region in contact with gum
Neck
131
Three pairs of salivary glands that empty secretions into mouth
1. Parotid glands
2. Submandibular glands
3. Sublingual glands
132
Parotid glands
Found anterior to ears
Mumps affect these salivary glands
133
Empty saliva into the floor of the mouth through small ducts
Submandibular and sublingual glands
134
Largest salivary glands
Parotid glands
135
Mixture of mucus and serous fluid
Saliva
136
Saliva function
Helps moisten and bind food together into a mass called bolus
Dissolves chemicals so they can be tasted
137
Salivary amylase
Begins starch digestion
138
Lysozymes and antibodies in saliva
Inhibit bacteria
139
Bolus
Mass of bound, chewed food
140
Soft, pink, triangular gland
Pancreas
141
Location of pancreas
Behind parietal peritoneum, mostly retroperitoneal
142
Pancreas extends from
across abdomen from spleen to duodenum
143
Produces a wide spectrum of digestive enzymes that break down all categories of food
Pancreas
144
Pancreas Secretes enzymes into
Duodenum
145
Alkaline fluid introduced with pancreas enzymes does what?
Neutralizes acidic chyme coming from stomach
146
Hormones produced by pancreas
Insulin
Glucagon
147
Largest gland in the body
Liver
148
Liver location
Right side of body under diaphragm
149
Liver parts
4 lobes suspended from diaphragm and abdominal wall by falciform ligament
150
Digestive role of liver
Produce bile
151
Bile leaves liver through the
Common hepatic duct an then it enters duodenum through the bile duct
152
Bile
Yellow-green watery solution
153
Bile contains
1.Bile salts and bile pigments (mostly bilirubin from the breakdown of hemoglobin
2. Cholesterol, phospholipids and electrolytes
154
What does bile do?
Break down fats
(Emulsifies)
155
Gallbladder location and appearance
Green sac
In shallow fossa on bottom of liver
156
When no digestion happens what happens in gallbladder?
Bile backs up in cystic duct for storage in gallbladder
157
While in the gallbladder, bile is concentrated by the
Removal of water
158
When fatty food enters the duodenum, what does the gallbladder do?
Spurts out stored bile
159
GI processes and controls are responsible for
Digestion and absorption
160
Propulsion
Moving food from one region of the digestive system to another
161
Alternating waves of contraction and relaxation that squeeze food along the GI tract
Peristalsis
162
Segmentation
Movement of materials back and forth to foster mixing in small intestine
163
Examples of mechanical breakdown
Mixing food by the tongue
Churning food by the stomach
Segmentation in the small intestine
164
Why is mechanical digestion important?
Prepares food for further degradation by enzymes
165
When does digestion occur
When enzymes chemically break down large molecules into their building blocks
166
Each major food group is broken down by ________ enzymes
Different
167
Carbohydrates are broken down to ____
Proteins are broken down to ___
Fats are broken down to ____&_____
Carbohydrates broken down to monosaccharides
Proteins broken down to amino acids
Fats broken down to fatty acids and glycerol
168
Amylase
Breaks down carbs
169
Breaks down proteins
Peptidase or prolease
170
Lipases
Break down fats
171
Carbohydrate digestion starts in _____ with which enzyme ?
The mouth
Salivary amylase
172
Protein digestion begins in the ____ with which enzyme?
Stomach
With pepsin
173
Lipids are emulsified by detergent action of
Bile salts from liver
Pancreatic lipase
174
Absorption
End products of digestion are absorbed in blood or lymph
Food must enter mucosal cells and then move into blood or lymph capillaries
175
No food absorption occurs in the
Mouth
176
Explain food ingestion and breakdown
1. Food goes in mouth, chewed
2. Mixed w/ saliva caused by mechanical pressure and psychic stimuli
3. Salivary amylase starts starch digestion
177
Food propulsion
Swallowing and peristalsis
178
Pharynx and esophagus have no
Digestive function
179
Pharynx and esophagus serve as
Passageways to stomach
180
Deglutition
Swallowing
181
Pharynx functions in
Swallowing
182
Two phases of swallowing
Buccal phase
Pharygeal-esophageal phase
183
Buccal phase
Voluntary
Occurs in mouth
Food made into bolus
Bolus forced into pharynx by tongue
184
Pharyngeal esophageal phase
1.Involuntary transport of bolus through peristalsis
2. Nasal and respiratory passages are blocked
3. Bolus moved to stomach
4. Cardioesophageal sphincter opens when food is pressed against it
185
Gastric juice is regulated by
Neural and hormonal factors
186
Presence of food or rising pH causes the release of
Gastrin
187
Gastrin causes stomach glands to produce
Protein-digesting enzymes
Mucus
Hydrochloric acid
188
Acidic pH function
1.Activates pepsinogen to pepsin for protein digestion
2. Hostile environment for microorganisms
189
Rennin
Digesting milk protein in infants; not produced in adults
190
Only items absorbed in stomach
Alcohol and aspirin
191
Waves of peristalsis occurred from the ______ to the _____ and force food through
fundus to pylorus
force food through pyloric sphincter
192
Grinding
Pylorus meters out chyme into the small intestine (3ml at a time)
193
Retropulsion
Peristaltic waves close the pyloric sphincter, forcing contents back into stomach; stomach empties in 4-6 hours
194
Chyme breakdown and absorption: Intestinal enzymes from the brush border function to
Break double sugars into simple sugars
Complete some protein digestion
195
Intestinal enzymes and pancreatic enzymes help to
Complete digestion of all food groups
196
Play a major role in the digestion of fats proteins and carbohydrates
Pancreatic enzymes
197
______ content neutralizes the acidic chyme and provides the proper environment for pancreatic enzymes to operate
Alkaline
198
Stimulates the release of pancreatic juice into the duodenum
Vagus nerve
Secretin
Cholescystokinin (CCK)
199
Hormones (secretin and cck) also Target the liver and gallbladder to release
Bile
200
Needed for absorption of fat soluble vitamins a d e k
Bile
201
Chyme
Bolus + gastric juices
202
Steps of regulation of pancreatic juice and bile
1. Chyme entering duodenum causes cells to secrete cholescystokinin and secretin
2. Cck and secretin enter bloodstream
3. When they reach pancreas, cck causes secretion of enzyme rich pancreatic juice. Secretin causes secretion of bicarbonate rich pancreatic juice
4. Causes liver to secrete more bile, cck stimulates the gallbladder to release stored bile .
Hepatopancreatic sphincter relaxesto allow bile to enter from both sources into duodenum
5. Stimulation by vagus nerve fibers causes release of pancreatic juice and weak contractions of gallbladder
203
Gastrin
Stimulates release of gastric juice
Stimulate stomach emptying
204
Intestinal gastrin
Stimulates gastric secretion and emptying
205
Histamine
activates parietal cells of stomach to secrete hydrochloric acid
206
Somatostatin
Inhibits secretion of gastric juice and pancreatic juice
Inhibits emptying of stomach and gallbladder
207
Secretin
Increases output of pancreatic juice rich in bicarbonate ions
Increases bile output by liver
Inhibits gastric mobility and gastric gland secretion
208
CCK cholecystokinin
Increases output of enzyme rich pancreatic juice
Stimulates gallbladder to expel stored bile
Releases sphincter of duodenal papilla to allow bile and pancreatic juice to enter the duodenum
209
Gastric inhibitory peptide
Inhibit secretion of gastric juice
Stimulates insulin release
210
Water is absorbed along the length of
Small intestine
211
End products of digestion absorbed by
Most substances absorbed through active transport
Lipids absorbed by diffusion
212
Substances are transported to the liver by
The hepatic portal vein
Lymph
213
Major means of moving food
Peristalsis
Chyme propulsion
214
Segmental movements function
Mix chyme with digestive juices
Aid in propelling food
215
No digestive enzymes are produced during
Nutrient breakdown and absorption
The resident bacteria digest the remaining nutrients
216
How do bacteria digest remaining nutrients
Produce vitamin K vitamin B and release gases
217
Water, vitamins, ions absorbed during
Nutrient breakdown and absorption
218
Feces contains
Undigested food residues
Mucus,
Bacteria,
Water
219
Propulsion of food residue and defecation
1. Sluggish peristalsis begins when food residue arrives
2. Haustral contractions are movements occuring most frequently in large intestine
3. Mass movements are slow powerful movements that occur 3 to 4 times a day
220
Haustral contractions
Most frequent movements in the large intestine
Slow powerful occur 3 to 4 times a day
221
Presence of feces and rectum causes a defecation reflex meaning
The anal sphincter is relaxed
Defecation occurs with the relaxation of the voluntary or external anal sphincter
222
Energy value of food is measured in
Kcal or Calories (C)
223
Chemical energy that drives cellular activities
Food oxidized into
Adenosine tri-phosphate
224
Nutrient
Substance used by the body for growth, maintenance and repair
225
Which are the major nutrients
Carbohydrates lipids proteins and water
226
Which are the minor nutrients
Vitamins and minerals
227
Diet consisting of _ food groups guarantees adequate amounts of all needed nutrients
5
228
Glycogenesis
Formation of glycogen by liver
229
Falciform ligament
thin, sickle-shaped, fibrous structure that connects the anterior part of the liver to the ventral wall of the abdomen
230
Haustra
saccules in the colon that give it its segmented appearance
231
Reverse peristalsis
Emesis
232
Serious inflammatory condition in which the colon mucosa protrudes through the colon wall is called
Diverticulitis
233
What carries excess cholesterol from body cells to liver
HDL
234
Gluconeogenesis
Making glucose from amino acids and fats
235
Hormone secreted by the duodenum inhibits secretion of gastric juices and stimulates the release of insulin
Gastric inhibitory peptide
236
Could be a contributor to pancreatitis
Chymotrypsin
237
Which Hormone is most responsible for the determining the basal metabolic rate
Thyroxine
