Digestive System Flashcards
1
Q
What structure control the most
A
Ileocecal valve
2
Q
Where is the most of your food digested
A
Small intestine
3
Q
Which of these is found in saliva
A
Lysozyme
4
Q
W/c of these an example of mechanical digestion
A
Chewing
5
Q
Which of these organs is an accessory organs of the digestive system
A
Gallbladder
6
Q
Function of saliva
A
Inhibit bacterial growth in the oral cavity
7
Q
Which of these is secreted by by the pancreas
a. CCK
b. Trypsin
c. Brush Border enzyme
d. Pepsin
A
Trypsin
8
Q
Which of these stimulates the contraction of gallbladder
a. Histamine
b. Gastrin
c. Secretin
d. CCK
A
Cholecystokinin
9
Q
What part of the brain maintains body temperature
A
Hypothalamus
10
Q
What hormones responsible for determining the basal metabolic rate
A
Thyroxine
11
Q
The alimentary canal also called:
A
GI tract
12
Q
Primary function of Digestive functions:
A
🔅Ingestion
🔅propulsion (peristalsis)
🔅mechanical digestion (food breakdown thru chewing)
🔅chemical digestion ( food breakdown thru digestion)
↪️ starts in mouth to intestine
🔅secretion and absorption (large intestine)
🔅compaction and defecation
13
Q
Digestive system composed of:
A
- Digestive tract
2. Accessory organs
14
Q
It is a muscular tube lined w mucous membrane
▪️mouth ➡️pharynx ➡️ esophagus ➡️ stomach ➡️ small intestine ➡️ large intestine ➡️ rectus / anus
A
Alimentary Canal (or GI tract or Gut)
15
Q
▪️ secretes products into digestive tract
▪️ consists of liver, gallbladder, pancreas and salivary glands
A
Accessory Organs
16
Q
▪️ provides access route for blood vessels, nerves, and lymphatics
▪️ stabilizes attached organs
▪️ prevents entanglement of intestines
A
mesentery in abdominopelvic cavity
17
Q
Increase surface area for absorbing nutrients
A
Permanent ridges and temporary folds
18
Q
Layers o the digestive tract:
A
- Mucosa
- Submucosa
- Muscularis externa
- Serosa
19
Q
- innermost lining
- mucous membrane moistened by glandular secretions
- simple columnar epithelium
- contain enteroendocrine cells w/c secrete gastrin
A
Mucosa
20
Q
- has large blood vessels and lymphatic vessels
- contains exocrine glands secreting buffers and enzymes into lumen
A
Submucosa
21
Q
Smooth muscle cells in two layers (inner circular layer and outer longitudinal layer) for movement along tract
A
Muscularis externa
22
Q
▪️layer of visceral peritoneum found along digestive tract in peritoneal cavity (not in oral cavity, pharynx, esophagus, and rectum) to adjacent structures
A
Serosa
23
Q
- It’s involved in local control of digestive activities
- contains sensory neutrons, parasympathetic and sympathetic fibres
🔘parasympathetic stimulation increases digestive muscle tone and activity
🔘sympathetic stimulation relaxes muscle and inhibits activity
A
Nerve Plexuses
24
Q
Two important nerve plexuses serve the alimentary canal
A
- Submucosal nerve plexus
- Myenteric nerve plexus
25
Food enters digestive tract as:
Bolus (moist, compact mass of material)
26
Bolus propelled along tract by:
Muscularis externa
27
Process of sequential contraction moving materials along tract called:
Peristalsis
28
▪️series of contractions to mix, churn, and fragment bolus.
▪️mixes materials w intestinal secretions
▪️occurs in small intestine and part of large intestine
Segmentation
29
Moistening, mixing food w saliva
Oral cavity, teeth, tongue: mechanical processing
30
Muscular propulsion of food into esophagus
Pharynx
31
Transports swallowed food to stomach
Esophagus
32
Chemical and mechanical processing
Stomach
33
enzymatic digestion and absorption
small intestine
34
dehydration and compaction of indigestible materials
Large intestine
35
🔹Contains tongue, saliva from salivary glands, teeth
🔹mastication (chewing)
🔹chemical digestion of carbohydrates and lipids begins here
Oral cavity
36
Process of teeth crushing and shredding food called:
mastication (chewing)
37
🔹protect the anterior opening (1)
🔹 form the lateral walls (2)
🔹 forms the anterior roof (3)
🔹forms the posterior roof (4)
1. Lips (labia)
2. Cheeks
3. Hard palate
4. Soft palate
38
🔹 fleshly projection of the soft palate
🔹 area contained by the teeth
🔹 attached to hyoid bone and by the lingual frenulum to the floor of the mouth
🔹palatine and lingual
1. Uvula
2. Oral cavity
3. Tongue
4. Tonsils
39
What is the purpose of the uvula?
▪️key role in the articulation of the sounds of speech
| ▪️smaller role in snoring and sleep apnea
40
mouth physiology 👄👅
🔹mastication (chewing) of food
🔹mixing masticated food w saliva
🔹initiation of swallowing by the tongue
🔹 allows for the sense of taste
41
Five elements of taste perception:
1. Salty
2. Sour
3. Bitter
4. Sweet
5. Umami (or savory)
42
Food is propelled in esophagus by the two muscle layers:
1. Longitudinal inner layer
| 2. Circular outer layer
43
🔹hollow, muscular tube 25cm long and 2cm wide
- descends posterior to trachea
🔹transports food and liquid from pharynx to stomach
Esophagus
44
Swallowing also called:
Deglutition
45
Same layers as rest of digestive tract:
Mucosa, submucosa, muscularis externa
46
Enters abdominopelvic cavity through opening in diaphragm called:
Esophageal hiatus
47
Two sphincters are positioned at the top and bottom of the esophagus- prevents:
Reflux or regurgitation of food
48
▪️Located on the left side of the abdominal cavity
| ▪️muscular, expandable, J-shaped tube ➡️ can hold 1-1.5L when full
Stomach
49
Food empties into the small intestine at the :
Pyloric sphincter (valve)
50
Stomach regions
🔹 Fundus
🔹 Cardiac
🔹 Body
🔹 Pylorus
51
- Prominent mucosal folds
- allows gastric expansion with filling
- flatten out with stomach expansion
Rugae
52
attaches the liver to the lesser curvature of the stomach
Lesser Omentum
53
attaches the greater curvature of the stomach and many other digestive organs to the posterior body wall
▫️contains fat to insulate, cushion, and protect abdominal organs
▫️ has lymph nodules containing macrophages
Greater omentum
54
Three layers of smooth muscle of the stomach
1. Circular layer
2. Longitudinal layer
3. Oblique layer
55
🔹 strengthens stomach wall
| 🔹 assists in churning needed to form chyme
Oblique layer
56
Alimentary canal also called:
Gastrointestinal (GI) tract or gut, is continuous, coiled
57
Stomach Functions:
1. Temporary storage tank and site for food breakdown
2. Secretion of gastrin
3. Regulates the rate of chyme into the small intestine
4. Digestion of food
5. Absorption of small quantities of H2O, and some dissolved substances (alcohol, aspirin)
58
Produce gastrin?
Enteroendocrine cells
59
Parietal cells secretes:
- Intrinsic factor
- hydrochloric acid
Chief cells secrete:
- pepsinogen
- rennin and gastric lipase in newborn (for milk digestion)
60
- Secrete most of acid and enzymes involved in gastric digestion
- dominated by parietal and chief cells
- secretes about 1500mL gastric juice daily
Gastric glands in fundus and body
61
Secrete mucus and hormones that coordinate and control Digestive activity:
Gastric glands in pylorus
62
▫️reverse peristalsis in the stomach
Vomiting
63
Vomiting centre of the brain
Medulla
64
▫️The body's major digestive organ, 2.5 - 7m long or 8-20" extending from the pyloric sphincter to the ileocecal valve
▫️major site of nutrient absorption into the blood
Small intestine
65
Three regions of small intestine:
1. Duodenum
2. Jejune my
3. Ileum
66
▫️The most important section of the small intestine
▫️shortest, 5% of length
▫️receives the chyme from stomach and secretion from the liver, gall bladder, and pancreas.
Duodenum
67
▫️most chemical digestion(enzyme) and nutrient absorption
| ▫️35% of the length
Jejunum
68
▫️extends from the jejunum to large intestine- ends at the ileocecal valve
▫️all that is left of the chyme by the time it reaches the ileum is water, cellulose (insoluble fibre-unable to digest) and bacteria
▫️60% of total length ➡️ 12"
Ileum
69
Enzyme produced by saliva
Salivary Amylase
70
Enzymes produced by intestinal cells (helps w breaking down)
Brush porter (BB)
71
Enzymes produced by pancreas
For fats and polysaccharide
72
Carries enzymes to the small intestine
Pancreatic duct
73
____formed by the liver, enters the duodenum through the bile duct ➡️ stored in gallbladder between eatings
▫️aids in digestion and absorption
▫️contains bicarbonate to neutralize acidic chyme
Bile
74
Three structural modifications that increase the surface area:
1. Microvilli
2. Villi
3. Circular Folds
75
Tiny projections of the plasma membrane (create a brush border appearance)
Microvilli
76
Fingerlike structures formed by the mucosa (increase surface area 600x)
Villi
77
▫️deep folds of mucosa and submucosa (mostly in jejunum)
Circular folds
78
▫️simple columnar epithelium on surface of villi carpeted w microvilli
▫️ secretes brush border enzymes
Brush Border
79
____ enzyme breakdown disaccharide into monosaccharides
Brush Border Enzyme
80
No blood flatlobules floating in the capillaries/blood stream
↪️dump in lacteals / lymphatic fluid
...
81
```
Produced very large amount of enzymes.
Other enzymes:
1. Pancreatic amylase
2. Pancreatic lipase
3. Proteases
```
Pancreas
82
_____ helps break fat lobules to little bits and get absorb in the lacteals.
Take flat lobules and emulsifies them
Bile Salts
83
______ _______ enter the duodenum with the bile at the same time at the hepatopancreatic ampulla
Pancreatic Juices
84
Major function of Large intestine:
1. Absorption of vits. and lots of water
2. Reabsorption of water from intestinal contents
3. Compaction of indigestible intestinal contents into feces
4. Storage of feces prior to defecation
85
Remaining bolus will sit in the large intestine for ____ to ____ hrs. Before it is expelled so it can become a semi-solid mass.
◻️12 to 24 hrs
86
The bacteria of Large intestine (take up about 30% of the content) termed called____
Normal Flora
87
The LI normal flora releases gases ___ and ____ (odorous) about 500mL/day
▫️methane
▫️hydrogen sulfide
These gas is called FLATUS
increase production with more CHO and beans
88
Three regions of Large Intestine:
1. Cecum
2. Colon
3. Rectum / Anus
89
In animal, Appendix -allows them to breakdown plant cellulose
In human, appendix is attached to cecum and it does nothing
90
It collects and stores material (LI) -begin process of compaction
Cecum
91
▫️It forms the last 15cm of digestive tract
▫️expandable for temporary storage of feces
▫️stretching triggers defecation reflex
Rectum
92
▫️ powerful peristalsis contractions -occur few times daily in response to distension of stomach and duodenum
▫️ begins at transverse colon and push feces along distal portion of Large intestine
Mass Movements
93
Tends to lose mass movement
Peristalsis
94
Opening of the large intestine. It has two sphincters which are normally closed except during defecation.
Anus
95
The two Anal Sphincters are:
1. External Anal Sphincter - formed by skeletal muscle and under voluntary control
2. Internal Involuntary Sphincter - formed by smooth muscle
96
Important vitamins produced by bacteria in colon:
1. Vitamin K
2. Vitamin B5
3. Vitamin B7 (biotin)
97
Feces is composed of:
```
▫️75% water
▫️5% bacteria
▫️mixture of indigestible materials
▫️inorganic matter
▫️remains of epithelial cells (lining of large intestines, mostly water, cellulose)
```
98
Forces feces into rectum
▫️distension triggers defecation reflex
▫️defecation when external Sphincter is voluntarily relaxed
Peristalsis
99
Accessory digestive Organs:
1. Teeth
2. Salivary Glands
3. Pancreas
4. Liver
5. Gallbladder
100
Humans has two sets of teeth:
1. Deciduous (baby or milk) teeth
▫️20 teeth are fully formed by age two
2. Permanent teeth
▫️ replace deciduous teeth around ages 6-12
▫️ a full set of 32 teeth. Third molars appear between ages 17 and 25
101
Classification of teeth
▫️ incisors - chisel shaped for cutting
▫️ fang-like for tearing or piercing
▫️ premolars - grinding
▫️ Molars - grinding
102
____ exposed part above the gingiva or gum
Crown
103
It covers the crown of tooth
Enamel
104
It forms the bulk of the tooth surrounding pulp cavity.
| Sensitivity in teeth
Dentin
105
It contains connective tissue, blood vessels, and nerve fibres
Pulp cavity
106
______ where the pulp cavity extends into the root
Root Canal
107
It is a region in contact with the gum. Connects crown to root
Neck
108
Cement-covers outer surface and attaches the tooth to periodontal membrane
Root
109
Salivary Glands contain enzyme and microbial
| Three pairs empty secretion into mouth:
1. Parotid
2. Submandibular
3. Sublingual
110
It is a mixture of mucus and serous fluids. Produced by salivary glands - 1L/day
It helps to form food bolus
Saliva
111
Saliva contains:
1. Salivary amylase (is an alkaline juice that begins the process of starch digestion)
2. lysozymes
3. Antibodies (inhibit bacteria)
112
The watery fluid of the saliva acts to _______ chemicals so they can be tasted (I.e. salty, sweet)
Dissolves
113
________It acts as chemoreceptors by dissolving saliva.
Tastebuds
114
The digestive enzymes and alkaline secretions form the
Pancreatic Juice -secretes 1,400mL/day (reabsorbed in LI)
115
The secretion of the digestive enzymes and bicarbonate is under control from the ____ and _____
1. Vagus nerve
| 2. Hormonal stimulation
116
The presence of chyme in the duodenum causes the release of the hormones _______ and ______ from the duodenum (both travels in blood)
▫️ CCK
| ▫️Secretin
117
Propelling mechanism:
Peristalsis
118
It is a hormone that stimulates release of pancreatic enzymes and the gallbladder to release stored fat
CCK
119
It is a hormone that stimulates bicarbonate secretion and causes the liver to secrete more bile.
Secretin
120
▫️Largest gland in body - Digestive function bile production
▫️connected to the gallbladder via the common hepatic duct
▫️highly vascularized organ
▫️receives a large flow of blood through the portal vein
Liver
121
Hepatic cells secrete a greenish yellowish substance called ____ which exist through hepatic bile ducts
Bile
122
Key role of the liver:
1. Produce bile
2. Does detoxification
3. All that goes to digestive system through liver, gets cleaned before it goes to vena cava
123
Normal pressure in portal system:
10mmHg (blood flows quite easily)
124
Digestive and metabolic functions of the liver?
Refer to pg 22 of the slide
125
____ the most abundant blood protein. It's purpose is to hold fluids in the bloodstream.
Albumin
* when blood albumin is too low, fluids move into the interstitial space ➡️edema
* water ff albumin;otherwise goes to interstitial space. Maintain blood vol
126
Cholesterol serves as building blocks of _____, ______, and _____
It is not used as ATP.
▫️hormone
▫️vit.D
▫️plasma membrane
127
A cholesterol is made by the ______. Only 15% should come from the diet.
A cholesterol damaging causes ARTEROSCHLEROSIS
Liver
128
Fats and cholesterol can't freely circulate in the blood- they circulate attached to ____
Lipoprotein
129
Two types of lipoproteins:
1. LDL (low density lipoprotein) - it adhere to blood vessels
2. HDL (high density lipoprotein) - it goes to liver to be detoxified and excreted.
130
Bile is formed by the _____ enters the _____through the ______ ➡️stored in ______ between meals
Livers➡️duodenum ➡️bile duct ➡️gallbladder
131
bile salts gets bound to ____
fats
132
Pancreatic juice enters the duodenum with the bile at the same time at the____
Hepatopancreatic ampulla
133
Only bile salts have a digestive function:
1. Emulsifies fats by breaking large fat globules into smaller ones
2. Allows for fat digestion and absorption of fat soluble vitamins
134
People with high cholesterol takes a ____drug
Statin ➡️ increase bile salt production and take cholesterol out of blood and excreted out into feces
135
Bilirubin comes from RBC; jaundice w/c is the accumulation of bilirubin in blood stream
We secrete 800 to 1000mL of bile per day
136
Hollow pear-shaped organ located in depression on posterior surface of liver.
▫️stores and concentrates bile bet meals
▫️stimulates by CCK to secrete bile - especially with consumption of fatty meal
Gallbladder
▪️the more fatty meals the more CCK release
137
Pancreatic enzymes works in a bicarbonate environment
You only mix the pancreatitis enzymes and bicarbonate until very close to small intestine
138
Peristalsis vs segmentation
Segmentation - take chyme and mix with bile together
139
Mechanical vs chemical digestion?
Mechanical - mixing food in mouth by tongue, churning food in stomach , segmentation in small intestine
Chemical- enzymes breakdown food molecules
▫️carb broken to simple sugar
▫️proteins broken to amino acids
▫️ fats broken to fatty acid
140
Two phases of swallowing:
1. Buccal phase (voluntary)
▪️occurs in mouth
▪️the bolus is forced into the pharynx by the tongue
2. Pharyngeal-esophageal phase
▪️involuntary transport of bolus by peristalsis
▪️nasal and respiratory passageways are blocked
▪️the cardioesophageal Sphincter is opened when food presses against it
▪️
141
Presence of food rising pH causes the release of hormone ______
Gastrin
- stimulates release of gastric juice
- stimulates stomach emptying
142
Gastrin causes stomach glands to produce:
▪️protein-digesting enzymes
▪️mucus
▪️hydrochloric acid (makes the stomach content very acidic)
▪️Acidic pH ( activates pepsinogen to pepsin for protein digestion)
143
Protein digestion enzymes:
▪️pepsin
▪️ Rennin
144
The most vigorous peristalsis and mixing action occur close to the ______
Pylorus
145
The ___________ of the stomach acts as a pump that delivers small amounts of chyme into the duodenum
Pyloric end
146
The peristaltic wave closes the pyloric valve, forcing most of the contents of the pylorus backward into the stomach
Retropulsion
147
The stomach empties in ____ to ____ hrs
4 to 6 hrs
148
Intestinal enzymes from the ____________ function to:
Brush Border
▪️ breakdown double sugars into simple sugars
▪️complete some protein digestion
149
_____ and _______ help to complete digestion of all food groups
▪️ intestinal enzymes
| ▪️ pancreatic enzymes
150
Release of pancreatic juice from the pancreas into the duodenum is stimulated by: (PNS)
▪️ Vagus Nerve
▪️ local hormones that travel via the blood to influence the release of pancreatic juice (and bile)
▫️secretin
▫️CCK
151
Acts as fat emulsifier.
| Needed for fat absorption and absorption of fat-soluble vitamins (ADEK)
BILE
152
Substances are transported to the liver by the ______
Hepatic portal vein or Lymph
153
End product digestion:
▪️ most substances are absorbed by _________ through cell membranes
▪️ lipids are absorbed by ______
▪️ active transport
▪️diffusion
154
Inhibits secretion of gastric juice and pancreatic juice
- innervated by nerve fibres
-source : stomach and duodenum
Opposite of Gastrin
Somatostatin
155
Feces contains :
▪️undigested food residues
▪️Mucus
▪️Bacteria
▪️Water
156
Haustral contractions are most seen in the ______
Large Intestine
157
Four main hormones help regulate digestive function:
1. Gastrin
2. Secretin
3. Cholecystokinin (CCK)
4. Gastric inhibitory peptide (GIP) - also stimulates insulin release from pancreas
158
Substance used by the body for growth, maintenance and repair:
▪️Nutrients
| (Carbohydrates, Lipids, protein)
159
What are Lipids?
▪️saturated fats (meats)
▪️unsaturated fats (nuts, seeds, and vegetable oils)
▪️cholesterol (egg yolk, meats, and milk products)
160
what is complete proteins?
it contain all essential amino acids (22 aa)
161
Sum of chemical reaction that occur in an organism
Metabolism
162
It is the breakdown of organic substances:
| i.e. Glycogen to glucose
Catabolism
163
It is a synthesis of new organic molecules
| i.e. Glucose converted into glycogen through insulin. It happens in liver and skeletal muscles (mostly)
Anabolism
164
Sum of all chemical reactions within cells
Cellular metabolism
165
Neurons and RBC use ______ as source of energy
Glucose
166
Average adult needs ________ calories each day
1500 - 3000 cal
167
Liver cells store _____ and ________ reserve for release when needed
▪️triglycerides
| ▪️glycogen
168
_______converts excess fatty acids to triglycerides for storage. Triglycerides can be converted back to fatty acids when needed.
Adipocytes
169
_____ are the body's preferred source to produce cellular energy (ATP)
Carbohydrates
170
Insulin can turn glucose to glycogen. Stores excess as glycogen.
....
171
ATP formation: all categories of food can be oxidized to provide energy molecules (ATP)
▪️ Monosaccharides
▪️ Fatty acids
▪️ amino acids
172
"Glycogen formation"
| Glucose molecules are converted glycogen and stored in the liver
Glycogenesis
173
"Glucose splitting" - breaking down glycogen
| - glucose is released from the liver into the blood after conversion from glycogen
Glycogenolysis
174
"Formation of new sugar"
| - glucose is produced from fats and protein (converts into glucose)
Gluconeogenesis
| ↪️happens thru starvation
175
Functions of cholesterol
- serves as structural basis of (1)________ and (2)_______
- is a major building block of (3)____________
1. Steroid hormones
2. Vitamin D
3. Plasma membranes
176
Cholesterol and fatty acids cannot freely circulate in the bloodstream. They are transported by______
Lipoprotein (lipid-protein complexes)
177
Mechanisms that may regulate food intake:
▫️levels of nutrients in the blood
▫️hormones
▫️body temperature
▫️psychological factors
178
Interference with the body's energy balance leads to:
▪️obesity
| ▪️malnutrition
179
It is the minimum resting energy expenditure of an awake, alert person.
Basal Metabolic Rate (BMR)
- average individual 70cal/hour
- varies depending on Thyroid hormone and muscle mass
180
It is the Total expenditure of a person performing regular ADL's
________ = BMR + energy expended on activities
Total Metabolic rate (TMR)
181
Activities that generate ATP also generate heat....
40% of energy generates ATP; 60% is heat
182
Body transfers heat by:
1. Radiation
2. Evaporation
3. Convection
4. Conduction
183
Heat promoting mechanism:
1. Vasoconstriction of blood vessels
| 2. Shivering- contraction of muscles produces heat
184
Heat Loss Mechanism:
1. Skin via radiation and evaporation
- increased skin blood flow
- evaporation of sweat cools skin
2. Increased respiration
185
When blood sugar levels are low, the liver can make sugar from amino acids and fats. What is this process called?
a. Glycogenesis
b. Glycolysis
c. Gluconeogenesis
d. Glycogenolysis
Gluconeogenesis
186
The specialized cells that produce mucus to lubricate the large intestine are called:
goblet
187
Chief cells of the gastric glands secrete___
pepsinogen
188
Gastrin, seceted by the gastric and duodenal mucosa, acts to __
Increase the secretions of the gastric glands
189
Pepsin initiates the chemical digestion of _____
Proteins
190
What organ produces enzymes capable of digesting all of the major categories of organic compounds?
Pancreas
191
Intrinsic factor is secreted by which cells of the gastric glands?
Parietal Cells
192
Where would the least of bacteria be found?
Stomach
193
What initiates the swallowing reflex?
Sensory receptors detecting the bolus in the pharynx
194
____________ duct carries saliva from the parotid gland into the oral cavity next to the second upper molar.
Stensen's duct
195
The parietal cells produce gastric intrinsic factor which is needed to absorb the vit _____ necessary for blood cell development
Vitamin B12
