Digestions Notes Flashcards
1
Q
The body needs nutrients for?
A
- Growth
- Maintenance
- Repair
2
Q
Nutrients include:
A
- Carbohydrates
- Proteins
- Fats
- Vitamins
- Minerals
- Water
3
Q
Digestion is:
A
The process of breaking food down into nutrients
4
Q
Digestion can be
A
Mechanical or chemical
1. Mechanical- chewing
2. Chemical- stomach acid
5
Q
The primary organs of the digestive system are arrange along a tube called?
A
Alimentary canal
6
Q
What is the gastrointestinal tract composed of
A
Organs and structures which food passes
7
Q
Where does digestions start
A
The mouth
8
Q
Where does digestion end?
A
The anus
9
Q
Accessory glands ____ the process of digestion
A
Assist
10
Q
Accessory organs and glands
A
- Salivary glands- produce enzymes, soften food
- Teeth
- Tongue
- Pancreas- maintains blood sugar, produces insulin
- Liver- removes toxins
- Gallbladder- produces bile that breaks down fats
11
Q
Functions of the digestive system
A
- Ingestion
- Propulsion
- Mechanical digestion
- Chemical digestion
- Absorption
- Defication
12
Q
Ingestion is what kind of process
A
Voluntary
13
Q
Propulsion
A
The forceful movement of food from one organ to the next
14
Q
Peristalsis
A
Alternating waves of contraction and relaxation that push food along GI tract
15
Q
How many layers of muscle does the alimentary canal have
A
2
16
Q
Reduces the diameter of the alimentary canal
A
Circular layer
17
Q
Shortens the sections of the alimentary canal
A
Longitudinal muscles
18
Q
Examples of mechanical digestion
A
- Tongue mixes food
- Teeth tear food
- Churning of food in stomach
- Segmentation in small and large intestines to mix food
19
Q
When does chemical digestion occur
A
When large food molecules are broken down into their building blocks
20
Q
What breaks down food into their building blocks
A
Enzymes
21
Q
Enzymes are protiens that ______ chemical reactions
A
Speed up
22
Q
What is required for hydrolysis reactions
A
Water
23
Q
Absorption
A
When nutrients travel from the GI tract into the blood stream in the Small intestine
24
Q
What carries nutrients to cells throughout the body
A
Bloodstream
25
The elimination of solid waste from the body
Deification
26
Un digested/unabsorbed food, water, bacteria
Feces
27
Digestive activity
1. Mechanoreceptors detect stretching of organ wall
2. Chemoreceptors detect factors such as solute concentration, pH and the presence of substrates and end products
3. The brainstem coordinates responses that activate or inhabit glands and muscles of the digestive system
28
What detects factors such as solute concentration, pH, and the presence if substrates and end products
Chemoreceptors
29
What coordinates responses that activate or inhibit glands and muscles of the digestive system
Brainstem
30
How is mechanical digestion accomplished in the mouth
Teeth, tongue, and salivary glands
31
What do salivary glands produce to begin chemical digestion
Enzymes
32
Anatomy of the mouth
- oral cavity
- lined with mucus membrane
- lips protect anterior opening
- cheeks form lateral walls
- hard and soft palate form roof
- tongue occupies the floor of the mouth
- tonsils located at the back of the mouth
33
What is another name for chewing
Mastication
34
What is the ball of digested food called
Bolus
35
Chemical digestion in the mouth begins with
Saliva
36
What does the enzymes salivary amylase do
-Begins digestion of carbohydrates
-polysaccharides (starch and glycogen) are broken down into disaccharides
37
3 salivary glands
- parotid
-submandibular
-sublingual
38
Saliva contains
- water
- salivary amylase
-mucus
-antibacterial substances
39
Amylase
Break down carbs
40
Lipase
Break down lipids
41
Swallowing is also called
Deglutition
42
Swallowing starts as voluntary and then
Involuntary reflexes take over
43
Pharynx
- area behind the nose and mouth
- oropharynx and laryngopharynx common passageway for food, air, and liquids
44
Food plus passes through the pharynx to the
Esophagus, stomach, small intestine, large intestine
45
The esophagus extends to the
-stomach
-25cm long
-posterior to the trachea (why we can preform a tracheotomy)
- passes through the diaphragm
46
How does the esophagus conduct food
Through peristalsis
47
The stomach
- j shaped organ
- expands from the inferior end of the esophagus
- secretes enzymes that digest protiens
-muscle contractions contribute to mechanical digestion
48
Gross anatomy of stomach
- 25mc long
-food enters through cardioesophagial sphincter
-pyloric sphincter is located at the terminal end just before the duodenum
-upper left quadrant of abdominal cavity
49
Muscle layers of stomach
-oblique muscle, circular and longitudinal layers
- three layers allow for churning of food
50
Mucus membrane
- lines stomach
- secretes protective mucus
- gastric pits secrete gastric juice
51
Gastric juice
- enzymes such as pepsinogen (secreted by chief cells) break down proteins
-allows b12 to be absorbed
-hydrochloride acid activates pepsinogen and transforms it into intestine
-Hormones such as gastric are stimulated by food and low pH and trigger the secretion of gastric juice
52
Major functions of the stomach
-stores food
-initiates protein digestion
- prepares food into a thick semi liquid called chyme
-gradually releases chyme into the small intestine
53
The small intestine
-the body’s major digestive organ
- digestion of all nutrients is completed and almost all absorption occurs in the small intestine
- extends from the stomach to the large intestine
- longest part of GI track (3-4m long, 2.5 cm in diameter)
- 3 subdivisions (duodenum, jejunum, and ileum)
54
The broad fan shaped fold of tissue that anchors the small intestine to the posterior abdominal wall
Mesentery
55
What branches through the mesentery
Blood vessels, nerves, and lymphatic vessels
56
What muscle lines the esophagus
Smooth muscle
57
Structural modifications of small intestine increase
Surface area
58
Structural modifications of the SI
- plicae circulares are deep circular folds of the intestinal lining
-villi are finger like projections of the mucosa
-microvilli are tiny projections of the plasma membrane of epithelial cells
59
The first portion of the small intestine
The duodenum
60
What process occurs in the duodenum
Enzymes from the intestinal cells and pancreas, and bile from the liver complete the chemical breakdown of food
61
Intestinal juice
-secreted by glands at the base of the villi
- composed mostly of water and alkaline mucus
- neutralizes the acidic shame from the stomach
- intestinal glands secrete 1-2 liters of intestinal juice per-day
62
Brush boarder enzymes
-bound to the surface of the microvilli
-complete the final stages of carbohydrate and protien digestion
-microvilli creates a fuzzy appearance
63
The liver
- the largest internal organ
-primary function is to secrete bile
- bile is a basic solution that digests fats
64
Where is bile stored and released
-stored in the gallbladder
-rereleased to the duodenum through the bile duct
-controlled by the hormones CCK and secretin
65
Bile is not
And enzyme
66
emulsification
- the process of breaking down fat droplets into smaller pieces
-aids the digestion of fats by pancreatic lipase by increasing surface area
67
Pancreatic juice
- enters the duodenum through the pancreatic duct
- contains enzymes that break down all types of nutrients
-contains bicarbonate which maintains a basic pH of 8
68
Pancreatic enzymes
Proteases
- trypsin, chymotryspin, carboxypeptidase
- complete digestion of protiens
Pancreatic amylase
- works with brush border to complete the digestion of carbs
Lipases
- important fat-digesting enzymes (assisted by the emulsification of fats by bile)
Production and release is controlled by CCK and secretin
69
Absorption
-occurs when the end products of digestion enter the capillaries of the villi after being transported into the intestinal cell plasma membranes
-fats enter north the capillaries and lymphatic vessels or lacteals by diffusion
70
Large intestine
-produces no digestive enzymes
-absorbs water and a few other substances and dries out indigestible waste
-1.5m in length 6-7cm in diameter
-extends from small intestine to anus
71
Subdivisions of the large intestine
- cecum
- appendix
- colon
-rectum
- anal canal
72
Four regions of the colon
- ascending colon
-transverse colon
-deceasing colon
-sigmoid colon
73
Which salve is located at the entrance of the large intestine and keeps food from re-entering the small intestine
Ileocecal valve
74
The ouch below the ileocecal valve
Cecum
75
The appendix
-finger like projection suspended from the cecum
-plays a role in the immune system by providing the cecum with bacteria after an illness
76
Sigmoid colon
-s-shaped
-stores feces
77
The rectum
-final storage area for feces
- where water is absorbed and mucus is secreted
78
Anus
The opening of the anal canal
79
Goblet cells
Secrete mucus to aid in deification
80
Bacteria in the colon
- variety of bacteria colonize the colon
- some ferment indigestible carbohydrates
-others a synthesize vitamin B and vitamin K
81
Primary function of the large intestine
Propel fecal matter and eliminate it from the body
82
Bowel movement
- also calle mass movements
- long slow moving contractions of the colon
- occur 3-4 time a day
- push contents of the colon towards the rectum
- once feces enter the rectum the need to dedicate us felt
- internal sphincter may be voluntary relaxed or constricted to delay the passage if feces
83
GERD
- gastroesophageal reflux disease
-acid reflux occurs when stomach acids back up in the esophagus
- weak cardioesophageal sphincter
- heartburn
-frequent reflux
84
Stomach ulcers
- hole or damaged area in the lining of the stomach most often caused by bacteria
- also called gastric ulcers
-primarily treated with antibiotics
-60% are caused by bacteria H. pylori
-20% are caused by NSAIDs such as aspirin or ibuprofen
85
Gallstones
- hard deposits of cholesterol
- pain is caused when stones move through or block bile duct
- surgical removal is most common treatment
86
Hepatitis
- inflammation of the liver usually caused by a virus
- type C is the deadliest infectious disease in the US
87
Pancreatitis
-Inflammation of pancreases when digestive enzymes are activated too soon and damage enzymes
-most commonly caused by gallstones or heavy alcohol use
88
IBD
-inflammatory bowl disease
-chronic inflammation of digestive tract, especially the large intestine
-includes crohns disease and ulcerative colitis
89
Appendicitis
- severe pain in lower right abdomen, nausea, vomiting
- treatment if removal of appendix, appendectomy
- can be fatal if ruptured
90
Cystic fibrosis
- inherited disease that causes a thick mucus to form in the lungs, pancreas, and other organs
-blocks secretion of digestive enzymes and bicarbonate solution from the pancreas
91
Hemorrhoids
- swollen veins in lower rectum
-can cause bleeding itching and pain
May result from straining during elimination
92
Vomiting and diarrhea
- caused by infection from a bacteria or virus such as norovirus
93
Cleft lip/palate
- occurs when when either the lip or palate (or both) fail to close during development
- leaving a split called a cleft
- one of the most common birth defects and can be fixed by surgery
94
PKU
-phenylketonuria is a rare genetic disorder that causes a build-up of the amino acid phenylalanine
- cause by a mutation in the gene for an enzyme that converts the amino acid into other compounds needed by the body
- in the US babies are screened for it at birth
- if untreated can result in Brain damage
95
Reflexes
- babies are both with the the rooting and sucking reflex
-triggered by touches of the cheek or anything on the roof of their mouth
96
Cancer
-there is an increase in the risk of cancer with age
-more than half of all cancers occur in people over the age of 65
-colorectal cancer is one of the most common types of cancers
