LEC 15 Flashcards
digestive system (109 cards)
1
Q
Digestive System common function of all organs involved
A
getting nutrients into the body
2
Q
Series of hollow organs from the mouth to the anus that together form the _______________ _____________
A
gastrointestinal (GI) tract
3
Q
Space in the hollow tube through which food and liquids travel
A
lumen
4
Q
Accessory (helper) organs (5)
A
- Salivary Glands
- Liver
- Gallbladder
- Pancreas
- Appendix
5
Q
Main organs involved in order: (9)
A
- mouth
- pharynx
- esophagus
- stomach
- small intestine
- large intestine
- sigmoid colon
- rectum
- anus
6
Q
Salivary Glands Function (4)
A
- moisten food
- bicarbonate maintains pH
- amylase digests starch
- lysozyme stops bacteria
7
Q
Liver Function (2)
A
- make bile
- many functions with processing/storing nutrients
8
Q
Gallbladder Function (2)
A
- store bile
- concentrate bile
9
Q
Pancreas Function (2)
A
- secrete digestive enzymes into small intestine
- secretes bicarbonate into small intestine to neutralize stomach acid
10
Q
Appendix Function
A
unknown
11
Q
Mouth Function (2)
A
- teeth chew food
- tongue positions and tastes food
12
Q
Pharynx Function (2)
A
- passageway for food and air
- helps to swallow
13
Q
Esophagus Function (3)
A
Move food from pharynx to stomach
1. Lining of esophagus produces lubricating mucus to help food slide down
2. Gravity assists peristalsis in propelling food down to stomach
14
Q
Stomach Function (3)
A
- store and mix food
- starts chemical digestion of proteins by enzymes and acid
- controls delivery to small intestine
15
Q
Small Intestine Function (3)
A
- digest proteins/fats/carbs
- absorbs most of water and nutrients
- secretes digestive hormones and enzymes
16
Q
Large Intestine Function (2)
A
- absorbs last of water and nutrients
- stores waste material
17
Q
Sigmoid Colon function
A
store feces
18
Q
Rectum
A
passageway for feces
19
Q
Anus
A
Expel waste (undigested material)
20
Q
Four layers of tissue in GI tract (inside to outside)
A
- Mucosa
- Submucosa
- Muscularis
- Serosa
21
Q
Mucosa Function
A
Allows nutrients to enter into blood
22
Q
Mucosa Location
A
innermost mucous membrane layer that lines digestive tract
23
Q
Submucosa Function
A
support mucosa
24
Q
Submucosa location
A
second innermost layer
b/w mucosa and muscularis
25
The submucosa is a layer of ___________ tissue containing __________ & ________ vessels, and __________.
1. connective
2. blood
3. lymph
4. nerves
26
Muscularis Function
motility of digestive tract
27
Muscularis location
b/w submucosa and serosa
28
Muscularis made up of ___ layers of ________ muscle.
1. two
2. smooth
29
Serosa Function (2)
1. protect digestive tract
2. anchor digestive tract
30
Serosa location
outermost layer of digestive tract
31
The serosa is the ________ tissue ________ covering.
1. connective
2. outer
32
Sphincters structure
thick rings of circular smooth muscle tissue
33
Sphincters function
Separate some of the organs within the digestive system
34
Types of Sphincters (6)
1. Upper esophageal sphincter
2. Lower esophageal sphincter
3. Pyloric sphincter
4. Ileocecal valve
5. Internal anal sphincter
6. External anal sphincter
35
Upper esophageal sphincter location
At the top of the esophagus, where it meets the throat
36
Lower esophageal sphincter location
Located at base of esophagus, opens and closes to allow food to enter stomach
37
Lower esophageal sphincter function
Prevents reflux of stomach contents back into esophagus
38
Lower esophageal sphincter malfunction can result in
acid reflux (a.k.a. GERD)
39
Pyloric sphincter location
Between the stomach and small intestine (duodenum)
40
Ileocecal valve location
Between the small intestine (ileum) and large intestine (cecum)
41
Internal anal sphincter location
Inside the anus, controlling involuntary bowel movements
42
External anal sphincter location
Outside the anus, under voluntary control for bowel movements
43
Digestive Process Steps (5)
1. Mechanical Processing & Movement
2. Secretion
3. Digestion
4. Absorption
5. Elimination
44
Digestive Process Step 1: Mechanical Processing & Movement
chewing and two types of movement to propel food forward and mix content of the lumen
45
Digestive Process Step 2: Secretion
fluids, enzymes, bile, etc are added along the way
46
Digestive Process Step 3: Digestion
broken down into smaller bits both mechanically and chemically
47
Digestive Process Step 4: Absorption
nutrients pass into blood or lymph fluids
48
Digestive Process Step 5: Elimination
undigested materials are removed from the body
49
Peristalsis steps (4)
1. Propels food forward
2. Smooth muscles are
stimulated ahead of bolus
to relax
3. Smooth muscles behind
bolus contract
4. Works to “squeeze” the
bolus in a forward direction
50
Peristalsis found in: (3)
1. esophagus (mostly)
2. stomach
3. intestines
51
Segmentation mainly in __________ tract
intestinal
52
Segmentation process (4)
1. Mixes contents of the lumen 2. Segments of smooth muscle contract and relax randomly
3. Moves in both forward and backward directions
4. Particles are pushed against the mucosa, leading to
absorption
53
Types of movements in digestive system (2)
1. Peristalsis
2. Segmentation
54
The mouth is the _________ to the digestive system.
entrance
55
Mouth: Physical digestion
Teeth bite and chew food small enough to swallow
56
Mouth: Positioning and taste of food (2)
1. Tongue (skeletal muscle) positions food over the teeth and pushes food into the pharynx
2. Involved in taste and speech
57
Mouth: Chemical digestion
Salivary glands produce saliva
58
What processes happen in the mouth:
1. Physical digestion
2. Positioning and taste of food
3. Chemical digestion
59
Components of saliva: (4)
1. Mucin
2. Salivary amylase
3. Bicarbonate
4. Lysozyme
60
Mucin function
moistens food
61
Salivary amylase function
begins chemical digestion of carbs
62
Bicarbonate function
maintains pH of mouth
63
Lysozyme function
protects teeth against bacterial aids
64
Phases of swallowing (2)
1. voluntary
2. involuntary
65
Esophagus structure
Muscular tube of skeletal and smooth muscle, connecting the pharynx to the stomach
66
Esophagus function
Transport food
67
How does the esophagus transport food? (2)
1. Lining of esophagus produces lubricating mucus to help food slide down
2. Gravity assists peristalsis in propelling food down to stomach
68
Stomach functions (3)
1. Storage
2. Digestion
3. Regulation of delivery
69
Stomach function: storage
Expands 1-3 liters of capacity to keep bolus until digestion and absorption occurs
70
Stomach function: digestion (3)
1. Using strong acids, chemical digestion of proteins occurs
2. Acids also kill bacteria
3. Mechanical digestion occurs by muscle contractions mixing contents
71
Stomach function: regulation of delivery
Controls how much of the contents enters into the small intestine
72
Gastric pits
millions of small openings in the mucosal layer that make gastric juice
73
Gastric juice is a combination of (2)
hydrochloric acid (HCl) and pepsin
74
Pepsin formed after ________ comes into contact with ______.
1. pepsinogen
2. HCl
75
Gastric juice forms _______ which is delivered to the
small intestine
chyme
76
Gastric juice (2)
1. Digests proteins and peptides into
amino acids
2. Gastric juice combines with partially
digested food.
77
Gastric juice gives the stomach acid a pH of ______.
2
78
Cells in stomach and gastric glands produce ________ that acts as a __________ barrier against the stomach acid
1. mucus
2. protective
79
peptic ulcers formed when?
When mucus layer in stomach becomes damaged, underlying tissues come into contact with acid
80
intrinsic factor produced by
Mucosal cells in gastric gland
81
intrinsic factor
protein that binds to vitamin B12 so it can be absorbed in the small intestine
82
Gastrin
hormone involved in digestion
83
Gastrin secreted from cells in the ________ ________
gastric glands
84
Each peristaltic contraction happens every ______ to _____ seconds
15 -25 seconds
85
How many hours to empty stomach?
2 to 6
86
What is absorbed in the stomach and why?
1. Alcohol (a little bit) and aspirin
2. Lipid soluble and cross the mucus barrier to
enter the blood stream directly from stomach
87
Small Intestine functions (2)
1. Digestion
2. Absorption
88
Small Intestine function: Digestion
1. Continue protein digestion in small intestine
2. Digest carbohydrates and lipids
89
Small Intestine function: Absorption (2)
1. Food components broken down to amino acids, monosaccharides, fatty acids and glycerol
2. Absorption of almost 90% of absorbable nutrients and water occurs in sm. intestine
90
Small Intestine parts (3)
1. Duodenum
2. Jejunum
3. Ileum
91
Duodenum (2)
1. 10 inches long
2. Remaining digestion occurs here
92
Ileum
1. Combined are approx. 10 feet long
2. Absorption occurs here
3. Has villi and microvilli (maximize
surface area (increase by 500x) and increase absorption ability)
93
Center of each villus: _______ __________
Blood capillaries
94
Lymphatic capillaries
lacteals
95
Lacteals (2)
1. Carry nutrients too large to enter the blood stream
2. Eventually enter the blood stream
96
Pancreas Location:
lies posterior to stomach
97
Pancreas endocrine function
ecretes hormones (insulin & glucagon)
into the bloodstream to regulate blood sugar
98
Pancreas exocrine function
produces and secretes digestive enzymes into ducts (including
pancreatic duct) which leads into the duodenum of the small intestine
99
Pancreas: Digestive secretions (4)
1. Sodium bicarbonate
2. Proteases (digest proteins)
3. Pancreatic amylase (digest carbs)
3. Lipase (digest lipids)
100
Pancreas: NaHCO3 secretion purpose
Sodium bicarbonate neutralizes the acidic chyme so digestive enzymes can work in optimal pH
101
Liver location
Upper right abdominal cavity
102
Liver function
Help digestion and absorption of lipids through the bile production
103
Bile
Watery substance that has electrolytes, cholesterol, bile salts, lecithin and bilirubin
104
Bile salts
1. emulsify lipids in small intestine = breaking into smaller fat droplets
2. small enough droplets = can be digested by lipases (from pancreas)
105
Hepatic Portal System
1. Carries nutrient rich blood directly from the digestive organs to the liver through the hepatic portal vein
2. The liver filters out any nutrients it stores
2. Venous blood continues to
the inferior vena cava = heart/lungs to be oxygenated
106
cirrhosis
Long term exposure to harmful substances = liver function impairment
107
Liver Non-Digestive Functions (6)
1. Storage of fat-soluble vitamins (A, D, E, K), iron, glucose in the form of glycogen
2. Makes plasma proteins (e.g. albumin and fibrinogen) 3. 3. Synthesis and storage of some lipids
4. Inactivate chemicals such as alcohol, hormones, drugs,
poisons
5. Converts toxic ammonia wastes into less toxic urea
6. Destroys old red blood cells
108
Gallbladder Location
Inferior and slightly posterior to liver in the upper right abdomen
109
Gallbladder Function
