1
Q
Mouth
A
Where the start of the digestive process begins, oral cavity is inside
2
Q
Teeth
A
Used to mechanically start digesting food. Consist of incisors, canine teeth, premolars, and molars
3
Q
Tongue
A
Used to taste food and shapes it into a bolus
4
Q
Salivary glands
A
- Secrete saliva into the mouth
- Saliva contains:
- –Glycoprotein to lubricate food for easier swallowing
- –Buffers to neutralize food (prevents tooth decay)
- –Antibacterial agents to get rid of bad bacteria
- –Amylase, which hydrolyzes starch
5
Q
Pharynx
A
- The throat, has openings to both the esophagus and the pharynx
- Leads to both the esophagus and the trachea
- Food and air pass through
6
Q
Epiglottis
A
A flap of cartilage and fibrous connective tissue over the opening of the larynx
7
Q
Esophagus
A
A muscular tube that brings moves boluses from the pharynx to the stomach by peristalsis
8
Q
Cardiac sphincter
A
A flap of muscle preventing the acidic contents (and chyme) from the stomach from moving up into the esophagus
9
Q
Stomach (gastrin?)
A
- The place where partially digested food is stored, and chemical and mechanical digestion occurs
- Gastrin: hormone that stimulates the secretion of gastric juice
- Acid inhibits the release of gastrin –> less gastric juice
10
Q
Pyloric sphincter
A
A flap of muscle controls the flow of partially digested food in the stomach to the small intestine
11
Q
Liver
A
- Glucose in blood converted to glycogen and stored in the liver
- Synthesizes many proteins
- Changes toxins into less toxic forms (alchohol/drugs -> inactive form)
- Produces bile
12
Q
Gallbladder
A
-Stores and concentrates bile
13
Q
Pancreas
A
- Produces pancreatic juice (digestive enzymes + alkaline solution rich in bicarbonate)
- Bicarbonate:
- –Acts as a buffer to neutralize the acidity of chyme as it enter the small intestine (raise pH)
- –Prevents ulcers
- –Activates pancreatic enzymes (amylase, lipase, proteases)
- –Secretes insulin into the bloodstream
14
Q
Small intestine
A
-In duodenum, mixing: chyme (from stomach), bile (from gallbladder), pancreatic juice, digestive enzymes (from gland cells in intestinal wall)
-All four types of large molecules are finished being digested here
-
15
Q
Cecum
A
-A pouch at the beginning of the large intestine, assists feces formation
16
Q
Appendix
A
- A small fingerlike extension of the cecum that contains many white blood cells that make a minor contribution to immunity
- Stores beneficial bacteria, reboots intestine after illness, immune functions as well
- Prone to infection
17
Q
Large intestine / Colon
A
- Absorbs water from the alimentary canal
- Remains of digestive food become more solid as they move along the colon by peristalsis
- Remaining water is absorbed and undigested solids are compacted into feces
- Home to mutualistic bacteria
18
Q
Rectum
A
- The place where excrement is held until the body is ready to release it
- Right above the anus
19
Q
Anus
A
-The opening where undigested materials are expelled
20
Q
***What is the difference between mechanical and chemical digestion? Where does each happen?
A
-Mechanical: physically breaking the food into smaller pieces
-Chemical: enzymes break apart the food at a molecular level
-
21
Q
Where does hydrolysis of each macromolecule happen? What are the products? What enzymes digest each type of macromolecule?
A
MOUTH (salivary glands):
Starch —[amylase]–> maltose + other dissac
STOMACH:
Big polypep. —[pepsin]–> small polypep
Starch —[amylase]–> maltose + other dissac (PANCREAS)
Dissac —[sucrase, lactase]–> monosacc (S INT)
Big polypep —[trypsin]–> small polypep (PANCREAS)
Small polypep –[peptidase/protease]–> amino acids (S INT)
Fat globules —[bile salts/emuls.]–> fat droplets (LIVER)
Fats —[lipase]–> fatty acids + glycerol (PANCREAS)
22
Q
What is the bolus?
A
-A lubricated ball of chewed food shaped by the tongue
23
Q
What does the epiglottis do?
A
- Flap of cartilage and fibrous connective tissue
- Larynx moves upward and tips the epiglottis down over the opening to the larynx
- Prevents food from passing into the trachea
24
Q
What is peristalsis?
A
-Waves of muscle contractions
-
25
What is in gastric juice? Gastric glands?
- Gastric juice: mucus, enzymes, and strong acid (pH 2)
- --Mucous cells --> mucus (lubricates + protects cells lining in stomach)
- --Parietal cells --> H ions and Cl (combine in lumen to form HCl)
- --Chief cells --> pepsinogen (inactive form of pepsin)
26
What is the role of HCL in the stomach?
- HCl converts pepsinogen to pepsin
- Pepsin begins the chemical digestion of proteins
- Pepsin production activates more pepsinogen production
27
What is chyme? How does it leave the stomach?
- Chyme is the end product of digestion in the stomach
- Acidic gastric juices mixed with partially digested food
- Leaves through the pyloric sphincter to the small intestine
28
What is H. pylori and what role does it play in the digestive system?
- Acid tolerant bacteria
- Burrows beneath the mucus and releases harmful chemicals
- Loss of protective mucus and damages cells in stomach lining
- Stomach wall may erode to create a hole --> infection, internal bleeding
29
***Where is bile produced? Where is it stored? Where does it eventually go and what is its use (what is it for)?
- Produced in liver
- Stored in gallbladder
- Breaks fat into smaller droplets that lipase can act on (emulsifier)
- It forms micelles around fat droplets to keep them from clumping together and getting larger
- Goes into the small intestine when needed
30
What does the pancreas do in digestion?
-It is the major source for most digestive enzymes and neutralizes HCL from the stomach.
-
31
***What are the roles of the liver in food metabolism?
-The liver produces bile that prevents fat droplets from getting too large
-
32
What is the function of villi and microvilli in the small intestine? What would happen if someone’s villi were greatly reduced in size due to illness?
-They increase the surface area of the small intestine for absorption of nutrients
-If a person’s villi were greatly reduced in size, that person may not get enough nutrients to survive and may need to get surgery
-
33
***What is the role of E.coli and other mutualistic bacteria in the large intestine? Are they beneficial or harmful in the L.I? In other parts of the body?
-They produce important vitamins that are absorbed into the bloodstream, most are beneficial
-
34
What is our microbiome? How is our intestinal microbiome impacted by the food we eat?
-An ecosystem of different bacteria on our skin and in our body
-Depending on the food we eat the diversity of the microbiome will increase or decrease
-Fibers that cannot be digested by the human body provide a major source of energy for bacteria
-Yogurt
-
35
How can one increase or decrease the diversity of one’s intestinal microbiome? Is more diversity better?
-More diversity is better and a person can change increase the diversity of their microbiome by eating more natural foods like berries and honey (decrease by meat and refined sugars)
-
36
How are the digestive systems of organisms adapted to the type of food they eat? (structural adaptations)
- Carnivore: large, expandable stomach
- Herbivores and omnivores have longer alimentary canals
- Herbivores have special chambers that house great numbers of microbes
- Many herbivorous mammals have cellulose-digesting microbes in the colon (and in a large cecum)
- Rabbits + some rodents eat some of their feces
- Cattle, sheep, deer: ruminants - four chambered stomach
37
***What are ulcers? What causes them and where do they most commonly occur?
- Ulcers happen when pepsin and HCl destroy cells faster than they can regenerate, eating through the stomach wall
- Mucus can be eroded by several causes: H. pylori bacterium infection or stomach exposure to: NSAIDS, alchohol, gastric hyper-acidity, cigarettes
- Result: damage to cells lining stomach
38
What is acid reflux / GERD and how can you treat it?
-Gastroesophageal reflux disease is when chyme from the stomach overflows through the gastroesophageal sphincter into the esophagus, irritating the lining of the esophagus
-It can be treated by lifestyle changes, medications, or possibly surgery
-
39
Diarrhea, constipation (cause, treatment)
- Diarrhea: too much water in feces (not enough time in LI), frequent watery elimination, dehydration
- Constipation: not enough fiber in diet (too much time in LI), infrequent elimination and compacted feces
40
***What prevents HCl from destroying the stomach lining?
-Mucus helps protect against HCl and pepsin
-New cells lining the stomach are produced every 3 days (by mitosis)
-
41
Lactose intolerance (cause, treatment)
- A lack of enzymes that can digest lactose in the small intestine causes digestive problems
- Inability to digest milk sugar, bloating + gas when dairy is consumed (produced by bacteria in intestines that feed on dissach. lactose)
- This leaves enzymes in the large intestine to deal with lactose, which cause gas and other problems
- Digestive enzymes can be taken to help with the problem
42
IBD (cause, treatment)
- Chronic inflammation of all or part of your digestive tract
- Severe diarrhea, pain, fatigue and weight loss
- Can be debilitating and sometimes leads to life-threatening complications
43
Intestinal gas
- Foods that produce gas (carbs)
| - When partially digested carbs reach the small intestine, bacteria digest them, giving off gas as a by-product
44
Celiac disease (cause, treatment)
- Auto-immune disease
- Foods that contain gluten
- Gluten triggers an immune system reaction in the SI that causes inflammation, which damages villi and decreases nutrient absorption
- Treatment: gluten-free diet
45
How are fats, proteins, and carbs absorbed by the small intestine?
- Fatty acids and glycerol absorbed by epithelial cells -> recombined into fats -> transported to lymph vessel -> cells
- Amino acids and sugars -> pass out of intestinal epithelium -> across thin wall of capillaries into blood -> cells
46
Gallstones
"stones" of bile salts in gall bladder, can be eliminated through narrow bile duct into digestive system (painful)
Biology
flashcards
Decks in class (18)
# Cards
-
Biotechnology21
-
DNA Test41
-
DNA History, Structure, and Replication26
-
Cell Respiration and Fermentation34
-
Circulatory System25
-
Cell Structure43
-
Cell Membranes41
-
Blood Glucose Metabolism10
-
Animals8
-
Respiratory System17
-
Basics of Human Nutrition9
-
Digestive System46
-
Enzymes46
-
pH and Protein Folding33
-
Biochemistry45
-
Water22
-
Intro to Biology35
-
Biotechnology0
