Digestive System Flashcards
1
Q
What is Herbivore?
A
The animals that feed only on plants and algae
2
Q
What is carnivore?
A
animals that feed only on meat
3
Q
What is omnivore?
A
Animals that feed on both plants and animals
4
Q
Most animals are______ feeders
A
Opportunistic
5
Q
An animal’s diet must satisfy 3 nutritional needs
A
1)chemical energy to produce ATP
2)raw material for biosynthesis
3)essential nutrients
6
Q
Two types of organic molecules must be obtained from diet____ and _____
A
organic carbon(from sugars)
organic nitrogen(proteins)
7
Q
What are essential nutrients?
A
Cannot synthesize in the body therefore must obtain from diet
8
Q
What are essential amino acids?
A
all organisms require 20 amino acids
Plants can produce all of them but animals contains enzyme that can synthesize half of these amino acids
9
Q
Human requires_____essential amino acids
A
8
ALL HIS TV MPT
Histidine is only needed for human infants.
Alanine
Leucine
Lysine
Threonine
Valine
Methionine
Phenylalanine
Tryptophan
10
Q
Animal proteins are____ and plants proteins are____
A
A-complete(contains all 20)
P-incomplete (lacks one or more)
11
Q
Why animals require essential fatty acids?
A
to synthesize cell membrane,signaling molecules and to store fats
12
Q
Can animals synthesize all essential fatty acids?
A
No
Although animals can synthesize many fatty acids,they lack enzyme to form double bonds in some essential fatty acids
13
Q
Example of essential fatty acid
A
Linoleic acid
14
Q
____ vitamins is required by humans
A
13
4 lipid soluble and 9 water soluble
15
Q
What are fat soluble vitamins and their func?
A
Vit A,D,E,K
Vit A(retinol)-components of visual pigment;maintenance of epithelial tissue
Vit D-aids in calcium and phosphorus absorption and bone formation
Vit E(tocopherol)-antioxidant;prevent damage to cell membranes
Vit K(phylloquinone)-blood clotting
16
Q
Fat soluble vitamins resources
A
A-green and orange vegatables
D-dairy products,egg yolk
E-vegetable oils,seeds,nuts
K-Green vegetables,tea and also made by colon bacteria
17
Q
Vit A deficiency can cause
A
blindness
skin disorders
impaired immunity
18
Q
Vit D deficiency
A
Ricket(bone deformities) in children
bone softening in adults
19
Q
Vit E deficiency can cause
A
Nervous system degeneration
20
Q
Vit K deficiency
A
defective blood clotting
21
Q
Overconsumption of which vitamin is dangerous to our body?
A
Fat soluble vitamins,the excess are deposited in body fat and can accumulate to toxic levels
22
Q
Water soluble vitamins and their resources
A
B1(Thiamine)
B2(Riboflavin)
B3(niacin)
B5(pantothenic acid)
B6(pyridoxine)
B7(Biotin)
B9(folic acid)
B12(cobalamin)
C(ascorbic acid)
Meats,grains,diary products and vegetables,citrus fruits
23
Q
Function of B1
A
Coenzyme for removing CO2
24
Q
Function of B2
A
Component of coenzyme FAD and FMN
25
Function of B3
Component of coenzyme NAD+ and NADP+
26
Function of B5
component of coenzyme A
27
Function of B6
coenzyme used in amino acid metabolism
28
Function of B7
Coenzyme in synthesis of fat,glycogen and amino acids
29
Function of B9
coenzyme in nucleic acid and amino acid metabolism
30
Function of B12
Production of nucleic acid and RBC
31
Function of Vit C
Collagen synthesis(connective tissue)
antioxidant
32
Beri Beri deals with which vitamin deficiency?
B1 Thiamine
Beri Beri(tingling,poor condition and reduced heart function)
33
Dietary mineral are _____ nutrients
inorganic (Fe, S)
34
Main function of Ca and its deficiency
Func-bone and tooth formation,blood clotting,nerve and muscle functions
Def-impaired growth, loss of bone mass
35
Main function of P and its deficiency
Func-bone and tooth formation,acid base balance, nucleotide synthesis
Def-weakness,Ca2+ loss and other minerals loss from bone
36
Main function of S and its deficiency
func-component of amino acid
def-impaired growth,fatigue and swelling
37
Main function of Mg and its deficiency
Func-enzyme cofactor,ATP bioenergetics
Def-Nervous system disturbances
38
Main function of F and its deficiency
Func-maintenance of tooth structure
def-higher frequency of tooth decay
39
Malnutrition is caused because of
lacks one or more essential nutrients in diet
40
Most common type of malnutrition in human
protein deficiency (insufficient amt of one or more essential amino acid)
41
Where can body get chemical energy in person with malnutrition?
First ,body breaks down stored carbohydrates and fats to obtain chemical energy and then breaking down proteins
There is no stored chemical energy,muscle shrink and brain become protein-deficient and die
42
Four stages of food processing
Ingestion, Digestion, Absorption, Elimination
43
4 main types of feeding mechanisms
1)filter feeder-aquatic animals
2)Substrate feeder-animals that live in or on food source
3)Fluid feeder-suck nutrients of fluids from host
4)Bulk feeder-most animals and humans eat large pieces of food
44
Digestion
Food is broken down into smaller molecules in order to absorb
45
Mechanical digestion
breaks the food into smaller pieces increasing surface area
i.e.chewing or grinding
46
Chemical digestion
Cleaves larger molecules into smaller molecules
carbohydrate-glucose
Proteins-amino acids
Nucleic acids-nucleotide
Phospholipids and fats -fatty acids
47
Chemical digestion is driven by ____ and is the process of _____
Enzymes
Enzymatic hydrolysis(breaking binds by adding water)
But in some animals,bacteria live in GI tract carry put chemical digestion
48
Absorption
cell absorbs smaller molecules such as amino acids and simple sugars
49
Elimination
Excretion of undigested material
50
How intercellular digestion takes place?
Cell engulfs solid food by phagocytosis and liquid by pinocytosis and formed vacuoles.
That newly formed vacuoles binds with lysosomes (contains hydrolytic enzymes) hydrolysis takes place and. then digestion occurs
51
Most animals,hydrolysis take place by_____
extracellular digestion
52
Animal with simple body plan have digestive compartment called_____
gastrovascular cavity with a single opening
53
Animals with complex body plans contains digestive tract with______ and is called_____
2 opening-mouth and anus
alimentary canal
54
Food moves along alimentary canal in ____
single direction
55
What are accessory glands?
glands that support in food by secreting digestive juice THROUGH DUCTS into alimentary canal.
56
Accessory glands that include in human alimentary canal
3 pairs of salivary glands
Pancreas
Liver
Gallbladder
57
Function of teeth in digestion
breaks down food into smaller pieces (mechanical breakdown)-that increases surface area and also facilitates swollowing
58
Food in oral cavity triggers the release of_____by _______
saliva by salivary glands
59
What are major components of saliva?
1)mucus-viscous mixture of salts,water, cells and slippery glycoproteins
2)buffer
3)antimicrobial agent
60
Function of saliva mucus
1)lubricate food fir easier swallowing
2)protects gum
3)facilitate taste and smell
61
Function of salivary buffer
prevent tooth decay by neutralizing acid
62
Function of salivary antimicrobial agent
protect against bacteria that enter oral cavity
63
Saliva contains large amt of enzyme _____
amylase-enzyme that break down starch and glycogen
Also contains in small intestine
Starch(glucose polymer of plant )
Glycogen(glucose polymer of animal)
64
Mechanical digestion and chemical digestion in oral cavity
Mechanical digestion-break down of large food into small pieces (TOOTH)
Chemical digestion-breakdown of starch and glycogen(SALIVARY AMYLASE)
65
How bolus formed?
When food is mixed with saliva (facilitated by tongue)
Tongue also push bolus into pharyx
66
When bolus reaches the pharynx,
pharynx contains 2 passageways
1)Esophagus-muscle tube connect to stomach
2)Trachea-connects to lungs
the bolus will pass into esophagus
67
Within esophagus,food is push by_____
peristalsis ,alternative waves of smooth muscle contraction and relaxation
68
Sphincter that contains in alimentary canal
1)sphincter b/w esophagus and stomach
2)sphincter b/w stomach and small intestine
3)2 sphincter b/w rectum and anus;inner involuntary and outer voluntary
69
Stomach is located ____
below diaphragm
70
Major function of stomach
1)storage -can store 2L of food and fluid
2)to make food into liquid suspension
Stomach produces gastric juice and mixes it with food by CHURNING ACTION.
71
What is a chyme?
ingested food mixing with gastric acid
72
Chemical digestion in stomach
1)HCl-disrupts the extracellular matrix that binds cells in meat and plant material and its has low pH (denature proteins and exposing their peptide bonds)
2)Pepsin(protease-protein digesting enzyme)-attack the peptide bonds of proteins
73
Many enzymes and proteins are denature in high acidic gastric juice.Is pepsin denature in HCl?
No, unlike other enzymes,pepsin works best in acidic environment
74
3 type of cells in stomach and its secretion
3 type if cells in gastric glands of stomach
1)Mucous cell-mucus (protects the lining of stomach)
2)Chief cells-pepsinogen(inactive form of pepsin)
3)Parietal cells-HCl
75
How long it takes to reach food from stomach to small intestine?
2-4hr
76
How long it takes food to reach colon from rectum?
12-24hrs
77
How HCl is secreted by parietal cells?
parietal cells use ATP in order to pump H+(proton pump) into stomach lumen.Chloride ions also diffuse into lumen.
Within lumen,H+ and Cl- ions combine to form HCl
78
How pepsinogen is secreted and activated?
Chief cells release pepsinogen into lumen(inactive) and HCl activate pepsinogen into pepsin(active).
Pepsin in turn activates more pepsin (Positive feedback)
79
Why parietal cells and chief cells is not digested even though they produce acidic gastric juice?
Both HCl and pepsin is secreted into lumen of the stomach,not in the cells of gastric glands
80
Why don’t HCl and pepsin digest the lining of stomach?
1)Mucus secreted by gastric glands protect against self-digestion
2)epithelial lining of stomach is added a new layer by cell division in every 3 days
81
What are ulcers?
damaged area of stomach lining (caused by acid-tolerated H.pylori bacteria)
82
What is largest compartment of alimentary canel?
small intestine
83
Most chemical digestion occurs in stomach.True or false?
false
in small intestine
84
Mechanical and chemical digestion in Stomach
Mechanical-Mixing of food with gastric juice (CHURNING)
Chemical-HCl and PEPSIN
HCl-destroys ECF of meat and plant and also denature proteins
PEPSIN-breaks peptide bonds of polypeptide
85
Parts of small intestine
1)Duodenum(main chemical digestion site)
2)Ileum-absorption of nutrients
3)Jejunum-absorption of nutrients
86
What will happen when chyme arrive the duodenum?
1)chyme mixes with digestive juices from pancreas,liver and gallbladder
2)with chyme arrival,duodenum stimulates release of secretin(secretin promotes release of bicarb from pancreas)
3)also secretes digestive juices
87
Function of bicarbonate
To neutralize acidic chyme and acts as buffer for chemical digestion
88
Digestive juice secreted by duodenum
1)Bicarbonate
2)Protease-Trypsin
3)Chymotrypsin
2 and 3 is inactive form and is activated in lumen of duodenum
89
How fat are digested in small intestine?
fats-insoluble in water and forms large globules
Fat digestion is facilitated by bile salts(acts as emulsifier to break fat and lipid globules)——>surface area တိုး
90
Bile is secreted by ____ and stored in _____
liver
gallbladder
91
Function of bile
Bile salts in fat digestion and the destruction of malfunctioning RBC in liver
92
Which part of the small intestine is mainly responsible for nutrient absorption?
ileum and jejunum
93
Why small intestine has large surface area?
Large folds in intestinal lining and including finger liker projections called villi.The villi itself contain many microscopic projections called microvilli.
surface area inside stomach is as the size of tennis court
94
Enormous surface area of small intestine greatly increases _____
the rate of nutrient absorption
95
Amino acids and sugars are transported into the blood by _____
passive transport but active transport allows more absorption
eg.fructose is absorbed by facilitated diffusion and other amino acids are absorbed by either passive or active
96
Amino acids and sugar diffuse into blood by_____
capillaries and veins
97
The capillaries and veins with nutrient-rich blood is converged into_____
hepatic portal vein-blood vessel directly lead to liver
From liver—->heart——>other organs
98
Advantages of nutrient first reach to liver
1)liver regulates the distribution of nutrients to other organs
2)being the main detoxification site,liver can detoxify the toxic substances included in nutrients
99
All nutrients leave the small intestine by bloodstream and pass through liver for processing.True or false?
false
digestion of fats takes a different path
100
Fats are digested by ____ enzyme
lipase
101
Fat is digested as______ in small intestine
fatty acids and monoglycerides
102
What happen when fatty acids and glycerol is absorbed by epithelial cells?
It recombines to form triglycerides and then coated with phospholipids, cholesterol and protein to form chylomicrons
103
Chylomicrons are _____
soluble in water
104
In existing small intestine,chylomicrons reach_____
lacteal(a vessel at the core of villi and also a part of lymphatic system)
105
Lymph containing chylomicrons pass into_____
larger vessels of the lymphatic system and eventually into the large veins that return directly to the heart
106
Small intestine reabsorb _____
water by osmosis (when sodium and other ions pass into lumen)
107
Parts of the large intestine
Colon
Caecum
Rectum
108
Small intestine connects to large intestine at _____
T-shaped junctions
One arm of T-rectum and anus
Other arm-caecum(a pouch)
109
Is caecum important in human?
No,it is important in animals that feed on plant materials
in humans ,caecum is small
110
Finger-shaped extension of caecum is called____ and it serves as ____
appendix
reservoir for symbiotic microbes
111
Main function of colon
Water reabsorption
112
It takes____ to pass the colon
12-24hrs
113
What will happen when colon lining is irritated (eg.bacterial infection)?
feces pass so quickly and less water reabsorb leading to diarrhea
114
Explain constipation
When feces remain so long in colon,more water reabsorb and feces become more compact
115
The material that cannot be digested in colon____
cellulose(plant fiber)
116
Function of rectum and anus
R-storage of feces
A-eliminate feces
117
Chemical digestion of carbohydrates
In oral cavity,pharynx and esophagus——>
polysaccharides (starch,glycogen) into smaller polysaccharides or maltose by SALIVARY AMYLASE
In stomach——>no reaction
In small intestine ——->smaller polysaccharides into disaccharides by PANCREATIC AMYLASES(pancreatic enzymes)
In small intestine——>Disaccharides into monosaccharides by ENZYMES FROM INTESTINAL EPITHELIUM
118
Chemical digestion of proteins
In oral cavity——>no protein digestion
In stomach——>Proteins into small polypeptides by PEPSIN
In small intestine——->Small poly peptides into smaller polypeptides by TRYPSIN AND CHYMOTRYPSIN(Pancreatic enzymes) and into small peptides by
PANCREATIC CARBOXYPEPTIDASE
In small intestine——->small peptides into amino acids by DIPEPTIDASES,CARBOXYPEPTIDASE,AMINOPEPTIDASE(enzyems form intestinal spithelium)
119
Chemical digestion of Nucleic acid
In oral cavity—->no digestion
In stomach——>no digestive
In small intestine(pancreatic enzymes)—>DNA and RNA into Nucleotides by PANCREATIC NUCLEASES
In small intestine (epithelial enzymes)—->Nucleotides into nucleosides by NUCLEOTIDASES and into nitrogenous bases,sugars and phosphate by NUCLEOSIDASE AND PHOPHATASES
120
Chemical digestion of fat
In oral cavity—->no digestion
In Stomach——>no digestion
In small intestine(pancreatic enzymes)—>fat(triglycerides) into glycerol,fatty acids and monoglycerides by PANCREATIC LIPASE
In small intestine(epithelial enzymes)—->no digestion
121
The action of the digestive system is controlled by_____ nervous system
enteric nervous system-network of neurons connected to digestive system
122
Gastrin is released by _____ and acts on ______ to _______
Stomach
Stomach to release gastric juice
(foodဝင်လာတဲ့အခါstomach wall stretchဖြစ်သွားရင် gastrinထွက် —>bloodstreamထဲရောက်ပြီးမှstomach ကိုactionပြန်ပေး)
123
Why herbivore and omnivores has longer alimentary canal than carnivores?
Plant materials are more difficult to digest than meat because it contains cellulose .Longer GI tract—->longer digestion and more surface area
124
CCK is released by ____ and stimulate_____
Cholecystokinin is released by Duodenum
and stimulates Pancreas to release enzymes and Gallbladder to secrete bile
125
Secretin is released by_____ and stimulates _____
S cells of duodenum
Pancreas to release bicarbonate(HCO3-)
bicarb neutralize chyme
126
CCK and secretin is released in respond to _____
Chyme -acidic mixture of digested food
127
How secretin and CCK slow digestion when chyme is rich in fat?
If chyme is rich in fats,high levels of secretin and CCK acts in stomach to inhibit peristalsis and secretion of gastric juices leading to slow digestion
128
What happen if diets contain more energy-rich molecules than it needs?
body stores excess energy
In humans, excess energy are stored in the form of glycogen in liver and muscle.
129
How stored energy are expanded when body lack in food?
Liver glycogen—->muscle glycogen—->fat
130
Normal blood glucose concentration
70-110mg/100 ml
131
Why glucose homeostasis is important?
glucose is the major fuel for cellular respiration and key sources of carbon for biosynthesis
132
Glucose homeostasis relies on 2 hormones:____ and _____
Insulin-glucagon(2 antagonistic hormones)
antagonistic-opposite effects
133
How insulin lower the blood glucose concentration?
When blood glucose lvl is above normal range,insulin stimulate the uptake of glucose from the blood to the body cells so decreasing blood glucose conc
134
How glucagon rise blood glucose lvl?
when glucose is below normal range, glucagon stimulates release of glucose from stored cells(i.e.liver cells)
135
___ is the primary site for action of insulin and glucagon
Liver
136
Regulation of glucose concentration after meal
after mealမှာဆိုbloodထဲမှာ glucose များ——>insulinလဲများ—->insulin promotes glycogen formation from glucose(Hepatic portal vein)
137
Regulation of glucose concentration between meal
Between mealမှာဆိုhepatic portal veinမှာ glucose နည်း—>glucagon stimulate liver to break down glycogen into glucose
138
Is insulin acts on all cells to glucose uptake ?
No ,insulin acts on nearly all cells EXCEPT BRAIN CELLS
Brain cells can take glucose with or without insulin
139
Glucagon and insulin is produced by _____
Pancreas-Islets of Lengerhans
alpha cells-glucagon
beta cells-insulin
140
Pancreas has both____ and ______ action
exocrine-bicarb and digestive enzymes
endocrine-insulin,glucagon
141
Main difference b/w Type 1 and Type 2 DM
Type 1-insulin is not produced (autoimmune disease that destroys beta cells)
Type 2-insulin is produced but receptors defect
142
Hormones for appetite acts on_____
satiety center in brain
143
_____ hormone stimulate appetite and _____ hormones suppress appetite
ghrelin+
Insulin-
Leptin-
PYY-
144
What are the two reasons required for animals to eat food?
To obtain ATP and get raw materials for biosynthesis.
145
What are the two types of organic molecules that needs to be obtained from diet
A source of carbon (such as sugar) and nitrogen from proteins
146
What are essential nutrients?
Cannot be synthesized in the body, have to obtain from the diet
147
What are essential amino acids?
Animals cannot synthesize these A/A. Plants and microorganism can. Most animals have the enzymes to synthesize about the half of the organic nitrogen.
Adult human needs 8 essential amino acid . ALL HIS TV MPT ( histidine not included)
Human infants need one more-HISTIDINE
IMPORTANT- human body can synthesize histidine and arginine but not in sufficient amounts so have to be supplied by diet
148
Does the animal products and plant product contain complete amino acid ?
Animal products such as meat, egg, cheese contain all the essential amino acids.
Some plant products are missing one or more acids, but eating a variety of plant proteins is sufficient to obtain all the essential A/A
149
What are essential fatty acids and why cant animals synthesize them?
Animals require fatty acids to form plasma membrane, store fat.
Animals lack enzyme that can form the double bonds in certain required fatty acids. Therefore, need to be supplied from the diet.
Omega 3 and omega 6 fatty acids
Include ALA, DHA, EPA omega 3
Also include Linoleic acid and Arachidonic acid (Omega 6). Sis in LA
150
Name fat soluble vitamins and their func
Vitamin A, D ,E , K
Vitamin A- visual pigments of the eyes
Vitamin D- require for calcium absorption and bone formation
Vitamin E-prevent damage to cell membranes Vitamin K- important in blood clotting
151
What types of vitamins might be harmful , if over consumed?
Fat soluble vitamins because over consuming water soluble Vit can be excreted from the urines
152
What are the sources of vitamin A, D, E , K and what are the consequences of their deficiency?
Vitamin A- green and orange vegetables, fruits and dairy products
Blindness, skin disorder, impaired immunity
Vitamin D- dairy products and egg yolk
-a-
Rickets in children(bone deformities) and bone softening in adults
Vitamin E- vegetable oil, nut and seeds ooo O o o Degenerative nervous system
Vitamin K- green veggie and tea, also made by colon bacteria
Defective blood clotting
153
Names of the water soluble vitamins
Their sources
B1 Thiamine
B2 riboflavin
B3 niacin
B5 pentotanic acid B6 Pyridoxine
B7 biotin
B9 folic acid B12 cobalamine
Meat-vegetables-grains-dairy products
154
What vitamin deficiency is associated with Beri beri?
Beri beri- tingling, poor coordination reduced heart func Associated with vitamin B1 thiamine
155
What happens when there is vit c deficiency ?
Scurvy- degeneration of skin and teeth, and delayed wound healing
156
What are the func of chlorine, and their deficiency?
Func- used to produce HCL acid in the gastr ic and nervous system , acid- base balance and osmotic balance
Impair- reduced appetite, mood disturbance ,muscle cramp
157
Magnesium source, functions and deficiency
Magnesium - vegetables, grains
Func- cofactors , ATP bioenergetics Deficiency- nervous system disturbance
158
Why does malnutrition occur?
Lack of one or more essential nutrients.
159
What is neural tube defects and how does it happen? Diagnosis?
Neural tube defect- tissue fail to enclose the developing brain and spinal cord in infants.
Reason- women with malnutrition gives birth Diagnosis- supplement folic acid in diet
160
What are the four stages of the digestive system ?
Ingestion , digestion, absorption and elimination
161
In digestion , how many processes are there?
1. Mechanical digestion - chewing increases the surface area
2. Chemical digestion - break down into small macromolecules
162
What is absorption ?
Absorption of small molecules such as amino acids and simples sugars
163
What is intracellular digestion?
A few animals such as sponge digest in this well.
Food is engulfed by pinocytosis or phagocytosis—— >lysosomes come fuse the food——> hydrolysis enzyme digest the food in the compartment
164
Extracellular digestion and how many types ?
1. Gastrovascular
Gastric- digest food+ vascular- spread nutrients throughout the body
A. Food enters the gastrovascular cavity, gastrodermis secretes the enzymes from specialized glands cells, digest food particles, food particles are next engulfed into food vacuoles—-> digestion, remaining food particles such as exoskeleton are eliminated from the mouth
2. Alimentary canal
165
What is the difference between the alimentary and gastrovascular?
Animals with the complex body structures have the alimentary canals- with a mouth opening and an anus,
Mammals- alimentary canal present
166
What are the names of the accessory glands that aid in the digestion of the food in the alimentary canal?
Three salivary glands + three glands - pancreas , gall bladder and the liver
167
Role of the stomach
Storage and process food into liquid suspension by the action of gastric acid
168
How is stomach protected from the self digestion?
The stomach lining renews every three days, by adding an epithelial layer
169
What is churning?
With the contraction and relaxation of the stomach, gastric juice brought into contact with all the stomach contents
Peristalsis also stimulates the passing of the food from the stomach to the small intestine every 2 to 6 hours, allowed by the sphincter located at the opening of the small intestine
170
Is small intestine shorter than the large intestine?
No, according to diameter, small length is the longest compartment of the alimentary system
171
When the food enters the duodenum, what enzymes are released by the pancreas?
Pancreas secreted bicarbonates from the stimulus of the hormone secretin.
2. Different molecules for different digestive enzymes
Eg. Trypsin and chymotrypsin for proteins
Lipase for lipids
Nuclease for N/A
Pancreatic amylase for carbohydrates
172
Apart from pancreatic enzymes, what other cells assist in digestion of the food in duodenum.
Epithelial lining of the duodenum also secretes the enzymes. Some are secreted into the lumens of the duodenum and whereas others bound to the surface of the epithelial cells. Together with the pancreatic enzymes, they complete the digestion in the duodenum
173
How are fats digested ?
Fats are water insoluble so difficult to be digested.
Bile emulsify fats and break apart fat and lipid globules_ ——> pancreatic lipase digest the fats
Other funcs of biles- destruction of the red blood cells that are no longer functional .
Biles are secretion of the liver, and stored in the gall bladder
174
Where does absorption take place?
Ileum and jejunum the remaining part of the small intestine
Microvilli present at the epithelial cells- increases the absorption rate
175
Feces contain cellulose fibres. True or false?
True, no caloric value but help in peristalsis
176
How many spinsters do rectum have?
Two. Inner involuntary and outer voluntary
Strong contraction of the colon urge to defecate/ filling the stomach triggers the effect so the urge to defecate follows a meal
177
How many teeth in mammals
32
Incisors canine premolar and molar
8. 4. 8. 12
178
Carnivore animals have ——— stomach
Expandable
They eat as much as meat while they can catch prey and store it in their expandable stomach, eg python-ingest a whole gazelle
179
Herbivores and omnivores have ———— alimentary canal compared to carnivores
Longer
Because plants are more difficult to digest than meat because it contain the cell walls. Therefore, longer alimentary canal allow more time and surface area for absorption
180
How does coexistence of bacteria in the human intestine benefit both parties ??
Bacteria in the human intestine produce vitamins such as biotin B7, Folic Acid B9 and vitamin K and it also develops the innate immune system , an immune system in which human are born with , and develop intestinal epithelium.
In turn, bacteria benefit from the host by stable host environment and supply of nutrients
181
Microbiomes are the same regardless of diet, disease and age. True or false ?
False
182
Why does H pylori causes stomach ulcers?
Stomach tissue uninfected and infected tested in the lab——> H pylori removes all other bacterial species from the stomach
There is now evidence that changes in the microbiome can play a role in obesity, nutritional deficiencies, diabe- tes, cardiovascular disease, and inflammatory diseases of the digestive system. There are even effects on brain func- tion and mood
183
How do herbivores digest cellulose without cellulase enz?
Many herbivores host symnbiotic bacteria and protists in the fermentation chambers in their alimentary canals. These bacteria can digest cellulose.
ANSWER
Cellulose breaks down into glucose and other sugars.
In some cases, bacteria uses glucose to prof cells nutrients such as A/A and vitamins
184
Where do symbiotic bacteria reside in the alimentary canals
In some animals- cecum.
Some——> large muscular pouch ( an esophageal pouch) Some ———> large intestine and Caecum
Therefore, nutrition are absorbed mainly in the small intestine, so nutrients from the symbiotic bacteria are passsed to the feces. The reason why rabbits and other animals eat feaces then passing the food through the alimentary canal second time
185
Can humans digest cellulose?
No.
186
Earthworm do not have mouth or digestive system. How do they survive?
Microbes’ nutrients by the action of chemoautotrophy by microbes using oxygen,carbon dioxide , HS, and NO3
187
Is the alimentary canal always active and hormones are always released?
No. Large gaps between the meals, alimentary canal each part functions upon the food arrival
188
Normal conc of glucose in blood
70-110 mg/ml
189
Glucose homeostasis maintained how?
Antagonistic actions of insulin and glucagon
190
Insulin acts on ————cells and does not act on the ——
Insulin acts on almost every cells to ensure the uptake of glucose from blood.
Exception- doesnt act on brain ——> brain can take up glucose whether or not insulin is present. Therefore, even if the supplies are low, brain almost always has access to the circulating fuels
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From which cells are insulin and glucagon secreted from the pancreatic cells?
Glucagon ——> alpha cells
Insulin———> beta cells
Alpha and beta cells of the Islets of Langerham
192
Pancreas has funcs in both ——— and —— systems
Endocrine and digestive
2 percent only secrete hormone
98 percent secrete bicarbonates and enzymes into the small intestine via the pancreatic ducts
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Why does DM occur?
Decrease response to insulin or deficiency of insulin
Instead, fat becomes the main substrate for metabolic reactions. In extreme cases, acidic metabolites accumulate during fat breakdown accumulate in the blood, threatening life by lowering blood pH and depleting sodium and potassium in the body
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Symptoms of the DM
1. Glucose in Urea
2. More water secretion copious urination
195
Type 1 diabetes cause
Autoimmune disease——> destroy beta cells of pancreas——> cannot secrete insulin
Treatment- injection of insulin several times a day
Appears during childhood
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Cause of type 2 diabetes
Target cells do not response to insulin and fail to take up glucose from the blood.
May be genetic or due to sedentary life style and obesity
The resistance to insulin signaling in type 2 diabetes is sometimes due to a genetic defect in the insulin receptor or the insulin response pathway. In many cases, however, events in target cells suppress activity of an otherwise functional response pathway. One source of this suppression appears to be inflammatory signals generated by the innate immune system
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——- hormone stimulate appetite and —— hormones inhibit appetite
Ghrelin hormone by stomach wall stimulate appetite by stimulating the satiety centre in the brain
Insulin, Leptin hormone - produced by adipose fat, and PYY- produced by small intestine after meal suppress appetite
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During fasting by muslims , what type of cells enable to do long hours fasting?
ACTH
Alpha cells of islets of langerhams
Beta cells of islets of langerhams Hypothalamus stimulating the AP hormones
Alpha cells
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Glycogen structure
Like amylopectin but highly branched therefore packed tightly together.
Alpha 1,4 + Alpha 1,6
200
Actions of insulin
1. GLUT 4 transporter binds to the cell membrane and uptake the glucose from the blood
GLUT transporter-glucose transporter
2. Glucose kinase action phosphorylates glucose to prevent it from leaving the cell cannot bind to GLUT receptor
3. Stimulate PFK hormone to stimulate the glycogen synthesis in the liver
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Other than glycogenolysis, how can glucose be increased in the liver from the glucose?
Gluconeogenesis
202
A site with most digestion is at ———
Duodenum
203
Blood is supplied to GI tract via
splanchnic circulation
204
Blood is supplied to GI tract via
splanchnic circulation
