Module 4 Flashcards
qqDigestion primarily occurs in what part of the digestive tract?
mucosa
For who is the risk for diverticulitis higher?
older, obese, smokers and physically inactive
How do we classify a prebiotic?
must be able to make it past the acidic stomach environment, be fermented by intestinal microbiota and change the activity of the microbiota in a beneficial way
How does churning occur?
innermost layer of diagonally oriented smooth muscle allows for the stomach walls to contract in varying patterns around its contents
How does diet alter the composition of the microbiome?
processed foods high in refined carbohydrates can negatively affect the diversity.
diets high in fibre have been shown to improve the equilibrium of gut microbiome and reduce risk of obesity
How does gastroesophageal reflux or acid reflux occur?
lower esophageal sphincter weakens over time. stomach acid can spill upward into esophagus resulting in a burning feeling.
How does leftover material move through the large intestine?
through peristalsis and segmentation which breaks material into smaller components while mixing it with digestive juices.
How does mucus helps the stomach?
provides lubrication and a medium in which chemical reactions can occur.
provides protective layer that stops stomach acid and juices from damaging stomach wall
How is HCL used for digestion?
highly corrosive acid, helps unravel proteins, exposing sites where enzymes can further break them down
How is the large intestine divided?
cecum, ascending, transverse, descending and sigmoid colons
How long does food remain in the stomach?
4-5 hours
How long does it take for material to pass through entire digestive tract?
2 or more days
How long is the small intestine?
about 6m
How to aid acid reflux?
weight loss, elevating head of bed, decreasing tobacco, alcohol, chocolate, large meals, spicy foods, and high fat meals
If immediate energy is needed, how does the liver help?
absorbs sugars such as fructose. if liver glycogen levels are low, can also store lacoste in form of glycogen until stores are full
If the diet is excessively low in carbohydrates, what happens to lipids?
lipids will primarily be metabolized to form ketones
In order to be absorbed, polysaccharides muscle be broken down into what?
Sugars : glucose, monosaccharides
In the small intestine, larger lipids are absorbed into what?
vessels called lacteals
Instead of being absorbed into the absorptive vessels along with almost all other nutrient subunits, where are larger lipids and fat-soluble vitamins absorbed into ?
lacteal (lymphatic vessel)
Is energy required for the absorption of glucose?
yes
Is the conversion of pyruvate to acetyl CoA an anaerobic or aerobic process ?
aerobic
Once carbohydrates are absorbed, what is the first organ they encounter?
the liver
Once food is chewed and mixed w saliva what does it form?
uniform cohesive structure called a bolus
Prebiotics are typically what length?
medium length carbohydrates
What 2 enzymes does saliva contain ?
salivary amylase: digests amylose (starch)
lingual lipase: digests lipids
What are condensation reactions?
combine molecules by liberating a water molecule
What are crypts. what do they allow? secrete?
invaginations on stomach wall. allows more stomach cells to be involved w digestion.
some crypts secrete hydrochloride acid, pepsinogen and mucus (also known as gastric juice)
What are diverticula?
weakened dtw leading to formation of outpouchings
What are enterocytes?
small intestine cells. helps increase total surface area
What are enzymes?
allow reactions to occur quick enough to meet the body’s needs.
What are gallstones?
hardened bile deposits that accumulate in the gallbladder or bile duct
What are hormone?
chemical messengers required for many physiological processes.
released from one area of the body and travel through the blood to different parts of the body
What are lymphatic vessels?
one way tubes filled with a watery non blood liquid that removes material from tissues.
What are peptic ulcers?
esophagus, stomach, or small intestine ulcers
What are prebiotics?
not living organisms. act as food for microbiome and supports its function
What are probiotics found to prevent?
antibiotic associated diarrhea, travellers diarrhea, acute respiratory infections, infant colic, and a type of colitis
What are probiotics?
cultures of living organisms, typically bacteria
What are risk factors for gallstones?
female, use of estrogen containing contraceptives, obesity, rapid weight loss, physically inactivity
diets higher in simple sugars, saturated fat and energy intake
What are sphincters?
found between certain organs, they regulate passage from one organ to the next.
composed of circular muscle that contracts to close opening and relaxes to open them.
What are symptoms of diverticulitis?
abdominal pain, fever, nausea and vomiting, change in bowel habits, rectal bleeding
What are the 2 main types of prebiotics?
fructose-ogligosaccharides and galactose-ogliosacchaides
What are the 2 types of digestion?
mechanical/physical: uses physical process such as chewing to break food apart
chemical digestion: uses enzymes to alter the chemical structure of nutrients
What are the 3 main divisions of the small intestine? how long are each?
duodenum- 25 cm
jejunum- 2m
ileum- 3m
What are the 3 main salivary glands in the mouth ?
parotid, submandibular, and sublingual
What are the accessory structures of the digestive tract?
liver, gallbladder, and pancreas
What are the functions of the pancreas?
blood-glucose regulating function : due to production and secretion of hormones insulin and glucagon, these secretions are released into bloodstream. (endocrine function)
pancreas secretions that are deposited into digestive tract are part of exocrine function (pancreatic juice)
What are the cells of the small intestines called?
enterocytes
What are the main layers of the the digestive tract wall?
(inside out) lumen->mucosa->submucosa-> muscular is-> serosa
What are the symptoms of diverticulitis?
persistent abdominal pain, nausea, vomiting, constipation
What are the symptoms of IBS?
abdominal pain, bloating, cramping, diarrhea, constipation and flatulence
What are ulcers?
open stored that can occur along the lining of a body structure.
can occur at multiple points of the digestive tract
caused by weakening of mucosal layer of dtw
What chemical digestion occurs in the stomach?
protein digestion
mixing food w enzymes
What digestive cancer has the highest mortality rate?
colorectal cancer (colon or rectum)
reduced risk through physical activity, weight management and dietary modification
What do amino acids look like?
21 amino acids
amine group connected to a unique side chain
What does a triglyceride look like?
3 fatty acids attacked to a glycerol back bone resembling a jellyfish!!
What does microbiome refer to ?
different genetic material found in our body due to presence of microorganisms such as bacteria
What does the suffix -ase denote
What prefix’s are normally used along w?
enzyme
prefix tellers us which substrate it acts on
(“sucrase” breaks down sucrose)
What factors can affect transit times?
age, activity levels, diet, gender, medication use, infection
What foods can cause IBS?
- fatty foods
- caffeine
- alcohol
- carbonated drinks
- spicy foods
- gluten
- articulated sweeteners
What is a hydrolysis reaction?
input of water helps to break down the molecule
What is a micelle?
lipid group with a ring of bile salts around it
What is active transport?
in addition to protein transporter, movement against concentration gradient requires energy.
amino acids and glucose
low to high
What is anabolism?
metabolism of smaller molecules coming together to make larger ones.
requires net input of energy
What is bicarbonate?
buffer that neutralizes chyme, making it less acidic and more conductive to physiological processes
What is bile?
lipid emulsifier. salts have a hydrophilic head ad hydrophobic tail. is arranged around lipid groups
What is cancer?
involves uncontrolled multiplication and spread of cells
What is catabolism?
breakdown of larger molecules into smaller ones. release energy
What is chemical digestion?
uses enzymes to alter the chemical structure of nutrients and reduces them to their building blocks
What is chyme?
semiliquid substance that leaves stomach. (from bolus)
What is constipation?
bowel movements that are difficult to pass or less frequent.
typically dry hard and painful stools
symptoms: abdominal pain and bloating
What is diarrhea?
matter passes too quickly through the large intestine, causing loose, liquid like stool
main causes: bacterial and viral infections
protective mechanism to expel infectious agents
What is digestion ?
separation of nutrients in food and breaks larger molecules into smaller ones so they can be absorbed.
polysaccharides->sugars
triglycerides-> fatty acids
proteins-> amino acids
What is diverticulitis?
inflamed outpouchings
What is diverticulosis?
bleeding diverticula
condition where outpouchings (diverticula) of the large intestine become inflamed and bleed
What is emulsification ?
process that allows hydrophobic lipids to be suspended in a watery environment. bile salts are required for this process
What is facilitated diffusion?
certain sugars that require a proteincertain sugars that require a proten transporter pass from an area of high concentration to low concentration.
absorptive
high to low
What is gastric lipase?
enzyme that continues the break down of lipids that lingual lipase began in the mouth
What is glycolysis?
first step of cellular respiration
6 carbon broken down into 2 carbfirst step of cellular respiration
6 carbon broken down into 2 molecules of 3carbon pyruvate
energy released (2 ATP)
anaerobic
What is hemorrhoids?
swollen and inflamed veins in the rectum and anus, which can be causeswollen and inflamed veins in the rectum and anus, which can be caused by:
1. chronic constipation
2. chronic diarrhea
3. prolonged sitting
4. low fibre diet
5. obesity
6. pregnancy
7. heavy lifting
8. aging
9. anal intercourse
10. genetics
What is lysozyme? Where is it found?
agent that disinfects arterial arriving in our food to help reduce the chances of the entry of an active infectious agent
found in saliva
What is mechanical digestion?
physical digestion.
uses physical processes like our teeth chewing and stomach churning to break food apart.
does not alter chemical composition of nutrients
What is metabolism?
sum of all chemical reactions that occur in an organism
What is microbiota?
refers to total composite of microorganisms found in our bodies.
includes viruses, fungi, and other microorganisms, but mostly bacteria
What is osmosis?
when there is a higher concentration of dissolved particles within villus, water moves into this area to decrease relative concentration
high to low
What is pancreatic juice?
contains several digestive enzymes (protease, lipase, amylase)
also contains bicarbonate
What is pepsinogen? what happens when HCL acts upon it?
proenzyme that is secreted by certain stomach cells.
only becomes active when acted upon by hcl, converting it into pepsin
What is peristalsis?
waves of muscle contraction to move a bolus of food forward.
What is simple diffusion?
fatty acids and fat-soluble vitamins that do not require a transporter can be absorbed along the spaces between phospholipids in enterocytes cell membrane.
movement from an area of a high concentration to one of a low concentration
high to low
What is the brush border?
microvilli border orientated towards lumen
stores certain digestive enzymes such as lactase, sucrase, and maltase
What is the chemical digestion of the mouth?
salivary breakdown of lipids and starch
What is the digestive tract?
long tube like structure that begins in the mouth and ends in the anus
What is the duodenum?
first part of small intestine, has a small opening that receives secretions from accessory structures
What is the esophagus?
conduit for food from pharynx to stomach
What is the flap that allows food into esophagus ?
epiglottis
What is the large intestines main function?
to package waste for easy removal
draws out water and packages waste into solid feces which is easier to excrete
What is the lumen?
inner cavity of the small intestine tube.
food and digestive secretions are found here
What is the lymphatic system?
network of tissues and organs that help rid the body of toxins, waste, and other unwanted materials.
components:
- lymphatic vessels
- lymph nodes
- lymphatic organs
- bone marrow
What is the main goal of amino acids?
promote growth and repair tissues
What are the functions of the lymphatic system?
- immune response to identify and fight infections by carrying white blood cells
- fluid balance: collect excess fluid from tissues ad return it to the bloodstream
- absorption of fat: absorbs dietary fats and fat soluble vitamins from digestive system
- waste removal: removes waste products and toxins
What is the microbiome?
large variety of non human genetic arterial within our bodies due to presence of these microorganisms
contains about 150x more genes than human DNA
What is the mucosa?
inner most layer of dtw that faces the lumen.
secretes mucus which keeps the dt moist and protects it from infection.
plays a critical role in absorption
What is the muscularis?
layer of dtw composed of smooth muscle.
responds to movement needs of dt, pushing food forward and helping it mix w digestive secretions
What is the pharynx? does absorption happen here?
throat, conduit from mouth to stomach. no further digestion or absportion occurs here
What is the primary site of digestion and absoprtion?
small intestine
What is the purpose of the enteric nervous system?
communicates with the brain but can also function independently.
helps regulate muscular contractions, messaging and digestive tract secretions
What is the serosa?
outermost layer of dtw
consists of a layer of connective tissue tat helps to reduce friction w organs adjacent or helps anchor it into place.
What is the submucosa ?
connects the mucosa to themore superficial muscularis layer
blood vessels, lymphatic vessels and nerves are found here.
What is thee mechanical breakdown of food in the mouth ?
tongue pushes food and helps mix w saliva and water
teeth rip food apart and help break into smaller parts
What mechanical digestion occurs in the stomach?
churning
What is gastric juice?
mixture of enzymes that contains several substances that facilitate digestion while protecting stomach walls.
Whats the role of the liver?
metabolism, detoxmetabolism, detoxification and digestion
production of bile which promotes lipid digestion
What sphincter allows chyme to enter the small intestine?
pyloric sphincter
What sphincter is found between esophagus and stomach?
lower esophageal sphincter
When energy intake is higher than energy expenditure what happens to the excess amino acids?
excess amino acids will be converted into lipid and stored in our fat cells
When we are not eating, what does the pharynx convey?
air. pharynx opens to the trachea allowing air to flow in and out of lungs
Where are prebiotics found?
asparagus, beet suga, garlic, onion, wheat, honey, banana, barley, tomato, rye, soy milk, peas, beans, seaweed
Where are probiotics found?
foods such as yogurt, kombucha
Where are secretions form pancreas, liver and gallbladder collected?
collected into a common tube that drains into the duodenum
Where can ulcers occur ?
- peptic ulcers occur in the lining of the stomach. (gastric ulcers: lining of stomach, duodenal ulcers: lining of duodenum)
- esophageal ulcers
- mouth (canker sores)
- genitals (can be caused by infections, inflammatory conditions or trauma
- corneal ulcers (cornea of the eye, caused by infections, injuries, or contact lens use
- pressure ulcers (bedsores): on skin and underlying tissues over bony areas of the body such as heels, ankles, hips, and tailbone
Where do excess amino acids go?
body proteins or converted to lipids for fat storage
Where do excess carbohydrates go?
glycogen storage or are converted to lipid for fat storage
Where do excess lipids go?
fat storage or other lipid compounds
Where do nutrients go if not used or stored in liver?
enters bloodstream then sent throughout body via cardiovascular system
Where does lipid metabolism occur?
liver
Where does the majority of absorption occur ?
small intestine
Where does the majority of digestion occur?
small intestine
Where is bile stored?
gallbladder for quick secretion when needed
Which parts of the body are capable of removing toxins from the body ?
lungs, kidneys, liver
Why do gallstones occur?
overabundance of cholesterol as compared to bile salts in bile
Why does the surface of the small intestine look fuzzy to the naked eye?
millions of villi on he membrane
Summary of Glucose Metabolism
- Glycolysis
- Breakdown of Pyruvate
- Citric Acid Cycle
- Electron Transport Chain
What is the process of Glycolysis?
1 glucose produces 2 pyruvate and ATP, anaerobic
What is the breakdown of Pyruvate?
produces acetyl CoA and ATP
Aerobic conditions - acetyl CoA is formed
Anaerobic conditions - pyruvate is formed
What is the Citric Acid Cylce?
acetyl CoA and oxaloacetate combine to produce CO2, water and capture of energy in GTP (NADH+H+, FADH2)
What is the Electron Transport Chain?
Electrons exchanged between electron transporters, leads to build up of protons on one side of the membrane, protons will move through proton pump called ATP synthase
What is Ketogenesis?
Diet is high in fat and very low in carbs, the citric acid cycle requires carbs
What is Beta-Oxidation?
Splits the fatty acid two carbon atoms at a time, then each two-carbon molecule can be used to form acetyl CoA
What is the equation for cellular respiration of glucose?
C6H12O6 + 6O2 –> 6CO2 + 6H2O + ATP
