Digestive System Flashcards
3 Types of Animals
Herbivores, Carnivores, Omnivores
4 main parts of digestion
Ingestion, Digestion, Absorption, Elimination
What is Ingestion
Act of eating
What is Digestion
Process of breaking down food in either mechanical or chemical digestion
What is Absorption
Uptake of nutrients by body cells
What is Elimination
passage of undigested material out of the digestive compartment
What is Mechanical Digestion and give an example of what part of the digestive system uses it
Mechinal digestion is the physical act of breaking food down into smaller pieces to increase surface are. The Oral cavity is an example of mechanical digestion
What is Chemical Digestion and list 1 example of it
Mechanical digestion is when chemicals/enzymes break down nutrients into into smaller molecules eventually macromolecules
What is Mammalian Digestive System
Also known as Gastrointestinal Tract, is when solid food is entered the body and solid food is expelled out of the body; humans and most ‘mammals’ use mammalian digestive system
What is the movement of rhythmic contractions of smooth muscles called, and list an example of where its used
Peristalsis, esophagus
Where is Indigestion taken place?
In the oral cavity
List the types of Chemical Digestion and Mechanical Digestion that takes place in the Oral Cavity
Mechanical Digestion:
Teeth - breaks down food into smaller pieces
Tongue - shapes food into bolus
Salivary glands - release saliva to lubricate the bolus/food
Chemical Digestion:
Salivary Glands - Salivary amylase which breaks down carbohydrates
Tongue - Lingual lipase which breaks down triglycerides
What is the Pharynx
a region at the end of our throat that opens the esophagus and trachea
What is the Epiglottis?
Flap that closes the entry to the trachea wen swallowing food
What 2 ends does the esophagus connect?
pharynx and stomach
What does the esophagus use to move the bolus to the stomach
peristalsis
What is Gastric Rugae?
A series of folds within the stomach
What are Sphincters
regulates the entry of bolus and prevents/regulates chyme from leaving the stomach
What is Gastric Juice?
Hydrochloric acid and Pepsin
What type of mechanical digestion happens in the stomach
Mechanical:
Rugae - churning (type of peristalsis) by expanding and contracting
What 3 types of cells are in the stomach
Parietal cells, Chief cells, Muscous/Giblet cells
What are Parietal Cells?
Release H+ and Cl- ions to make HCl. They dont make HCl because it would destroy the cell from the inside to it releases the ions and let them bond together in the stomach it also protects the stomach from harmful bacteria as its very acidic.
What are Chief Cells?
Secrete inactive pepsinogen, when active its pepsin. Pepsin becomes active in an acidic environment, hence the HCl. Digests proteins
What are Mucous/Goblet cells?
secretes mucus which protects the stomach lining so HCl and pepsin won’t Destry the stomach and cells.
Where are all the parietal, chief, goblet cells located in the stomach?
In gastric pits on the interior of the surface of the stomach
What is the chemical digestion in the stomach?
Chief cells release pepinsogen which activated in an acidic environment to pepsin which digests proteins. Parietal cells release H+ & Cl- ions to form HCl
What is the longest section of the digestive system in mammalian digestive systems?
The small intestine reaching over 6 meters/20feet
What is the small intestine known for?
Digestion and absorption
What and where is the duodenum and where is it located?
Duodenum is the beginning part of the small intestine, its where chyme rom the stomach mixes with intestinal digestive juices from: gallbladder, liver, pancreas, and the small intestine.
What types of digestion does the pancreas use?
chemical digestion releases pro-enzymes and zymogens
What are pro-enzymes and zymogens? and how to you tell the difference between the active vs non-active enzymes?
Pro-enzymes and zymogens are the inactive version of the enzymes. If there is a ‘ogen’ at the end or ‘pro’ in the beginning its a pro-enzymes/zymogens. Eg. trypsinogen, prolipase
What types of pro-enzymes/zymogens and the active enzymes does the pancreas release
- Trypsinogen - Trypsin = polypeptide
- Chymotrypsinogen - Chymotrypsin - polypeptide
- Procarboxypeptidase - Carboxypeptidase = Polypeptides
- Prolipase - Lipase = fats
- Proamylase - Amylase = starch/saccarides
- Pronucleases - Nucleases = nucleic acids
Are the pancreatic juices alkaline or acidic and why so?
alkaline to neutralize the acidic chyme from the stomach
Where is Bile produced and what does it do?
Produced in the liver and stored in the gallbladder. Bile aids in the absorption of fats, it uses a type of mechanical digestion called emulsification to increase the surface area of fats into small droplets so that lipase can digest the fats easier.
What are some other things that the Liver does?
- Detoxifies the blood
- Stores vitamins and iron
- Stores glucose and glycogen
- Converts glycogen to an unstable sugar to raise blood sugar levels when its low
- Breaks down hemoglobin, insulin, and hormones
- Converts ammonia to urea
- Destroys old blood cells
What are Villi and Microvilli and where is it located?
Increases surface area for absorption, located all around in the small intestine. Villi Is the bigger one and microvilli is attached to the villi, smaller
What does each Vilus contain?
lacteal, cappilarory network, nerves, epithelium.
How are Glycerol and fatty acids absorbed.
Triglycerides are broken down into fatty acids and mono-glycerides then phospholipids, cholesterol and proteins to form chylomicrons which transport the fats into the lacteal.
How are amino acids and sugars absorbed
they pass through the epithelium and enter the blood stream
Where does the capillaries, and lacteals lead to after the small intestines (villi)?
leads to the hepatic portal vein which then delivers the blood to the liver to get filtered then the heart to get re-oxygenated.
What is Cecum? and where is it located within the digestive system
Cecum is a pouch that connects the large intestine to the small intestine. It also aids the fermentation of plant material.
Where is the appendix connected to? and what does it do?
Comes of of the cecum, aids in immunity
what are major roles of the large intestine?
reabsorption of water, mineral ions (chlorine, sodium)
What happens to the feces as it moves through the large intestine?
becomes more solid as most of the water present would get reabsorbed into the body.
What bacterium are present in the large intestine specifically the colon? and what is the purpose of that?
Strains of Escherichia coli, which some produce vitamin k, biotin, folic acid which are reabsorbed into the blood stream.
What is Gastrin and what does it do
?
Gastrin is a hormone that stimulates the production of gastric juices. It becomes active when bolus enters the stomach and stretches the gastric rugae (stomach lining)
What happens when Chyme exits the stomach and enters the duodenum in terms of hormones?
The presence of Chyme triggers the cell lining of the duodenum to release Cholecystokinin (CCK) and Secretin into the blood stream. CCK triggers the gallbladder to contract to release bile into the duodenum and the pancreas to release pancreatic juices into the duodenum. Secretin triggers the pancreas to release HCO3- ions to neutralize the acidic Chyme.
What happens when the Chyme in the stomach is rich in fats in terms of hormones?
OF the chyme is rich in fats, CCK and Secretin would be produced more and would inhibit the stomach peristalsis thus slowing the digestion movement, and would stimulate the liver and pancreas to produce more bile/pancreatic juices.`
What happens when you have lo blood sugar in terms of glucose homeostais
Glucagon in produced in the pancreas with alpha cells, which then stimulates the liver to breakdown glycogen to glucose and release in the blood stream
What happens when a carbohydrate-rich meal in ingested in terms of glucose homeostasis
insulin levels rise with the help of beta cells in the pancreas, which triggers the synthesis fo glycogen and transported through the blood stream to the liver to be stored.
What is Osmoregulation?
controlled movement of solutes between the body’s internal fluids and the external envoirnment
What is osmolarity
Total solute concentration expressed in miliosmoles (mOsm)
What is the osmolarity of the human blood?
300 mOsm/L
What is iso/hypo/hyper-osmotic?
- Iso-osmotic - net movement of water is equal in both directions
- hyper-osmotic higher concentration inside than out
- Hypo-osmotic lower solute [] inside than outside
What organs are involved in exception of water/urine?
Skin - sweats out electrolytes and water
Lungs - removing CO2
Liver - breaks down toxic substances in blood, as well as produce urea
large intestine - removes some water from faces during absorption
Where are the kidneys located
2 bean shaped organs located just below the rib cage
What are the 3 main ‘tubes’ that are attached to the kidneys
Renal Artery - blood going into the kidney
Renal vein - blood exiting the kidney
Ureter - Urine exists the kidney and drain out the ureter
Where does the urine go after the Kidney?
Drains into the Ureter which leads it to urinary bladder, then when its finally ready to get expelled it goes through the urethra
What are the 2 distinct regions of the kidneys?
Outer renal cortex and the inner renal medulla
What are renal pyramids and how many are there?
there are 8 and they are part of the inner renal medulla
How are the Renal Medulla connected to the Ureter?
Each renal pyramid is connected to a minor calyx which connects with another minor calyx to form a major calyx. When the major calyx merge together it forms the renal pelvis which is then connected to the ureter
What is a nephron
functional unit of the kidney. Consists of one ling tubule and a ball of capillaries (glomerulus)
how many nephrons are in eat adult and the approx length
1 million and 80 km
What is a Glomerulus
ball of capillaries
What is a Bowman’s Capsule
A capsule that surrounds and receives filtrate from the glomerulus capillaries
What are the 3 parts to produce urine
Filtration, reabsorption, and secretion
Where does filtration occur in the nephron
Renal corpuscle (Bowmans capsule and glomerulus)
Which arteriole enters the glomerulus and exits?
efferent = exit afferent = going in
