A&P Exam 1 Flashcards
What are the components of the large intestine?
Cecum, colon, rectum
Primary functions:
Recover fluid & electrolytes
Store feces until they can be eliminated
Which part of gi tract?
Large intestine
Blind sac at ileocecal junction in carnivores
Large in hind gut fermenters
Cecum
Part of large intestine where some microbial digestion occurs in all species
Colon
What type of species?
Simple, tubular colon; poorly developed cecum
Carnivores
What species are hindgut fermenters?
Equidae, rabbits, most rodents (guinea pigs, chinchillas, rats)
What type of stimulation generally increases motility in the colon and increased mucus secretion in most species?
Parasympathetic nervous system
Terminal portion of the large intestine
Nervous system control of motility and secretions similar to colon
Numerous mucus-secreting glands lubricate & aid passage of contents
Sensory receptors detect stretching and stimulates defecation response
Capable of more expansion than colon
Rectum
Composed of internal and external muscular sphincters
Anus
The internal anal sphincter is under what type of nervous system control?
Autonomic (involuntary)
This type of nervous stimulation causes relaxation of the internal anal sphincter
Parasympathetic
External anal sphincter is under what type of control?
Voluntary
What receptors increase the sense or need for defecation?
Anal mucosal receptors
Largest gland in the body
Considered a glad because it produces and excretes bile
Liver
Whatever term refers to liver?
Hepatic
The liver is divided into several lobes called:
L lateral, l medial, quadrate, r medial, r lateral, caudate
Functions of what?
Removes toxins, infectious agents, etc that enter the body through the wall of the gi tract
Stores and metabolizes nutrients absorbed from the gi tract
Produce bile
Synthesize albumin and other proteins
Gluconeogenesis
Liver
Blood vessel system that transports blood capillaries in the intestines to capillaries in the liver called hepatic sinusoids
Hepatic portal system
Capillaries in the live that fill with blood
Hepatic sinusoids
Blood leaves the liver through what vein and then enters the right atrium
Caudal vena cava
What types of nutrients are absorbed through the gi tract and are stored in the liver?
Glucose, amino acids, some vitamins minerals
What 3 contents is bile made of?
Bile acids, cholesterol, bilirubin
These are critical for digestion and absorption of fats and fat-soluble vitamins in the small intestine
In bile
Bile acids
Excessive hemolysis, impaired liver function, and bile duct obstruction can cause what?
Increased bilirubin
Bile is stored in what
Gallbladder
Stimulation by what causes gallbladder contraction which forces bile down common bile duct and into the duodenum
Cholecystokinin (CCK)
What 2 species do not have a gallbladder?
Horses and rats, continuously secrete bile into duodenum
Most bile acids are reabsorbed in the ileum where they enter portal circulation.
Therefore, blood levels of bile acids should be
Very low
Decreased functional hepatic mass, abnormalities of portal circulation (ports systemic liver shunt), and choke static disease (stasis of the gallbladder) cause bile acid concentrations to
Increase
Stasis of the gallbladder
Cholestatic disease
Liver synthesizes important blood proteins such as this one.
Maintains proper fluid balance in the blood
Albumin
What type of levels of albumin cause fluid to leak out of the capillaries resulting in fluid moving into the tissues or body cavities
Decreased albumin
Fluid in the tissues
Edema
Fluid in a cavity
Effusion
Glucose absorbed from gi tract may be stored in the liver as glycogen in a process called
Glycogenesis
Glucose stored in the liver is in what form
Glycogen
If body is in need of glucose, glycogen is broken down by the liver in a process called
Glycogenolysis
Glucose can also be made in the liver from amino acids through a process called
Gluconeogenesis
Both and endocrine and exocrine gland
Pancreas
The pancreas secretes these 3 enzymes through the pancreatic duct into the small intestine
Amylase
Lipase
Proteases (trypsin)
What enzyme helps with carbohydrate digestion?
Amylase
What enzyme aids in fat digestion
Lipase
What enzyme aids in protein digestion
Proteases (trypsin)
The pancreas also secretes this into the duodenum to help neutralize the acidity of contents and maintains the pH in the duodenum needed for proper enzyme function
Bicarbonate
These functions are indicative of what organ and which function of the organ?
Beta cells produce insulin which moves glucose from blood to tissues (diabetes mellitus, insulinoma)
Alpha cells produce glucagon which stimulates the liver to perform glyconeogenesis or gluconeogenesis.
Endocrine pancreas
How does ruminant stomach differ from monogastrics?
1 true stomach and 3 forestomachs, adapted to digesting plants
The process of swallowing food, regurgitating it to on it some more before swallowing it again
Rumination
Smallest, most cranial compartment of the forestomach compartments
Muscular wall is continuous with the rumen and the 2 contract in a coordinated manner
Separated from rumen by the ruminoreticular fold
Reticulum
Common term for bovine traumatic reticuloperitonitis
Usually caused by ingestion of sharp metallic objects that settle in the reticulum, and can irritate or even perforate its lining
Can even lead to pericarditis
Hardware disease
Prevention of hardware disease?
Place magnet in stomach
Large fermentative vat
Largest forestomach
Series of muscular sacs partially separated from one another by long muscular folds of rumen wall called pillars
Rumen
Chemical splitting of complex organic compounds into relatively simple substances
Fermentation
Series of muscular sacs partially separated from one another by long muscular folds of rumen wall called
Pillars
Reticuloruminal contractions allow for these 3 things
Mixing and stirring of contents
Regurgitation
Eructation
Rumen motility is controlled by the
Parasympathetic nervous system
Rumen pH, presence of volatile fatty acids, consistency of ingesta in the rumen, stretch receptors, and feedback from the brain stem and other parts of the gi tract determine what
Rte and strength of contraction
Enzymes produced by the glands in monogastric animals cannot digest what
Cellulose and pectin in the cell wall of plants
Microbial proteases do what
Break down protein into peptides
Rumen bacterial surfaces have cellulose enzymes that
Convert cellulose into simple sugars
Simple sugars and peptides are absorbed by the microbes and converted to
Volatile fatty acids (VFAs)
Some peptides are converted to ammonia and used by the microbe to create their own
Amino acids and proteins
VFAs are absorbed into the bloodstream
Liver converts VFAs into
Glucose, adipose tissue, milk fat and other components
If a ruminant isn’t eating, the microbes eventually die and aren’t there to digest food when they start to eat again. Treatment?
Transfaunation
Reticulorumen contractions move ingesta and microbes in this forestomach
Muscular organ with many muscular folds
Breaks food particles down further
Absorbs any remaining VFAs
Removes bicarbonate ions so they don’t interfere with the acid pH of the abomasum
Absorbs some water from the ingesta
Omasum
True stomach, functions same as a monogastric stomach
Only compartment with glandular lining
HCl and digestive enzymes, needed for breakdown of feeds, are secreted into abomasum
Low pH facilitates initial protein breakdown. And kills bacteria which have spilled over from the rumen
Carbs are digested
Abomasum
Newborn ruminant’s gi tract functions primarily as monogastric gi tract
Rumen and reticulum are nonfunctional at birth
This groove in the wall of reticulum conveys liquid from the esophagus directly to the omasum
Rate of development of the rumen and reticulum affected by type of diet (milk vs grain)
Reticular groove (esophageal groove)
Modifications of cecum and colon in nonruminant herbivores allow fermentative digestion in the
Hindgut
These are produced by microbes and absorbed from the cecum and colon for energy needs just as in the rumen of ruminants
VFAs
