topic 4: digestive system Flashcards
describe the process of digestion (occurs in stomach and small intestine)
food contains a mix of proteins, carbohydrates, and fats that are too large to be directly
absorbed into the bloodstream-> need to undergo enzymatic digestion ( glands secrete these digestive enzymes). result of process produces smaller molecules-> can be absorbed by the bloodstream and transported to body part for metabolism
describe the process of absorbtion(occurs in small intestine)
-protein-> amino acid and
carbohydrates-> monosaccharides & disaccharides pass through walls of the intestine villi into the blood capillaries
-transported to liver by hepatic portal vein for metabolism
-fat-> fatty acid and glycerol transforms into chylomicrons by attaching a protein coat
-chylomicrons are absorbed into lymphatic systm through walls of the villi and id carried as chyle which enters the circulation through the heart
what is a philtrum
- The upper lip is split vertically by a division known as the philtrum.
functions of the tongue
Aid in the prehension of food.
* Help in the formation of a food bolus ready for swallowing
* Fur Grooming
* Thermoregulation, e.g. dogs pant to cool the body.
* Vocalization – production of sound involves movements of
the tongue and lips
what are the four types of teeth
incisor: grooming
canine: holding prey
pre-molars: shearing flesh off the bone
molars: grinding
what is the permanent dental formula of the dog
3-1-4-2
3-1-4-3
what is the permanent dental formula in cat
3-1-3-1
3-1-2-1
function of the epiglottis
The epiglottis closes to prevent food entering the larynx.
what are the five different parts in a monogastric stomach
Cardia
* Fundus
* Body
* Pyloric antrum
* Pylorus
functions of the different parts of a monogastric stomach
Cardia: controls the entry of food, and prevent
back flow.
* Fundus: secretes gastric juice and some protective mucous
* Body: continuation of the fundus
* Pyloric antrum: grinds up swallowed food and secretes gastrin (HCL)
* Pylorus: muscular sphincter
* regulates the movement of food from the stomach into the duodenum
* Prevents food backflow
what is the major function of the small intestine
Function: major site of enzymatic digestion and absorption.
what are the three parts of the small intestine
-duodenum
-jejunum
-ileum
List and describe the function of the enzymes present in intestinal juice.
Maltase: converts maltose to glucose.
2. Sucrase: converts sucrose to glucose and fructose.
3. Lactase: converts lactose to glucose and galactose.
4. Enterokinase: converts trypsinogen to trypsin.
5. Aminopeptidase: converts peptides to amino acids.
6. Lipase: converts fats to fatty acids and glycerol.
Describe the structure and functions of the villi
The epithelium of the small intestine is folded into structure called villi
which increase the surface area of the organ for digestion and
absorption. Each villus has a border of microvilli which form a brush
border to further increase the surface area.
Describe two main types of smooth muscle contraction for the movement of
digestive tract.
Peristaltic contraction: coordinated contraction and relaxation of
muscle layer, resulting movement of food
* Segmental contractions: mix the GI tract contents
Does large intestine contains villi and digestive glands?
The large intestine has no villi and no digestive glands, but there are
goblet cells, which secrete mucus to lubricates the faeces
what are three parts of the large intestine
-caecum: blind-ending tube joining the ileum and the ascending colon
-colon: Water, vitamins and electrolytes are absorbed by the colon ensuring that the body does not lose excessive water and become dehydrated.
-rectum
Describe the structure and function of Anal sphincter.
function: controls the passage of faeces
structure: *Internal anal sphincter: inner ring of smooth muscle (involuntary control)
*External anal sphincter: striated muscle and is
under voluntary control.
What are the main components of dog and cat’s saliva
Saliva is 99% water and 1% mucus
function of saliva in dogs and cats
-lubricate food-> making it easier to swallow
-thermoregulation
Exocrine gland of pancreases secretes (to small intestine)
- Proteases:
- Break down protein into amino acids
- Eg. trypsin
- Bicarbonate:
- Neutralize the acid and provides an alkaline environment for
pancreatic enzymes. - Pancreatic Lipase:
- Break down fats
- Pancreatic Amylase: break down starch
Pancreatic endocrine glands secrete the hormones
- Insulin
- by beta cells of pancreas
- decrease blood glucose
- Glucagon
- by alpha cells of the pancreas
- Keep blood glucose level high
- Somatostatin
- by delta cells
- growth hormone–inhibiting hormone (prevent rapid reproduction of cells)
function of gall bladder
for storage of bile produced by the liver
function of bile
break down fats into fatty acids
Describe the anatomical location of a liver.
- The liver is located in the
cranial part of the abdomen,
caudal to the diaphragm and
cranial to the stomach and
intestines. - Generally the bulk of the liver
is on the right of the midline
function of liver
- Carbohydrate metabolism: excess glucose is stored as glycogen in
the liver - Protein metabolism: Production of plasma proteins: such as:
albumin, fibrinogen, prothrombin and globulins - Fat metabolism: the liver converts fatty acids and glycerol into
phospholipids (for formation of cell membranes) and cholesterol - Formation of bile: to aid in digestion\
- detoxification of harmful substances
Describe anatomical structure of hepatic lobule
Running through the lobule are
minute blood space called sinusoids
* Sinusoids carry blood from the
hepatic portal vein
-sinusoid drains into the central vein at
the centre of each lobule.
The central veins flow to the hepatic
vein and,
* then to the caudal vena cava,
* Between the hepatocytes are tiny
channels called bile canaliculi (contain
bile).
* The canaliculi drain into the bile
ducts.
What are the names of the four chamber compartments of ruminant stomach and function
Reticulum: acts as a collection compartment of foreign objects from the food.
• Rumen: allows bacterial and chemical breakdown of fiber.
• Omasum: “Grind” the food material and prepares the food for chemical breakdown.
• Abomasum: the majority of chemical breakdown take place, mixes foods with digestive enzymes (pepsin, rennin, bile, etc.)
