topic 4: digestive system

Question 1

describe the process of digestion (occurs in stomach and small intestine)

Answer 1

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

Question 2

describe the process of absorbtion(occurs in small intestine)

Answer 2

-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

Question 3

what is a philtrum

Answer 3

• The upper lip is split vertically by a division known as the philtrum.

Question 4

functions of the tongue

Answer 4

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

Question 5

what are the four types of teeth

Answer 5

incisor: grooming
canine: holding prey
pre-molars: shearing flesh off the bone
molars: grinding

Question 6

what is the permanent dental formula of the dog

Answer 6

3-1-4-2
3-1-4-3

Question 7

what is the permanent dental formula in cat

Answer 7

3-1-3-1
3-1-2-1

Question 8

function of the epiglottis

Answer 8

The epiglottis closes to prevent food entering the larynx.

Question 9

what are the five different parts in a monogastric stomach

Answer 9

Cardia
* Fundus
* Body
* Pyloric antrum
* Pylorus

Question 10

functions of the different parts of a monogastric stomach

Answer 10

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

Question 11

what is the major function of the small intestine

Answer 11

Function: major site of enzymatic digestion and absorption.

Question 12

what are the three parts of the small intestine

Answer 12

-duodenum
-jejunum
-ileum

Question 13

List and describe the function of the enzymes present in intestinal juice.

Answer 13

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.

Question 14

Describe the structure and functions of the villi

Answer 14

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.

Question 15

Describe two main types of smooth muscle contraction for the movement of
digestive tract.

Answer 15

Peristaltic contraction: coordinated contraction and relaxation of
muscle layer, resulting movement of food
* Segmental contractions: mix the GI tract contents

Question 16

Does large intestine contains villi and digestive glands?

Answer 16

The large intestine has no villi and no digestive glands, but there are
goblet cells, which secrete mucus to lubricates the faeces

Question 17

what are three parts of the large intestine

Answer 17

-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

Question 18

Describe the structure and function of Anal sphincter.

Answer 18

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.

Question 19

What are the main components of dog and cat’s saliva

Answer 19

Saliva is 99% water and 1% mucus

Question 20

function of saliva in dogs and cats

Answer 20

-lubricate food-> making it easier to swallow
-thermoregulation

Question 21

Exocrine gland of pancreases secretes (to small intestine)

Answer 21

• 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

Question 22

Pancreatic endocrine glands secrete the hormones

Answer 22

• 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)

Question 23

function of gall bladder

Answer 23

for storage of bile produced by the liver

Question 24

function of bile

Answer 24

break down fats into fatty acids

Question 25

Describe the anatomical location of a liver.

Answer 25

• 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

Question 26

function of liver

Answer 26

• 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

Question 27

Describe anatomical structure of hepatic lobule

Answer 27

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.

Question 28

What are the names of the four chamber compartments of ruminant stomach and function

Answer 28

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.)