The digestive system Flashcards
ingestion
the process of taking food into the body; this takes place in the mouth
Digestion
the process of breaking down the food into small chemical units; this occurs in the stomach and small intestine
Absorption
the process whereby the chemical units pass into the blood and are carried to the liver; this occurs in the small intestine
Metabolism
the process in which the chemical units are converted into energy for use by all the organs of the body; this takes place mainly in the liver
Excretion
the removal of any remaining indigestible material
What is the oral cavity also known as?
mouth or buccal cavity
What does the oral cavity contain?
tongue, teeth and salivary glands
Prehension
to pick up food
mastication
chewing
Philtrum
the vertical split in the upper lip
gustation
taste
papillae
tiny fleshy nodules that cover the tongue
What is the function of the papillae?
gustation
grooming
movement of food boluses caudally towards the pharynx
what does saliva consist of?
99% water and 1% mucous
What are the names of the salivary glands?
Zygomatic
Sublingual
Mandibular
Parotid
Where is the zygomatic salivary gland located?
Close to the eyeball within the orbit
Where is the sublingual salivary gland located?
medial to the mandible, under the mucosa covering the underside of the tongue
Where is the mandibular salivary gland located?
caudal to the angle of the jaw
Where is the parotid salivary gland located?
between the base of the ear and the mandibular glands
what is the function of saliva?
to lubricate food making mastication and swallowing easier
Thermoregulation - panting and grooming
in omnivores it contains amylase which begins carbohydrate digestion
deglutition
Swallowing
What is the pharynx
a muscular tube lined with mucous membrane, connecting the back of the nasal and oral cavities with the oesophagus and the larynx and trachea.
What is the average time for food to pas down the oesophagus?
15-30 seconds
What are the functions of the stomach?
to act as a reservoir for food
to break up food and mix it with gastric juices
to begin the process of protein digestion
Where is the stomach located?
on the left side of the cranial abdomen
Where does food enter the stomach from?
the cardiac sphincter
Where does food leave the stomach?
the pyloric sphincter
What is the name of the mesentery attached to the lesser curvature of the stomach?
Lesser omentum
What is the name of the mesentery attached to the greater curvature of the stomach?
greater omentum
Where is the spleen located?
within the layers of the greater omentum
What are the 3 sections of the stomach called?
Cardia
fundus
pylorus
Where are the goblet cells found?
in all parts of the stomach
What is the function of the goblet cells?
to secrete mucous to lubricate the food and to protect the stomach wall from damage by the digestive enzymes
Where are chief cells found?
within the fundus
What is the function of chief cells?
secrete pepsinogen, the precursor to the active enzyme pepsin which breaks down proteins into peptides
Where are parietal cells found?
within the fundus
What is the function of parietal cells?
secrete hydrochloric acid, this creates a pH which enables pepsin to work effectively
What are the 3 parts of the small intestine?
Duodenum
Jejunum
Ileum
Where does food enter after passing through the the pyloric sphincter?
The duodenum
What happens in the small intestine?
Enzymic digestion and absorption
Where does the pancreas lie?
Within the loop of the U shaped duodenum
Where does the pancreatic duct and the common bile Duct empty into?
The duodenum
What is the name of the gland in the duodenum?
Brunner’s glands
What is the name of the digestive enzymes that the Brunner’s glands secrete?
Succus entericus
What does the duodenum lead on to?
The jejunum
What is the last section of the small intestine called?
Ileum
What is the name of the digestive glands within he wall of the jejunum and ileum?
Crypts of lieberkuhn
What are the crypts of lieberkuhn?
Digestive glands within the walls of the jejunum and ileum
What is the name of the part of the ileum that ends and joins the caecum?
Ileocaecal junction
What are villi?
Leaf-shaped folds of the epithelial layer of the small intestine
What is the function of the villi?
To increase the surface area of the epithelium to maximise the efficiency of the digestive and absorption process
What is chyle?
A milky fluid resulting from fat digestion carried by the lacteals
What is a lacteal?
A lymphatic capillary that carries chyle from the small intestine to the cisterna chyli in the dorsal abdomen
What does the exocrine part of the pancreas secrete?
Digestive enzymes and bicarbonate
Where does the gall bladder lie?
Within the lobes of the liver
What stimulated the release of gastric juice?
The hormone gastric secreted from the stomach wall
What hormone stimulates the secretion of gastric juice?
gastrin
What does gastric juice contain?
Mucus
hydrochloric acid
pepsinogen
pepsin
What gives gastric juice its acidic pH?
Hydrochloric acid
what is the first part of the large intestine that joins with the ileum?
Caecum
What is the function of the caecum in carnivores?
It has no significant function
What happens in the colon?
Water, vitamins and electrolytes are absorbed
What is the name of the part of the colon that runs through the pelvic cavity?
Rectum
What structures marks the end of the intestinal tract?
Anal sphincter
What is the largest gland in the body?
the liver
What is the cranial aspect of the liver in contact with?
the diaphragm
What is the caudal aspect of the liver in contact with?
The stomach, duodenum and right kidney
what is the main section of the stomach called?
The Fundus
What holds the stomach to the abdominal wall?
Omentum
What hold the intestines to the abdominal wall?
Mesentery
