What is digestion?
The Hydrolysis of food polymers into monomers (such as monosaccharides, fatty acids, nucleotides, and amino acids)
What kind of digestion begins in the mouth?
Both physical and chemical
What are the two major groups of the digestive system?
The alimentary canal (GI tract) and the accessory organs
What are the accessory organs?
Teeth, Salivary Glands, liver, Gallbladder, pancreas (Exocrine and endocrine)
All openings to the environment are covered in what epithelium?
Stratified squamous epithelium
What makes up the GI Tract?
Mouth, pharynx, esophagus, stomach, small intestines, and large intestines
What are the four layers of the alimentary canal?
Mucosa, submucosa, muscularis externa and either a serosa or a adventitia
What portion of the alimentary canal is simple squamous epithelium?
Mouth, Oral Cavity, Pharynx, esophagus
What portion of the elementary canal is simple columnar epithelium with goblet cells?
Stomache, small intestine, and Large intestine
What covers the surface of the tongue?
Papillae or tastebuds
What propels food through the esophagus?
A peristalsis motion.
How many muscles does the esophagus have?
2- circular and longitudinal
What controls food passage into the stomach?
Gastroesophogeal Sphincter (also called LES or cardiac sphincter)
Name the regions of the stomach
Cardiac region, fundus, body, Pyloric region
What are the ridges in the stomach called?
Rugae- allows for expansion
How many muscles does the stomach have?
3-circular, longitudinal, oblique
What do the gastric glands in the stomach do? Where are these found?
- Gastric pits
- Secrete Hydrochloric Acid and hydrolytic enzymes that break down proteins
- *HCI by parietal cells
- *pepsin by chief cells
Whats the purpose of the mucus glands in the stomach?
- Prevent self-digestion
- What is processed food in the stomach called?
Where does the most digestion take place in the stomach?
What controls food moving from the stomach to the small intestine?
What are the three regions of the small intestine?
- Jejunum (main absorption)
- Ileum (joins large intestine at the ileocecal valve or ileoceum sphynter) (has peyers patches)
What is the main function of the small intestine?
Nutrient absorption occurs here
What are villi, microvilli, and plica?
- Vili: finger-like projections of the mucosa tunic of the SI give a velvety texture
- Microvilli: also called brush border cells on the columnar epithelium that have brush border enzymes
- Plicae: circular folds in SI increase surface area and absorption 5x
What do brush border enzymes do?
Help complete digestion along with enzymes produced by the pancreas.
What are the subdivisions of the Large Intestine?
Cecum, vermiform appendix, colon, rectum, and anal canal
What are the regions of the large intestine?
- Ascending colon, right colic (hepatic) flexure, transverse colon, left colic (splenic) flexure, descending colon, and the sigmoid colon (shaped like an "S")
- *cats do not have the sigmoid colon
- *rectum comes after sigmoid colon
What are the two sphincters from the rectum to the anus?
- Involuntary sphincter-smooth much
- Voluntary sphincter-skeletal muscle
What special glands does the duodenum have?
What's the main function of the large intestine?
- Moving fecal matter, and maintaining proper water
- Also creating Vit B and K by intestinal bacteria which absorbs into blood stream
What are baby teach called?
Deciduous or milk teeth
What's the number of deciduous teeth vs. permanent teeth?
- 2,1,0,2/2,1,0,2 x 2= 20 deciduous teeth
- 2, 1, 2, 3/2,1,2,3 x 2=32 permanent teeth
What are the paired salivary glands?
Parotid, submandibular, and subligual
What is the purpose of saliva?
- Consists of mucin which moistens foods and binds it into a bolus
- Salivary amylase breaks down starts from polysaccharides (starches and carbs) to disaccharides and glucose.
Which is the largest gland in the body and is also called the great equalizer?
What is the liver's digestive function?
- Produce bile which leaves the liver through the common hepatic duct and enters the duodenum at the bile duct.
- Bile emulsifies fats to make them easier to digest and absorb
What is the purpose of the Gallbladder?
Stored backed up bile through cystic duct from the liver until it is needed in the digestive process.
How many lobes does the liver have? Name and identify them.
4 lobes: Right lobe, left lobe, caudate lob, quadrate lobe
What are liver cells called?
What are sinusoids? What lines them?
- Blood filled spaces in liver
- They are lined with Special phagocytic cells called kupffer cells
What are the pancreas' two functions?
- Endocrine: produces hormones insulin and glucagon
- Exocrine: produces enzymes such as HCO3- for ph balance, amylase for carb breakdown, lipase for fat breakdown, and trypsin for protein breakdown.
What do bicarbonate ions prevent in the duodenum?
Where is insulin and glucagon made in the pancreas?
What are the working cells in the pancreas?
What requirements do enzymes have to work well?
Proper pH and temperature (37C)
Enzymes are known as what?
- Ez+S-->EzS-->Ez+ product