Looks like no one added any tags here yet for you.
Two divisions of the digestive system:
alimentary canal and accessory organs
The alimentary canal includes what structures?
mouth, pharynx, esophagus, stomach, small intestine, and large intestine
What do the accessory organs do?
aid in digestion by secreting digestive enzymes
The accessory organs include what structures?
salivary glands, liver, gallbladder, and pancreas
What is the function of salivary glands?
to moisten food
Salivary glands release:
digestive enzymes
What are the 3 pairs of salivary glands?
parotid, submandibular, and sublingual glands
The mouth has what type of epithelium?
stratified squamous epithelium
Parotid gland
largest gland, anterior to the ear
Sublingual gland
smallest gland, inferior to tongue
Submandibular gland
along mandible
Bolus
mushy food, ready to go down the digestive system
How does mechanical digestion work?
by utilizing the tongue and teeth via mastication
How does chemical digestion work (specifically in the oral cavity)?
by utilizing saliva released from salivary glands
What are the layers of the digestive tract wall?
mucosa, submucosa, muscularis externa, and serosa
Mucosa
innermost layer, lines the inner lining of each one of the digestive organs with columnar epithelium, produces mucus for substances to move through the digestive system
Blood and lymph vessels of the mucosa are found in the
laminapropia connective tissue layer
Submucosa
embedded with vessels, nerves and lymphatics
The built in network of nerve cells in the submucosa is the
submucosal plexus
Muscularis externa
made of smooth muscle, aids in peristalsis and segmentation
The network of neurons in between the two layers of the muscularis externa is called the...
myenteric plexus
Serosa
outermost layer, houses arteries, veins, and lymphatics
Absorption of nutrients occurs through the
mucosal epithelium
A lack of closure of the esophageal sphincter can cause
acid reflux or GURD
What 4 regions make up the stomach?
cardia, fundus, body, and pylorus
The stomach has what 3 sheets of muscle?
circular, longitudinal, and oblique
What is the purpose of the 3 sheets of muscle in the stomach?
to aid in rotational movement, churning the bolus
Gastric folds (rugae)
allows stomach to expand and hold food and liquid contents
What is chyme?
liquified contents, released from pyloric sphinchter
Small intestine is all about
absorption
What are the 3 parts of the small intestine?
duodenum, jejunum, and ileum
What are the 3 modifications of the small intestine wall that increase surface area?
villi, microvilli, and plicae circularis
Each villi has
lacteals that absorb lipids
Each microvilli has
capillaries that absorb carbohydrates and proteins
Mesentery
connecting piece, holds most structures together
Remaining components from the small intestine go into the
large intestine
Tenia coli
aids in holding the large intestine structure together
Ascending colon
located on right side, from cecum to transverse colon
Transverse colon
courses from ascending to descending colon
Descending colon
courses from transverse colon to sigmoid colon
Sigmoid colon
S shaped
Rectum
anterior to sacrum, has nerves and retains feces until defecation
Cecum
blind pouch inferior to ileocecal valve
Appendix
hangs on cecum, considered vestigial structure, aids in immune system by filtering bacteria
Haustram
creates more feces and allows it to be excreted out
Liver
creates bile
Gallbladder
stores bile
Bile from the gallbladder is released into the…
major duodenal papilla
Pancreas is considered what type of gland?
endocrine and exocrine
The pancreas produces
insulin and glucagon
The pancreas has a main pancreatic duct that meets the
minor duodenal papilla
How are carbohydrates broken down?
salivary amylase is released by salivary glands and in the small intestine pancreatic enzymes break them down to monosaccharides
How are proteins broken down?
pepsin in the stomach breaks polypeptides down and pancreatic enzymes break them down to amino acids
How are lipids broken down?
gastric lipase in the stomach breaks down lipids and bile turns into pancreatic lipase and breaks lipids down to monoglycerides and individual fatty acids