Digestive System: Accessory Organs

Question 1

Oral cavity

Answer 1

• cheeks form lateral walls of oral cavity and contain buccinator muscle. Helps us tense and move around food bolus
• lips form anterior wall. Red from superficial blood vessels, reduced keratin. Special kind of epithelium
• palate forms superior boundary — separates from nasal cavity
  > anterior 2/3 hard and bony
  > posterior 1/3 soft and muscular

Question 2

Tongue

Answer 2

• formed from skeletal muscle and covered with stratified squamous epithelium
• papillae with taste buds cover surface
• stratified squamous epithelium: found in regions where you need protection

Question 3

Functions of saliva

Answer 3

• moistens ingested food for easier swallowing
• moistens, cleanses, and lubricates oral cavity structures -> keep taste buds clean so we can taste other foods
• contain amylase = enzyme that helps break down food
• contains lysosome to help inhibit bacterial growth
• dissolves tastants and food molecules so that taste receptors can be stimulated

Question 4

Salivary glands - cells

Answer 4

• mucous cells: secrete mucin
• serous cells secrete watery fluid with ions, lysozyme, and salivary amylase
• secretion of both is stimulated by parasympathetic division of ANS

Question 5

Sublingual gland

Answer 5

• inferior to tongue
• secrete all of its saliva through these holes

Question 6

Parotid gland

Answer 6

• largest, located anterior and superior to ear
• sends little duct all the way through your whole face and into this opening right at the back wall of your oral cavity, right next to your 2nd molar up on the top

Question 7

Submandibular gland

Answer 7

• inferior to the mandible
• secrete it’s saliva through this one little submandinular duct into a particular little hole underneath your tongue

Question 8

Pharynx

Answer 8

• divided into 3 regions: nasopharynx, oropharynx, and laryngopharynx
• back wall of pharynx = continuation of your esophagus

Question 9

Pharyngeal constrictor muscles

Answer 9

• contract sequentially pushing material down toward esophagus
• contract from top to bottom
• think constrictor = squeezing

Question 10

Liver

Answer 10

• located in upper right quadrant of abdominal cavity
• main fxn are to filter blood and produce bile
• has a right and left lobe

Question 11

Porta hepatis

Answer 11

• area where blood vessels and bile ducts enter and leave liver

Question 12

Liver — histological organization

Answer 12

• hepatocytes: are liver cells. doing fxn of the liver
• they are arranged into hepatic lobules
• at the periphery of each hepatic lobule is portal triad with an artery, vein, and bile duct

Question 13

Hepatocytes

Answer 13

• produce bile and secrete into bile duct
• receiving blood from intestines
  > duodenum, jejunum, and ileum = absorbing blood into our SMV and our IMV and our splenic veins = send it off to the liver and then we’re going to send branches of it next to these hepatocytes
  > blood will filter through these hepatocytes
• after that it can now detoxify drugs, metabolites, and poisons
• store excess nutrients and vitamins and release when needed (ex: glucose)
• synthesize blood plasma proteins such as albumins, globulins, and proteins required for clotting

Question 14

Branches of hepatic portal vein

Answer 14

• carries blood from GI tract to liver to these hepatocytes
• rich in nutrients and other absorbed substances
• relatively poor in oxygen
• carry deoxygenated blood thru the porta hepatis and then send this blood past all of these hepatocytes
• going to help us to filter the blood through these cap beds
• blue

Question 15

Branches of hepatic artery

Answer 15

• Branch of celiac artery
• carries oxygen rich blood to capillary beds and liver, which then leave as a venous blood
• red

Question 16

Branches of bile duct

Answer 16

• Bile is greenish fluid that breaks down fats and is produced by hepatocytes
• released to duodenum be a common bile duct
• green

Question 17

Gallbladder

Answer 17

• Attached to inferior aspect of liver
• saclike organ that concentrates and stores bile
• connected to common bile duct via cystic duct
• Gallbladder commonly form goal stones. Once they start to do this it’s usually easier to remove the whole organ to fix the reason that you’re producing stones

Question 18

Gallbladder sphincter

Answer 18

• Sphincter valve controls flow of bile into and out of gallbladder
• liver produces bile, and we secrete that bile thru our bile duct
  > Then, you go all the way down to the duodenum or if we don’t need any bile rn we can store that bile into the gallbladder

Question 19

Pancreas

Answer 19

• Has a head, body, and tail
• Head is covered by duodenum
• The pancreas is retroperitoneal (behind the peritoneum), which makes it difficult to access surgically
  > behind peritoneal cavity

Question 20

Pancreas - mixed endocrine and exocrine

Answer 20

• Exocrine pancreas secretes digestive enzymes and bicarbonate
• = pancreatic juice
• Secretes pancreatic juice into main pancreatic duct, which drains into (major duodenal papilla in) duodenum

Question 21

Major duodenal papilla

Answer 21

• Both common bile duct and main pancreatic duct empty into duodenum through major duodenal papilla

Question 22

Oral cavity parts

Answer 22

• Lips, cheeks, palate, tongue, salivary gland