Chapter 5 Flashcards
Rugae
irregular ridges in the mucous membrane covering the anterior portion of the hard palate in oral cavity
uvula
small soft tissue projection, hangs from the soft palate. aids in production of sounds and speech
papillae
small raised areas on the tongue, contain taste buds that are sensitive to the chemical nature of foods and allow discrimination of different tastes as food moves across the tongue
tonsils
masses of lymphatic tissue located in depressions of the mucous membranes, lies on both sides of the oropharynx (part of the throat near the mouth)
-> filters to protect body from invasion and produces lymphocytes
Enamel
- outermost layer of a crown
- protects the tooth
- translucent
- hardest tissue in body
Dentin
- main substance of the tooth, lies beneath enamel
- > cementum covers, protects, and supports the dentin in the root
- > a periodontal membrane surrounds the cementum and holds the tooth in place in the tooth socket
pulp
- lies underneath dentin
- blood vessels, nerve endings, connective tissue, and lymphatic vessels are within the pulp canal (aka root canal)
saliva
- exocrine glands produce saliva which lubricates the mouth
- saliva contains enzymes as well as healing growth factors such as cytokines
saliva is released from:
- parotid gland
- submandibular gland
- sublingual gland
pharynx or throat
- serves as a passageway both for air travelling from the nose to the windpipe (trachea) and for food traveling from the oral cavity to the esophogus
- swallowing=degluttion
- cartilaginous flap of tissue, epiglottis, covers trachea so that food cannot enter and become lodged there
esophagus
fibromuscular tube extending from the pharynx to the stomach
-Peristalsis is the involuntary, progressive, rhythmic contraction of muscles in the wall of the esophagus (and other gastrointestinal organs), propelling a bolus (mass of food) down toward the stomach.
stomach
- > has three main parts:
1. fundus
2. body
3. antrum
lower esophageal sphincter (LES)
relaxes and contracts to move food from the esophagus into the stomach
pyloric sphincter
allows food to leave the stomach and enter the small intestine when it is ready
Stomach
- folds in the mucosa lining the stomach are called rugae.
- > rugae increases surface area for digestion and contain glands that produce the enzyme pepsin to begin digestion of proteins
- > hydrochloric acid is also secreted to digest proteins and kill any bacteria remaining int food
small intestine (small bowel)
- duodenum: receives food from the stomach as well as bile from the liver and gallbladder and pancreatic juices from the pancreas. enzymes and bile help to digest food further
- jejunum
- ileum
the jejunum connects with the ileum and the ileum attaches to the first part of the large intestine
->villi line the walls of the small intestine. The tiny capillaries (microscopic blood vessels) in the villi absorb the digested nutrients into the bloodstream and lymph vessels.
large intestine (large bowel)
three main components:
- cecum
- colon
- rectum
-> appendix hangs from cecum- has no clear function
- > colon has four segments:
1. ascending
2. descending
3. transverse
4. sigmoid
-> large intestine recieves fluid waste products of digestion and stores these wastes until they can be released from the body
liver
- produces bile
- one of the pigments found in bile is *bilirubin
- bilirubin is produced from the breakdown of hemoglobin during normal RBC destruction
- bacteria in the colon degrade bilirubin into a variety of pigments that give feces a brown color. Bilirubin and bile leave the body in feces
if bile duct is blocked or liver is damaged and unable to excrete bilirubin into bile, bilirubin remains in the blood stream, causing jaundice
gall bladder
bile travel thru the hepatic duct into the cystic duct
- cystic duct leads to the gallbladder, a pear shaped sac under the liver which stores and concentrates the bile for later use
- when food present in the stomach the gall bladder contracts releasing bile from cystic duct into the common bile duct
pancreas
-secretes pancreatic juices that are released into pancreatic duct which joins with the common bile duct just as it enters the duodenum
emulsification
bile breaks apart large fat globules
Without bile, most of the fat taken into the body remains undigested, and stools may appear fatty.
true
other functions of the liver besides the production of bile
- > maintaining normal blood glucose levels. The liver removes excess glucose from the bloodstream and stores it as glycogen (starch) in liver cells. When the blood sugar level becomes dangerously low, the liver converts stored glycogen back into glucose via a process called glycogenolysis. In addition, when the body needs sugar, the liver can convert proteins and fats into glucose, by a process called gluconeogenesis.
- > manufacturing blood proteins, such as albumin and those necessary for blood clotting
- > releasing bilirubin, a pigment in bile
- > clearing drugs and poisons (toxins) from the blood
portal vein brings blood to the liver from the intestines
true
pancreas is both an exocrine and an endocrine organ
as an exocrine gland:
-it produces enzymes to digest starch, such as amylase (amyl/o = starch, -ase = enzyme); to digest fat, such as lipase (lip/o = fat); and to digest proteins, such as protease (prote/o = protein).
as an endocrine gland (secreting into the blood stream):
-pancreas secretes insulin
portal vein (hepatic portal vein)
- lies between the small intestine and the liver
- This vein is not a true vein because it doesn’t conduct blood directly to the heart as do other veins. In liver disease, blood backs up into the portal vein, causing portal hypertension (high blood pressure) and esophageal varices.
amylase
enzyme secreted by the pancreas and salivary glands to digest starch (amyl/o)
bile
digestive juice made in the liver and stored in the gallbladder. breaks up large fat globules.
common bile duct
carries bile from the liver and gallbladder to the duodenum
glycogen
starch; glucose is stored in the form of glycogen in liver cells
lipase
pancreatic enzyme necessary to digest fats
