Digestive System Flashcards
Name the 9 regions of the anterior abdominal wall. What organ is in each region.
- ) Right Hypocondriac region- Liver and gallbladder
- ) Epigastric region- Stomach
- ) Left Hypocondriac region- Diaphram and spleen
- ) Right Lateral Region- Ascending colon of L. Intestine
- ) Umbilical Region- Small intestines
- ) Left Lateral Region- descending colon of L. Intestine
- ) Right Inguinal Region- Cecum and Appendix
- ) Pubic Region- Urinary Bladder
- ) Left Inguinal Region- Sigmoid Colon
Mesentery-
is a double layer of peritoneum, a sheet or two of serous membrane fused together, that extends from the body wall to the digestive organs
Describe the layers in the Peritoneal cavity
- ) Visceral Peritoneum- covers the external surfaces of most digestive organs
- ) Parietal Peritoneum- lines the body wall and is continuous w/ the Visceral Peritoneum
- ) Peritoneal Cavity- lies b/n the digestive organs and the abdominal wall. It contains lubricating serous liquid that it produces to allow the digestive organs to glide easily along one another and the abdominal wall
Falciform Ligament
Binds the anterior aspect of the liver to the anterior abdominal wall and liver
Lesser Omentum
connects the liver to the lesser curvature of the stomach and the beginning of the Duodenum
Greater Omentum
connects the greater curvature of the stomach to the posterior abdominal wall
Mesentary (where)
From the posterior abdominal wall to the jejunum and ilium
Transverse Mesocolon
posterior abdominal wall to the transverse colon
Sigmoid Mesocolon
connects the posterior pelvic wall to the sigmoid colon
Retroperitoneal
some organs have a mesentery at first, but because of complex rotations during development they end up against the posterior abdominal wall outside of the peritoneal cavity. (pancreas, duodenum, kidney, ascending and descending collon, rectum)
What are the processes of Digestion?
- ) Ingestion
- ) Mechanical breakdown
- ) Digestion
- ) Propulsion
- ) Absorption
- ) Defecation
Where and how does Ingestion occur in the body?
Ingestion occurs at the oral cavity when food is voluntarily placed into the mouth
Where and how does propulsion take place in the body?
Throughout-In the oral cavity propulsion starts with the swallowing initiated by the tongue, propelling food into the pharynx. Peristoltic waves in the esophagus cont to move things along. In the stomach peristaltic waves mix food with gastric juices and propel it into the duodenum. In the small intestines smooth muscles mixes digestive juices and propels it down through the iliocecal valve. In the large intestines feces is propelled toward the rectum by haustral churning and mass movements.
Where and how does mechanical breakdown happen in the body?
Mechanical breakdown happens in the oral cavity with mastication by the teeth and mixing movements of the tongue. In the stomach gastric juices and peristaltic waves help breakdown food further and propel it. In the small intestines digestive juices along with smooth muscle help propel and breakdown contents further.
Where and how does digestion occur in the body?
In the mouth the chemical breakdown of starch and fats is begun by salivary amylase and lipase secreted by salivary glands. in the stomach digestion of protein begins in the stomach by pepsin while gastric lipase digests fats. In SI, Bile from the liver and gallbladder emulsifies fat; digestive enzymes from the pancreas and brush border enzymes attached to microvilli membranes complete digestion of all classes of food.
Where and how does absorption occur in the body?
In the stomach a few fat soluble substances are absorbed (aspirin, alcohol, some drugs). Small intestines breakdown products of carbohydrates, protein, fat, and nucleic acid digestion, plus vitamins, electrolytes, and water are absorbed by active and passive mechanisms. In the large intestines most remaining water, electrolytes (largely NaCl) and vitamins produced by bacteria.
Where and how does defecation occur in the body?
Reflex triggered by rectal distension, eliminates feces from the body.
What are the four basic in the digestive walls?
- ) Mucusa (Epithelium, lamina propria, muscularis mucosa)
- ) Submucosa
- ) Muscularis externa (inner circular layer and outer longitudinal layer)
- ) serosa Adventitia
Gingiva
is the gum line at the neck of the tooth and is continuous with the peridontal ligament
Hard Palate
anterior roof of the mouth, the bones associated with this are the palatine processes of the maxilla, the tongue forces food along the rigid surface to the back of the throat.
Soft Palate
posteriorly on the roof of the mouth, is a mobile flap that rises to close off the nasopharynx during swallowing.
Uvula
fleshy extension of the soft palate, salivary glands run through, prevents food from going to the nasopharynx
Tongue
Occupies the floor of the mouth, during chewwing the tongue manipulates food with saliva into a compact mass called bolus, during swallowing the tongue moves the bolus posteriorly in the pharnyx. Innervated by the Trigeminal 5 nerve ant. 2/3, glossopharyngeal 4 nerve post. 1/3, vagus 10 nerve post 1/4, Facial 7 nerve ant. lat. 1/3
Lingual Tonsils
lingual tonsils are a collection of lymphatic tissue located in the lamina propria of the root of the tongue. This lymphatic tissue consists of the lymphatic nodules rich in cells of the immune system
Palatine Tonsil
palatine tonsils are a pair of soft tissue masses located at the rear of the throat (pharynx). Each tonsil is composed of tissue similar to lymph nodes, covered by pink mucosa (like on the adjacent mouth lining). Running through the mucosa of each tonsil are pits, called crypts
Taste Buds
Are contained in the epithelium on the tops of papillae. The five specific tastes received by taste receptors are saltiness, sweetness, bitterness, sourness, and savoriness, often known by its Japanese term “umami” which translates to ‘deliciousness
Papillae filiform
pointed and keratinized, roughen the tongue enabling it to grasp. Anterior portion of tongue
Papillae Fungiform
resemble tiny mushrooms, vascular core for a red appearance, scattered widely over tongue surface, taste buds occur on the tops of epithelium on this papillae
Papillae Circumvallate
Line up in V-shape bordering the posterior 1/3 of the tongue, taste buds on the side of this papillae, border b/n mouth and parynx
Salivary Gland-
3 salivary glands and where
Produce saliva, a complex mixture of water, ions, mucus, and enzymes. Helps to dissolve food chemicals for taste, moisten mouth, wets foods, binds food into bolus. The enzymes amylase and lipase begin digestion of carbohydrates and fats.
- ) Parotid Gland- anterior to the ear, largest, duct ends near molars
- ) Sublingual Gland- floor of the oral cavity inferior to the tongue, ducts at lateral base of tongue
- ) Submandibular Gland- medial surface of the mandibular body, duct at the base of the frenulum of the tongue, gleek
Dentition formula
(2I, 1C, 2P, 3M top/2I, 1C, 2P, 3M bottom) x2= 32 teeth
incisors, canines, premolars, molars
Tooth Crown
Crown is the exposed region of the tooth above the gum line. The surface of the crown covered in enamel bears forces for chewing
Tooth Neck
Small region where the two main regions of the tooth (crown and root) meet at the gum line
Tooth Root
Region of the tooth below the surface of the gumline, (includes: root canal, peridontal ligament, cement, and dentinal tubules)
Tooth Enamel
hardest substance in the body, covers the surface of the crown, lacks cells and vessels for regineration, densely packed hydroxyapatite crystals (same calcium salts found in bone)
Tooth Dentin
underlies the enamel cap and forms the bulk of the tooth, bonlike tissue with mineral and collagen components, radial striations are called dental tubules, lacks internal blood vessels
Tooth Cementum
the external surface of the tooth root is covered in calcified connective tissue cement. Cement attaches the tooth to the peridontal ligament, anchoring the tooth
Pulp Cavity
in the center of the tooth, in the root region of the tooth it becomes the root canal. Loose conective tissue containing blood vessels and a nerve
Peridontal Ligament
Anchors the tooth in the bony socket of the mandible (lower) and maxilla (upper)