Digestive System Flashcards
1
Q
Name the 9 regions of the anterior abdominal wall. What organ is in each region.
A
- ) 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
2
Q
Mesentery-
A
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
3
Q
Describe the layers in the Peritoneal cavity
A
- ) 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
4
Q
Falciform Ligament
A
Binds the anterior aspect of the liver to the anterior abdominal wall and liver
5
Q
Lesser Omentum
A
connects the liver to the lesser curvature of the stomach and the beginning of the Duodenum
6
Q
Greater Omentum
A
connects the greater curvature of the stomach to the posterior abdominal wall
7
Q
Mesentary (where)
A
From the posterior abdominal wall to the jejunum and ilium
8
Q
Transverse Mesocolon
A
posterior abdominal wall to the transverse colon
9
Q
Sigmoid Mesocolon
A
connects the posterior pelvic wall to the sigmoid colon
10
Q
Retroperitoneal
A
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)
11
Q
What are the processes of Digestion?
A
- ) Ingestion
- ) Mechanical breakdown
- ) Digestion
- ) Propulsion
- ) Absorption
- ) Defecation
12
Q
Where and how does Ingestion occur in the body?
A
Ingestion occurs at the oral cavity when food is voluntarily placed into the mouth
13
Q
Where and how does propulsion take place in the body?
A
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.
14
Q
Where and how does mechanical breakdown happen in the body?
A
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.
15
Q
Where and how does digestion occur in the body?
A
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.
16
Q
Where and how does absorption occur in the body?
A
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.
17
Q
Where and how does defecation occur in the body?
A
Reflex triggered by rectal distension, eliminates feces from the body.
18
Q
What are the four basic in the digestive walls?
A
- ) Mucusa (Epithelium, lamina propria, muscularis mucosa)
- ) Submucosa
- ) Muscularis externa (inner circular layer and outer longitudinal layer)
- ) serosa Adventitia
19
Q
Gingiva
A
is the gum line at the neck of the tooth and is continuous with the peridontal ligament
20
Q
Hard Palate
A
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.
21
Q
Soft Palate
A
posteriorly on the roof of the mouth, is a mobile flap that rises to close off the nasopharynx during swallowing.
22
Q
Uvula
A
fleshy extension of the soft palate, salivary glands run through, prevents food from going to the nasopharynx
23
Q
Tongue
A
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
24
Q
Lingual Tonsils
A
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
25
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
26
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
27
Papillae filiform
pointed and keratinized, roughen the tongue enabling it to grasp. Anterior portion of tongue
28
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
29
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
30
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.
1. ) Parotid Gland- anterior to the ear, largest, duct ends near molars
2. ) Sublingual Gland- floor of the oral cavity inferior to the tongue, ducts at lateral base of tongue
3. ) Submandibular Gland- medial surface of the mandibular body, duct at the base of the frenulum of the tongue, gleek
31
Dentition formula
(2I, 1C, 2P, 3M top/2I, 1C, 2P, 3M bottom) x2= 32 teeth
incisors, canines, premolars, molars
32
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
33
Tooth Neck
Small region where the two main regions of the tooth (crown and root) meet at the gum line
34
Tooth Root
Region of the tooth below the surface of the gumline, (includes: root canal, peridontal ligament, cement, and dentinal tubules)
35
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)
36
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
37
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
38
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
39
Peridontal Ligament
Anchors the tooth in the bony socket of the mandible (lower) and maxilla (upper)
40
Esophagus
Muscular tube that propels food to the stomach. Its lumen is collapsed when it is empty. Begins as a continuation of the pharynx, passing through the esophogeal hiatus at the diaphram, then join the stomach at the cardial orifice where a cardiac sphincter acts to close off the lumen and prevent regurgitation of stomach acids.
41
Layers of the Esophagus
1.) Mucosa
a-epithelium is nonkeratinized stratified squamous epithelium.
b-mucous glands secrete a thin
mucus
c-when empty mucusa and submucosa in longitudinal folds
2.) submucosa-mucus glands secrete lubricating mucus
3.) Muscularis Externa- skeletal muscle the first 1/3, mix of skeletal and smooth muscle the mid 1/3, and smooth muscle the inferior 1/3
4.) Adventitia-external layer , not suspended in peritoneal cavity
42
What happens to the mucosa at the junction of the esophagus and the stomach?
an abrupt transition of stratified squamous epithelium (esophagus) to simple columnar epithelium (stomach)
43
Oropharynx
the part of the pharynx that lies between the soft palate and the hyoid bone.
44
laryngopharynx
laryngopharynx is where both food and air pass. It can be found between the hyoid bone and the larynx and esophagus, which helps guide food and air where to go. It is a part of the pharynx
45
Stomach
J-shaped, food storage tank, food is turned into a paste called chyme here, starts the breakdown of food proteins by secreting a digestive enzyme called pepsin, hydrochloric acid destroys harmful bacteria, has the ability to absorb some things (water, electrolytes, alcohol, aspirin), and food is here for approximately 4hrs
46
Stomach cardia
"near the heart" region of the stomach, is comprised of a ring shaped zone encircling the cardial orifice at the junction w/ the esophagus, includes cardiac sphincter
47
Fundus
the stomachs dome, is tucked under the diaphram
48
Stomach Body
large midportion of the stomach that ends at the funnel shaped pyloric part
49
Pylorus
Funnel shaped portion of stomach "gatekeeper" to the duodenum
50
Pyloric Sphincter
controls the entry of chyme into the intestines
51
Rugae
numerous longitudinal folds in the mucosa of the stomach, most visible when the stomach is empty, resulting expansion in volume accommodates the increasing quantity of food.
52
Greater Curvature
convex left surface of stomach, greater omentum attaches here connecting it to the post abdominal wall. Innervated by left gastric epiploic artery
53
Lesser Curvature
Concave right surface of stomach, lesser omentum liver to lesser curvature of stomach, innervated by right gastric artery
54
Layers of stomach
1. ) Mucosa
- simple columnar epithelium
- gastric glands: mucus neck cells, parietal cells, cheif cells, enteroendocrine cells
2. ) Submucosa
3. ) Muscularis externa
- INNER OBLIQUE, middle circular, outer longitudinal
4. ) Serosa
55
Small Intestine
Longest part of the alimentary canal, most enzymatic digestion and virtually all absorption of nutrients, (digestive enzymes secreted by pancreas into SI), pyloric sphincter to the large intestines
56
Histology- in stomach
1. ) Surface Mucous Cell- secretes mucus
2. ) Mucous neck cell- secretes mucus
3. ) Parietal Cell- secretes HCl and gastric intrinsic factor
4. ) Cheif cell- secretes pepsinogen; begins protein digestion
5. ) Enteroendocrine Cell- Secretes gastrin, which stimulates secretion by parietal cells
57
Duodenum
5% shortest subdivision of the small intestines immediately following the stomach, it receives digestive enzymes from the pancreas via the pancreatic duct, it receives bile from the liver and gallbladder via the bile duct, contain brunner glands which secrete alkaline fluid that protect it from acid chyme
58
duodenal papilla
duodenal papilla is a rounded projection (sphincter) at the opening of the common bile duct and pancreatic duct into the duodenum, known as the hepatopancreatic ampulla. The major duodenal papilla is the primary mechanism for the secretion of bile and other enzymes that facilitate digestion.
59
Jejunum
40% middle subdivision of the Small intestines
60
Ileum
60% last subdivision of the small intestine, meets with the cecum of the large intestines
61
Ileocecal Valve
is a sphincter muscle valve that separates the small intestine and the large intestin
62
Histology Small Intestine Mucosa
1. ) Enterocyte- completes digestion and absorbs nutrients across microvilli
2. ) Goblet cells- secrete mucus
3. ) Enteroendocrine cell- secretes secretin or cholecystokinin which stimulates the release of bile and pancreatic juice and inhibits secretions
4. ) Paneth Cell- Secretes substances that destroy bacteria
63
plicae circulares
plicae circulares. : the numerous permanent crescentic folds of mucous membrane found in the small intestine especially in the lower part of the duodenum and the jejunum
64
Villi
any of the fingerlike or threadlike projections from the surface of certain membranous structures, typically serving to increase surface area and facilitate the passage of fluid or nutrients, covered in absorptive enterocytes (some goblet cells as well) and incase the lacteal
65
Microvilli
brush border projections on top of a villus or villi. Amplify absorptive surface even further, plasma membrane contains enzymes that complete the breakdown of nutrients
66
Lacteals
the lymphatic vessels of the small intestine which absorb digested fats, inside each villus
67
Intestinal Crypts
indentations between villi that secrete intestinal juice (gland) conatins paneth cells that destroy bacteria
68
Large Intestine
last major organ of the alimentary canal, main job is to absorb water and electrolytes from the digested mass resolting in semisolid feces, propulsion is weak other then mass peristaltic movements which pass over the colon a few times a day pushing feces towards the rectum
69
Histology of large intestines
1. ) colonocyte- absorbs water, electrolytes, and vitamins
| 2. ) Goblet cells- secrete mucus
70
Cecum
beginning sac-like structure of the large intestines in the right iliac fossa. iliocecal valve prevents backflow of feces into the small intestines.
71
vermiform appendix
vermiform appendix is a narrow, worm-shaped structure that protrudes from the posteromedial aspect of the cecum, 2 cm (or less) below the insertion of the ileum into the cecum. Thought to store good bacteria to support digestive rebooting previously
72
ascending colon
ascending colon (or right colon) is the beginning part of the colon. It is usually located on the right side of the body, extending from the cecum upward. Although the colon is a continuous structure, the piece that is considered the ascending colon ends where the colon bends, just below the liver and gallbladder
73
hepatic flexure
hepatic flexure. : the right-angle bend in the colon on the right side of the body near the liver that marks the junction of the ascending colon and the transverse colon
74
Transverse colon
transverse colon is the longest and most movable part of the colon. It crosses the abdomen from the ascending colon at the hepatic or right colic flexure with a downward convexity to the descending colon where it curves sharply on itself beneath the lower end of the spleen forming the splenic or left colic flexure
75
Splenic Flexure
splenic flexure is in the sharp bend between your transverse colon and descending colon in your upper abdomen. It's situated next to your spleen.
76
descending colon
descending colon is the part of the large intestine from the splenic flexure to the beginning of the sigmoid colon. The function of the descending colon in the digestive system is to store the remains of digested food that will be emptied into the rectum
77
sigmoid colon
sigmoid colon (or pelvic colon) is the part of the large intestine that is closest to the rectum and anus. It forms a loop that averages about 35–40 cm (13.78-15.75 in) in length. The loop is typically shaped like a Greek letter sigma (ς) or Latin letter S (thus sigma + -oid).
78
rectum
the final section of the large intestine, terminating at the anus.
79
internal anal sphincter
internal anal sphincter, IAS, (or sphincter ani internus) is a ring of smooth muscle that surrounds about 2.5–4.0 cm of the anal canal; its inferior border is in contact with, but quite separate from, the external anal sphincter
80
external anal sphincter
external sphincter is a layer of voluntary (striated) muscle encircling the outside wall of the anal canal and anal opening. One can cause it to expand and contract at will, except during the early years of life when it is not yet fully developed
81
Epiploic appendages
are small pouches of the peritoneum filled with fat and situated along the colon, but are absent in the rectum. (small omentum or absorption possibly)
82
taenia coli
are three separate longitudinal ribbons (taeniae meaning ribbon in latin) of smooth muscle on the outside of the ascending, transverse, descending and sigmoid colons.
83
Haustra
The haustra (singular haustrum) of the colon are the small pouches caused by sacculation (sac formation), which give the colon its segmented appearance.
84
LI crypts
intestinal glands in the colon are often referred to as colonic crypts. The epithelial inner surface of the colon is punctuated by invaginations, the colonic crypts. The colon crypts are shaped like microscopic thick-walled test tubes with a central hole down the length of the tube (the crypt lumen). house goblet cells
85
Liver-
| segments and location
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Largest Gland in the body, filters blood, detoxifies chemicals and metabolizes drugs, produces bile then stored in the gallbladder, stores glucose from the blood as glycogen for use by the body, processes fats amino acids and store certain vitamins, makes blood proteins
Segments-
1.) Right Lobe
2.) Left Lobe
3.) Caudate Lobe (medial superior)
4.) Quadrate Lobe (medial inferior)
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86
Ligamentum Venosum
ligamentum venosum is the fibrous remnant of the ductus venosus of the fetal circulation. Usually, it is attached to the left branch of the portal vein within the porta hepatis
87
Falciform Ligament
falciform ligament is a ligament that attaches the liver to the front body wall, and separates the liver into the left medial lobe and left lateral lobe
88
Ligamentum Teres
was umbilical vein in fetus, round ligament of the liver (or ligamentum teres, or ligamentum teres hepatis) is the remnant of the umbilical vein that exists in the free edge of the falciform ligament of the liver. The round ligament divides the left part of the liver into medial and lateral sections
89
bare area
bare area of the liver (nonperitoneal area) is a large triangular area on the diaphragmatic surface of the liver, devoid of peritoneal covering. It is attached directly to the diaphragm by loose connective tissue
90
coronary ligament
coronary ligament of the liver refers to parts of the peritoneal reflections that hold the liver to the inferior surface of the diaphragm
91
Hepatocytes
liver cells
- rough ER manufactures blood proteins
- smooth ER produces bile salts, detoxifies poisons
- peroxisomes detoxify poisons (alcohol)
- golgi apparatus packages secretory products
- mitochondria provide energy for liver processes
- glycosomes store sugar
- great capacity for regeneration
92
Triad Lobule components brief discription
1. ) hepatic arteriole-one in each corner of hexagon
2. ) Hepatocytes-main cube like cell
3. )central vein-runs through center of triad lobule
4. ) hepatic portal venule-one in each corner of hexagon
5. ) sinusoids-capillaries b/n hepatocytes
6. ) Kupffer cells-forms the lining of the sinusoids of the liver and is involved in the breakdown of red blood cells
7. ) bile ductule-one in each corner of the hexagon
8. ) bile canaliculi- tube b/n hepatocytes collects bile for bile duct
93
blood flow of liver (better expansion)
Blood flows through the liver tissue and empties into the central vein of each lobule. The central veins coalesce into hepatic veins that collect the blood leaving the liver and bring it to the heart
94
gallbladder
gallbladder is a small hollow organ where bile is stored and concentrated before it is released into the small intestine. In humans, the pear-shaped gallbladder lies beneath the liver
95
Bile Flow
right and left hepatic ducts>common hepatic duct>Bile duct>hepatopancreatic ampulla and sphincter
gallbladder>cystic duct>Bile duct>hepatopancreatic ampulla and sphincter
bile from the liver and gallbladder share the bile duct and sphincter
96
Pancreas
a large gland behind the stomach which secretes digestive enzymes into the duodenum. Embedded in the pancreatic islets, which secrete into the blood the hormones insulin and glucagon
97
Pancreas ducts and cells
pancreatic duct- main duct that runs along pancrease, meets with the bile duct at the hepatopancreatic ampulla
accessory pancreatic duct- directly from pancreatic duct to the duodenum
zymogen cell-inactive precursor of an enzyme. ... Enzymes like pepsin are created in the form of pepsinogen, an inactive zymogen. Pepsinogen is activated when chief cells release it into the gastric acid, whose hydrochloric acid partially activates it
Acinar cells-cells of the pancreas that produce and transport enzymes that are passed into the duodenum where they assist in the digestion of food.
98
Pituitary gland
Anterior-regulates several physiological processes including stress, growth, reproduction, and lactation. Its regulatory functions are achieved through the secretion of various peptide hormones that act on target organs including the adrenal gland, liver, bone, thyroid gland, and gonads
posterior-secretes the hormone oxytocin which increases uterine contractions and antidiuretic hormone (ADH) which increases reabsorption of water by the tubules of the kidney
cells involved-thyrotropes, lactotropes, corticotropes, somatotropes and gonadotropes
