Module 10 Flashcards
What are the two groups of the digestive system?
Digestive tract (alimentary canal)
Accessory digestive organs
Which group does the mouth, oral cavity, pharynx, esophagus, stomach, small intestine, large intestine, and anus.
Digestive tract (alimentary canal)
What group are the tongue, teeth, salivary glands, liver, bilary ducts and gallbladder, and pancreas part of?
The accessory digestive organs
The digestive tract, also known as the alimentary canal, is a continuous tube that starts in the … and ends inferiorly with the … canal.
oral cavity, anal
What are the five functions of the digestive system?
Digestion
Absorption
Secretion
Motility
Elimination of Waste
What is this?
The process of mastication (chewing) crushes food in the mouth into smaller pieces to facilitate chemical processing by enzymes into small molecules.
Digestion
What is this?
Digested food moves slowly through the large intestine, to facilitate water and nutrient uptake into the body
Absorption
What is this?
In the presence of food, cells of the stomach’s mucosal wall release gastric acid to perform chemical digestion.
Secretion
What is this?
When food is swallowed, muscles in the esophageal wall contract and relax to push food through esophagus down to the stomach.
Motility
What is this?
Leftover materials, which are not absorbed or utilized by the body, are eliminated by the process of defecation.
Elimination by Waste
What are the four layers of the digestive tract wall? From innermost to outermost
Mucosa
Submucosa
Muscularis Externa
Serosa or Adventitia
What are the three parts of the mucosa?
surface epithelium, lamina propria, muscularis mucosa
What is surface epithelium?
Type of epithelial layer which reflects the expected function of the organ. Examples: secretion, absorption, protection
What is lamina propria?
Layer of loose connective tissue under surface epithelium
What is muscularis mucosa?
Layer composed of smooth muscle fibres under the lamina propria
What is the submucosa? What is it made of?
Layer below mucosa. Made of dense irregular connective tissue, contains blood vessels, lymphatics, glands, nerve plexuses.
What is the muscularis externa made of? What is between the layers?
Circular and longitudinal layers of smooth muscle with nerve plexus in between layers.
What are the plexuses responsible for?
Muscular contraction to propel food through the digestive tract
What is the outermost layer of the digestive tract made of?
Either serosa or adventitia
When the outer layer is a serous membrane, it is known as…
Serosa
When the outer layer is composed of loose connective tissue, it is known as…
adventitia
What is serous membrane?
Single layer of thin, flat cells that form a membranous sheet and secrete lubricating fluid
What is the first part of the digestive tract?
Oral cavity
What are the two parts of the oral cavity?
Vestibule - space between the cheeks and lips and gums and teeth
Oral Cavity Proper - other areas of the mouth
What makes up the superior border of the oral cavity?
Palate
What is the palate divided into?
Hard palate (bone)
Soft Palate (muscle)
What is the posterior extension of the soft palate called?
Uvula
What is the muscle associated with speech, taste, and the mechanical manipulation of food?
The tongue
What do the intrinsic muscles of the tongue do?
Control shape of tongue
What do the extrinsic muscles of the tongue do?
Move the tongue during chewing and speech
What is on the interior surface of the tongue that anchors the tongue to the floor of the mouth?
Frenulum
What are the superior and lateral surfaces of the tongue covered in?
Papillae
How many types of papillae are there?
4
Some papillae contain … which give humans sense of gustation.
Taste buds
What secretes digestive enzymes and mucus to help break down food while chewing?
Salivary glands
What are the three types of salivary glands?
Parotid
Submandibular
Sublingual
What does the parotid secrete?
Serous (watery) fluid
Where is the parotid located?
anterior and inferior to ear opening
What does the submandibular secrete?
serous and mucous (viscous) fluid
Where is the submandibular located?
Inferior to mandible
What does the sublingual secrete?
mucus
Where is the sublingual located?
Inferior to tongue
What are the two sets of teeth humans have?
Deciduous
Permanent
What do deciduous teeth consist of? How many total?
2 incisors
1 canine (cuspid)
2 molars
in each quadrant of jaw
TOTAL = 20 teeth
What do permanent teeth consist of? How many total?
2 incisors
1 canine (cuspid)
2 premolars (bicuspids)
3 molars
in each quadrant of jaw
TOTAL = 32 teeth
What are the two pairs of third molars in the permanent set of teeth called?
Wisdom teeth
What are tonsils? What tissue? Where are they found? Whats their role?
Collections of lymphoid tissue found in areas of pharynx. Play role in immune system
What are the three tonsils?
Palatine
Pharyngeal
Lingual
What is the 25 cm long muscular tube that extends from the pharynx to the stomach?
Esophagus
What is the epithelium type in the mucosa of esophagus?
stratified squamous epithelium
protects from friction as food travels from oral cavity to stomach
What does the submucosa of esophagus contain?
Mucus-secreting glands to help lubricate passage of food
What does muscularis externa consist of in esophagus? Where is each type?
Both smooth and skeletal muscle.
Upper 1/3 skeletal
Middle 1/3 skeletal and smooth
Lower 1/3 smooth
Is esophagus covered by adventitia or serosa?
Mostly adventitia
What are the three regions of the stomach (top to bottom)?
Fundus
Body
Antrum
What is antrum continuous with?
First part of small intestine (duodenum)
The shape of the stomach gives rise to the lesser and greater …
curvatures
What is the structure that hangs off the greater curvature of the stomach? It is an apronlike structure that covers and protects the abdominal viscera.
Greater omentum
What is special about mucosa of stomach?
Folded into ridges called rugae
What are rugae? What’s the purpose of rugae?
Non-permanent folds and allow the stomach to expand following ingestion of food or liquid
What is the epithelium of the stomach? What does it contain?
Simple columnar; contains gastric glands. Secretes mucus to protect stomach from acids
Which layer of stomach contains blood vessels, lymphatics, glands, and nerve plexuses?
Submucosa
Whats the function of constituents of submucosa?
Supply tissue with oxygen and control contraction of musculature
What are the three layers of smooth muscle in the muscularis externa? What are the directions they’re arranged into (3)?
Outer longitudinal
Middle circular
Inner oblique
Is stomach covered in serosa or adventitia
Serosa
What are the three parts of the small intestine?
Duodenum (25cm)
Jejenum (2.5m)
Ileum (3.5m)
What shape is the duodenum? What does it enclose?
C-shaped
Encloses head of pancreas
Where does most of the jejunum lie?
In upper left quadrant of abdomen
Where does most of ileum lie?
Right lower quadrant of abdomen
What are the fingerlike projections that extend to the lumen of the small intestine called?
Villi
The epithelium of small intestine is found on …
villi
The epithelium in intestine is…
Simple columnar
The epithelium of intestine has many absorptive cells whose apical surfaces have…
microvilli / brush border
What does the lamina propria of the mucosa form (small intestine)? What does it contain?
Core of each villus
Contains blood capillaries and lymphatic capillaries
What are collections of lymphatic tissue located in lamina propria of small intestine called? Where are they abundant?
Peyer’s patches
Ilium is where they are abundant
What does the mucosa contain (small intestine)? What are they? What do they secrete?
Intestinal glands (crypts of Lieberkuhn)
These are deep folds of mucosa between some villi and secrete intestinal juices
The mucosa and submucosa of the small intestine form … which are permanent transverse folds that help increase the surface area for absorption
Pilcae circulares
The submucosa of the duodenum is notable as it has … that secrete …
duodenal (Brunner’s) glands that secrete alkaline mucus
What’s the purpose of this mucus secreted by Brunner’s glands?
helps protect small intestine from stomach acid that pay be present in partially digested food after leaving stomach. Glands not found in submucosa of jejenum and ileum.
Muscularis externa - small intestine. What are the two smooth layers of muscle in small intestine organized into?
Circular and longitudinal layers
What is located between two layers of muscle in small intestine?
Nerve plexus
What is the outermost layer of small intestine made of?
Serosa
What are the three sections of the colon?
Cecum
Colon
Rectum
What is the extension off of the cecum?
Vermiform appendix
What are the four sections of the colon?
Ascending
transverse
descending
sigmoid
What part of the colon extends from the cecum up the right side of the abdomen to join transverse colon just below the liver?
Ascending
What part of the colon extends from below the liver, crossing the abdomen to join the descending colon below the spleen?
Transverse
What part of the colon extends down the left side of the abdomen from the splenic end of the transverse colon to the sigmoid colon?
Descending
What part of the colon is the s-shaped terminal portion leading into the rectum?
Sigmoid
What extends from sigmoid colon to anal canal and is last portion of large intestine. It temporarily stores fecal matter.
Rectum
What is the epithelium of large intestine? What does it contain an increasing amount of towards anus?
Simple columnar. Goblet cells
In anal canal, a change from simple columnar to … takes place
Stratified squamous
… glands also present in large intestine.
Intestinal
In large intestine, accumulations of lymphatic tissue are present in the …
Lamina propria and submucosa
The submucosa contains blood vessels, lymphatics, and nerve plexuses
The outer longitudinal layer of muscularis externa of cecum & colon forms how many longitudinal bands? What are these called? When they contract up the wall of the large intestine, they form sac-like structures called what?
Three (teniae coli)
Haustra
In the rectum, the three teniae coli merge to form the…
continuous longitudinal muscular layer
In the anal canal, the circular muscular layer thickens into the internal anal …, which is involved with waste excretion.
sphincter
What is the large intestine covered by? Adventitia or serosa?
can be covered by either
What are the longitudinal ridges in the anal canal called?
Anal column
