Module 10 Flashcards
What are the structures of the digestive tract?
- mouth
- oral cavity
- pharynx
- esophagus
- stomach
- small intestine
- large intestine
- anus
what is another name for the digestive tract?
the alimentary canal
what are the accessory digestive organs?
- tongue
- teeth
- salivary glands
- liver
- biliary ducts
- gall bladder
- pancreas
what are the layers of the digestive tract?
- mucosa
- submucosa
- muscularis externa
- adventitia or serosa
what are the three different types of mucosa in the digestive tract?
- surface epithelium (reflects expected function of organ)
- lamina propria (loose connective tissue under the surface epithelium)
- muscularis mucosa (composed of smooth muscle fibres under the lamina propria)
submucosa of the digestive tract is located where? composed of what? and contains what?
- below mucosa
- dense irregular connective tissue
- contains blood vessels, lymphatics, glands, and nerve plexuses
muscularis externa of the digestive tract i composed of?
circular and longitudinal layers of smooth muscle with nerve plexuses between the layers
what are the nerve plexuses in the muscularis externa of the digestive tract responsible for?
muscular contraction to propel food through the digestive tract
the outermost layer of the digestive tract is either ____ or _____
serosa or adventitia
when is the outer layer of the digestive tract serosa?
when the outer layer is a serious membrane, which secretes a lubricating fluid
when is the outer layer of the digestive tract adventitia?
when the outer layer is loose connective tissue
what are the two parts of the oral cavity?
- the vestibule (space between cheek, lips or gums)
2. oral cavity proper (other areas of the mouth)
what six structures are found in the oral cavity?
- palate
- tongue
- salivary glands
- teeth
- pharynx
- tonsils
what makes up the superior border of the oral cavity?
the palate
what is the palate divided into?
- hard palate (bone)
2. soft palate (muscle)
what is the uvula?
posterior extension of the soft palate
what is the tongue?
a muscle associated with speech, taste, and the mechanical manipulation of food
what are the two kinds of tongue muscles and what do they do?
1) intrinsic muscles - control the shape of the tongue itself
2) extrinsic muscles - move the tongue during chewing and speech
what is the frenulum? where is it found?
found on the inferior surface of the tongue.
Anchors the tongue to the floor of the mouth
the superior and lateral surfaces of the tongue are covered in ______
papillae (projections or bumps)
how many kinds of papillae are there?
4 - some of which are taste buds
what do the salivary glands do?
secrete digestive enzymes and mucous to help break down food during mastication
what are the three salivary glands?
- parotid
- submandibular
- sublingual
what does the parotid gland secrete?
serous (watery) fluid
what does the submandibular gland secrete?
serous and mucous (viscous) fluids
what does the sublingual gland secrete
mucous (viscous) fluids
what are the two classifications of teeth?
- deciduous teeth (baby teeth)
2. permanent teeth
how many deciduous teeth are there?
20
how many permanent teeth are there?
32
deciduous teeth consist of ____ in each quadrant of the jaw
2 incisors, 1 canine (cuspid), 2 molars
permanent teeth consist of ____ in each quadrant of the jaw
2 incisors, 1 canine (cuspid), 2 premolars (bicuspids), and 3 molars
what is another name for the premolars
bicuspids
what are tonsils? what is there role?
collections of lymphoid tissue found in areas of the pharynx. role in the immune system
what are the three tonsils?
- pharyngeal tonsils
- palatine tonsils
- lingual tonsils
what is the esophagus? where is it?
a muscular tube extending from the pharynx to the stomach
how long is the esophagus?
25cm
what is the mucosa of the esophagus made up of? why?
stratified squamous.
It protects the esophagus from friction as food travels from the oral cavity to the stomach
what does the submucosa of the esophagus contain? what does that help with?
contains mucus-secreting glands, which help lubricate the passage of food
how is the muscularis externa different in the esophagus than in other structures?
in the esophagus, this layer includes both smooth AND skeletal muscles whereas in other structures, it usually only has smooth muscle
what is the breakdown of the musclaris externa in the esophagus
upper 1/3 = only skeletal muscle
middle 1/3 = mixed skeletal and smooth muscle fibers
lower 1/3 = entirely smooth muscle
what covers the esophagus
adventitia
stomach anatomy: the greater _____ hangs off the greater curvature
omentum
the top part of the stomach is called the
fundus
the middle part of the stomach is called the
body
the bottom part of the stomach is called the
antrum
is the stomach covered in serosa or adventitia?
serosa
the mucosa of the stomach are folded into ridges and folds called ____
rugae
what are rugae?
non-permanent folds that allow the stomach to expand following ingestion of food or liquid
what kind of epithelium is the mucosa of the stomach? what does it contain?
simple columnar. contains gastric glands
the epithelium of the mucosa of the stomach secretes what? why?
secretes mucous, which helps protect the stomach from stomach acids secreted by the gastric glands. These acids facilitate chemical digestion of food
what is contained in the submucosa of the stomach
blood vessels, lymphatics, glands, and nerve plexuses to supply the stomach tissue with oxygen and control contraction of the musculature
how many layers of smooth muscle does the stomach have
3
why does the stomach have another layer of muscle than the esophagus?
the stomach needs the extra muscular power to churn food and push it towards the intestine
what are the three layers of smooth muscle of the stomach?
- outer longitudinal
- middle circular
- inner oblique
approx how long is the small intestine?
6m
the small intestine is attached to the _____ abdominal wall
posterior
what are the three portions of the small intestine (in the correct order)
- duodenum
- jejunum
- ileum
dudenum
- 25cm
- c shaped
- encloses the head of the pancreas
how long is the jejunum?
2.5m
which portion of the small intestine is the longest?
the ileum
how long is the ileum?
3.5m
which portion of the small intestine actually attaches to the posterior abdominal wall?
the ileum
what are the 5 kinds of mucosa found on the small intestine
- epithelium
- villi
- lamina propria
- intestinal glands
- plicae circulares
the epithelium of the small intestine is found on the ____
villi
what kind of epithelium is found in the stomach
simple columnar with many absorptive cells whose apical surfaces have microvillli, also known as a brush border
what does the brush border do?
increase surface area of absorption of nutrients
between the absorptive cells in the epithelium of the stomach, there are ________
goblet cells
what do the goblet cells in the epithelium of the stomach do?
secrete mucous to help lubricate the passage of food
what are the villi in the stomach and what do they do
fingerlike projections that extend into the lumen of the small intestine
what does the lamina propria do?
forms a core for each villus, which contains blood capillaries and lymphatic capillaries
what are the collections of lymphatic tissue located in the lamina propria called?
Peyer’s patches
Peyer’s patches are abundant primarily in the ___
ileum
what’s another name for the intestinal glands of the small intestine
“crypts of Leberkuhn”
What are the Plicae circulares?
permanent transverse folds that help increase the surface area of absorption
the duodenum contains ______ glands that secrete ____ mucous
the duodenum contains duodenal (Brunner’s) glands that secrete alkaline mucous
purpose of the alkaline mucous secretes by Brunner’s glands?
to help protect the small intestine from the stomach acid that may be present in the partially digested food after leaving the stomach
how many smooth muscle layers does the small intestine have?
2 (circular and longitudinal)
what is located between the two layers of smooth muscles in the small intestine?
a nerve plexus
what is the outermost layer of the small intestine?
serosa
what are the three sections of the large intestine? (in order)
- cecum
- colon
- rectum
what is the cecum?
first portion of the large intestine and has an extension off of it called the vermiform appendix (looks like a worm)
what are the four sections of the colon?
- ascending colon
- transverse colon
- descending colon
- sigmoid colon
the ascending colon extends from the ____ to the ______
cecum to the hepatic flexure
what’s another name for the hepatic flexure
right colic flexure
what;s another name for the left colic flexure?
splenic flexure
the transverse colon extends from the ____ to the ______
hepatic flexure to the splenic flexure
the descending colon extends from the ____ to the ______
splenic flexure to the sigmoid colon
what does the sigmoid colon lead to q
the rectum
where is the rectum located?
extends from the sigmoid colon to the anal canal
what is the mucosa of the large intestine made up of?
similar to small intestine except without plicae circularis or villi
goblet cells in the large intestine are most abundant in the ___
anus
in the anal canal, the epithelium switches from simple columnar to _______
stratified squamous
what kind of epithelium is found in the large intestine?
simple columnar and contains an increasing amount of goblet cells
the intestinal glands of the large intestine function in the same way as the small intestine but in addition…
accumulations of lymphatic tissue are present in the lamina propria (and submucosa)
the submucosa of the large intestine contains..
blood vessels, lymphatics, glands and nerve plexuses
what is the makeup of muscularis externa in the cecum and colon?
the outer longitudinal layer forms three longitudinal bands (teniae coli) that contract and form the sac-like structures called haustra
what is the makeup of muscularis externa in the anal canal?
the circular muscle layer thickens as the internal anal sphincter that is involved with waste secretion
is the large intestine covered in serosa or adventitia?
BOTH! some regions covered in serosa, some in adventitia
what are the two features of the anal canal
1) anal column (longitudinal ridges in the canal)
2) internal and external sphincters ( help with excretion of waste)
