Digestive System 1 Flashcards
Outline the activities of the digestive system
Activities include: 1) intake 2) mechanical breakdown 3) chemical breakdown by enzymes 4) absorption of nutrients 5) elimination of undigested matter
3 parts of the digestive system
1) oral cavity 2) tubular digestive system 3) accessory glands
4 components of the WALL of the GI tract
1) mucuosa (epithelium, lamina propria, musculais mucosa) 2) submucosa 3) muscularis externa 4) serosa
3 components of the mucosa layer of the wall
1) epithelium (stratified squamous epithelium) 2) lamina propria (areolar CT) 3) muscularis mucosa (inner circular and outer longitudinal layers of smooth muscle)
what components are inside the lamina propria that attaches mucosa epithelium?
1) aereolar CT 2) blood vessels 3) lymphatic tissue 4) glands.
the intestines are suspended by____
mesentaries
3 components of the submucosa layer
1) submucosal gland 2) blood vessel 3) submucosal nerve plexus
the muscularis externa is composed of an inner ___ layer and an outer ___ layer with a ____ nerve plexus in between.
the muscularis externa is composed of an inner CIRCULAR layer and an outer LONGITUDINAL layer with a MYENTERIC/AUERBACH nerve plexus in between.
the submucosa has ___ that controls contraction of muscularis mucosa
ganglia (submucosa plexus of meissner)
T/F: auerbachs plexus is located in the submucosa
FALSE. the auerbachs plexus is located in the muscularis externa between the two layers, but the PLEXUS OF MEISSNER is a ganglia located in the submucosa.
The serosa is made of this _____ connective tissue.
thin areolar connective tissue.
Serosa involves the mesothelium layer, or ___ ___, which covers the tract. What is it made of?
Serosa involves the mesothelium layer, or VISCERAL PERITONEUM, which covers the tract. made of simple squamous epithelium (but the serosa is made of areolar connective tissue)
3 zones of the lip
1) cutaneous (external surface where moustache could grow) 2) vermillion (red part of lip) 3) Internal zone/oral mucosa
what type of epithelium makes up the cutaneous zone of the lip?
thin KERATINIZED stratified sqamous epithelium
T/f: the vermillion zone of thel ip contains glands and hair follicles.
false. no glands = readily gets dry with cold weather.
how does the vermillion zone get its red color?
lots of blood vessels. Has very thin stratified squamous epithelium.
What type of epithelium composes the internal zone? what does this zone contain?
made of stratified squamous epithelium (WET/NON keratinized). Has accessory salivary glands.
What is this a slide of? Label it.
Lip section.
- S= CUTANEOUS skin layer (where moustache grows, may contain follicles (F) and sweat glands)
V= Vermillion layer. Contains blood vessels and thin layer os stratified squamous epithelium that is transparent to blood vessels, allowing for characteristic red hue of lips
OM = oral mucosa Internal zone (faces lumen inside mouth) = is opposite side of skin. Contains minor salivary glands (G) and muscle (M)
The mouth is lined by ___ ___ epithelium, which is mainly ____ except;
STRATIFIED SQUAMOUS epithlium. Mosly NON-Keratinized except HARD PALATE, GUMS, and FILIFORM PAPILLAE of tongue.
3 types of accessory salivary glands
1) serous (stains dark) –> produces thin, watery secretions.
2) mucous –> appear clear.
3) mixed.
V shaped groove of the tongue
sulcus terminalis
the ___ ___ attaches the ventral surface to the floor of the oral cavity
lingual frenulum
the anterior portion of the tongue has 3 types of papillae. What ar they?
1) filiform
2) fungiform
3) folliate
Most numerous type of tongie papillae. Are they keritanized or not? Do they have taste buds?
filiform. They are HEAVILY keratinized and do NOT HAVE taste buds.
___ papillae are shaped like mushrooms and are scattered among filiform papillae. How are they seen macroscopically on the tongue? Do they have taste buds?
FUNGIFORM PAPILLAE. Appear as red dots on tongue because they have LOTS OF CAPILLARIES. Houses some taste buds.
Function of filiform papillae
provides friction to help move food during chewing.
What types of papillae hosue taste buds?
fungiform, foliate and vallate papillae.
when do foliate papilae develop?
in young childhood.
largest type of papillae
circumvallate (vallate) papillae at the back of the tongue. LEAST numerous but contain the largest amount of taste buds.
circumvallate papillae are surrounded by grooves with ___ ___ glands, which function to:
grooves with SEROUS vonEBNER glands, which function to dissolve food.
where are cirucmvallate papillae found?
along SULCUS TERMINALIS at posterior portion of tongue.
What attaches the ventral surface of the tongue to the oral cavity
the lingual frenulum
If you clean your tongue emaculately, it still appears white. Why?
because of the abundant filiform papillae that are heavily keratinized. The keratin appears whiteish.
label
F= fungiform papillae. Has some taste buds, lightly kertainized.
FI= filiform papillae. no taste buds. heavily keratinized.
SS= stratified squamous epithelium.
TB= taste buds on circumvallate pallate at sulcus terminalis
GL= salivary glands (serous von ebners) emptying into clefts.
____ papillae are well developed in children but poorly developed in adult humans. Where are they located? Do they contain taste buds?
FOLLIATE papillae. Located on the edge of the tongue near the back (on ridges). Contains taste buds.
How is the taste pore on a taste bud comrpised?
microvilli project through opening at free surface (taste pore)
Three types of cells for tastebuds and their characteristics
1) support cells: slender and dark staining
2) taste cells: slender and light staining.
3) basal cells: cuboidal cells at the base
label
5 main “flavours” we sense.
1) salty
2) sour
3) sweet
4) bitter
5) umami: repsonse to salts of glutamic acid (MSG)
What are our two sets of teeth?
1) 20 deciduous teeth (baby teeth)
2) 32 permanent teeth. (2 incisors, 1 canine, 2 premolars and 3 molars) (x4)
3 anatomical parts of the tooth
1) crown
2) neck
3) root
the __ of the tooth sits in the ___ socket in the jaw bone . How is the root connected to the bone?
sits in the alveolus of the jaw bone. Connected to the bone via periodontal ligament.
what is the visible portion of the tooth
crown
the ___ is the junction of the crown and the root
neck
label
the cementum covers ____
ROOTS anchoring the tooth to alveolar bone of the jaw
3 main “hard tissues” of the teeth
1) enamel
2) dentin
3) cementum
Dentin consists of 70% ___ ____ crystals and 30% organic matter, namely _____ and ____
70% hydroxyapatite crystals and 30% organic matter (collagen I and GAGs)
Dentin is formed by _____. How are these cells formed? What are the extensions classed? What do the initially produce?
odontoblasts. derived from the MESENCHYME of a developing pulp cavity. Extensions are called TOMES fibers, or DENTINAL TUBULES. Odontoblasts produce predentin, which later mineralizes to form dentin.
PC = pulp cavity (inside tooth)
O= odontoblasts
OP= odontoblast process (tomes process) (dentinal tubules)
P= Predentin (collagen) which is why its blue under mallory trichrome stain
D= dentin (mineralized with calcium hydroxyappatite)
purpose of the odontoblast processes
odontoblasts processes connect the odontoblasts to the dentin they secreted. Helps with the maintenance of dentin in adult teeth.
___ covers the crown of the tooth. What is its composition?
enamel. 98% calcium hydroxyappatite forming ENAMEL PRISM columns.
Enamel is produced by ___ cells. How did these cells form?
produced by ameloblast cells that are formed from INNER ENAMEL EPITHELIUM created by the EPITHELIAL ORGAN which stems from the DENTLA LAMINA embryonic epithelium.
Lablel
Ameloblasts are surrounded by ___ ___.
Each ameloblast produces one ___ ___ (column). Are there cellular processes in enamel like in dentin?
ameloblasts are surrounded by connective tissue. Each ameloblast produces one enamel prism. There are no cellular processes.
CT: connective tissue
A= ameloblasts
E= enamel
D= dentin.
____ covers root. Function? What cells give rise to it?
the CEMENTUM covers root. Similar to bone. Function is to anchor tooth toe alveolus via periodontal ligament. Formed by cementoblasts.
the pulp cavity houses the ___ ___, which communicaes via foramen at apex of root. What kind of connective tissue is it composed of? what else does it have?
DENTAL PULP. made of AREOLAR CT with many capillaries, nerves and fibers.
the periphery of dental pulp contains ____, which contact the surrounding dentin by processes.
contains odontoblasts
What kind of fibers can you find in the dental pulp
reticulin fibers, and fine collagen fibers. also nerve fibers.
the blood and nerve supplies enter the pulp cavity via the ___ ___ at the apex of the ____
apical foramen at the apex of the roots.
What is this? label.
this is dental pulp found in the pulp cavity inside the tooth.
D= dentin surrounding the pulp cavity
O= odontoplasts on periphery of dental pulp
V= venules and capillaries.
