HistoGI part 1 Flashcards
What forms the inner lining of the tubular organs?
mucosa
What are the 4 components of the tubular structures mucosa
epithelium; basement membrane; lamina propria; muscularis mucosae
What is the tubular structures muscularis mucosa made up of?
smooth muscle, sometimes lacking or replaced by elastic fibers
What is the tubular structures submuscosa made up of?
conenctive tissue, glands, blood vessels and nerves
What is the tubular structures supporting wall made up of?
smooth or skeletal muscle, bone cartilage,
what is the tubular structures adventia or the serosa made up of>
loose connective tissue,
what is tubular structures adventia referred to as serosa
when its covered by mesothelium
What are the surface features of the lip?
cutaneaus area, red area, oral muscosa,
What is the lip cutaneous area made up of?
stratifed squamous keratinizing epithetlium, has sweat glands, hair and sebaceous glands
what is the lip red area made up up?
stratifed squamous keratinizing epithetlium,tall papillae with vsacular netowrk
what is the lip oral mucosa made up of?
stratifed squamous keratinizing epithetlium,, and has serious mucous glands
Is the submucosa distinguishable in the lip?
no it blends with the mucosa
The supporting wall of the lip is made up of?
skeletal muscle of the orbcularis oris
the cheek is different from the lip’s mucosa and submucosa how?
has more elastic tissue to preventing biting of mucosa
What is the cheeks suppproting wall?
buccinator
the mucosa of the hard plate is made up of?
Stratified squamous keratinizing epithelium
and lamina propria (many papillae with vsacular core)
Where is the submucosa absent in the hard plate?
in the midline, Anterior 1/3 has much fat
Posterior 2/3 has many mucous glands
what is the supporting wall of the hard plate?
bone
What is the mucosa of the soft plate made up of?
Stratified squamous keratinizing epithelium on oral side
Pseudostratified columnar ciliated epithelium on nasal side
and lamina propria
what is the submucosa of the soft plate made up of?
mixed glands
waht is the supporting wall of the soft plate
skeletal muscle and CT
what is the ventral surface of the tongue made up of
Stratified squamous non-keratnizing epithelium
Mixed glands beneath epithelium
What does the dorsal surface of the tongue mucosa contain
Stratified squamous keratinizing epithelium
Lamina propria connects to underlying c.t.
Modified to form various papillae
Serous glands beneath circumvallate papillae
Mucous glands empty into tonsillar crypts
What is the supporting wall of the tongue
skeletal muscle arranged in 3 planes
What is the nerve supply to the tongue?
Anterior 2/3 by cranial nerves V & VII
Posterior 1/3 by cranial nerves IX and X
what are the tongue papillae?
Filiform
Fungiform
Circumvallate
Foliate
What is the most common?
filiform
Where is filiform papillae found?
Occur in parallel rows across tongue
Keratinization most obvious at tip of papillae
Where are the fungiform papillae found?
Fewer in number; more numerous towards tip of tongue
Characteristcs of the funigform papillae?
Club shaped
May have slight reddish tint due to underlying vascularization
Some taste buds in epithelium
Supplied by cranial nerve VII
Where is the Circumvallate Papillae? how mnay of them are there?
Adjacent to sulcus terminalis
7-12 in number
What are characterics of the Circumvallate Papillae
Each papilla is surrounded by a deep trench or moat
Taste buds numerous in sides of papillae
Supplied by cranial nerve IX
Serous glands of von Ebner empty into trench
Do humans have foliate papillae?
Not really, have assocaited taste buds
What papilla are assocaited with taste buds?
circumvallate, fungiform, and foliate papillae
Where are taste buds?
embedded in epithelial layer
what are the 3 types of taste buds
Sustentacular (supporting) cells
Taste receptor cells
Basal cells (give rise to other 2 types)
What are the function of taste buds
Perceive modalities of taste (salt, sweet, sour, bitter)
how fast do taste buds turn over?
10 days, regnerated when nerve is reconnected and the nerve fibers have regenerated-NERVE DEPENDANT
Enamel of the teeth is produced by
Ameloblasts
consists of 3% protein; 97% mineral
Produce dentin during tooth growth and some throughout life
Dentin of the teeth are made by
Odontoblasts
composed of 30% organic; 70% mineral
CEmentum of the teeth is made by and does what?
Cementoblasts
Anchors tooth to periodontal ligament
Periodontal ligament of the teeth are made by and do what
Fibroblasts
Anchors tooth to alveolar bone
Dental lamina aka primary teeth are of what orgin?
ectodermal origin- neural crest derivative
dental lamina give rise to
Gives rise to enamel organ (tooth germs) Five tooth germs in each half of mandible or maxilla
Dental papilla are of what origin
Mesodermal in origin
what does the dental papilla give rise to
cells which form dentin
what does the Labial lamina do?
Separates lip and cheek from developing gums and teeth
Tooth germs for permanent teeth develop when and where
Develop from dental lamina on lingual side of primary teeth, beginning at 10th week of life
When do moral teeth germs develop?
i. 1st molar – 4th month intrauterine life
ii. 2nd molar – 1st year of age
iii. 3rd molar – 4 years of age
What do the Ameloblasts develop from
dental lamina
What do ameloblasts do? Do we always have them
Produce enamel only during tooth growth
Ameloblasts lost with tooth development
what do odontoblasts develop from
dental papilla
what are the major salivary glands
Parotid gland
Submandibular gland
Sublingual gland
WHAT ARE THE minor glands
Mucous-serous glands in lamina propria and submucosa of oral cavity
what is saliva made up of
Water, cellular & bacterial debris, leukocytes, salts, salivary amylase, mucus, secretory IgA, desquamated epithelial cells
HOW MUCH do we produce a day
1000-1500 ml saliva/day in humans
What are the functions of saliva
Lubrication & moistening of buccal mucosa and lips
Washes mouth of cellular and food debris
Moistens food for easy swallowing
Moistens food for tasting
Enzymes may initiate digestion of the food
What is the morphology of major salivary glands
Connective tissue capsule (capsule of parotid is especially pronounced)
Lobes and lobules
What are the 5 ducts?
excretory duct, Striated duct, Intercalated duct
muscous alveolus, serous alveolus
What is the Excretory duct made up of?
Epithelium is stratified squamous non-keratinizing near oral cavity, sourrounded by CT
where is the excretory duct?
Found in interlobar and interlobular areas,
where is the striated duct?
within the lobule
what is a straited duct consist of
Epithelium is simple columnar or high cuboidal
Basal part of cell has striations and is eosinophilic due to infoldings of the plasma membrane and the presence of mitochondria
Where is the Intercalated duct
within the lobule
WHAT are some characteristics of the intercalated duct
Epithelium is cuboidal to low cuboidal epithelium, No striations evident, Lumen is very narrow, Part near secretory unit provided with myoepithelial cells
What are characteristics of the Mucous alveolus
Cuboidal or columnar cells, Nuclei compressed near base of cell, Apical portion of cell light staining with H and E, but PAS positive
What are characteristics of th Serous alveolus
Cuboidal or columnar cells, Distinct nuclei, Cells have rough endoplasmic reticulum at base with zymogen granules in apex
what are myoepithelial cells and where are they found
Specialized smooth muscle cells
Between serous and/or mucous cells and basement membrane
what do myoepithetlial cells do?
Assist in discharge from the secretory cells
Associated with both the secretory unit and the beginning of the intercalated duct
What are demilunes? where are they?
Secretory units that contain both serous and mucous cells. Formed by serous secreting cells Occupy the blind end of the secretory unit
what are the parotid glands made up of?
Prominent connective tissue capsule with c.t. separating lobes & lobules
Fat cells and fatty tissue common
Striated and intercalated ducts prominent
what kind of secretion comes form the parotid gland
Acini almost 100% serous
What is the submandibular gland made up of
Connnective tissue capsule present but not conspicuous
Striated ducts well defined
Intercalated ducts scarce
Mucous alveoli frequently capped with serous demilunes
what kind of secretion comes form the submandibular gland
Acini are 10-25% mucous & the rest serous
what is the sublingual gland made up of
Connective tissue capsule indistinct Connective tissue septae are present within the gland Excretory ducts prominent Striated ducts not prevalent Intercalated ducts non-existent
what is the secretion made up of coming from the sublinguinal gland
Acini 75% mucous with serous demilunes
whats the path of the esophagus
Begins at level of cricoid cartilage, passes through superior and posterior mediastinum, pierces the diaphragm, and becomes continuous with the stomach
What is the mucosa of the esphagus made up of
Epithelium-stratified squamous non-keratinizing; it is replaced every 2-3 days
what is the lamina propria of the esophagus made up of
Loose connective tissue, Mucous glands (cardiac glands in upper and lower thirds)
what is the muscularis mucosae of the esphagus made up of
Very well developed layer, Smooth muscle fibers oriented primarily in a longitudinal direction, with some inner circular
the Submucosa esophagus is made up of
Mucous-secreting glands in middle third Submucosal nerve plexus present, but difficult to identify Contains larger blood vessels and lymphatics
Muscularis externa of the esophagus is made up of
Upper third is skeletal muscle
Middle third is primarily smooth, with some skeletal
Lower third is smooth muscle
Myenteric nerve plexus located between outer and inner layer
Circumvallate papillae
are innervated by?
CN9
Fungiform taste buds are innervated by?
CN7
The muscles of the tongue is innervated by?
hypoglossal 12!
