Anatomy and Cell Biology 3309 Lecture Notes - Lecture 28: Periodontal Fiber, Cementum, Myoepithelial Cell
2 May 2018
School
Department
Professor
Histology Lecture 4 – Semester 2
Tongue & Salivary Glands
Learning Objectives
- Compare 4 kinds of papillae on the surface of the tongue
- Give the location of taste buds and describe their structure
- Explain the composition and function of saliva
- Identify the main glands that produce saliva
- Describe histological differences between these glands
- Describe the location and function of myoepithelial cells
- Name 3 types of ducts and compare their histological features
QUESTION
Which of the follow statements regarding the periodontal ligament is TRUE?
a. It is composed of collagen type 1
b. It extends from the cementum to the enamel
c. It extends from the dentin to the cementum
d. It is composed of elastin
e. It extends from dentin to alveolar bone
- Periodontal ligament connects cementum to alveolar bone
- NOT composed of elastin, mainly composed of type 1 collagen
- 3 types of salivary glands – named according to their location
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- Tongue is divided into symmetrical structures
o There is a midline = median sulcus
- If you look at the surface, there are projections coming off the surface = lingual papillae
o Papillae come in different sizes and shapes
o Most obvious ones are in the back of the tongue; show up in a V formation
▪ Up to 8/12
▪ = Circumvallate papillae
o At the edge of your tongue, there are ridges = Foliate Papillae
o In the remaining surface, you can mostly see tiny bumps = Fungiform Papillae (mushroom
form papillae)
o Tiny ones that are very hard to see, finger like protrusions = Filiform Papillae
Tongue
- Combination of two sections; one low power and one lower
- 2 SURFACES:
o Can see part of the epithelium that covers the surface
o Underneath the tongue, there is also a surface
o Not much of a difference between the two surfaces EXCEPT there are ONLY papillae in the
upper surface, not found in the lower surface
o Stratified squamous epithelium
- Underneath the epithelium there is loose connective tissue (lamina propia) and some dense CT
- Vast majority of the body of the tongue is made of skeletal muscle
o Most times we are in control of our tongue
o Skeletal muscles are running in various different planes (across, longitudinally, obliquely)
o There is a lot of innervation
- Tongue is a great place to review and find small peripheral nerves that innervate the tongue
find more resources at oneclass.com
find more resources at oneclass.com
Lingual Papillae
- The upper surface is covered by lingual papillae
- Filiform Papillae:
o First they form conical structures, highly keratinized
o Function = Mechanical grip
o No taste buds
o Epithelium overtop the filiform papillae tend to keratinize
- Fungiform Papilla
o Mushroom shaped (young mushroom before it forms a cap)
▪ Round, blunt ending
o Connective tissue underneath forms 3 dermal papillae reaching into one of the fungiform
papillae
o Dorsal taste buds
o Visible with the naked eye
o Function = detection of taste (due to the taste buds)
- Fungiform and filiform papilla
- Cats have a lot of filiform papilla that are keratinized
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Compare 4 kinds of papillae on the surface of the tongue. Give the location of taste buds and describe their structure. Describe the location and function of myoepithelial cells. Name 3 types of ducts and compare their histological features. It extends from the cementum to the enamel. It extends from the dentin to the cementum. Not composed of elastin, mainly composed of type 1 collagen. 3 types of salivary glands named according to their location. Tongue is divided into symmetrical structures: there is a midline = median sulcus. In the remaining surface, you can mostly see tiny bumps = fungiform papillae (mushroom form papillae: tiny ones that are very hard to see, finger like protrusions = filiform papillae. Combination of two sections; one low power and one lower. Underneath the epithelium there is loose connective tissue (lamina propia) and some dense ct. Tongue is a great place to review and find small peripheral nerves that innervate the tongue.
