The oral cavity

Oral Cavity
The oral cavity is lined with stratified squamous epithelium, which may be keratinized, partially keratinized,or nonkeratinized depending on the location
? masticatory mucosa is the keratinized cell layers resist damage from abrasion and are best developed on the gingiva (gum) and hard palate. The lamina propria in these regions rests directly on the periosteum of underlying bone.
? lining mucosa is Nonkeratinized squamous epithelium predominates in the over the soft palate, cheeks, the floor of the mouth, and the pharynx,the posterior region of the oral cavity leading to the esophagus. Lining mucosa overlies a thick submucosa containing many minor salivary glands, which secrete continuously to keep the mucosal surface wet, and diffuse lymphoid tissue. Throughout the oral cavity, the epithelium contains transient antigen-presenting cells and rich sensory innervation.
The lips
The central core of the lip contains the orbicularis oris (skeletal) muscle, which is innervated by the facial nerve , and contributes to lip movement and facial expressions.
The Lips are divided into the three regions:
A. external (skin) region It is covered by keratinized stratified squamous epithelium. The sebaceous glands in the dermis are associated with hair follicles, and sweat glands are present. The skin of the lip is like thin skin and can be divided into epidermis and dermis.
B. The vermilion zone of the lip is covered by parakeratinized stratified squamous epithelium. Sebaceous glands (Fordyce granules or spots) may be found in the connective tissue and are not associated with hair follicles. These glands have ducts that release their oily product directly onto the surface of the lip. The vermilion zone appears red because of many blood vessels near the surface of the thin and translucent epithelium . This region can become thick and forms the sucking pad in infants.
C. Internal region (labial mucosa) of the lip is an example of lining mucosa, which is covered by nonkeratinized stratified squamous epithelium and contains many elastic fibers; it is very flexible and can be stretched. Its submucosa layer contains many minor salivary glands (mucous glands). The minor salivary glands in the lips are often called labial glands.
Dr.Hameda abdulmahdi College of Medicine /Dep. of anatomy & histology
2nd stag e
2
The palate
It is divided into an anterior hard palate (possessing a bony shelf in its core) and a posterior soft palate (possessing skeletal muscle in its core). The palate separates the nasal cavity from the oral cavity. Therefore, the palate has a nasal aspect and an oral aspect. The entire nasal aspect of the palate (with the exception of the uvula) is lined by pseudostratified ciliated columnar epithelium (respiratory epithelium).
1. The hard palate is lined on its oral aspect by stratified squamous parakeratinized to stratified squamous keratinized epithelium (masticatory mucosa). it contains adipose tissue anteriorly and minor mucous salivary glands posteriorly in the oral aspect of its connective tissue, the lamina propria in these regions rests directly on the periosteum of underlying bone.
2. The soft palate is lined on its oral aspect by stratified squamous nonkeratinized epithelium(lining mucosa). It contains minor mucous salivary glands in the oral aspect of its connective tissue.