Anatomy II Head & Neck BY: DR.Yahya Alfarra
The Mouth The Lips: The lips are two fleshy folds that surround the oral orifice . They are covered on the outside by skin and the inside by mucous membrane. The substance of the lips is made up by the orbicularis oris muscle . Thephiltrumis the shallow vertical groove seen in the midline on the outer surface of the upper lip. thelabial frenulae” Median folds of mucous membrane connect the inner surface of the lips to the gums.
Oral cavity • It is divided into 2 parts : vestibule & mouth proper 1) The vestibule of the mouth (labial cavity) it’s a narrow space between the lips & cheeks (externally) and the gums (internally) This slit like space communicates through the oral fissure between the lips. 2) The cavity of the mouth proper (buccal cavity) • It’s roof : is formed by both the hard (infront)& soft palates(behind). • It’s floor: is formed by the tongue note: A fold of mucous membrane called thefrenulum of the tongueconnects the undersurface of the tongue in the midline to the floor of the mouth • It’s side: are formed by the dental arches carrying the teeth.
Sensory nerve supply of mucous membrane of the mouth: • The roof is supplied by greater palatine & nasopalatine nerves. ( a branch of Mx, nerve) • The floor is supplied by lingual nerve,(abranch of Md. Nerve) • The cheek is supplied by the buccal nerve, (a branch of Md. Nerve)
The Teeth Deciduous Teeth : There are 20 deciduous teeth: four incisors, two canines, and four molars in each jaw. They begin to erupt about 6 months after birth and have all erupted by the end of 2 years. The teeth of the lower jaw usually appear before those of the upper jaw. Permanent Teeth There are 32 permanent teeth: four incisors, two canines, four premolars, and six molars in each jaw . They begin to erupt at 6 years of age. The last tooth to erupt is the third molar, which may happen between the ages of 17 and 30.
The tongue • Definision : it’s a muscualr organ formed of a mass of muscle covered by mucous membrane. • Site: it lies on the floor of oral cavity • Parts of tongue : 1- oral part = mobile tongue = ant.2/3 of tongue 2- pharyngeal part : post. 1/3 of tongue
Intrinsic muscles: They all lie inside tongue They change the shape of tongue They include: 1- vertical muscle fibers 2- transverse muscle fibers 3- sup. Longitudinal m. fibers 4- inf. Longitudinal m. fibers They are all supplied by hypoglossal N. Extrinsic muscles: They are inserted into tongue They move the tongue & change its shape They include : 1- genioglossus m. 2- hyoglossus m. 3- styloglossus m. 4- palatoglossus m. They are all supplied by hypoglossal N. EXCEPT palatoglossus(supplied by ??) Muscles of tongue
Nerve supply of tongue 1) motor supply : hypoglossal N. supplies all muscles of the tongue except palatoglossus which is supplied through vagus N. 2) Sensory supply : a ) ant. 2/3: * taste sensation: is carried by chorda tympani * general sensation : carried by lingual N. b ) post. 1/3 : all sensation are carried by ??
Blood supply of tongue • Arterial supply : lingual A. • Venous drainage: lingual V. which drains into I.J.V.
The palate • Def. : it’s apartion seperating the nasal cavity above from the oral cavity below. • It’s formed of 2 parts: 1) hard palate: a bony septum between nose & mouth 2) Soft palate: a fleshy septum between nasopharynx & oropharynx
1) hard palate • It forms 2/3 of the palate & consists of palatine process of maxilla & horizontal plates of palatine bone.
2) Soft palate • It forms of : a ) palatine aponeurosis : The palatine aponeurosis is a fibrous sheet attached to the posterior border of the hard palate which give attachment to all Palatine muscles. b ) palatine muscles N.B : conical projection in midline of post. Border of soft palate called UVULA.
Muscles of soft palate 1 ) Tensor palatini 2 ) levator palatini 3 ) palatoglossus 4 ) palatopharyngeus 5 ) Muscles uvulae
Nerve supply of the palate 1 ) motor : all palatine Ms. Are supplied by vagus nerve except : Tensor palati which is supplied by Md. N. 2 ) Sensory : greater palatine n. sypply hard palate Lesser palatine n. : supplies soft palate. N.B : glossopharyngeal n. supplies soft palate.
N.B. TONSILS 1 )palatine tonsils : located between the ant. & post. Pillars 2 ) lingual tonsils : in the roof of tongue 3 ) pharyngeal tonsils: in the roof of nasopharynx.