Metabolism Anatomy Flashcards
What happens to blood from the digestive system?
Collected in the hepatic portal vein then transmitted to the liver for processing before it enters the systemic circulation via the hepatic veins to the inferior vena cava
What are the boundaries of the oral cavity?
Anterior = lips Posterior = palate down to epiglottis (vertically) Roof = hard and soft palate Floor = tongue
Describe the hard palate
Made of the palatine process of the maxilla and the horizontal plate of the palatine bone
Describe the soft palate
Made of fibrous tissue with muscle fibres from the muscles that move it (levator palatine, tensor palatine and musculus uvulae)
What is the vestibule?
Space between the teeth and the cheek
What is the oral cavity proper?
Occupied mostly by the tongue
What is the frenulum?
A fold of mucosa that attaches the tongue to the mouth floor
Where does the palatine tonsil lie?
In the fossa formed between two folds of mucous membrane which project down from the soft palate (palatoglossus and palatopharygeus arches)
Where is the parotid gland located?
Occupies the triangular space made by the ramusof the mandible, the external ear and the upper SCML muscle
Where is the submandibular gland located?
In the diagastric (submandibular) triangle which takes a U shape around the posterior border of the mylohyoid muscle
Describe the sublingual gland
Group of small lands in the mouth floor either side of the tongue, they open with separate ducts on the plica sublingualis
What is the plica sublingualis?
Fold of mucous membrane between the tongue and the body of the mandible
How many teeth does an adult have?
32 permanent teeth; 2 incisors, 1 canine, 2premolars and 3 molars on each side of the jaw (x4)
How are the teeth attached to the mouth?
Via the periodontal membrane; attaches the tooth to the socket in the alveolar part of the mandible
What is the auriculo-temporal nerve?
Branch of the mandibular nerve (V3) which carries sensory and secreto-motor fibres to the parotid gland
Describe the nerve supply to the parotid gland
Supplied by the auriculo-temporal nerve (branch of V3) which has sensory fibres that are supplied via V3 and parasympathetic secreto-motor fibres that are supplied by the glossopharyngeal nerve (CN IX) through the lesser petrosal nerve which synapses in the otic ganglion before joining the auriculotemporal nerve
What is the chorda tympani?
Branch of facial nerve (CN VII) that conveys taste sensation from the anterior 2/3rds of the tongue and carries secreto-motor (parasympathetic) innervation to the submandibular and sublingual glands
Describe the nerve supply to the submandibular gland and sublingual gland
Chorda tympani (branch of facial nerve, CN VII) carries secreto-motor (parasympathetic) fibres to the gland; joins the lingual nerve for a distance and then separates to go to the submandibular ganglion and then post-synaptic fibres from this ganglion innervate these two glands
Describe the body of the tongue
Anterior 2/3rds form the body of the tongue, and this is covered by mucosa that is derived from the ectoderm
Describe the root of the tongue
Posterior 1/3 forms the root of the tongue and is covered by mucosa derived from the endoderm
What is the sulcus terminalis of the tongue?
Forms the boundary between the anterior and posterior of the tongue (root and body) and it is V-shaped
What is the foramen cecum of the tongue?
The most posterior point of the sulcus terminalis (boundary between the body and root of the tongue)
Name the intrinsic muscles of the tongue
Superior longitudinal, inferior longitudinal, vertical and transverse
What is the function of the intrinsic muscles of the tongue?
Help in changing the shape of the tongue and moving the tip in different directions
What is the function of the extrinsic muscles of the tongue?
Attach the tongue to the bony structures around it and move the tongue during swallowing or sticking out
Name the extrinsic muscles of the tongue
Styloglossus - muscle to the styloid process
Genioglossus - muscle to the mandible (genu=chin)
Hyoglossus - muscle to hyoid bone
Palatoglossus - muscle to palate (move tongue during swallowing or sticking out)
What is the function of the palatoglossus?
Move the tongue during swallowing or sticking out
What is the nerve supply to the intrinsic and extrinsic muscles of the tongue?
Hypoglossal nerve (CN XII) which is a purely motor nerve EXCEPT for nerve supply to palatoglossus which is innervated by vagus nerve (CN X)
Where does the hypoglossal nerve travel?
Beneath the tongue
Describe the superior constrictor muscle of the pharynx
Originates from the medial pterygoid plate and the pterygomandibular raphe
Describe the middle constrictor muscle of the pharynx
Arises from the angle between the lesser and greater horns of the hyoid bone
Describe the inferior constrictor muscle of the pharynx
Arises from the oblique line on the lateral surface of the thyroid cartilage and the fascia covering the cricothyroid muscle
What is the midline pharyngeal raphe?
Formed by the 3 constrictor muscles of the pharynx
What is the nasopharynx?
From the base of the skull to the level of the soft palate
What is the oropharynx?
From the soft palate to the base of the tongue
What is the laryngopharynx (hypopharynx)?
Space above and behind the laryngeal opening
What are the four muscles of mastication?
Temporalis, masseter, medial pterygoid and lateral pterygoid
Which muscles of mastication act to close the mouth?
Temporalis, masseter and medial pterygoid
Which muscle of mastication acts to open the mouth?
Lateral pterygoid
What is the nerve supply to the muscles of mastication?
V3 (mandibular branch of trigeminal nerve)