Generality
" Hard palate " and " soft palate " are the anatomical names, respectively, of the anterior portion and of the portion of the surface that delimits the oral cavity at the top.
Hard palate and soft palate have substantial differences, although at the sight they may seem very similar. For example, the hard palate has a bony and periosteal component, of which the soft palate is completely deprived; for its part, the soft palate has 5 muscles, of which the hard palate is completely lacking.
From the functional point of view, the hard palate and the soft palate offer a fundamental contribution to three processes: chewing, swallowing and phonation (ie the emission of words).
Short review of what the Palate is
The palate is the upper wall of the oral cavity or, as other definitions prefer to describe it, the "roof of the mouth".
The palate includes bones, muscle tissue and mucous tissue.
What are the Hard Palate and the Soft Palate?
The hard palate and the soft palate are, respectively, the anterior portion and the posterior portion of the so-called roof of the mouth (or palate).
Although they are scarcely distinguishable at sight, the hard palate and the soft palate are quite different from each other; in fact, under the mucosa lining common to both, the hard palate has a bone component, which in the soft palate is completely absent and replaced, in a certain sense, by a muscular component .
Anatomy
To better appreciate the anatomical characteristics of the hard palate and soft palate, it is necessary to describe the latter separately.
Hard palate
The hard palate is, substantially, a bone formation provided with a double coating: a more intimate covering, corresponding to a layer of periosteum, and a more external covering, corresponding to a layer of mucosa.
Closely related to the periosteum, the mucosa of the hard palate can be distinguished in upper and lower .
Example of respiratory mucosa, the upper mucosa is the mucosal layer of the hard palate that looks towards the nasal cavities.
An example of an oral mucosa, on the other hand, the lower mucosa is the mucosal layer of the hard palate oriented towards the mouth cavity; this mucosa is, obviously, the most interesting, as regards the description of the hard palate.
The hard palate constitutes 2/3 of the palate and, due to the position it occupies, acts as an element of separation between the nasal cavities and the oral cavity.
To remember!
The hard palate is the anterior portion of the palate.
BONE COMPONENT
The bone component of the hard palate results from the contribution of:
- The palatine processes of the two maxillary bones e
- The horizontal laminae of the two palatine bones .
Did you know that ...
The maxillary bone and the palatine bone are two equal bones of the skull ; more precisely, they are two of the 14 bony elements that make up the skeleton of the so-called splancnocranium, one of the two large subdivisions of the skull (the other is the neurocranium ).
COATING WITH MUCO-PERIOSTAL: RAGHE PALATINE AND RAFE PALATINO
Near the maxillary arch, the particular mucosa-periosteal covering (muco-periosteal covering) of the hard palate forms, with a transverse position, irregular-looking ridges, called palatine wrinkles (or palatine ridges ), whose task is to facilitate the movement of food in the direction of the pharyngo-laryngeal complex.
Furthermore, in the middle position (ie in the middle) and just before the boundary with the soft palate, it gives rise to a line in relief with a longitudinal sense, which is called rafe palatino .
RELATIONSHIPS
The hard palate borders on:
- The alveolar arch of the maxilla, at the level of the antero-lateral margin (ie on the front and laterally);
- The soft palate, at the level of the posterior margin (ie back);
- The nasal cavities, above;
- The oral cavity, inferiorly.
What is the alveolar arch of the jaw?
The alveolar arch of the jaw is the part of this bone in which the grooves for the roots of the teeth reside.
BLOOD CIRCULATION
The inflow of oxygenated blood to the hard palate is the task of the major palatine artery, a branch of the maxillary artery .
On the other hand, a group of veins of the so-called pterygoid venous plexus deal with the drainage from the soft palate of oxygen-poor blood.
INNERVATION
The innervation of the hard palate belongs to the major palatine nerve and to the nasopalatine nerve (or spheno-palatine nerve ); the major palatine nerve and the nasopalatine nerve are two branches of the so - called pterigo-palatine ganglion, which is the nerve formation that brings together the fibers of the maxillary nerve and of the nerve in the pterygoid canal .
The innervation of the hard palate is exclusively sensitive.
LYMPHATIC CIRCULATION
At the level of the hard palate, the circulating lymph drains, in large part, into the deeper upper cervical lymph nodes and, to a lesser extent, into the retropharyngeal lymph nodes .
Upper deep cervical lymph nodes and retropharyngeal lymph nodes belong to the large family of so-called lymph nodes in the neck .
Soft palate
Representing the one missing third of the palate, the soft palate is a muscular formation, covered with oral mucosa, which, precisely because of the rich component of muscles, is endowed with a marked mobility.
According to the most classical anatomical descriptions of the soft palate, two characteristic portions can be identified on the latter: the so-called horizontal portion and the so-called vertical portion .
The horizontal portion is the natural continuation of the hard palate; compared to the latter, obviously, it lacks the bone component and the periosteum.
The vertical portion, on the other hand, is a sort of prominence oriented towards the floor of the oral cavity, concave, in the initial part, and convex, in the terminal part, which culminates with an anatomical element surely known to most people: the uvula .
It is important to point out that the posterior margin of the soft palate is, so to speak, free, since, behind it, there is the empty space that joins the nasal cavities to the oral cavity ( nasopharynx or nasopharynx ).
To remember!
The soft palate is the back of the palate.
MUSCLES OF THE SOFT PALATE
The muscles of the soft palate are in all 5 and are called: tensor muscle of the palatal veil, palatoglossus muscle, palato-pharyngeal muscle, levator palatal muscle and uvula muscle .
- Tensor muscle of the palatal veil.
Origin: on the medial pterygoid plate of the sphenoid bone (sphenoid fossa);
Terminal insertion: on the palatal aponeurosis ;
Innervation: it is up to the medial pterygoid nerve (branch of the maxillary nerve);
Function: provides the tension of the soft palate, a fundamental movement for swallowing.
- Palatoglossus muscle.
Origin: on the palatal aponeurosis;
Terminal insertion: on the tongue ;
Innervation: it is up to the pharyngeal plexus (derivation of the vagus nerve );
Function: allows the rear part of the tongue to be raised and moved backwards to ensure optimal swallowing.
- Palate-pharyngeal muscle.
Origin: on the palatal aponeurosis;
Terminal insertion: on the upper edge of the thyroid cartilage ;
Innervation: it is up to the pharyngeal plexus (derivation of the vagus nerve);
Function: serves to "pull" the pharynx and larynx upwards, so as to guarantee breathing.
- Elevating muscle of the palatal veil.
Origin: on the temporal bone and on the Eustachian tube ;
Terminal insertion: on the palatal aponeurosis;
Innervation: it is up to the pharyngeal plexus (derivation of the vagus nerve);
Function: provides for the elevation of the soft palate, an indispensable movement for swallowing.
- Uvula muscle.
Origin: at the rear edge of the hard palate;
Terminal insertion: on the mucous membrane of the uvula;
Innervation: it is up to the pharyngeal plexus (derivation of the vagus nerve);
Function: provides for the elevation of the uvula.
What is the palatal aponeurosis?
Attached to the posterior edge of the hard palate, the palatal aponeurosis is a fibrous sheath of the palate, whose main task is to support the muscles of the soft palate.
RELATIONSHIPS
The soft palate borders on:
- The hard palate, anteriorly;
- The nasopharynx, posteriorly;
- The oropharynx, below;
- The nasal cavities and, in a sense, also the entrance of the Eustachian tube, superiorly.
BLOOD CIRCULATION
The inflow of oxygenated blood to the soft palate is the task of the minor palatine arteries (branches of the descending palatine artery ) and of the ascending palatine artery (branch of the facial artery ).
The drainage from the soft palate of oxygen-poor blood, on the other hand, belongs to a group of veins that join the already known pterygoid venous plexus.
INNERVATION
The innervation of the soft palate includes both fibers of a sensitive nature (sensory innervation) and motor fibers (motor innervation).
The aforementioned nerves include the palatine maggiore and naso-palatino (or spheno-palatine) and the palatine nerve minor .
Like the palatine maggiore and naso-palatino nerves, the palatine minor nerve also comes from the pterigo-palatine ganglion, which is the nerve formation that groups the fibers of the maxillary nerve and the pterygoid canal nerve.
The motor innervation of the soft palate, instead, is up to the nerves of the pterygoid plexus (which, as readers will remember, reach the levator muscles of the palatine, palatoglossus, palate-pharyngeal vein and the uvula muscle) and to the pterygoid nerve medial (which, as previously stated, reaches the tensor muscle of the palatal veil).
Two curiosities about the uvula
- The sensitive innervation present on the soft palate causes the touch of the latter, in particular on the uvula, to trigger the vomiting stimulus.
- Recent studies have shown that the uvula has no role in the phenomenon of snoring .
Function
Hard palate and soft palate have a fundamental role in the processes of chewing food, swallowing food and phonation (ie issuing the word).
Hard palate
The hard palate is involved in chewing and, during speech, in the issuance of palatal consonants .
During chewing, the hard palate causes the food to move towards the pharynx-larynx complex, a complex after which the esophagus begins.
To make it capable of such an action are the known palatine wrinkles, present on the initial tract, just after the alveolar arch of the jaw.
As far as the dynamics of discourse are concerned, on the other hand, the hard palate offers a support to the language, from which it is possible that the sounds corresponding to the "c", to the "n" or to the "l" and sounds that do not fall within the alphabet arise. Italian, but they are present in many languages of the world.
Did you know that ...
Mammals (including humans, if there is no special surgical treatment) that are born with a defective hard palate die shortly after birth, as they are unable to suckle breast milk.
Soft palate
The soft palate allows correct swallowing and, during the speech, guarantees the emission of the velar consonants .
During swallowing, the soft palate moves in such a way as to induce the closure of the passage to the nose (rhinopharynx) and the closure of the airways. This prevents the food (which is now called the food bolus ) from taking the path that leads to the nasal cavities and the path that leads to the trachea, and, at the same time, allows it to undertake a single path, the most appropriate one, which is the way to the esophagus .
As for the dynamics of speech, instead, the soft palate allows the generation of sounds corresponding to the letters "k", "g", "x" or "y".
Curiosity
During sneezing, the soft palate has the task of diverting part of the excretion towards the mouth.
diseases
Hard palate and soft palate may be at the center of various medical conditions, some of which involve both, while others are specific to either the first or second.
Among the medical conditions that can simultaneously affect the hard palate and the soft palate, cleft palate is worth mentioning.
Among the medical conditions that can affect either the hard palate or the soft palate, we note the palatal abscess, for the hard palate, and the herpangina and the pemphigus vulgaris, for the soft palate.
Did you know that ...
Cleft palate is a congenital disease of hard palate and soft palate, which involves the presence, on the latter, of a cracking .
Fortunately, cleft palate is a treatable condition with excellent results; in fact, an ad hoc surgical procedure exists, which allows to close the anomalous opening present on the hard palate and soft palate.
