The head’s muscles can be split into two main groups: the mimic muscles as well as the muscles for mastication. The principal functions of mimic muscles are the transmission of emotions via facial expressions, as well as participation in defensive actions like blinking or blinking. The primary role of the muscles in mouth mastication is that they move the jaws of the lower part to grind food.
The mimic muscles possess a few specific characteristics. As you are aware bones are the attachment points of the common skeletal muscles. The muscle connects to the bone, typically close to the joint closest to it. When it contracts, the muscle is able to force the bone to set in motion the closest joint and, as a result, we observe the motion that the bone undergoes.
Mimic muscles in contrast to other muscles in the skeletal structure, connect directly to the facial skin and move the facial skin.
Another characteristic of facial muscles is that they do not have fascia. Fasciae are thick connective membranes that are the basis for most of the human muscles of the skeletal system. If you are a cook, and you enjoy cooking meat, you’ve probably observed white, dense films that reside on muscle fibers. They are called fascia. Face muscles can be free of fascia.
A further feature is the topography of muscles that mimic. The muscles mimic are situated in the natural openings on the head, like the nose, mouth ears, and orbital boundaries.
Let’s examine the major muscles that mimic humans.
Epicranius Muscle
Epicranius muscles are the biggest facial muscle on the face. The epicranius muscle is composed of two parts which are the frontal portion and the occipital portion. Both of these parts are connected to a strong tendon plate known as galea erotica.
The frontal portion begins from the supracranial aponeurosis and is attached to the skin over the eyebrows. That’s why we attribute the epicranius muscles to the muscles mimicking the face. The occipital muscle is located from the upper nuchal line in the skull, to the posterior portion of the supracranial Aponeurosis.
Function: The occipital region gently pulls the scalp towards the side, and the frontal part draws the scalp towards its side. When fixing the supracranial Aponeurosis the contraction of the frontal abdomen raises eyebrows.
Orbicularis Oculi
It is a massive muscular structure that is prominent and encircles the eye. It is a prominent, large muscle that surrounds the. The orbicularis oculi are divided into three distinct parts that are the orbital part and the palpebral portion and the lacrimal component.
The orbital area is situated within the orbit. It is the biggest part and, actually, covers all the other circular muscles in the eye. When it contracts, the muscle pulls on and squeezes the skin surrounding the eyes, and then squeezes it tight.
The palpebral component is the base of the muscles for the eyelids. The muscles contract, closing the eyes.
The lacrimal area is tiny, making it very difficult to detect with no proper preparation. The lacrimal area is responsible for getting tear fluid from the eye during crying.
Procerus Muscle
It is a small, rectangular muscle that is located between the eyes, on the boney nose’s base. When it expands, it is able to compress the skin above and below the eyes. The result is a frown with visible vertical folds in between the eyes.
Nasalis Muscle
The nasalis muscle is composed of two components. The transverse one is located on the outside. It covers the wing of the nose and is visible from the outside. It then begins dividing laterally before entering the tendon.
We are able to see only the wing portion when we employ a specific dissection method because the wing portion wraps over the nose’s wings from the inside and connects with the cartilage of the nose.
The nasalis muscle and both parts of the muscle cooperate to stretch the nasal wings for the nose to be narrowed a bit.
Orbicularis Oris Muscle
As with many mimic muscles, the muscle or binoculars is divided into two components. In this instance, we have the labial and marginal parts. The labial portion is actually the lip, and we look directly at a person. The margin is more rounded and is located around the labial portion.
When contracted, the margin part of the lip opens as if they were tubes and the lip part will close the lips.
Buccinator Muscle
The buccinator muscle is big, and it is covered by the muscles involved in the mastication (we will be discussing this in the near future) as well as the zygomatic muscle and is completely covered in its buccal fat pad. The formation of adipose tissue is evident, especially in overweight infants and obese people.
The buccal muscle in the bilateral contract (that is when both right and left muscles are at work) is pressed by the cheeks towards their teeth and pulls them backward while during unilateral contraction muscles pull the lip’s corner laterally.
Zygomaticus Major and Zygomaticus Minor
The two muscles are easily identified since they both originate from the front of the Zygomatic bone. Both muscles share an identical shape and sit very close to one another. To differentiate the two muscles, keep in mind that the zygomaticus muscle is near the nose.
The zygomaticus major muscles are interspersed into the circular muscles of the mouth. the zygomaticus minor muscles are linked to the skin within the region of the Nasolabial fold.
Both muscles function almost synergistically to carry out similar duties. The major muscle zygomaticus is responsible for pulling the corner of your lips upwards and then laterally. The minor muscle zygomaticus pulls the lips’ corners as well, defining lines of the nasal fold. It results in a grin expression on the upper lip.
Muscles of Mastication
Mastication muscles are powerful, strong, and vital for survival and nutrition. The human body has 4 pairs of malocclusion muscles two of which are of special importance to the plastic anatomy of the face because they play a role in the development of the contours of the face.
Temporalis Muscle
The temporalis muscle is big, flat, and covers every inch of the temporal fossa. In contrast to the other muscles that masticate that are located on the skull, the temporalis muscles are located in the skull’s vault. The temporalis muscle originates from several bones simultaneously which include the temporal, the frontal, parietal, as well as pterygoid.
Multiple muscle bundles connect downwards and centrally, making an extremely strong tendon that attaches to the coronoid mandible.
Feel the tightening of the temporalis muscle when you put your fingers onto the fossa of your temporal lobe. Then squeeze your teeth repeatedly to mimic chewing.
Masseter Muscle
It is also a strong and visible muscle. The chewing muscle sculpts the skin during the period of contraction and is particularly noticeable when people are slimmer.
Both muscles are directed diagonally posteriorly and connect to the masticatory tuberosity on the lower jaw.
Basic Topography of the Head
The topography of the body is where body components are examined in the context of organ systems, not body parts. Today, for instance, we’ll be looking at the basics of head topography. It’s not just the skull, but also the muscles of your head as well as other anatomical structures which form significant landmarks in plastic anatomy.
Head Borders
In order to draw the line between the neck from the head We need to create a straight line beginning from the chin towards the lower part of the jaw, then proceed to the mastoid process, and end with the lower Occipital Protuberance.
Cerebral and Facial Parts of the Head
The skull forms the skull’s skeleton The boundaries of the cerebral and facial areas of the skull are in line with the boundary of cerebral and facial parts of the skull.
To mark the line between the facial and cerebral areas of the head, it is necessary to draw a line beginning from the brow arches. Then, move down and along the zygomatic arch to the rear of our head. Then, starting from the zygomatic arches, we continue to follow the line until the top of the auditory canal’s exterior.
We have an area of separation between the facial and cerebral sections of the head.
Head Regions
Determining the boundaries of space is an essential part of topographic anatomy. To analyze the different regions within the brain, we need to be able to distinguish the facial and cerebral regions that comprise the skull.
Areas of the Cerebral Section of the Head
On the cerebral part of the head, we can see three areas – the front-parietal-occipital region, the temporal, and the mastoid. The frontal-parietal-occipital region is unpaired, the other two areas are paired.
The frontal-parietal-occipital regions are bordered:
In front, with the orbital edge of the frontal bone
Behind – starting with the neck’s upper part;
Laterally – along an upper temporal line that runs through the bone of the parietal.
The temporal area is bordered by
In front, with the zygomatic processes in frontal bones, and the process that is frontal of the zygomatic bone
Behind – using the temporal line
Above – using the temporal line
Below is an arch zygomatic.
Mastoid Region
The mastoid region is the boundary of the mastoid process.
Regions of the Facial Part
Orbital Region
The borders of the region of the orbit are the same as bone orbital cavities
Upper – the edge of the orbit of frontal bones.
Lower – the infraorbital edge of the upper jaw, and the adjacent zygomatic bone
Lateral – zygomatic bone;
Medial – the frontal part that runs through the jaw’s upper part, and the nasal portion of the bone that is frontal.
Nose Region
The nasal region is based on the contours of the outside portion of the nose, comprising the root, back the apex, wings, and back.
Zygomatic Region
The zygomatic border region is akin to those contours that define the body of the zygomatic bone.
Infraorbital Region
The region’s infraorbital borders:
Laterally and in the back of the zygomatic region
Medial – including the nasal region
Above the orbital region
Bottom – with cheeks.
Buccal Region
The buccal region is bordered by:
The medial furrow consists of the nasal
Laterally, with the parotid-masticatory zone;
The bottom ridge is located with the lower edges of lower jaws;
Above that, with the zygomatic and infraorbital zones.
Mouth Region
The mouth region is bordered by:
Above – with the brand new area
Below – is the chin region;
Laterally, on both sides – with buccal areas.
Chin Region
The chin’s border:
Above – with the region at the front of your mouth.
Laterally on both sides with buccal areas
Bottom – an upper edge on the jaw.
Parotid Masseteric Region
Borders of the Parotid masseteric region:
Above is the infraorbital area of the facial region as well as the temporal brain region.
Lower jaw – the bottom edge;
Medial – with buccal area
Laterally, using the auricle.