The platysma muscle is a
superficial
Superficial may refer to:
* Superficial anatomy, is the study of the external features of the body
*Superficiality, the discourses in philosophy regarding social relation
* Superficial charm, the tendency to be smooth, engaging, charming, slick an ...
muscle
Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscl ...
of the
human
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...
neck
The neck is the part of the body on many vertebrates that connects the head with the torso. The neck supports the weight of the head and protects the nerves that carry sensory and motor information from the brain down to the rest of the body. In ...
that overlaps the
sternocleidomastoid
The sternocleidomastoid muscle is one of the largest and most superficial cervical muscles. The primary actions of the muscle are rotation of the head to the opposite side and flexion of the neck. The sternocleidomastoid is innervated by the access ...
. It covers the anterior surface of the neck superficially. When it contracts, it produces a slight wrinkling of the neck, and a "bowstring" effect on either side of the neck.
Structure
The platysma muscle is a broad sheet of muscle arising from the
fascia covering the upper parts of the
pectoralis major muscle
The pectoralis major () is a thick, fan-shaped or triangular convergent muscle, situated at the chest of the human body. It makes up the bulk of the chest muscles and lies under the breast. Beneath the pectoralis major is the pectoralis minor, ...
and
deltoid muscle
The deltoid muscle is the muscle forming the rounded contour of the human shoulder. It is also known as the 'common shoulder muscle', particularly in other animals such as the domestic cat. Anatomically, the deltoid muscle appears to be made up o ...
. Its fibers cross the
clavicle
The clavicle, or collarbone, is a slender, S-shaped long bone approximately 6 inches (15 cm) long that serves as a strut between the shoulder blade and the sternum (breastbone). There are two clavicles, one on the left and one on the rig ...
, and proceed obliquely upward and medially along the side of the neck. This leaves the inferior part of the neck in the midline deficient of significant muscle cover.
Fibres at the front of the muscle from the left and right sides intermingle together below and behind the
mandibular symphysis, the junction where the two lateral halves of the
mandible
In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower tooth, teeth in place. The mandible sits beneath the maxilla. It is the only movabl ...
are fused at an early period of life (although not a true symphysis). Fibres at the back of the muscle cross the
mandible
In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower tooth, teeth in place. The mandible sits beneath the maxilla. It is the only movabl ...
, some being inserted into the bone below the oblique line, others into the skin and
subcutaneous tissue
The subcutaneous tissue (), also called the hypodermis, hypoderm (), subcutis, superficial fascia, is the lowermost layer of the integumentary system in vertebrates. The types of cells found in the layer are fibroblasts, adipose cells, and macr ...
of the lower part of the face. Many of these fibers blend with the muscles about the angle and lower part of the mouth.
Sometimes fibers can be traced to the
zygomaticus major muscle
The zygomaticus major muscle is a muscle of the human body. It extends from each zygomatic arch (cheekbone) to the corners of the mouth. It is a muscle of facial expression which draws the angle of the mouth superiorly and posteriorly to allow one ...
, or to the margin of the
orbicularis oris muscle
In human anatomy, the orbicularis oris muscle is a complex of muscles in the lips that encircles the mouth.
It is a sphincter, or circular muscle, but it is actually composed of four independent quadrants that interlace and give only an appearance ...
. Beneath the platysma, the
external jugular vein
The external jugular vein receives the greater part of the blood from the exterior of the cranium and the deep parts of the face, being formed by the junction of the posterior division of the retromandibular vein with the posterior auricular vein ...
descends from the
angle of the mandible __NOTOC__
The angle of the mandible (gonial angle) is located at the posterior border at the junction of the lower border of the ramus of the mandible.
The angle of the mandible, which may be either inverted or everted, is marked by rough, obliq ...
to the
clavicle
The clavicle, or collarbone, is a slender, S-shaped long bone approximately 6 inches (15 cm) long that serves as a strut between the shoulder blade and the sternum (breastbone). There are two clavicles, one on the left and one on the rig ...
.
Nerve supply
The platysma muscle is supplied by the
cervical branch of the
facial nerve
The facial nerve, also known as the seventh cranial nerve, cranial nerve VII, or simply CN VII, is a cranial nerve that emerges from the pons of the brainstem, controls the muscles of facial expression, and functions in the conveyance of tas ...
.
Blood supply
The platysma muscle is supplied by branches of the
submental artery and
suprascapular artery
The suprascapular artery is a branch of the thyrocervical trunk on the neck.
Structure
At first, it passes downward and laterally across the scalenus anterior and phrenic nerve, being covered by the sternocleidomastoid muscle; it then crosses ...
.
Relations
The platysma muscle lies just deep to the subcutaneous fascia and
fat
In nutrition science, nutrition, biology, and chemistry, fat usually means any ester of fatty acids, or a mixture of such chemical compound, compounds, most commonly those that occur in living beings or in food.
The term often refers spec ...
.
It covers many structures found deeper in the neck, such as the
external carotid artery
The external carotid artery is a major artery of the head and neck. It arises from the common carotid artery when it splits into the external and internal carotid artery. External carotid artery supplies blood to the face and neck.
Structure
T ...
, the
external jugular vein
The external jugular vein receives the greater part of the blood from the exterior of the cranium and the deep parts of the face, being formed by the junction of the posterior division of the retromandibular vein with the posterior auricular vein ...
,
the
parotid gland
The parotid gland is a major salivary gland in many animals. In humans, the two parotid glands are present on either side of the mouth and in front of both ears. They are the largest of the salivary glands. Each parotid is wrapped around the ma ...
,
the
lesser occipital nerve
The lesser occipital nerve or small occipital nerve is a cutaneous spinal nerve. It arises from cervical spinal nerve 2, second cervical (spinal) nerve (along with the greater occipital nerve). It innervates the scalp in the lateral area of the ...
,
the
great auricular nerve
The great auricular nerve is a cutaneous nerve of the head. It originates from the cervical plexus, with branches of spinal nerves C2 and C3. It provides sensory nerve supply to the skin over the parotid gland and the mastoid process of the tempor ...
,
and the
marginal mandibular branch of the
facial nerve
The facial nerve, also known as the seventh cranial nerve, cranial nerve VII, or simply CN VII, is a cranial nerve that emerges from the pons of the brainstem, controls the muscles of facial expression, and functions in the conveyance of tas ...
.
Variation
Variations occur in the extension over the face and over the clavicle and shoulder. The platysma muscle may be absent or interdigitate with the muscle of the opposite side in front of the neck; attachment to clavicle, mastoid process or occipital bone occurs. A more or less independent
fasciculus
''Fasciculus vesanus'' is an extinct species of stem-group ctenophores known from the Burgess Shale of British Columbia, Canada. It is dated to and belongs to middle Cambrian strata.
The species is remarkable for its two sets of long and short ...
, the
occipitalis minor muscle, may extend from the fascia over the
trapezius muscle
The trapezius is a large paired trapezoid-shaped surface muscle that extends longitudinally from the occipital bone to the lower thoracic vertebrae of the spine and laterally to the spine of the scapula. It moves the scapula and supports the ...
to fascia over the insertion of the
sternocleidomastoid muscle
The sternocleidomastoid muscle is one of the largest and most superficial cervical muscles. The primary actions of the muscle are rotation of the head to the opposite side and flexion of the neck. The sternocleidomastoid is innervated by the access ...
.
Function
Wrinkling
When the entire platysma muscle is in action, it produces a slight
wrinkling of the surface of the skin of the
neck
The neck is the part of the body on many vertebrates that connects the head with the torso. The neck supports the weight of the head and protects the nerves that carry sensory and motor information from the brain down to the rest of the body. In ...
in an oblique direction (at an angle to the midline). It creates a distinctive "bowstring" effect on either side of the neck, where fibres move away from the midline.
Jaw and lip movement
The anterior portion of the platysma muscle, the thickest part of the muscle, depresses the lower
jaw
The jaw is any opposable articulated structure at the entrance of the mouth, typically used for grasping and manipulating food. The term ''jaws'' is also broadly applied to the whole of the structures constituting the vault of the mouth and serv ...
. It also draws down the lower lip and angle of the mouth in a
frown
A frown (also known as a scowl) is a facial expression in which the eyebrows are brought together, and the forehead is wrinkled, usually indicating displeasure, sadness or worry, or less often confusion or concentration.
The appearance of a fr ...
. However, the platysma muscle plays only a minor role in depressing the lower lip, which is primarily performed by the
depressor anguli oris muscle
The depressor anguli oris muscle (triangularis muscle) is a facial muscle. It originates from the mandible and inserts into the angle of the mouth. It is associated with frowning, as it depresses the corner of the mouth.
Structure
The depres ...
and the
depressor labii inferioris muscle
The depressor labii inferioris (or quadratus labii inferioris) is a facial muscle. It helps to lower the bottom lip.
Structure
The depressor labii inferioris muscle arises from the lateral surface of the mandible. This is below the mental foram ...
.
Clinical significance
In a similar fashion to other muscles, the platysma muscle is vulnerable to tears,
strains and
muscle atrophy, among many other possible conditions.
Injury
The platysma muscle is vulnerable to neck injuries that may
penetrate it, as it is both superficial and thin.
Penetrating trauma
Penetrating trauma is an open wound injury that occurs when an object pierces the skin and enters a tissue of the body, creating a deep but relatively narrow entry wound. In contrast, a blunt or ''non-penetrating'' trauma may have some deep dama ...
in the neck injuries can be defined as any that completely penetrate the platysma muscle, making it an important landmark.
CTA (
computed tomography angiography
Computed tomography angiography (also called CT angiography or CTA) is a computed tomography technique used for angiography—the visualization of arteries and veins—throughout the human body. Using contrast injected into the blood vessels, ...
) may be used to visualise
arteries
An artery (plural arteries) () is a blood vessel in humans and most animals that takes blood away from the heart to one or more parts of the body (tissues, lungs, brain etc.). Most arteries carry oxygenated blood; the two exceptions are the pu ...
and
veins
Veins are blood vessels in humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated b ...
, such as for complex injuries from
gunshot wounds
A gunshot wound (GSW) is a penetrating injury caused by a projectile (e.g. a bullet) from a gun (typically firearm or air gun). Damages may include bleeding, bone fractures, organ damage, wound infection, loss of the ability to move part ...
or
stab wounds
A stab wound is a specific form of penetrating trauma to the skin that results from a knife or a similar pointed object. While stab wounds are typically known to be caused by knives, they can also occur from a variety of implements, including bro ...
, and is useful to image any damage to the muscle.
This minimises the number of
exploratory surgeries that need to be performed, thus improving the handling of the condition.
Neck surgery
When neck surgery is performed, the platysma muscle usually needs to be cut through to access deeper structures.
Fibres need to be sutured together accurately to prevent abnormal
scar
A scar (or scar tissue) is an area of fibrous tissue that replaces normal skin after an injury. Scars result from the biological process of wound repair in the skin, as well as in other organs, and tissues of the body. Thus, scarring is a na ...
retraction, which may look unsightly.
Plastic surgery
Wrinkly skin of neck caused by decrease in muscle tone leading to thinning and shortening of muscle is the secondary complication of facial nerve palsy and can be associated with the normal aging process. Neck bands in the area above the platysma muscle become most noticeable with age.
These may be aggravated by
weightlifting
Weightlifting generally refers to activities in which people lift weights, often in the form of dumbbells or barbells. People lift various kinds of weights for a variety of different reasons. These may include various types of competition; promo ...
or
facelift
A facelift, technically known as a rhytidectomy (from the Ancient Greek () "wrinkle", and () "excision", the surgical removal of wrinkles), is a type of cosmetic surgery procedure used to give a more youthful facial appearance. There are mul ...
procedures. This may be known as platysma dyskinesia or "turkey neck".
Conservative management Conservative management is a type of medical treatment defined by the avoidance of invasive measures such as surgery or other invasive procedures, usually with the intent to preserve function or body parts. For example, in appendicitis, conservati ...
may be used. Alternatively, interventions include
botulinum toxin injection and
platysmaplasty. Platysmaplasty is a surgery in this area, that can be open or closed; in the latter a specialised instrument called a plastymotome is used that allows the surgery to be done without incisions. It takes approximately 2 weeks for the symptoms to be reduced.
Adipose tissue
Adipose tissue, body fat, or simply fat is a loose connective tissue composed mostly of adipocytes. In addition to adipocytes, adipose tissue contains the stromal vascular fraction (SVF) of cells including preadipocytes, fibroblasts, vascular e ...
is found above the platysma muscle, so
liposuction
Liposuction, or simply lipo, is a type of fat-removal procedure used in plastic surgery. Evidence does not support an effect on weight beyond a couple of months and does not appear to affect obesity-related problems. In the United States, lipo ...
of the neck may be performed fairly easily without the need to pierce it.
It is also important to not damage the platysma muscle to prevent
bleeding
Bleeding, hemorrhage, haemorrhage or blood loss, is blood escaping from the circulatory system from damaged blood vessels. Bleeding can occur internally, or externally either through a natural opening such as the mouth, nose, ear, urethra, vag ...
.
Images
File:Platysma.png, Platysma is visible at bottom, in neck
References
;Books
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Muscles of the head and neck