The platysma muscle or platysma 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 and ...
muscle
Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...
of the
human
Humans (''Homo sapiens'') or modern humans are the most common and widespread species of primate, and the last surviving species of the genus ''Homo''. They are Hominidae, great apes characterized by their Prehistory of nakedness and clothing ...
neck
The neck is the part of the body in many vertebrates that connects the head to the torso. It supports the weight of the head and protects the nerves that transmit sensory and motor information between the brain and the rest of the body. Addition ...
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 acces ...
. 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.
Etymology
First recorded in the period 1685–1695, the word comes via
Neo-Latin
Neo-LatinSidwell, Keith ''Classical Latin-Medieval Latin-Neo Latin'' in ; others, throughout. (also known as New Latin and Modern Latin) is the style of written Latin used in original literary, scholarly, and scientific works, first in Italy d ...
from
Greek
Greek may refer to:
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group
*Greek language, a branch of the Indo-European language family
**Proto-Greek language, the assumed last common ancestor of all kno ...
''plátysma'', a plate, literally, something wide and flat, equivalent to ''platý(nein)'', to widen, + -''sma'', a variant of the
resultative suffix ''-ma''. The botanist
William T. Stearn argues that ''platýs'', "in Greek compound words, usually signifies ''broad'', rarely ''flat''," which describes the platysma's broad sheet of muscle.
Structure
The platysma muscle is a broad sheet of muscle arising from the
fascia
A fascia (; : fasciae or fascias; adjective fascial; ) is a generic term for macroscopic membranous bodily structures. Fasciae are classified as superficial, visceral or deep, and further designated according to their anatomical location.
...
covering the upper parts of the
pectoralis major muscle and
deltoid muscle
The deltoid muscle is the muscle forming the rounded contour of the shoulder, human shoulder. It is also known as the 'common shoulder muscle', particularly in other animals such as the domestic cat. Anatomically, the deltoid muscle is made up o ...
. Its fibers cross the
clavicle
The clavicle, collarbone, or keybone is a slender, S-shaped long bone approximately long that serves as a strut between the scapula, shoulder blade and the sternum (breastbone). There are two clavicles, one on each side of the body. The clavic ...
, 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
In human anatomy, the facial skeleton of the skull the external surface of the mandible is marked in the median line by a faint ridge, indicating the mandibular symphysis (Latin: ''symphysis menti'') or line of junction where the two lateral ha ...
, the junction where the two lateral halves of the
mandible
In jawed vertebrates, the mandible (from the Latin ''mandibula'', 'for chewing'), lower jaw, or jawbone is a bone that makes up the lowerand typically more mobilecomponent of the mouth (the upper jaw being known as the maxilla).
The jawbone i ...
are fused at an early period of life (although not a true symphysis). Fibres at the back of the muscle cross the mandible, 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, or 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 ma ...
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 face. It arises from either zygomatic arch (cheekbone); it inserts at the corner of the mouth. It is innervated by branches of the facial nerve (cranial nerve VII).
It is a muscle of facial expres ...
, 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 not a true sphincter, as was once thought, as it is actually composed of four independent quadrants that interlace and give only an a ...
. Beneath the platysma, the
external jugular vein
The external jugular vein is a paired jugular vein which 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 wi ...
descends from the
angle of the mandible
__NOTOC__
The angle of the mandible (a.k.a. gonial angle, Masseteric Tuberosity, and Masseteric Insertion) 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 ...
to the
clavicle
The clavicle, collarbone, or keybone is a slender, S-shaped long bone approximately long that serves as a strut between the scapula, shoulder blade and the sternum (breastbone). There are two clavicles, one on each side of the body. The clavic ...
.
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 ta ...
.
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 t ...
.
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 specif ...
.
It covers many structures found deeper in the neck, such as the
external carotid artery
The external carotid artery is the major artery of the head and upper neck. It arises from the common carotid artery. It terminates by splitting into the superficial temporal and maxillary artery within the parotid gland.
Structure
Origin
T ...
, the
external jugular vein
The external jugular vein is a paired jugular vein which 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 wi ...
,
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 m ...
,
the
lesser occipital nerve
The lesser occipital nerve (or small occipital nerve) is a cutaneous spinal nerve of the cervical plexus. It arises from second cervical (spinal) nerve (C2) (along with the greater occipital nerve). It innervates the skin of the back of the up ...
,
the
great auricular nerve
The great auricular nerve is a Cutaneous nerve, cutaneous (sensory) nerve of the head. It originates from the second and third spinal nerve, cervical (spinal) nerves (C2-C3) of the cervical plexus. It provides sensory innervation to the skin over ...
,
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 ta ...
.
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 sho ...
, 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 human spine, spine and laterally to the spine of the scapula. It moves the scapula and ...
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 Anatomical terms of motion#Flexion and extension, flexion of the neck. ...
.
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 in many vertebrates that connects the head to the torso. It supports the weight of the head and protects the nerves that transmit sensory and motor information between the brain and the rest of the body. Addition ...
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. 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 for ...
.
Clinical significance
In a similar fashion to other muscles, the platysma muscle is vulnerable to tears,
strains and
muscle atrophy
Muscle atrophy is the loss of skeletal muscle mass. It can be caused by immobility, aging, malnutrition, medications, or a wide range of injuries or diseases that impact the musculoskeletal or nervous system. Muscle atrophy leads to muscle weakne ...
, 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 in the neck injuries can be defined as any that completely penetrate the platysma muscle, making it an important landmark.
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, im ...
may be used to visualise
arteries
An artery () is a blood vessel in humans and most other animals that takes oxygenated blood away from the heart in the systemic circulation to one or more parts of the body. Exceptions that carry deoxygenated blood are the pulmonary arteries in ...
and
veins
Veins () are blood vessels in the circulatory system of 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 those of the pulmonary and fetal c ...
, such as for complex injuries from
gunshot wounds or
stab wounds, 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 fibrosis, 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 Organ (anatomy), organs, and biological tissue, t ...
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 or weight lifting generally refers to physical exercises and sports in which people lift weights, often in the form of dumbbells, barbells or machines. People engage in weightlifting for a variety of different reasons. These can ...
or
facelift procedures. This may be known as platysma
dyskinesia
Dyskinesia refers to a category of movement disorders that are characterized by involuntary muscle movements, including movements similar to tics or chorea and diminished voluntary movements. Dyskinesia can be anything from a slight tremor of t ...
or "turkey neck".
Conservative management
Conservative treatment 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 (also known as body fat or simply fat) is a loose connective tissue composed mostly of adipocytes. It also contains the stromal vascular fraction (SVF) of cells including preadipocytes, fibroblasts, Blood vessel, vascular endothel ...
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, lip ...
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, urethr ...
.
Images
File:Platysma.png, Platysma is visible at bottom, in neck
File:Braus 1921 375.png, Platysma
Weblinks
References
;Books
*
{{Authority control
Muscles of the head and neck