Depressor Labii Inferioris
The depressor labii inferioris (also known as the Quadratus menti) is a small quadrilateral muscle located in the lower-jaw area of the face on both sides of the chin / lower-mouth.
The points of origin and insertion, and the actions of the depressor labii inferioris muscle:
|Origin:||External oblique line of the lower jaw (mandible)|
|Insertion:||Integument (skin) of the lower lip.|
|Actions:||Affects facial expression by moving skin tissues in the area of the lower jaw|
Some of the fibres of the depressor labii inferioris muscle are directly continuous with other adjacent muscles. This muscle also contains much yellow fat intermingled in among its fibres.
The depressor labii inferioris is one of the muscles of the head, neck, and face taught as part of many courses in Indian Head Massage. As this is a popular therapy we have included several pages that may be of interest to students of Indian Head Massage. See, for example, the page about skeletal structures of the head and neck.
See the page about Facial Muscles to view the location of the depressor labii inferioris muscle.
(This page consists of an interactive, rather than just a labelled, diagram, so you'll have to test yourself by guessing which muscle is the depressor labii inferioris until you find the correct label.)
More about Muscles:
- The structure of muscle tissue and the structure of muscle cells
- Labelled diagrams of the muscles in different parts of the body including anterior muscles, posterior muscles and facial muscles
- Various other pages about e.g. types of muscle contractions, movements at joints, muscular disorders and related topics such as books about sports medicine
- Anterior Muscles
- Posterior Muscles
- Facial Muscles
- Muscle Terminology (Definitions)
- 1. Structure of Muscle
- 2. Structure of Muscle Cells
- 3. Muscle Filaments
- 4. Sliding Filament Theory
- 5. Neuromuscular Junction
- 6. Actions at Neuromuscular Junction
- Types of Muscle Contractions
- Muscular Disorders
- Effects of exercise on muscles