Muscles of the Face

Summary

This video delves into the intricate world of facial muscles, focusing on three main groups: sphincters like the orbicularis oculi and oris, muscles of facial expression including levator labii superioris, depressor labii inferioris, mentalis, zygomaticus minor and major, and triangularis, which control various expressions from smiling to frowning. It also touches on muscles of mastication, such as the masseter and temporalis, which are crucial for chewing. The video promises a separate exploration of muscles of the hyoid and neck, inviting viewers to continue their anatomical journey.

Takeaways

• 😃 The video discusses the muscles of the face, specifically focusing on muscles of facial expression, mastication, and facial sphincters.
• 👁 The orbicularis oculi is a sphincter muscle that closes the eye, while the orbicularis oris presses the lips together.
• 👃 The nasalis muscle is not a true sphincter but functions to close the nostrils when depressed.
• 😏 The levator labii superioris elevates the upper lip, and the depressor labii inferioris depresses the lower lip.
• 😠 The mentalis muscle, also known as the pout muscle, protrudes the lower lip.
• 😊 The zygomaticus minor and major are involved in smiling by pulling the corners of the mouth upwards and at an angle.
• 😠 The triangularis muscle is responsible for frowning, as it pulls the corners of the mouth downwards and laterally.
• 🦷 The muscles of mastication include the masseter, which elevates the mandible when it contracts.
• 😕 The buccinator muscle does not move the jawbone but compresses the cheeks during chewing.
• 🔄 The temporalis muscle is a synergist with the masseter, also elevating the mandible due to its attachment to the coronoid process.
• 📚 The video will have a separate segment for muscles of the hyoid and neck, indicating further content on the topic.

Q & A

What are the main categories of facial muscles discussed in the video?

The main categories discussed are the muscles of facial expression, the muscles of mastication, and the sphincters of the face.

What is the function of a sphincter muscle?

A sphincter is a circular muscle that guards an opening.

Name the sphincter muscles mentioned in the video and their functions.

The orbicularis oculi closes the eye, and the orbicularis oris presses the lips together.

Why is the nasalis not considered a true sphincter?

The nasalis is not considered a true sphincter because it is not a completely circular muscle, although it does guard an opening by shutting off the nostrils when depressed.

What are the functions of the levator labii superioris and the depressor labii inferioris?

The levator labii superioris elevates the upper lip, and the depressor labii inferioris depresses the lower lip.

Which muscle is referred to as the 'pout muscle' and what is its function?

The mentalis is referred to as the 'pout muscle' because it protrudes the lower lip.

How do the zygomaticus minor and zygomaticus major contribute to facial expression?

The zygomaticus minor and zygomaticus major assist in smiling by pulling the corners of the mouth upwards and at an angle.

What is the function of the triangularis muscle?

The triangularis muscle is a frown muscle because it pulls the corners of the mouth downwards and at an angle.

Describe the role of the risorius muscle in facial expression.

The risorius muscle pulls the corners of the mouth laterally.

Which muscles of mastication were mentioned, and what are their functions?

The masseter and temporalis muscles were mentioned. The masseter elevates the mandible, and the temporalis also elevates the mandible, acting as a synergist with the masseter. The buccinator, while not moving the jawbone, compresses the cheeks.

What is mastication?

Mastication means chewing, so any muscle involved in chewing can be called a muscle of mastication.

Outlines

00:00

😄 Facial Muscles and Expressions

This paragraph introduces the topic of facial muscles, focusing on those responsible for facial expressions and mastication. It defines a sphincter muscle and identifies the orbicularis oculi and oris, as well as the nasalis. It then discusses the muscles involved in facial expressions, such as the levator labii superioris, depressor labii inferioris, mentalis, zygomaticus minor and major, and triangularis. These muscles are responsible for various expressions like smiling and frowning. The paragraph also explains that these muscles move the skin rather than joints.

Keywords

💡muscles of facial expression

These are muscles that control facial movements, allowing us to express emotions such as smiling and frowning. They are unique because they typically attach to the skin, enabling them to move it. Examples from the script include the zygomaticus minor and major, which help in smiling, and the triangularis, which is used for frowning.

💡sphincter

A sphincter is a circular muscle that guards an opening in the body by contracting and relaxing. In the face, examples include the orbicularis oculi, which closes the eye, and the orbicularis oris, which presses the lips together. The video also mentions the nasalis, which isn't a true sphincter but functions similarly by affecting the nostrils.

💡orbicularis oculi

This is a circular muscle around the eye that allows it to close. It is an example of a facial sphincter mentioned in the script, emphasizing its role in protecting the eye by controlling its opening.

💡orbicularis oris

This muscle encircles the mouth and is responsible for pressing the lips together. It's another example of a facial sphincter, playing a crucial role in actions like speaking and eating.

💡nasalis

Although not a true sphincter, the nasalis muscle helps control the nostrils. The video explains that it can shut off the nostrils when depressed, which is an important function for facial expressions and breathing regulation.

💡levator labii superioris

This muscle elevates the upper lip, contributing to facial expressions such as sneering or showing distaste. It illustrates how specific muscles are responsible for particular facial movements.

💡depressor labii inferioris

This muscle depresses the lower lip, helping to create expressions like sadness or disapproval. The script uses it to demonstrate the variety of muscles involved in facial expressions.

💡zygomaticus major and minor

These muscles are involved in smiling by pulling the corners of the mouth upwards and at an angle. They highlight the coordinated action of facial muscles to create specific expressions.

💡mentalis

Known as the 'pout muscle,' the mentalis protrudes the lower lip. This term is used in the script to describe how different muscles contribute to common facial expressions.

💡masseter

This muscle is crucial for mastication (chewing) by elevating the mandible (jawbone). It is highlighted in the script to show the functional diversity of facial muscles, some of which move joints unlike those purely for expression.

💡buccinator

This muscle compresses the cheeks, which is important for actions like blowing or sucking. The script includes it to explain muscles of mastication that don't move the jawbone but are still essential for chewing.

💡temporalis

This muscle also aids in elevating the mandible, working synergistically with the masseter. It is used in the script to illustrate how multiple muscles can work together to perform the same action, enhancing our understanding of mastication.

Highlights

Introduction to the muscles of the face, specifically facial expression, mastication, and sphincters.

Definition of a sphincter: a circular muscle guarding an opening.

Orbicularis oculi closes the eye.

Orbicularis oris presses the lips together.

Nasalis muscle guards the nostrils but isn't a true sphincter.

Levator labii superioris elevates the upper lip.

Depressor labii inferioris depresses the lower lip.

Mentalis is known as the pout muscle because it protrudes the lower lip.

Zygomaticus minor and major assist in smiling by pulling the corner of the mouth upwards and at an angle.

Triangularis is a frown muscle because it pulls the corners of the mouth downwards and at an angle.

Risorius pulls the corners of the mouth laterally.

Facial expression muscles move the skin, not joints.

Muscles of mastication move the mandible, such as the masseter.

Masseter elevates the mandible, connected to the angle of the mandible and zygomatic bone.

Buccinator compresses the cheeks.

Temporalis elevates the mandible, similar to the masseter, and is considered a synergist with it.

Mastication refers to chewing, involving any muscle related to this action.

Conclusion and preview of next video on the muscles of the hyoid and neck.

Transcripts

hey everyone so in today's video I'm

gonna talk about the muscles of the face

specifically I'm gonna talk about the

muscles of facial expression the muscles

of mastication and the sphincters of the

face

so the definition of a sphincter is a

circular muscle which guards an opening

on the face there is the orbicularis

oculi which closes the eye and the

orbicularis Oris which presses the lips

together and there's also the nez alice

which isn't a true sphincter because

it's not a completely circular muscle

but it does guard an opening because it

kind of shuts off your nostrils when you

depress it moving on to the muscles of

facial expression

there's the levitt or lay-by superiores

and the depressor lay by inferiors

so the Leavitt or lay by superiores

elevates the upper lip and the depressor

lay by inferiority depresses the lower

lip on the chin is a muscle called the

mentalis which is the pout muscle

because it protrudes the lower lip the

zygomaticus minor and zygomaticus major

both assist in smiling because they pull

the corner of the mouth upwards and at

an angle and the triangularis is a frown

muscle because it pulls the corners of

the mouth downwards and at an angle

the resource it's hooked to the corner

of the mouth but you see it runs side to

side so it pulls the corners of the

mouth laterally so all of these muscles

are just moving skin they're not moving

a joint the muscles of mastication some

of them are actually moving a joint

because they're moving the mandible so

the masseter is hooked to the angle of

the mandible and the zygomatic bone so

when it contracts and pulls upwards it

elevates the mandible and the Bucks

inator

this one doesn't move the jawbone it

just compresses the cheeks

the temporalis also elevates the

mandible just like the masseter because

you see it's hooked here to the coronoid

process of the mandible and then it

pulls this way so when it does that it's

going to elevate the mandible so because

it has the same action as the masseter

we can say it's a synergist with the

masseter also when you hear muscles of

mastication mastication just means

chewing so any muscle that has to do

with chewing you can call a muscle of

mastication

so that's everything I'm gonna talk

about in this video I'm going to make a

separate video for the muscles of the

hyoid and the muscles of the neck have a

great day and have fun studying