Fun Fact – incisors

incisors

Anatomy def: a sharp-edged tooth at the front of the mouth, adapted for cutting; four incisors in each jaw.

Outlander def: front eight teeth (four on top, four on bottom) used for threatening, nipping, biting, ripping!

Learn about the incisors and all the other teeth in Anatomy Lesson #14, Jamie and Claire of The Anatomy of a Kiss!

Read about Jamie’s beautiful, teeth in the Outlander book:

His features were indistinct, but the moonlight caught the gleam of teeth as he grinned. “Well then, since ye don’t want me to hurt myself, I suppose that means as you’re comin’ with me?”

And…

He reached out for one of the long-bladed grasses and pulled it smoothly from its sheath… Square white teeth crunched down on the grass stem.

Read about the effect of the standing stones on Claire’s teeth in Outlander book:

The sounds were all around me, making my teeth ache and my head spin. My vision began to blur. I do not know now whether I went toward the cleft in the main stone, or whether it was accidental, a blind drifting through the fog of noise.

View Angus’ missing incisors as he threatens a Redcoat in Starz episode 105, Rent!

And…

See Claire bare her teeth at BJR in Starz episode 106, The Garrison Commander!

And…

Watch Jamie’s incisors, erm, pay homage to Claire in Starz episode 109, The Reckoning!

A deeply grateful,

Outlander Anatomist

 

Anatomy Lesson #29: The Eyes Have It!

ep 109 Dougal eyebrows 01 KLS editedAn apocryphal story about Abraham Lincoln, 16th US President, claims he was taking a vote during a cabinet meeting on whether or not to sign the Emancipation Proclamation. All of his cabinet secretaries voted nay, whereupon Lincoln raised his right hand and declared: “The ayes have it!” 🤗

Today, the “eyes have it” as we begin a discussion which, due to complexity, will span more than one anatomy lesson! So, welcome all students to the first in a series of eye lessons: Anatomy Lesson #29, The Eyes Have It!

The eye is arguably the most elegant and complex sense organ of the human body. Its duty is to provide vision thereby increasing our perception of both inner and outer worlds (Photo A). John Ruskin (1819 – 1920), a leading English art critic of the Victorian era, put vision into clear perspective: “The greatest thing a human soul ever does in this world is to see… To see clearly is poetry, prophecy and religion, all in one.”

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photo A

The eyeball is marvelous but it doesn’t work in a vacuum. Surely, you’ve read about celebrities who are accompanied by a full entourage of assistants? Well, the eyeball has a similar assemblage. For the eyeball to work optimally, it requires help from a small host of accessory structures: eyebrows, eyelids, eyelashes, bony orbit, periorbital fat, lacrimal apparatus and extrinsic muscles. Today, we will learn how eyelids, eyebrows and eyelashes augment vision.

We’ll start today’s anatomy lesson with the eyebrows, a major human facial feature. In anatomy, the eyebrow is known as the supercilium (pl. supercilia). Eyebrows are linear growths of coarse hair that protect the eyeballs from the sun’s rays as well as sweat, rain, dandruff and other debris. The Greek physician Herophilos (335-280 B.C.) first suggested that the brows are “adorned with hair, so that if copious perspiration came, it would be contained by this ‘check-point’ of hair placed in its way until it is wiped off, so that it could not obstruct the eyes.” The eyebrow arch favors this explanation as it typically peaks over the eye and slants to each side ensuring that moisture wicks around the eyeball and towards temple or nose.

Delicious Dougal-Dude exhibits a fine example of manly arched brows; brow power to the max as he reminds Colum that he is dad-of-the-lad, Hamish. Colum should be grateful; after all, Dougal was showing fealty by lying wi’ his laird’s lovely Lady Letitia (Starz episode 109, The Reckoning).

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Besides protecting the eyeballs, eyebrows are vital in human communication by signaling mood changes such as anger, surprise, concern and even sexiness. Jamie’s eyebrows are furiously flapping in this Starz scene (episode 109, The Reckoning). Och! Weel, Claire’s dark dirk dare is agonizing for Jamie – runs counter to the man’s natural instincts. Ken the distress telegraphed by his eyebrows? At this point, yes, yes, lassie! Anything!

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Eyebrows also add major definition to the face. In a recent MIT study, subjects were asked to identify celebrities whose eyes or eyebrows had been digitally erased. Surprise! Subjects could correctly identify 60% of celebrities if eyes were blocked but only 46% if eyebrows were erased suggesting that eyebrows are more significant than eyes in identifying faces.

We humans like to mess with our anatomy and eyebrows are no exception: tattooing, waxing, plucking, brushing, coloring, trimming, stenciling, darkening, shaving, piercing, tweezing and threading (Photo B). And, of course, cosmetic surgery can lift eyebrows or Botox can be used to reduce skin lines near the brows to create a more youthful look.

Beauty eyes makeup closeup. Long eyelashes, perfect skin

photo B

Time for an eyebrow quote from Outlander book:

“Because I want to look at you,” I said. He was beautifully made, with long graceful bones and flat muscles that flowed smoothly from the curves of chest and shoulder to the slight concavities of belly and thigh. He raised his eyebrows. “Well then, fair’s fair. Take off yours”…

Here ye go. Breathe! Panting is OK, but no fainting (Starz episode 107, The Wedding)!

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Next up, anatomy of the palpebrae (pl.) or eyelids. Eyelids (Anatomy Lesson #11) are moveable flaps of skin that overlie the eyeballs. Upper and lower lids join on the nasal side at the medial canthus (Photo C – red arrow); the lateral canthus marks their fusion at the temporal side (Photo C – blue arrow). The elliptical opening between the eyelids is the palpebral fissure.

The upper lid is larger and more mobile than the lower and each lid covers the eyeball differently. With the eyelids open, the upper lid normally overlaps the upper cornea (and deeper-lying iris) but the lower lid sits just below the cornea (Photo C). With the eyelids closed, the upper lid moves down to cover the entire cornea. Note: if the lids of an eye at rest are open widely such that the entire cornea (and iris) is exposed, then one should consider being evaluated for possible causes (Grave’s disease, orbital cellulitis, exophthalmos, to name a few).

Try this: Open your eyelids and gaze into a mirror. Find medial and lateral canthi (pl.). Where are your eyelids relative to the iris (the iris is the best landmark because the transparent cornea is difficult to identify in a forward gaze)? Close the eyelids and gently probe the corneal bulge and realize that in this position, the upper lid completely covers the cornea.

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photo C

Except for parts of the external genitalia, eyelid skin is the thinnest of the entire body. Each lid contains a flexible connective tissue plate: the superior tarsus of the upper lid and inferior tarsus of the lower lid. Tarsi (pl.) add body and shape to the eyelids allowing them to cup the eyeball surface (Photo D – vertical section through eyelids and eyeball). Eyelids close to protect the eyeball from trauma, debris, and excessive light; they also help create the tear film and spread it across the eyeball surface.

Try this: Grip your upper lid between thumb and index fingers and gently squeeze. Feel the superior tarsal plate pop between your fingers? Now repeat with the lower lid and realize that the inferior tarsal plate is much smaller than the superior version.

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photo D

Eyelids are well equipped with sebaceous glands to keep the skin supple and sweat glands to cool the skin and eliminate wastes (Anatomy Lesson #5). But, the inner surfaces of superior and inferior tarsi house unique tarsal (meibomian) glands, specialized glands that release meibum, an oily substance that seals the eyelids when closed and also traps the tear film so it won’t spill over the eyelids (Photo E).

Try this: Look in a mirror and gently pull down your lower eyelid to evert and expose the inner surface (the upper lid is harder to evert). Locate the pale yellow lines arranged perpendicular to the lid margin – these are your tarsal glands!

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photo E

Each set of eyelids (Anatomy Lesson #13) is moved by three muscles: orbicularis oculi, levator palpebrae superioris and superior tarsal muscle of Müeller.

Orbicularis oculi muscle (OO) has two parts: an orbital part consists of large muscle loops that overlie bones of the eye socket (Photo F – labelled O); a palpebral part is confined to upper and lower eyelids (Photo F – labelled P). Both orbital and palpebral parts attach to the medial palpebral ligament, a tough band of connective tissue at the medial canthus of each eye (Photo F – red arrow).

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photo F

The orbital part of OO is under voluntary control meaning we can contract the muscle at will; this action squeezes the flesh surrounding the eyelids.

Jamie presents an agonizing example from Starz episode 116, To Ransom a Man’s Soul: his eyelids are slightly open but the skin around them is puckered because the orbital part of OO is contracted. He has confused his beloved Claire with the awful yuk-man! Pax, Jamie, Claire has ye in her healing hands!

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The palpebral part of OO contracts voluntarily to close the eyelids in a conscious blink. Volition is especially evident when we wink – voluntarily contracting the palpebral part of one eyelid.

Do you know how often we blink? Although we can voluntarily contract the palpebral part of OO, it is routinely under unconscious control meaning the brain signals the muscles to contract about 15 times every waking minute. This automated blinking cleanses, renews and redistributes the tear film. Also, if an object flies toward the eyeball, the palpebral part reflexively contracts and closes the lid to protect the cornea. This unconscious response relieves our conscious brain of instructing the palpebral muscles to contract every four seconds while we are awake (see the gif below in slow-mo).

Try this: Open your eyelids. Now contract the flesh around the lids, an action accomplished by the orbital part of OO. Now, relax the flesh around the eyelids and then deliberately blink both eyes or wink one; contraction of the palpebral part of OO causes this action. Next, close the lids of one eye and place a fingertip in the medial canthus. Move the finger gently up and down. Feel the tough ridge of tissue? This is the medial palpebral ligament which provides an attachment site for OO.

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The second set of eyelid muscles is levator palpebrae superioris (LPS). Each of these strap-like muscles originates deep in the eye socket and passes forward to insert on the superior tarsal plate of the same side (Photo G). LPS is under voluntary control; its contraction lifts the upper eyelid so light can enter the eyeball. Lacking comparable muscles, the lower eyelids glide open by gravity.

Finally, the third muscle acting on each eyelid is the superior tarsal muscle of Müeller; this small muscle spans from the underbelly of LPS to the superior tarsus (Photo G). Made of a different type of muscle (the body has three types – the rule of three in anatomy!), it can never be moved voluntarily and thus is always under autonomic control. Surprise, shock, pain, loud noises or scary events cause the superior tarsal muscle to contract swiftly and suddenly and the eyelids fly open. This is considered a survival mechanism allowing more light to enter the eyeball so we can quickly identify potential threats.

Figure0077B eyelid muscles KLS edited

photo G

Do we see Müeller’s muscle at work in Starz episodes? Oh, aye. Here are three good examples!

SURPRISE! Across a time barrier of two centuries, Jamie hears Frank shout “my wife is NOT with another man!” Sorry Frank, but she is! Naw… Jamie’s upper eyelids fly open because Hugh Munro’s arrow interrupted some serious hand sex (Starz episode 108, Both Sides Now). Bad timing Hugh – no more gaberlunzies for you!

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SHOCK! Jamie’s upper lids flash open; he is shocked, shocked I say, as he kens that bears aren’t the only creatures that poop in the woods! Wee Willie says he was busy taking a piss (yeah, right) when the red coats captured Claire. She was thrashing about and she’s gonna get thrashed again after Jamie gets her (Starz episode 109, The Reckoning)!

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PAIN! Müeller’s muscle quickly activates as Claire silently embroiders her initials into her handsome hubby’s side. Jamie, she warned ye to stay away from that damned double-dealing Duke! Och, aren’t nurses supposed to be gentle (Starz episode 110, By the Pricking of My Thumbs)?

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Next, let’s view some fun facts about eyelashes. Also known as cilia, eyelashes are short, thick hairs that grow in double or triple rows along the rims of our eyelids (Photo H). Eyelashes naturally curl: upper lashes curve upward and lower lashes curve downward; this design keeps the hairs from interlacing when the lids close. Also, please don’t pull out eyelashes; lashes take 7-8 weeks to regrow but constant pulling can lead to permanent loss. Natural eyelash color may differ from head hair although dark-haired individuals tend to have darker eyelashes than light-haired folks. Eyelashes help capture debris headed for the eyeball surface. Similar to cat whiskers, they are sensitive to touch and provide warning if an object approaches the eyeball so the lids can reflexively close.

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photo H

Many cultures consider long eyelashes a mark of beauty although there is one (Hazda of Tanzania) wherein women trim their eyelashes! Eyelash length is enhanced with mascara, extensions or false eyelashes although enhancing is nothing new. As far back as the Bronze Age kohl was used as eyeliner and lash enhancer and remains the eye cosmetic of choice in some parts of the world. In the west, mascara, eyeliner, eyeshadow, eye putty and tints are used to color the lashes or their bases (Photo I). Also, a mess of tools are used to alter eyelashes such as curlers, applicators and shields. Eyelash transplants are available although it uses head hair so if you go that route,  plan on regular haircuts! Finally, there is also a glaucoma-treatment drug with a side effect of eyelash growth. Whew!

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Photo I

And as if this isn’t enough fussing with our lashes, eyelash jewelry is now in vogue (Photo J)!

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Photo J

Eyelashes are fraught with many problems: infection with parasitic crab lice; ingrown lashes; loss of lashes; abnormal grown of lashes on other parts of the eyelid; itching, redness and flakiness; and styes/stys. And, did you know that 98% of humans harbor a harmless commensal mite (Demodex folliculorum) in the follicles of our eyelashes and eyebrows? In the US, the National Center for Biotechnology Information (NCBI – PubMed/NIH) posts numerous concerns about dreadful reactions to glues used in eyelash extensions and other cosmetic eye issues. Wherever you live, please get informed before enhancing the eye or its accessory parts with anything new or weird.

Clinical Correlation: Two major types of sores plague the eyelashes. One type is the stye/sty, the blockage of a sweat gland at the base of the eyelashes that produces a hordeolum, a painful, red, swollen bump (Photo K). A chalazion develops if a tarsal gland becomes blocked. Initially both types of sores are red, swollen and painful. However, over time, the chalazion becomes hard and non-tender whereas the sty/hordeolum continues to sting like a skelping!

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Photo K

Let’s finish this lesson with Outlander images and book quotes about eyelashes and eyelids. Want to see a lovely lassie with long lush lashes? Yep, its wee Jenny staring into shark eyes after BJR sticks his bloodied finger into her mouth (Starz episode 112, Lallybroch). Jamie says his sis has great eyelashes (Outlander book):

—she’s got blue eyes, like mine, but prettier, wi’ black lashes all around.

Maybe so; maybe faux? They look real to me!

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Shortly after their marriage, Claire muses that Jamie has unusual eyelashes (Outlander book).

… His lashes were long… Oddly colored, though; dark auburn at the tips, they were very light, almost blond at the roots.

Claire gits up close and personal as she gazes at Jamie’s long, thick ginger lashes (Starz episode 107, The Wedding). She just interrupted his kiss and he can still smile? What a lad!

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Of course, Outlander book readers ken that our Hero Jamie canna wink (urging non-readers to get with the remedial reading program. Wink, wink!):

He blinked at me like a large red owl—some congenital tic made him incapable of closing one eye in a wink—and I laughed.

Now, Jamie’s not quite blinking like a big old red owl in the image below but the palpebral parts of OO are contracted (Starz episode 107, The Wedding). Seems he is totally bummed because he thinks that Claire didna like IT! What the hey is IT? Ha ha! Seems Murtagh, Rupert and Ned gave Jamie a load of shite about women: they told him women didna like IT! But, they were dead wrong about not-a-wet-nurse Claire. She does like IT!

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Even cray-cray LegHaire, that lying little lass, contracts the palpebral part of OO as she lowers her upper lids. She is sooo sad for her puir Jamie – sob – trapped in a loveless marriage with a cold English bitch (Starz, episode 110, By the Pricking of My Thumbs)! Her lad must get swine drunk before he can stand to plow Claire’s field. SMACK! Seems LungHaire’s cheek just received a bit ‘o Claire’s “healing touch.” Oh, and she’s dead wrong about Mistress Claire; she does like IT! Shouting now!

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Murtagh’s Morning Mistake: he interrupts Jamie’s breakfast (Starz episode 110, By the Pricking of My Thumbs). Snort! Godfather, your eyelids are open now (levator palpebrae superioris is contracted) and ye look a wee bit sheepish. That’s right…baaaad timing! Baaaa!

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Here’s proof of Murtagh’s uh, oh (Starz episode 110, By the Pricking of My Thumbs): with both eyelids closed (palpebral parts of OO contracted and covering her corneas), Claire is basking in the afterglow of “the gift that keeps on giving” – Ira’s words, not mine. Yep, she likes IT!

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So students, Outlander proves that the eyes have it: lashes, lids and brows working together for the greater good!

All together now:

Sing me a song of gal who’s not gone,

Say could that lass be Claire?

Some are dead wrong as she loves her man strong,

Challenge her will if ye dare!

Jamie’s her man,

She belongs to his clan,

She’s part of his blood and bone!

Her eyes are for him; she’ll risk life and limb

‘till their life on earth shall be done!

Oh, sing me a song…

 

A deeply grateful,

Outlander Anatomist

 

photo creds: Netter’s Atlas of Human Anatomy, 4th ed. (Photos D, E, G); Clinically Oriented Anatomy, 5th ed. (image of orbicularis oculi); Starz; www.consumerreports.org (image of eyelash jewelry); www.giffy.com (blinking eyes); www.quotesgram.com (Panda bears); www.rakis.com.au (image of eyebrows); www.web.md.com (image of stye); www.en.wikipedia.org (images of man’s eyebrow; sty; eyelashes; gif of blink)

“Jamie’s Chin – Manly Mentus”

A hearty hello to valued anatomy students! Today’s Anatomy Lesson #26 is the Chin. A few months back several students asked for a lesson on Jamie’s chin so here it is. Serendipitously, this past week I also followed an avid Facebook discussion focused entirely on Jamie’s chin. Being a demure lady (snort!) I canna repeat the ideas that were posted; suffice it to say they were imaginative! Mmmphm. And, as Herself mentions the chin often in her Outlander books, let’s go!

English idioms about body parts are always fun to consider. Interestingly there are not many about the chin and most are concerned with either stamina or aggression: keep your chin up, take it on the chin, lead with the chin, catch it on the chin, wag one’s chin and to quote a particular portly pig (and some rappers) “not by the hair of my chinny chin chin!”

Right off the bat, let’s get the most important chin issue resolved and out of the way: Jamie’s chin is the strongest, handsomest and most manly mentus in filmdom (Starz episode 102, Castle Leoch)! Gah! Not sure I can keep me train of thought, but I’ll try!

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So verra delighted and deeply (ha ha) grateful that this man was chosen to play the King of Men! Even English nobility shares this opinion. Consider the Duke of Sandringham swiping his fingers across Jamie’s most excellent chin (Starz episode 110, By the Pricking of My Thumbs):

“Alas, my servants are chosen for their beauty, not their belligerence.”

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“You, of course, contain within you a sublime combination of the two!”

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This smarmy old rascal is spot on: Jamie, you are indeed a sublime blend of beauty and belligerence! Best you look askance at the Duke and his roving fingers; Claire willna like him fondling yer chinny chin chin! Sandringham invokes the lyrics from “You Did It” (My Fair Lady): “Oozing charm from every pore. He oiled his way around the floor.” Grrrreasy!

Now for chin anatomy: More than 200 years ago, the German physician, naturalist, physiologist and anthropologist, Johann Friedrich Blumenbach (1752 – 1840) declared that the chin is a uniquely human feature. Nowadays, most naturalists agree that elephants (Photo A) and perhaps two other mammals have chins but few species other than humans can lay claim to this body part.

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Photo A

A few scholarly circles hotly debate, why do we have a chin and what is its purpose? One cool idea posits that the human chin emerged due to speech and mastication (chewing) patterns. Indeed, computer models show that mechanical stress relating to muscle pull could contribute to chin development.

Another proposed reason for the human chin is sexual dimorphism, the different appearance of a body part between the genders. Typically, female chins are smaller and rounder and male chins are bigger and squarer. Such differences, it is argued, contribute to attractiveness and augment mate selection. And, don’t our Claire and Jamie demonstrate chin sexual dimorphism to a T (Starz episode 101, Sassenach)?

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Alas, the June 2015 Smithsonian reports that the chin didn’t develop to make us swoon nor to accommodate speech or distribute the stress of chewing. Rather, newest thinking declares the chin is the by-product of a shrinking face: over the eons, the face has decreased in size and tilted inward which in effect pushes chin and jaw outward. As for me, I prefer the sexual rif, thank you very much!

More chin anatomy: the mentus (Latin meaning chin) has several topographical features. First, the chin (Photo B –black arrow) and nose are typically the most forward projecting parts of the face. The chin has a bony base but the fleshy, moveable tip is the chin pad. From the point of the chin a pair of bony horizontal ridges project backward (Photo B – green arrow) each ending as a bony angle (Photo B – purple arrow). Between the lower lip and the chin is a horizontal skin groove, the mentolabial sulcus (Photo B – blue arrow).

Try this: What, there’s work to do already? Yep! Grip and wiggle your chin pad. Next, find your mentolabial sulcus, left and right horizontal bony ridges and bony angles. Very nice and good for you!

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Photo B

The projecting point of the mandible (Latin meaning jawbone) provides the bony foundation for the chin. The mandible arises during fetal life where it develops as right and left halves joined in the midline by a thin plate of fibrocartilage (Anatomy Lesson #24). The paired mandibular halves persist until the second year of life when the joint ossifies into a vertical bony ridge, the mandibular symphysis (Photo C – drawing of newborn skull).

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Photo C

During childhood, the chin persues the adult form as a midline triangular-shaped mental protuberance flanked on each side by a mental tubercle (Photo D). In the midline above the protuberance lies the unpaired bony ridge, the mandibular symphysis or symphysis menti (Photo D – black arrow).

Try this: Once again locate your mentolabial sulcus. Move one fingertip just below the sulcus and wiggle it back and forth. Do you feel a faint ridge? This is your symphysis menti. Move the finger downward to the bony tip. This is your mental protuberance. Now move your fingers to the left and right; do you feel a pair of small bony bumps? These are the mental tubercles. Well done!

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Photo D

Let’s consider more about the mandible (Anatomy Lesson #11 and Anatomy Lesson #13), the parent bone of the mentus. The mandible (unpaired after two years of age) is the strongest, largest and lowest bone of the skull and is its only moveable bone. It has a U- or V- shaped body (Photo E) expressed as the lower bony ridges mentioned above. The body ends posteriorly as the bony angles of the mandible (Photo E – only left side labelled). Jutting upward and backward from each mandibular angle is a strong bar of bone, the ramus. In the midline are bony features of the chin as described above. Lastly, the mandible has an upper alveolar part (Photo E) that serves as a receptacle for 16 adult teeth which in the best case scenario includes: four front incisors, two canines (BJR’s dog teeth – black arrows), four premolars and six molars.

Try this: Palpate the body and angles of your mandible. Look in a mirror, open your mouth and find incisors, canines, premolars and molars (if present). If your mouth is too dark to clearly see the teeth, shine a flashlight into the mirror; the light reflects back into your mouth and nicely illuminates that inner sanctum!

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Photo E

Each mandibular ramus ends in two bony projections: a condylar process the head of which articulates with a socket in the temporal bone at the TMJ (temporomandibular joint) and the sharp coronoid process (Photo F) onto which attaches a muscle of mastication (see below). On the inner surface, each ramus has an opening, the mandibular foramen, for passage of a nerve. On the outside of the chin are left and right mental foramina (pl.) which also transmit nerves.

 

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Photo F

Warning: The next image (Photo G) shows a deep dissection of the head and neck. Please skip if you find such images challenging. Three important nerves on each side of the face are pertinent to our discussion. The paired mandibular nerves (branches of Cranial Nerve V) exit the skull deep to each cheek bone (zygomatic arch – Anatomy Lesson #9). Each mandibular nerve produces left and right inferior alveolar nerves or IANs that enter the mandible via the mandibular foramina (shown in Photo F) to supply sensation to the lower teeth. Ouch! Yes, IANs are the culprits that transmit tooth pain! Along the way, each IAN gives off a mental nerve which exits via its respective mental foramen and provides sensation to lower lips, gums and chin. Bet Jenny didna ken that a nerve was named after her kindly brown-haired laddie!

Try this: Straddle your mentus with thumb and forefinger. Place them about the same vertical level as your canine teeth. Press down gently until you feel slight hollows and a tingle. These are your mental nerves exiting the mental foramina.

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Photo G

A discussion of the chin is incomplete without considering associated muscles. A whopping 28 muscles attach to the mandible – yes, that’s 14 muscles per side! I won’t name them all. Muscles that attach to the mandible (see below) act on seven different head and neck regions. Suffice it to say that each side of the mandible has four muscles for chewing, one moves the cheek, three move the lower lip, one wrinkles neck skin, three move the tongue and two help us swallow. As if this weren’t enough, several of these muscles aid in speech by moving lips, tongue and hyoid bone (Anatomy Lesson #12). Whew! The mandible (and its chin) truly is a workhorse for head and neck muscles.

Three of the 14 muscle pairs mentioned above are easily demonstrated. Each mentalis muscle arises from the mental protuberance and inserts into the lower lip (Photo H). As they contract, the lip elevates and protrudes as in a pout; simultaneously, the skin of the chin wrinkles. They also add bulk to the chin pad. Each masseter muscle arises from the zygomatic arch (Photo H – black arrow) and inserts into body and angle of the mandible; contraction closes the jaw. The temporalis muscles are the third pair of muscles for today. These fan-shaped muscles arise from the sides of the skull and insert onto the coronoid processes (shown in Photo F) of the mandibular rami. Contraction closes and retrudes (pulls backward) the mandible.

Try this: Return to the mirror and wrinkle your chin-skin. Congrats! You just activated your mentalis muscles. Next, place your fingers in the hollow of each temple; close your teeth and retrude (pull back) the mandible. You should feel tension in each temporalis as they contract. Finally place fingertips just anterior to each mandibular angle. Bite down and feel the masseters tense as they close the mandible.

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Photo H

Are these muscles at work in Outlander? Oh, to be sure! Geillis offers us a wonderful visual as she interrogates Claire before sentencing at the witch’s trial (Starz episode 111, The Devil’s Mark)! Why are you here in Scotland (English lassie has no idea) and when will you stop lying (tell the truth, the whole truth and nothing but the truth!)? Here, Geillis opens her mandible using muscles of mastication (lateral pterygoids) that we have yet to learn and are not visible from the skin surface. With the mandible widely opened, the masseter is pulled taut (green arrow) and the temporalis is stretched creating a hollow at the temple (blue arrow). Try it yourself; it works!

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Next, Geillis closes her mandible using the powerful masseter muscles (black arrow). This wild wily witch needs some answers before she becomes kindling at her own personal bar-b-que!

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Mentalis muscles are at work “Down by the Riverside” as Sassynach and Big Red One go at it hammer and tongs! After Claire wounds an astonished Jamie with her sharp 20th century tongue, she feels verra sad (Starz episode 109, The Reckoning). This sassynach is the best chin-skin-wrinkler and lower-lip-pouter in the whole of Scotland! Yep, her mentalis muscles are working hard here!

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Finally, no chin discussion would be complete without considering chin shape: is a chin smooth, dimpled, creased, clefted or using urban-speak, the awful “butt chin” (who dreamed that one up)? All these chin shapes are considered normal variants but, interestingly, the cleft chin is most common in people of European descent.

Science teachers may use the cleft chin as an example of a dominant genetic trait. But like the earlobe (Anatomy Lesson #24), the broad range of chin types should not be observed if simple dominant-recessive inheritance is at work. Other possible explanations for chin shapes include variable gene penetrance but this is beyond our present discussion.

Humans have long favored chin dimples as a mark of beauty. In Persian literature, the chin dimple is a “well” into which a poor lover falls and becomes trapped! Because a forest of growth covers the chins of most Starz Highlanders (the lads, no the lassies!), assessing their chin dimples is a challenge.

Consider dear Dougal whose chin and mandible are thickly furred. In honor of my good friend Jo Kc and the myriad of other Dougal fans, this image is for us! Here, big bad bro Colum abuses Dougal with names like “half-wit” and “numbskull” (Starz episode 110, By the Pricking of My Thumbs). Please employ your virtual imagination to identify as many chin and mandibular features as possible. Enjoy!

ep 110 Dougal chin KLS edited

Clean-shaven Highlanders are more rare than a wild haggis but here is that cutie, Willie; his is an excellent example of a smooth chin (Starz episode 114, The Search). Nice eyes, laddie!

ep 114 Willie chin KLS edited

Do ye like Claire’s wee but thoroughly charming chin dimple? Her chin enjoys one degree of separation from the smooth type. Here, she implores her husband: “Come back to me James Frasier” (Starz, episode 110, By the Pricking of My Thumbs). Oh, no! That clever, cunning Colum is sending her darling Jamie away!

ep 110 Claire chin KLS edited

Moving two degrees of freedom from a smooth chin, Jamie’s awesome chin crease sends many a heart into cardiac arrest (Starz episode 113, The Watch)! Ye can see it well despite the bit o’ scruff that typically adorns his manly mentus. Herself writes about this in Outlander book:

“Good.” He loosened his grip and turned me to face him. At close range, I could see the bristle of auburn stubble on cheek and chin. I brushed my fingers across it; it was like the plush on an old- fashioned sofa, stiff and soft at the same time.”

Ummm, gulp!

ep 114 Jamie chin KLS edited

Oh, what? You canna see Jamie’s chin crease clearly enough? Okay, here is the only image of a clean-shaven Jamie I can find in the episodes (Starz opening credits). Do ye ken the crease now? Of course ye do. Won’t be sleeping tonight? Oooh, so sorry! Join the bazillions of fans who L-O-V-E Jamie’s chin!

into-Jamie-shaven-chin-KLS-edited

Okay folks let’s finish this lesson with a short pop quiz using matching questions. Here are six numbered structures followed by six lettered photos with arrows indicating the body part. Match the named structure with the body part. Answers appear at the end. Ready. Set. GO!

STRUCTURE:

  1. Mentolabial sulcus
  2. Angle of mandible
  3. Body of mandible
  4. Mentus
  5. Mentalis muscle
  6. Masseter muscle

photo-A

A

photo-B

B

photo-C

C

photo-D

D

photo-E

E

photo-F

F

ANSWERS:

1 = B   (Starz episode 110, By the Pricking of my Thumbs)

2 = C   (Starz episode 108, Both Sides Now)

3 = F   (Starz episode 110, By the Pricking of my Thumbs)

4 = E   (Starz episode 111, The Devil’s Mark)

5 = D   (Starz episode 111, The Devil’s Mark)

6 = A  (Starz episode 109, The Reckoning)

Hope you did well on the matching quiz. Let’s close this anatomy lesson with a big old chinny chin treat!

Ode to Jamie’s Chin

Jamie Fraser has a chin, a manly chin has he.

His tender fuzz will give you a buzz

And maybe two or three!

Dream of petting Jamie’s chin and leave a kiss or two.

It’ll grieve you much, but do not touch

Lest his wife come into view!

Claire Fraser is a lucky lass but a jealous wench is she.

Dinna touch his chin or she’ll slap your skin

into eternity!

 yum

(Starz episode 112, Lallybroch)

A Deeply Grateful,

Outlander Anatomist

Photo creds: Starz, Netter’s Atlas of Human Anatomy, 4th ed., Clinically Oriented Anatomy, 5th ed., www.en.wikipedia.org (elephant)