Fun Fact – Zygomatic Arch

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Learn more about the zygomatic arch (cheek bone) in Anatomy Lesson #8, “Jamie Takes a Beating and Claire’s Healing Touch!”

And from Outlander book:

Looking at that strong, young, determined face, with its broad cheekbones and solid jaw, I felt for the first time that this preposterous scheme of Dougal’s might actually have been a reasonable suggestion…

The broad cheekbones and long, straight, knife edged nose were plainly a MacKenzie inheritance.

Watch Claire pat the swollen flesh (Ha!) over Jamie’s left zygomatic arch after his beating in the great hall, Starz episode 102, Castle Leoch!

A deeply grateful,

Outlander Anatomist

Colum’s Legs and Other Things, Too!

Thanks for running to class today, Outlander anatomy students! Today’s Anatomy Lesson #27 is on the Leg. Upper and lower limbs are both fascinating and complex puzzle pieces of our human anatomy (Photo A). Four Anatomy Lessons (#19, #20, #22, #23) have covered the upper limb but only one dealt with the lower limb (Anatomy Lesson #7). This leg-a-thon has been slooow in coming, but Colum’s legs are begging for some well-deserved attention!

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Photo A: Dream Object by Jim Shaw

We all know that Colum’s legs captured Claire’s attention from the get-go. Here, her glass face shows what she thinks “plain and clear” (Starz episode 102, Castle Leoch). She’s surprised when the laird catches her riffling through his personal letters and books and then she is startled by his unusual physique.

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Herself records Claire’s thoughts (Outlander book):

“At the moment, though, my discomfort arose from the fact that the beautifully modeled head and long torso ended in shockingly bowed and stumpy legs. The man who should have topped six feet came barely to my shoulder. … ‘I welcome ye, mistress,’ he said, with a slight bow. ‘My name is Colum ban Campbell MacKenzie, laird of this castle.’ ”

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Colum’s bowed and twisted legs burden him with two “gifts that keep on giving”: pain and discomfort. Scientific explanations for his disability are coming up soon but first we must learn normal anatomy of the leg. So let’s get a leg up and start trotting!

In Anatomy Lesson #7, “Jamie’s Thighs or Ode to Joy,” we learned that anatomists define the leg differently than is common. In anatomy, the lower limb is divided into thigh, the region between hip and knee joints; leg, the region between knee and ankle joints; and foot, the remainder of the limb (Photo B). Colum’s entire lower limbs are affected by his disability but as that entails too much anatomy for a single lesson, we will focus on the anatomical leg.

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Photo B

As always, we begin with the bony foundation. The lower limb contains 29 bones, one fewer than the upper limb: the thigh contains one bone, the leg contains two and the foot has 26.

The femur or thigh bone is the longest and by most measures the strongest bone of the human body (Photo C – right femur). Its bony details (and Jamie’s thighs) were covered in Anatomy Lesson #7 so we will skip them today.

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Photo C

Each leg contains two bones, the tibia situated medially (closer to body midline) and the fibula positioned laterally (away from body midline). Although not shown in Photo D, strong ligaments bind tibia and fibula to each other and also to femur and a few foot bones.

Parts of the sturdy tibia are subcutaneous thus its sharp anterior border and medial surface are easily palpated. Its proximal (near) end forms a bony plateau for the knee joint and its distal (far) end forms the medial malleolus or inner ankle bone (Photo D).

The needle-shaped fibula (Latin meaning clasp – as the pin of a brooch) is difficult to palpate except at its ends: the head forms a bony knob at the outside of each knee and the lateral malleolus is the outer ankle bone (Photo D). Fibulae are useful because surgeons can harvest most of their lengths for bone grafts (e.g. mandibular reconstruction) with little deficit as long as both fibular ends are left intact.

Try this: Place fingers on the front of your leg. Palpate the sharp anterior border of tibia or shin bone, the part that gets barked on projecting surfaces. Ouch! Move fingers toward the inside of your leg and feel the hard, flat medial surface of tibia. Move fingers to the inner ankle and tap the bony medial malleolus of tibia.

And try this: Next, move fingers to the muscle mass at the side of your leg; it covers most of fibula except at each end. The bony knob you feel near the knee is the head of fibula. Find the bony outer ankle or lateral malleolus of fibula. Together, medial and lateral malleoli (pl.) form a strong box-like frame for a foot bone which will be covered in a later lesson (Photo D- green arrow).

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Photo D

The leg contains 12 muscles; we’ll cover four. The first muscle is tibialis anterior (Anatomy Lesson #9), the muscle savaged by a boar’s tusk at the tynchal (Starz episode 104, The Gathering). Tibialis anterior is a strong fleshy muscle that hugs the outer surface of the tibia. It arises from the tibia and inserts into a foot bone (Photo E – right tibialis anterior). Contraction dorsiflexes the foot meaning it lifts the toe-end of the foot toward the sky, an action critical for walking and running. It also helps invert the foot, meaning to turn the sole of foot toward the midline.

Try this: Plant a shoeless foot on the floor. Leave the heel planted but lift the toe-end of your foot skyward. This is dorsiflexion. Replant the foot and turn sole inward to face the midline; this is inversion (some practitioners call this supination). Return the foot to dorsiflexion and palpate the tense fleshy muscle just lateral to your tibia; this is tibialis anterior.

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Photo E

Want to see a really cute tibia (red arrow) and tibialis anterior muscle (blue arrow)? Of course ye do! Here is Claire the morning after (Starz episode 107, The Wedding). Yep…her curvaceous legs are beautiful and her crossed toes make her look soooo innocent but we all ken what those toes did last night! Jamie, weel, he’s hungry. How about a bite, Claire?

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At the side of the leg is fibularis longus (aka peroneus longus). A long spindle-shaped muscle that arises from head of fibula, its tendon passes under the foot and inserts on a bone near the instep (Photo F). Fibularis longus contracts to evert the foot meaning it turns the sole away from the body midline. Think of a novice ice skater: ankles knock together and soles turn outward – this is eversion of the feet. Fibularis longus also helps plantar flex (point) the foot.

Try this: Plant a shoeless foot on the floor. If you can, turn your foot so the sole faces to the side and your inner ankle moves closer to the ground. This is eversion (some practitioners call this pronation) of the foot. With the foot in this position, feel the tense muscle running down the outside of your fibula; this is fibularis longus. Now point the foot, this is plantar flexion also aided by fibularis longus.

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Photo F

The back of the leg contains seven muscles but we will cover only two. First is gastrocnemius (Latin and Greek meaning stomach of the leg); this odd name reflects the bulging shape of the calf created by gastrocnemius. This muscle spans two joints: knee and ankle. It also has two heads, one arising from each side of the femur (Photo G). The heads unite high in the leg but about midway down the calf the muscle gives way to the calcaneal or Achilles tendon.  The longest and strongest tendon of the body, it inserts into the calcaneus or heel bone (Photo G, green arrow).

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Photo G

Contraction of the gastrocnemii (pl.) flexes the legs at the knee joints and plantar flexes (points) the feet. These are powerful muscles and each is active during fast movements such as running, jumping and dancing.

Gastrocnemii are verra active during a shinty game (Starz episode 104, The Gathering). Run ruaidh Jamie! Big bad Uncle Dougal is hot on your handsome Highland heels! Run, run as fast as you can; you can’t catch the ginger-haired man!

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Covered by boots, we canna see the gastrocnemii but they are also busy as Murtagh, um, “executes” his version of the Highland sword dance (Starz episode 114, The Search).

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The soleus (Latin meaning sandal) is a large, flat muscle deep to each gastrocnemius. Soleus arises from the back of tibia and fibula and joins gastrocnemius to form the Achilles tendon (Photo H).  Because gastrocnemius and soleus share the Achilles tendon, some anatomists consider them a single muscle, the triceps surae (Latin meaning three-headed calf muscle). Soleus crosses only the ankle joint so it helps plantar flex the foot. But equally important, soleus is a postural muscle that helps us stand aright; if not for its constant backward pull, we would do a face-plant!

Now, here’s an interesting factoid: besides plantar flexion and posture maintenance, soleus helps prevent stasis of venous blood. A large leg vein (posterior tibial) passes deep to soleus so when the muscle contracts, venous blood is moved towards the heart against gravity. For this contribution, the soleus is also called the sural pump. This is so important that some health providers recommend soleus exercises for inactive patients to help prevent deep venous thrombosis (DVT or blood clots). And, smart passengers on long air flights should flex and point their feet every couple of hours (activates the soleus pump), walk around, wear loose-fitting clothes, etc., to help prevent blood clots.

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Photo H

A comment or two about the calcaneal/Achilles tendon, the most commonly injured tendon of the human body!  Explosive actions such as jumping or a sudden pushing off can tear the tendon or avulse it from its insertion on the heel bone. Achilles tendon injury is much more common in males than females and accompanies increased athletic activity (especially after years of sedentary lifestyle), the effects of aging or the use of some antibiotics.

And, just so we understand its origins, the Achilles tendon is named for the mythical Greek hero Achilles who was slain during the Trojan War when Paris’ poisoned arrow hit the heel, his only vulnerable body part (Photo I). As a wee lad, his mom held him by the heel and dipped him in the River Styx to grant him indestructibility but, sadly, that heel didna get baptized!

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Photo I

Want to see a manly example of an Achilles tendon (Starz episode 112, Lallybroch)? Weel…Jamie has one! First off, the lad has long tibiae and fibulae (pl.) which lend his calves a lean, lengthy leg-look. Red arrows mark the junctions between Jamie’s gastrocnemius muscles and his Achilles’ tendons which continue down the legs to end at the heel bones (blue arrow). Nice runner’s legs, laddie! Getting into that mill pond? Take good care; Claire willna like it if ye freeze off her fav body part!

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Now, we are done with normal anatomy, so let’s apply it to Outlander! Returning to Colum MacKenzie (Starz episode 104, The Gathering), Claire’s considers Colum and his brother, Dougal (Outlander book):

“Now there was a strange man. A cultured man, courteous to a fault, and thoughtful as well, with a reserve that all but hid the steely core within. The steel was much more evident in his brother Dougal. A warrior born, that one. And yet, to see them together, it was clear which was the stronger. Colum was a chieftain, twisted legs and all. Toulouse-Lautrec syndrome. I had never seen a case before, but I had heard it described. Named for its most famous sufferer (who did not yet exist, I reminded myself), it was a degenerative disease of bone and connective tissue.”

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Question #1: Does Claire correctly diagnose Colum as suffering from Toulouse-Lautrec syndrome? Let’s take a closer look.

Henri de Toulouse-Lautrec (aka Henri Marie Raymond de Toulouse-Lautrec-Monfa, 1864-1901) was a 19th century artist who garnered fame as a painter, printmaker, illustrator and draughtsman. A contemporary of Gauguin and van Gogh, his work embraced the colorful, daring and glaring life of Bohemian Paris and his subjects were often members of that social stratum. His works are highly valued. Ten years ago, his painting of a young laundress (La blanchisseuse, 1889) sold for a record US $22+ million (Photo J)!

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Photo J

Toulouse-Lautrec was the first born child of an aristocratic French family whose parents were first cousins. By eight years of age, his talent for drawing and painting had surfaced, but problems with growth and development soon followed. At 13, Henri fractured his right femur and a year later, his left, but the breaks never healed properly. His legs ceased to grow such that as an adult, he stood 4’ 8” (1.42 m). His trunk was adult-sized but his legs remained those of a child (Photo K).

Fast forward to 1962; a pair of French physicians (Maroteaux and Lamy) described a rare clinical entity (1.7/1 million births) dubbed pycnodysostosis (Greek meaning dense, defective condition of bone) or Toulouse-Lautrec syndrome. Pycnodysostosis is inherited if a child receives a recessive gene for the disease from each parent, an unlikely outcome unless parents are closely related. However, because genetic testing was unknown during Henri’s lifetime, it is surmised that he suffered from this disease (there are other possibilities).

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Photo K

Now, lace up your shoon, gobble down your haggis and bear with me for a bit of microscopic anatomy. We humans think of our skeletons as static structures but this is so not so! Each bone is a living organ that is restructured and remodeled throughout life by action of two bone cells: osteoblasts (bone-forming cells) that make bony matrix and osteoclasts (Greek meaning bone + broken) that breakdown bone. Osteoclasts (Photo L – blue dashed line) are multinucleated giant cells many times larger than our red blood cells (Photo L – red dashed line). A third bone cell, the osteocyte, also has bone activity but we will not cover this cell today. Our bones are remodeled as we grow, age, gain or lose weight, experience pregnancy, change exercise regimes, or mend broken bones; all possible because of osteoblasts and osteoclasts.

It turns out that pycnodysostosis/Toulouse-Lautrec sufferers cannot make an enzyme (Cathepsin K) essential for protein breakdown. Because osteoclasts lack this enzyme these cells cannot break down bone; thus, bones neither remodel nor mend properly. Make sense?

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Photo L

Lacking just ONE enzyme, Toulouse-Lautrec sufferers experience these painful and debilitating symptoms:

  • Stature: adult males stand less than 150 cm (4’ 11’); adult females are shorter.
  • Bones: bones are dense because osteoclasts cannot resorb them. Bones are brittle and fracture easily especially weight-bearing bones of the lower limbs, mandible (Anatomy Lesson #26) and clavicles (Anatomy Lesson #3).
  • Skull: bones of forehead (frontal bone), back of head (occipital bone), nose and mandible as well as the teeth do not form properly. The anterior fontanel (‘soft spot” on top of the head) remains widely open, possibly why Toulouse-Lautrec consistently wore a hat.
  • Hands: skin over the back of fingers is deeply wrinkled; nails are flat and grooved. Distal phalanges are short (Anatomy Lesson #22 & Anatomy Lesson #23).
  • Spine: defective vertebrae cause the spine (Anatomy Lesson #15) to  curve laterally (scoliosis).
  • Impotency and/or sterility: Toulouse-Lautrec purportedly contracted syphilis from a prostitute who served as his model – his history suggests he was not impotent but he is not known to have sired children. Alcoholism (absinthe for pain), tertiary syphilis and his weakened constitution took his life at 37. Colum was apparently sterile because Dougal ensured his bloodline by begetting Hamish with Letitia (Starz episode 109, The Reckoning). Dougal also assured Colum “that she was tender and sweet as a ripe peach and all that a man could want in a woman” (Outlander book) implying that Colum did not know his wife sexually (impotent).

Answer to Question #1: Yes, Claire very likely correctly diagnosed Colum’s disability as Toulouse-Lautrec syndrome (pycnodystosis).

Question #2: Does Diana’s description of Colum’s symptoms match with those of Toulouse-Lautrec syndrome? You be the judge. Claire reflects in Outlander book:

“Victims often appeared normal, if sickly, until their early teens, when the long bones of the legs, under the stress of bearing a body upright, began to crumble and collapse upon themselves. The pasty skin, with its premature wrinkling, was another outward effect … that characterized the disease. …. As the legs twisted and bowed, the spine was put under stress, and often twisted as well, causing immense discomfort to the victim. … Because of the poor circulation and the degeneration of connective tissue, victims were invariably sterile, and often impotent as well.”

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And another quote from Outlander book: Here, Ned Gowan explains to Claire:

“Colum was a whole man to the age of eighteen or so,” … “but soon after the marriage he had a bad fall, during a raid. Broke the long bone of his thigh, and it mended poorly.” …“And then,” Mr. Gowan went on with a sigh, “he rose from his bed too soon, and took a tumble down the stairs that broke the other leg. He lay in his bed close on a year, but it soon became clear that the damage was permanent.

Okay, let’s all be the judge!

Answer to Question #2. My opinion: Claire’s description and the visuals of Colum’s legs almost exactly match the symptoms of Toulouse-Lautrec syndrome or pycnodysostosis. Colum’s thigh muscles are abnormally twisted and grooved (above photo – red arrows) due to his poorly mended femora (pl.). His right fibula also appears to have been broken and mended badly (below photo – blue arrow) and his twisted Achille’s tendon (below photo – red arrow) is displaced laterally. Remember Claire’s offer to massage the base of Colum’s spine rather than his legs? Nerves innervating the legs emerge near the base of the spine explaining why spinal massage of that region might provide temporary relief. Colum suffered greatly with his laird’s legs but make no mistake: “this clan remains under the charge of this man!”

The visual presentation of this terrible syndrome was very convincing and well done. Way to go Colum, Claire, Diana and CGI team!

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Here is an interesting and apropos tidbit about a cute cat (Photo M). The Scottish fold cat (aka Highland Fold, Longhair (Laoghaire?), Longhair Fold) is a domestic cat with ears that fold forward toward the nose. They also suffer from distorted limb bones and arthritis. The breed is the result of a genetic mutation in a single barn cat named Susie (Perthshire, Scotland, 1961). But most pertinent here, the Scottish fold syndrome belongs to the same group of cartilage and bone disorders as Toulouse-Lautrec syndrome. Yep, it does!

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Photo M

Now, let’s end this lesson with some fun frivolous facts about legs (here meaning the entire lower limb)!

  • Michael Flatley (Riverdance) insured his legs in 1999 for US $40 million.
  • In 1836, Mexican General Santa Anna held an elaborate state funeral for his amputated leg.
  • The average person takes 6,000 -9,000 steps per day: 28,000 – 42,000 miles in a 70 year lifespan. This exceeds the circumference of the globe!
  • The “legs up the wall” yoga pose relieves anxiety, stress and tired legs (lie on back near a wall. Lift lower limbs up the wall and scoot butt against the wall). It feels marvelous as blood drains from the lower limbs!
  • Svetlana Pankratova of Russia purportedly has the longest legs of any woman in the world – at 1.32 m or 4.33 ft. (Does the Guinness rep realize that she is wearing heels? Not exactly a scientific measurement). Her hip joints and my oxters are at the same height!

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Be grateful! Kick your own legs up in the air if ye can and offer a hand to those whose legs dinna work quite so well!

A Deeply Grateful,

Outlander Anatomist

Photo creds: Netter’s Atlas of Human Anatomy, 4th ed., Starz, www.greekmyths-greekmythology.com (Achilles), www.montessoricats.com (Buddha cat), www.news.asiatown.net (Svetlana Pankratova), www.praz-delavallade.com (Jim Shaw painting), www.reddit.com (Scottish Fold cat), www.wikipedia.org (La blanchisseuse and Toulouse-Lautrec photos), Robert M. Hunt (B&W osteoclast)

“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!

ep-111-Geillis-masseter-KLS-edited

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!

ep-109-Claire-mentalis-01-KLS-edited

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)