Category: Mini Anatomy Lesson

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Mini Anatomy Lesson: Scoping Out A Scope!

Hallo the house!

Welcome all anatomy students. I haven’t posted a lesson for a while, but Outlander Season 8 has given me new material to plumb. 🤓

I thoroughly enjoyed episode 802,  “Prophecies.” This busy episode was made all the more riveting by the steady and creative hand of Caitriona Balfe in her directorial debut. The woman is soooo talented! 👸🏻

One scene captured my immediate attention: Frances and Claire in the surgery scoping out a scope! A microscope, that is. 🔬

This clever scene swiftly covers a broad range of anatomical topics:

    • Microscope
    • Paramecia
    • Stomach
    • Mucous membrane
    • Slipperiness

Let’s take a closer look at each of these topics because we want to learn as much anatomy as possible. 📚

Microscope: First up, let’s discuss that magnificent microscope through which Francis peers!

Claire’s scope is either an accurate model of an 18th century scope or it is truly from that era. This image below shows an 18th century microscope that is a very close cousin.

Scope out the arrows to learn more about the microscope! 🔎

    • Red Arrow: Indicates the eyepiece lens; it magnifies the object being examined.
    • Blue Arrow: Indicates the objective lens which adds more magnification of the object.
    • Orange Arrow: Marks the optical tube (barrel). This directs light from the objective lens to the eyepiece lens.
    • Green Arrow: A glass slide which holds a drop of fluid and the object(s) to be observed.
    • Yellow Arrow: A mirror reflects light upward through the object and into the microscope.  It can be adjusted to enhance the amount of light entering the scope.

Notice: Frances holds a knob at the right side of the optical tube. This is the focus control, used to move the optical tube up and down to accurately focus on the object. 👁 The coarse knob is not visible on the scope in the image, below.

Both are compound microscopes, so named because two lenses are used to magnify an object; this is much more powerful than a single lens.

How it works: Light strikes the mirror and is reflected upward through the  slide and the objective lens, into the optical tube and through the eyepiece lens. It then enters the eye creating an image on our retina of whatever is on the slide. That image is transferred as electrical signals to our visual cortex where we actually “see” the image.  We do not see the image in our eyeball. 😮

Please note the candle flame in front of Claire’s microscope (above image). This provides light to the mirror. However, because there is a huge window to Frances’ left, I would skip the flame and turn the mirror to collect more visible light from the outside window! 🪟

Paramecia: Frances spies slipper-shaped creatures wriggling in the drop of water. These beasties are paramecia (pl.). The dark fragments in the slide are likely organic matter from a stagnant pond where Claire undoubtedly collected her specimen.

Paramecia are unicellular (single cell) organisms belonging to the Protist group. Historically, paramecia were categorized as members of the kingdom of Animalia. This changed in 1969 when they were moved into a kingdom all their own, the Protists.  Recently, due to in depth DNA analysis, Paramecia now reside in the Eukaryota Domaine along with other protists, fungi, plants and animals. 

Paramecia live in fresh, brackish, and marine waters. Claire was correct, these creatures do not cause human disease so ingesting them does not make us ill, although plenty of other stuff in pond water can make us sick.

These wee creatures have been studied so widely in research labs and in biology classrooms they are sometimes called microscopic lab rats! This is why Claire uses them as a teaching tool for young Frances.

Stomach: Claire tells Frances that our stomach protects and supports us because it:

    • Is thick-walled ✅
    • Contains mucus ✅
    • Secretes acid ✅
    • Digests proteins ✅

Check, check, check and check! True on all counts. Claire is one smart lassie. 😇

Most organs of the gastrointestinal tract have two layers of muscle in their walls but the stomach has three (longitudinal, circular & oblique), making it thick-walled, indeed!

The stomach lining is indented with pits, all lined with countless cells. The next drawing depicts cells lining such a pit. Surface mucous cells and mucous neck cells produce mucus which flows onto the stomach surface.  

Notice a difference in spelling?  This is not an error. 😮 Mucus is the noun form and mucous is the adjective. 

Claire scores again: mucus does help protect the stomach surface from irritating substances. It also lubricates the surface, provides immune defense, and aids in absorption.

Another type of cell found deeper in the pits (next image), the parietal cell, (orange) produces hydrochloric acid (HCl). Our gastric HCl is a pH of  1-3, which is highly acidic.  Just for perspective, the muriatic acid used to clean swimming pools is also hydrochloric acid! 😳

Little wonder we sometimes take an antidote to soothe an acid stomach? 💊

Lastly, the chief cell (yellow) produces an enzyme which along with HCl, alters and breaks down ingested protein.

Mucous Membranes: 

Claire explains to Miss Frances that most of our organ are lined with mucous membranes. These  surfaces are kept moist constantly by various mechanisms, a major one being mucus. 

Mucous membranes are found throughout the gastrointestinal tract,  respiratory tract, urinary tract, and parts of the reproductive tract. Even our conjunctivas and middle ears contain a few mucus-secreting cells. Mucous membranes are so ubiquitous that the average body contains roughly 2,153 sq ft of mucous membrane, roughly the same square footage as many homes!

The name, however,  is unfortunate because not all mucous membranes produce mucus. Go figure! 🤔  An alternative name for mucous membrane is mucosa, a term I prefer because it doesn’t automatically imply that a given mucous membrane produces mucus.

Slipperiness: 

“Snot? My stomach is full of snot?” Frances glances down at her tummy.  “Well, yes,” says Claire.

Claire then explains how mucus helps our bodies be slippery when and where needed.  For example, to help during the birth of a baby.

Oops! This is where Claire’s lesson goes a wee bit off the rails. 😉

You see, the vagina (birth canal) has no mucous cells or mucous glands of any kind in its structure.  

Wait! What? My students were invariably astounded by this bit of science. But, this is why I love science and not opinion. Just because two bodily fluids are sticky does not mean are both  are mucus.

For example, the vaginal fluid during sexual arousal is a slippery, protein-rich transudate produced by engorged blood vessels; it is not mucus!  Ditto, the vaginal slipperiness during childbirth relies on this same vaginal transudate. 😎 

So, is there no mucus in the female reproductive tract? Well, there is some. The uterine lining produces some mucus. In fertile women, the uterine cervix produces a mucous plug (CMP) that stays intact until mid-cycle when it becomes more watery and penetrable by spermatozoa. During pregnancy, the CMP prevents vaginal bacterial from entering the uterine cavity.

There are also some mucous glands (Bartholin’s) near the external opening of the vagina that help moisten the area between the vulva. But, to reiterate, the vagina does not produce mucus.

Again, if no significant mucus is present, what causes vaginal slipperiness during childbirth?

This is how it works: Amniotic fluid, that surrounds the fetus,  is a complex mixture of maternal fluid, fetal urine, nutrients, antibodies, hormones and fetal cells.  Roughly one tablespoon of mucus from the CMP (0.03%) joins the amniotic fluid and together is normally discharged as childbirth approaches. But, the amniotic fluid often totally evacuates before labor even begins.

The slipperiness of the birth canal comes from those proteins of the vaginal transudate. And, yes, this slipperiness does help during childbirth (as well as during intercourse). 

Just so you know, the CMP in post-menopausal women disappears due to lack of hormonal support. However, HRT (hormone replacement therapy) can  restore the CMP in older women.

Other than this wee issue, Claire does a lovely job of explaining numerous biological details to a Frances, a wide-eyed and grateful student!  👀

Hang in there, Frances, I am sure there will be much more to learn from Dr. Claire. Jane would be proud!

I hope you enjoyed scoping out the scope, today. Watch for another lesson soon!

The deeply grateful,

Outlander Anatomist

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Photo credits:

Outlander Anatomy; Starz; Sony; www.Alamy.com; www.medline.gov; www.vmicro.iusm.iu.edu; www.momjunction.com; www.ourcancerstories.com; www.visiblebody.com;

 

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Mini Anatomy Lesson – William’s Wound!

Hello, anatomy students!

Good to see you again so soon. 😉

Today’s lesson explores the horrific circumstances leading to an intended amputation of William’s forearm.

Just so you know what to expect, this lesson does contain a number of rather gruesome images!

William’s wound appears in Outlander episode 704,  “A Most Uncomfortable Woman.”

A short recap: William hastily rides through the Great Dismal Swamp. His steed, Jupiter, is startled by a snake, which looks very much like a copperhead to me!

Jupiter unseats William who tumbles down a steep hillside hitting a fallen tree snag during his rapid descent.

As William comes to rest, he assesses the damage to his arm. Oh, dear,! A branch broke off the snag and buried itself into his right forearm. Ouch! 😱

Being of Fraser blood, he grits his teeth and pulls it out! 😬 Then, using his stock as a bandage, he wraps the wound under pressure and moves forward with his mission. This time, on foot, as Jupiter has hightailed it leaving William alone and without supplies or the notes from Captain Richardson! 😳 

Later,  he hears a sound. Looking up, he spies an “Indian” who speaks a Scot’s version of the King’s English. 😜  Wolf’s Brother (Ian Murray Jr.) in the flesh!

A very nice chit-chat ensues as they exchange bona fides.  Then Ian spies Williams’s wound. Um….best get that taken care of. Because, by now that oozing wound looks pretty yucky! 🤢

Ian sets about building a wee fire and boils a pot of water. Then he crouches beside William, pulls his knife from its sheath, and begins to free the wound of several splinters. Ouch! 😮

The blood clots are well done. 👍🏻

Then he pours boiling/hot water over the wound to try to cleanse and perhaps sterilize it? Oh, boy, that hurts! 🤯

Ian hustles William to the cabin of one Dr. Denzel Hunter and  his sister, Rachael. They help William onto a table and Denzel takes a quick keek. Oh, dear, that looks bad. Rachael, fetch me the saw!

After some protestations from Ian and William (it is his forearm, after all!), Dr. Hunter begins to saw. Suddenly, pus oozes from the wound and Denzel declares that the bile has been freed and there will be no need for a hack job today! 🪚

Much later, Williams shares his travail with fellow soldiers. Here, from “A Breath of Snow and Ashes:”

“Wandered round the Great Dismal Swamp for three days in a fever,” he said. “Some … Indians found me and got me to a doctor. I nearly died, and”–he lowered his brows and gave Zeb a piercing look–“the doctor was just about to cut off my arm, when the abscess burst and he cauterized it. You might not be so lucky, hey?”

Sometime later, Rachel tells William his scar has healed well. It looks like the star that guided the wisemen to the Christ child and it suits him. In the book, his scar looks like a comet.

A quote from “A Breath of Snow and Ashes:”

‘The wound was still red and puckered, the skin around it unpleasantly white and moist. It was, however, undoubtedly healing; the arm was no longer swollen, and the ominous red streaks had disappeared. “Well,” she said consideringly, “it’s a fine scar, I think. Well knit, and rather pretty.” 


Anatomy and Pathology: Now that the recap is over, let’s discuss the pathology of William’s wound. You may recall, that pathology, which literally translates to “knowledge of sorrow,” is abnormal anatomy, so we are not far off the mark. 🤓

I propose we review one issue at a time, so here we go!

The Accident:  I have been asked if I think the accident was plausible. My short answer is, yes. My reasoning is that William is a large man, rolling downhill, rapidly. All that weight with an extended arm and yes, it is possible. 🤔

Believe it or not, this issue is covered by Newton’s (next image) second law of motion which states that F = ma, in which net force is equal to mass times acceleration due to gravity.

Stated more plainly, the force with which William’s extended arm struck the wooded spike equals William’s mass times acceleration rolling downhill.

I asked my physicist son, Diedrich, to help with variables such as hypothetical mass, rate of descent, incline, size of branch, etc. He did the calculations and William  struck the branch with roughly 163 ft-lbs of force!  Consider that this force was expended onto a stick no more than 1” in diameter. Well, suffice it to say, that force is more than sufficient to snap the branch, break the skin, pierce the muscle, and even fracture one or both forearm bones (radius and ulna)! 😱

Make sense? Gooood! 🤗

Penetrating Wound: Poor William suffers what pathologists categorized as a penetrating wound. This occurs when a sharp object pierces the skin and creates a single opening into either tissues or a body cavity.  Clearly, there is one wound and the tissues in this instance are the meaty flexor muscles of his forearm. 💪🏻

Our flexor forearm (the palm side) houses eight muscles (15% of us have only seven). The spike would have driven deep into probably 2-3 of these muscles. This means any bacteria or other pathogens on the swampy branch would have sunk deeply into the tissues. This is why the wound became infected.

Inflammation: Ian unwraps William’s arm and spies a swollen,red, painful wound that will feel hot to the touch. These are four of the cardinal signs of acute inflammation, the body’s common response to injury and  infection.

Inflammation is heralded by five cardinal signs, four were described 2,000 years ago by Celsius. These are:

  • rubor (redness)
  • calor (heat)
  • tumor (swelling)
  • dolor (pain)

and….

  • functio laesa (loss of function) the fifth cardinal sign was added 200 years later by Galen, surgeon to Roman emperor, Marcus Aurelius.

    Does William’s Wound show all five cardinal signs of acute inflammation? Well, yes, yes it does! It is painful, swollen, red, hot, and he has lost normal use of the forearm. 

A current day example: The image below shows acute inflammation of the great toe (hallux) due to an ingrown toenail. The toe is red, swollen, warm, sore, and difficult to use.

Cleaning the Wound: I have to say, Ian was caring and compassionate to clean the splinters from William’s Arm.

But, I must protest! Ian has seen Auntie Claire take care of enough trauma to know that he should either cauterize that knife tip in the fire, or plunge it into the boiling water for a bit. Inserting the tip of a  dirty blade will introduce more pathogens into the already infected wound! 

And, pouring boiling/hot water into the wound? That  isn’t much help, either and was traumatic for William. Much better to let the water cool a bit and then cleanse the wound with the “sterilized “ liquid.

The amputation: When I saw this, I thought. Um……No! Denzel grabs his amputation saw and starts sawing away on William’s arm!  Now, this enactment exactly follows what is recorded  in “A Breath of Snow and Ashes:”

He had—he was told sometime after the fact—narrowly escaped loss of the arm: Dr. Hunter had grasped it and placed his amputation saw just above the wound, only to have the abscess that had formed below it burst in his hand. Seeing this, the doctor had hastily drained the wound, packed it with garlic and comfrey, and prayed—to good effect.

It was very dramatic, but you should know that a doctor with training like Denzel’s would not start sawing on skin. The saw teeth will rip and tear skin and muscle causing even more pain and morbidity for the patient. Instead, a practitioner used an amputation knife to slice the flesh around the bone and then saw through the bone. Below is an example of a typical amputation knife and an amputation saw of the time. 🔪🪚

As horrifying as this sounds, a capable practitioner could remove a limb very swiftly this way, reducing the trauma to the sufferer.

Finally, as Denzel puts pressure on the limb, pus bursts from the deep lying abscess. After removing the pus, the wound was carefully cleaned and wrapped..

Pus is a  thick yellowish or greenish opaque liquid produced in tissues infected with pyogenic bacteria such as Streptococcus or Staphylococcus (Not all infections elicit pus formation). Pus is formed of dead white blood cells, bacteria, tissue debris, and serum.

The term pus derives from the Latin and it has been used since the 14th C. Again, since Denzel is a well-trained physician, he would have likely used the term pus rather than bile.

Finally let’s consider William’s scar. Here, he recounts his travail to fellow soldiers…..from “A Breath of Snow and Ashes:”

Look,” he said, displaying the long, comet-shaped scar on his forearm. “That’s what happens when you get an abscess.”

Both Zeb and the doctor peered at the scar, impressed. It had been a splinter wound, he told them, caused by a lightning-struck tree.

Big, kudos to the FX folks. I thought the slightly reddened, puckered, and contracted scar was believable. Well done!

I hope you enjoyed this review of William’s Wound.

Until we meet again, fare thee well! 

The deeply grateful,

Outlander Anatomist

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Photo creds: Sony/Starz, www.myclevelandclinic.org, www.en.Wikipedia.org, www.teachmeanatomy.info, www.teachmesurgery.com

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Anatomy Mini-Lesson – Popliteal Aneurysm!

Greetings Outlander anatomy students!

Much time has passed since my last post partly because I am nursing broken bones of my left ankle. I am working off an iPad, instead of my desktop computer, so it is slow going. 😱

Today’s lesson details Mr. Walter Woodcock’s dilemma as presented in Outlander episode 705, Singapore.

You will recall, Walter lies in the infirmary at Fort Ticonderoga with a significant injury to his right foot. The wound has turned gangrenous so an amputation is required.

Claire arrives to witness a medical dispute between Dr. Denzel Hunter and the pompous, Lieutenant Stactoe.

Curious Claire asks, what is going on? 🤔

Denzel recommends an above-knee amputation for Walter. Stactoe is adamant that a below-knee amputation makes for a more functional limb.

Stactoe is correct that in most circumstances, every attempt is made to salvage as much of a limb as is possible.

However, Denzel explains that Walter has a popliteal aneurysm, thus, an above-the-knee amputation is necessary! Claire palpates Walter’s calf and agrees with Denny.

Oh, oh! This changes everything! 🤔

There ensues a wee strammash when Stactoe says Claire will not use boiling water on HIS instruments. This is a direct quote from Diana’s An Echo in the Bone:

You will ruin the temper of the metal, subjecting it to boiling water!”

“No,” I said, keeping my own temper—for the moment. “Hot water will do nothing but clean it. And I will not use a dirty blade on this man.”

“Oh, won’t you?” Something like satisfaction glimmered in his eyes, and he clutched the blade protectively to his bosom.”

In the episode, Stactoe stomps off. But, no worries, Denzel to the rescue with his own set of fine surgical instruments!

To understand the implications of a popliteal artery aneurysm, let’s look at the anatomy of the arterial supply to the knee.

Essentially all of the lower limb is supplied by the huge femoral artery which begins at the groin and descends through the front of thigh. Near the top of the knee, the artery passes to the back of the knee and is renamed the popliteal artery (next figure). It then descends behind the knee joint. At the bottom of the joint, it splits into two and then into a third artery, all of which receive new names and supply lower leg and foot.

The hollow behind the knee joint is the popliteal fossa.

Try This:  Make a fist, bend opposite knee slightly, and tuck your fist into the hollow behind your knee. This is the popliteal fossa. Remove your fist and insert middle and ring fingers into the hollow. Press. You may be able to feel the pulsing of the popliteal artery in the popliteal fossa.

Feel it? Good job, students! 🤗

   
Next. The aneurysm! 🤓

A popliteal artery aneurysm, known by the acronym PAA, is a weak spot in the wall of the popliteal artery. Pressure exerted by arterial blood causes the weak spot to balloon into a palpable bulge behind the knee joint. This is of concern because if the aneurysm should burst, the blood loss would be difficult to control especially in an amputee.

Some causes of PAA are:

  • Atherosclerosis
  • High blood pressure
  • Wear and tear of the popliteal artery due to over use of knee joint
  • Weakening of the artery wall

The image show a couple different types of PAA.


Now, back to the episode!

Claire palpates Walter’s leg and agrees with Denzel. An above-knee amputation is best to avoid the aneurysm bursting with uncontrolled hemorrhaging.

A clear view of his damaged, gangrenous foot can be seen in the next image.

Unfortunately, Claire places her hands on either side of his calf. She cannot feel a PAA in this location because there is no popliteal artery behind the calf. Her hands should be up in the hollow of the knee.

Nevertheless, she gets an A+ for trying! 🤩

Also, in real life, the stench of gangrene would likely require them to mask and use some type of ointment under the nose to distract from the odor. 😮

And, today, imaging modalities would be used to determine the type and extent of a PAA.

In the final scene with Walter, Claire breaks the sad news that his condition does not permit him to be evacuated with the other patients.  He is to be left behind. 😢

Claire has a wonderful bedside manner which comes from her compassionate and caring heart. Hopefully,  the British will treat Walter well. 🤞🏻

Mercy! 😉

I hope you enjoyed today’s lesson. Just remember, if you ever feel a pulsing bulge behind  the knee, make an appointment swiftly or get into urgent care. A PAA is no joke!

The deeply grateful,

Outlander Anatomist

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Photo creds: Sony/Starz, www.myclevelandclinic.org, www.uptodate.com