Anatomy Lesson #50: Care for us – Oh Pancreas!

Tommy Lee Jones, starring as Hawk Hawkins in Space cowboys (2000), said it best (Image A):

Where the hell is the pancreas, anyway?  I don’t even know what the damn thing does beside give you cancer!

Terrific question, Hawk! Welcome anatomy students to Lesson #50, the pancreas. Our goal today is to answer Hawk’s question and more: what is the pancreas, what does it look like, where is it located, what does it do, and what diseases plague it?

This is the 7th and final lesson of the immense gastrointestinal tract and associated organs! Turns out, pancreas is one of these “Klingon” organs.

Although Diana hasn’t written a great deal nor has Starz episodes showed much about the pancreas, there are bits and pieces here and there. As always, these are scattered throughout the lesson. I hope you find the pancreas as compelling as your body does. Off we go!

space cowboys movie poster
Image A

History: Herophilus (335-280 BCE), Greek anatomist and surgeon (Image B), helped found the ancient school of Medicine in Alexandria, Egypt. He also championed human dissection and was the first to describe the pancreas. Students may recognize Herophilus because he also featured in Anatomy Lesson #34, The Amazing Saga of Human Anatomy.

Image B Herophilus

Gross Anatomy: The word, pancreas, comes from the Greek pan, meaning “all,” plus the Greek kreas, meaning “flesh;” so, “all flesh.” A seemingly odd term until one views the pancreas and then, it seems sensible as it appears markedly fleshy, soft, and squishy (Image C).

pancreas
Image C pancreas

Outlander Fix #1: Answering Hawk’s first question, “Where the hell is the pancreas, anyway?”, Mary-Mary-Quite-Contrary knows (Starz episode 211, Vengeance is Mine). Or, rather, Mary’s Knife-Knows! Och, lass, that is Jamie’s dirk. Careful! Verra sharp!

mary holding a knife in outlander episode 211
The dirk finds it’s mark, pretty much where the pancreas lives! A grim ending to a vicious valet. And he isn’t the only one taking a hit from a blade in this episode. Written by our own beloved Diana, this gratifying chapter brings some very bad players to their just desserts (Starz episode 211, Vengeance is Mine), although that mad bastard captain remains at large. Come on S.3!

image of a man being stabbed from outlander episode 211

On to anatomy!

Pancreas Location: The pancreas (Image D) lies in the upper abdominal cavity behind the stomach (Anatomy Lesson #46: Splendid Stomach, Wobbly Wame). Oriented almost horizontally, it extends from the curve of duodenum to the spleen, a distance of some 6” (15 cm). In this position, it contacts stomach, spleen, duodenum, colon, jejunum, bile ducts, and major intestinal blood vessels. Pillowed among other soft abdominal organs, its location is pertinent, especially in pancreatic cancer as we shall shortly see. It lies between T12 and L2 vertebral levels.

Try this: Place thumb on the xiphoid process (tip of sternum – Anatomy Lesson #15: Crouching Grants – Hidden Dagger) and little finger of the ipsilateral (same) hand on your umbilicus. The xiphoid process is located at T9-T10 vertebral levels; the umbilicus at L3-L4. Now, place a finger of the contralateral (opposite) hand midway between xiphoid and umbilicus – this is the approximate vertebral level where your pancreas dwells. These new terms are thrown in to enlarge your anatomy vocab!

 

image of the pancreas
Image D

Divisions: Although many sources describe three divisions of the pancreas, it actually has five: head, neck, body, tail, and uncinate process (Image E). The head tucks into the C-shaped curve of duodenum. A short neck lies between head and body. The body supplies most of its 6” length. The tail tucks into the spleen (review Image D). The uncinate process (Latin meaning hook-shaped) is the smallish part that tucks in behind some large blood vessels of the gut.

You might consider these segments as rather arbitrary, but they are very useful in localizing disease entities, particularly pancreatic cancer.

image of the parts of the pancreas

Image E

Gland: The pancreas is an organ but it is also a gland meaning it produces and releases secretions (products). It is also a mixed gland meaning it it is both exocrine and endocrine gland. Now, most glands are either exocrine or endocrine in type, but the pancreas is unusual because it is both.

Exocrine: Exocrine glands release products into ducts which carry the secretions to a destination. In this case, pancreatic exocrine secretions flow into the pancreatic duct (Image F) which joins the common bile duct (Anatomy Lesson #49, Our Liver – The Life Giver!) before entering the duodenum. Pancreatic exocrine secretions include an array of enzymes that digest various dietary substances, including:

  • carbohydrates
  • lipids (fats)
  • proteins
  • nucleic acids (DNA, RNA)

Finally, the duct system draining the pancreas produces bicarbonate to help neutralize acidic foodstuffs released by the stomach into the duodenum (Anatomy Lesson #46, Splendid Stomach, Wobbly Wame).

Image F

Endocrine: Endocrine gland secretions are picked up and distributed throughout the body by the blood stream –  no ducts involved! And most of such secretions are classified as hormones or hormone-like substances. The pancreas produces its hormones via small spherical islands of cells formally known as pancreatic islets of Langerhans (brilliant German pathologist). About 3 million tiny islets (Image G – violet clusters) are scattered throughout the pancreas although more are concentrated in the tail region.  Their combined mass is only about 2 grams (.0022 pounds). Yet, their effects in the body are profound!

These tiny clusters contain five different types of cells, producing the following compounds:

  • glucagon (stimulates cells to release glucose – raises blood sugar levels)
  • insulin (causes cells to absorb glucose – lowers blood sugar levels)
  • somatostatin (regulates release of glucagon and insulin)
  • pancreatic polypeptide (regulates intestinal function)
  • ghrelin, the “hunger hormone” (regulates appetite –  pancreas produces small amounts of this compound – stomach is major source)

Image G

Outlander Fix #2: Yay! Claire fixes her mind on her pancreas in Dragonfly in Amber book. Yep, she does! (Psst…the image is from their Paris days – Starz episode 203, Useful Occupations and Deceptions – not from Lallybroch.)  Not a perfect match with the quote, but Claire in bed is always good, especially if Jamie is nearby. Dinna ken how Claire’s mind fixes around her pancreas, but I do trust the lass! <g>

As I began to hover on the edge of sleep, my mind fixed somewhere around my pancreas, I could dimly hear the sounds of small Jamie pattering down the hall to his mother’s bedroom—roused from sleep by a full bladder, he seldom had the presence of mind to take the obvious step, and would frequently blunder down the stair from the nursery in search of assistance instead.

image of Jamie and Claire in bed
Buh-bye Claire – Thank you for the pancreas lesson!

Microscopy: Exocrine and endocrine pancreas are readily differentiated by microscopy. Bear with me, folks-without-training-in-microscopy, as I explain. Image H is a thin slice of pancreas stained with dyes (H&E).  The red globs are pre-enzymes inside deep purple exocrine cells. After release as enzymes, they enter the pancreatic ducts and are transported to the duodenum. The pale violet blob in the center is a pancreatic islet of Langerhans. This blob contains tiny purple ovals, nuclei of the five different cell types mentioned above; collectively, these islets form the endocrine part of the pancreas. In 3-D, the pale blob is spherically- shaped.

This exercise is important to explain how anatomical pathologists diagnose disease. They learn to recognize normal pancreas (and all other organs) in the microscope. This enables them to determine if a tissue sample lies outside that expectation and, if it does, what disease does it best match. This ability is called pattern recognition. Got it? Grand!

Image H

Diseases: Like other organs, the pancreas has its own palate of diseases and many have devastating effects. There are three major players:

  • Pancreatitis: means inflammation of the pancreas. Acute and chronic types. Most common cause is alcoholism. Its own enzymes start digesting pancreatic tissue – Painful!
  • Diabetes mellitus: Types 1 and 2 interfere with sugar (glucose) uptake by body cells, although causes are different.
  • Pancreatic cancer: one of the more infamous cancers, it has a very low survival rate – overall five year survival rate is only 7%.

Outlander Fix #3: Claire’s own words from Dragonfly in Amber book inform us of a L’Hôpital des Anges’ patient with sugar sickness (Type 1 diabetes). Starz episode 203, Useful Occupations and Deceptions, faithfully brings Diana’s lines to life!

I bent over a pallet at the edge of the floor. A very thin woman lay listlessly under a single blanket, her eyes drifting dully over us without interest.

It wasn’t the woman who had attracted my attention, so much as the oddly shaped glass vessel standing on the floor alongside her pallet. The vessel was brimming with a yellow fluid—urine, undoubtedly.

psssst: The oddly shaped glass vessel used in the episode is an Erlenmeyer flask. It wasn’t invented until 1861 <g>

I was mildly surprised; without chemical tests, or even litmus paper, what conceivable use could a urine sample be? Thinking over the various things one tested urine for, though, I had an idea. I picked up the vessel carefully, ignoring Sister Angelique’s exclamation of alarmed protest. I sniffed carefully.

Sure enough; half-obscured by sour ammoniac fumes, the fluid smelled sickly sweet—rather like soured honey. I hesitated, but there was only one way to make sure. With a moue of distaste, I gingerly dipped the tip of one finger into the liquid and touched it delicately to my tongue.

…Sister Angelique was watching with sudden interest. … “Are you thirsty, Madame?” I asked the patient. I knew the answer before she spoke, seeing the empty carafe near her head. “Always, Madame,” she replied. “And always hungry, as well. Yet no flesh gathers on my bones, no matter how much I eat.” She raised a stick-thin arm, displaying a bony wrist, then let it fall as though the effort had exhausted her.

I patted the skinny hand gently, and murmured something in farewell, my exhilaration at having made a correct diagnosis substantially quenched by the knowledge that there was no possible cure for diabetes mellitus in this day; the woman before me was doomed.

In subdued spirits, I rose…“Could you tell from what she suffers, Madame?” the nun asked curiously (Mother Hildegarde in the Starz episode). “Only from the urine?” “Not only from that,” I answered. “But yes, I know. She has—” Drat. What would they have called it now? “She has … um, sugar sickness. She gets no nourishment from the food she eats, and has a tremendous thirst. Consequently, she produces large quantities of urine.” … “And can you tell whether she will recover, Madame?” “No, she won’t,” I said bluntly. “She’s far gone already; she may not last out the month.”

Is Jamie please with Claire tasting urine and treating scrofula? Noooo….he doesn’t want his pregnant wife messing with piss and pus! Och!

History of Diabetes Mellitus: Diabetes was described three millennia before Claire sampled her patient’s urine. About 1500 BCE, Sushruta, the Indian physician, wrote the first description of diabetes mellitus, noting that ants and flies were attracted to the urine of people with a mysterious disease causing intense thirst, enormous urine output, and wasting away of the body.

In 250 BCE, Apollonius of Memphis (Egypt), coined the term diabetes meaning “I pass through.” Later, mellitus, Latin for “honey-sweet,” was added to emphasize the sugar content of the urine and to distinguish diabetes mellitus from diabetes insipidus, a disorder of the pituitary gland also characterized by intense thirst and high production of urine.

Finally, the Greek physician, Aretaeus (Image I) wrote this description in the second century AD:

“Diabetes is … not very frequent … being a melting down of the flesh and limbs into urine … for the patients never stop making water, but the flow is incessant, as if from the opening of aqueducts. It consists in the flesh and bones running together into the urine … the illness develops very slowly. The nature of the disease is chronic, and it takes a long period to form; but the patient does not live long once the disease is fully established; for the melting is rapid, the death speedy. Moreover life is disgusting and painful; thirst, unquenchable … and one cannot stop them either from drinking or making water”.

Image I

Simple Physiology: Our bodies contain millions of cells. These cells use glucose to make energy for our daily activities: heartbeat, muscle contraction, fighting redcoats. Snort! How do cells get glucose? When you eat or drink, food is broken down inside the gut into simple proteins, lipid components, and sugars, mostly glucose. Glucose enters the bloodstream and circulates. Although circulating glucose contacts body cells, they cannot absorb it on their own.

So, circulating glucose stimulates pancreatic (beta) islet cells to release insulin into the blood stream. Insulin circulates with the glucose and acts as a key to permit body cells to absorb glucose. No matter how much glucose circulates in the bloodstream, insulin is required for it to enter the cells: no insulin – no glucose uptake! The following brief  You Tube cartoon illustrates the process very well.

Oh, and just so you ken, insulin produces 9 effects in the body. Glucose uptake is only one of these.

I like this cute T, but it is slightly misleading. The pancreas doesn’t really ask for sugar. Rather, pancreatic cells check blood glucose levels and as those levels rise, it releases insulin to induce body cells take in sugar. If glucose blood levels fall below normal, then the pancreas releases glucagon which mobilizes stored glucose for released into the blood stream. A very clever check and balance system.


Image J shirt

Type 1 (I) Diabetes Mellitus (DM): Simply put, Type 1 DM is a chronic condition wherein the pancreas produces little or no insulin so glucose cannot enter cells. Instead, glucose stays in the bloodstream, spilling into the urine, and pulling water with it; hence, the continuous thirst and high urine production (polyuria). Even today, there is no cure for Type 1 DM but it can be managed, usually with daily doses of insulin.

The exact cause of Type 1 DM remains unknown despite decades of intense research. In many, the body’s own immune system mistakenly destroys insulin-producing (beta) cells of the pancreatic islets. Both genetics and viral infections appear to play important roles in the development of diabetes.

Type 2 (II) DM: Type 2 DM occurs when the pancreas doesn’t produce enough insulin or cells are unable to recognize the insulin and use it properly, a state known as insulin resistance. Insulin resistance is the most common cause of Type 2 DM. Here, genetics and lifestyle are important risk factors. According to the US CDC, obesity and lack of physical activity are responsible for 95% of Type 2 DM in the US!

Pancreas Transplant: Yes, these surgeries are done. A pancreas transplant is a surgical procedure to place a healthy pancreas from a deceased donor into a person whose pancreas no longer functions properly (Image K). Most transplants are done to treat Type 1 DM, and, occasionally for Type 2. Although a transplant offers a potential cure for DM, it is generally reserved for folks with serious diabetes complications because the side effects of a pancreatic transplant are significant.

The donor pancreas plus the segment of duodenum that receives the pancreatic duct are transplanted into the cecum of the large intestine (Anatomy Lesson #48, The Big Guy!). So, the recipient then has a pelvic pancreas. Such surgeries must be disclosed to new health care professionals so they are aware of unexpected changes in typical anatomy.


Image K

Pancreatic Cancer: Many of us have lost a family member, friend, or acquaintance to pancreatic cancer. This type of cancer is often detected late, spreads rapidly, and has a poor prognosis. Why? Unfortunately, early stages of this cancer are mostly asymptomatic. Later stages are associated with symptoms, but these can be non-specific, such as lack of appetite and weight loss. So, the cancer may be advanced before detected.

Pancreatic cancer is staged 0-IV depending on its spread (Image L). Early in this lesson, we learned that the pancreas is in contact with duodenum, jejunum, colon, spleen, stomach, bile ducts, and blood vessels, providing many opportunities for metastases. Also, these surrounding organs are soft, so a spreading cancer has considerable space to grow before creating an organ stramash.

As you might assume, the prognosis is better for those whose pancreatic cancer is diagnosed at an early stage. The median survival rate after diagnosis and medical treatment is still abysmal: only 6 to 12 months. Let us be grateful it isn’t one of the three most common cancers.

True story: one of my neighbors was diagnosed with pancreatic cancer in the 1960’s. She survived a Whipple procedure, a.k.a., pancreaticoduodenectomy, which is why it is called a Whipple! This horrific surgery removes head of pancreas, duodenum, gallbladder, part of common bile duct, and part of stomach. She was a lucky lady who raised three sons and survived into her 80’s!

A possible piece of good news: New Scientist magazine (15 April 2017) reports that, by chance, a drug used to treat strokes has been found to significantly prolong the lives of mice with pancreatic cancer. Turns out, pancreatic cancers are protected by a capsule of connective tissue that acts like a coat of armor. Australian researchers found the stroke drug, fasudil, weakens the capsule, making it easier for chemotherapeutic agents to reach the tumor. Drug trials in humans are planned. Fingers crossed!


Image L

Let’s close this lesson on a happier note with Culinary Considerations.

Sweetbreads or Sweet breads??? Let’s get this out of the way, right now! Sweetbreads are thymus and pancreas (and, often salivary glands). Yes, people eat pancreas (Image M), gah! I canna like this as I have met too many of these organs on the dissection table. To me, sweetbreads are Awful-Offal! They do enjoy legions of fans, so dive in, if they work for you. You can have my share <G>


Image M

On the other hand, sweet breads (Image N) are verra hard to resist, especially the homemade variety.  Yummy, yummy, yummy, in my tummy, tummy, tummy! ‘Nuf said!


Image N

Let’s give the last word to American poet Robert Frost because he was creative enough to write a poem about sweetbreads.

Quandary

You drive me to confess in ink:
Once I was fool enough to think
That brains and sweetbreads were the same,
Till I was caught and put to shame,
First by a butcher, then a cook,
Then by a scientific book.
But ’twas by making sweetbreads do
I passed with such a high I.Q.

Dear Robert: the butcher, baker and candlestick maker – och! -butcher, cook, and science book are correct! Sweetbreads dinna include brain!

A deeply grateful,

Outlander Anatomist

Photo Creds: Starz, www.123rf.com (Image E pancreas parts), www.blog.kingarthurflour.com (Image N sweet breads)
www.cancer.gov (Image D pancreas site), www.dypatil.edu (Image B Herophilus), www.en.wikipedia.org (Image I Aretaeus), www.fanart.tv (Image A Space Cowboys), www.healthtop.com (Image C pancreas), www.mayoclinic.org (Image K pancreatic transplant; Image L Pancreatic Cancer), www.medicalwork.com (Image G pancreas mixed gland), www.medievalspanishchef.com (Image M sweetbreads), www.pancreatic.org (Image F pancreas ducts), www.shutterstock.com (Image H pancreas histo), www.threadless.com (Image J shirt)

Anatomy Lesson #49, “Our Liver – The Life Giver!” – GI Tract 6

Hallo, anatomy students! Welcome to Anatomy Lesson #49, Our Liver – The Life giver. We finished our exploration of the GI tract proper (lips through anus), and today, we continue with associated organs of the GI tract. In former lessons, we learned that during embryonic development, various organs arise as outgrowths of the gut tube (Anatomy Lesson # 44, “Terrific Tunnel – GI Tract I”). Such organs retain these connections throughout life, so their products flow via ducts (tubes) into the GI tract proper.

Liver is on our docket today. Liver develops during intrauterine life as an outgrowth of the nascent gut, retaining its attachment via a system of hepatic ducts. And, as the title correctly states, liver is a “giver,” not a “taker.” Liver is the type of “anatomical“ personality we crave in our lives, as it is the seat of many life processes!

As always, this lesson sports Outlander images and quotes about liver. What? Are there really liver quote from our fav books and TV series? Indeed, there are!

Word Origin: Liver, is an Anglo-Saxon word (1325) for liv-er or lifer. Logically, the etymology for liver infers “life,” although the original intent is lost. The name is apt, though, because many vital life functions occur therein. And, our very busy liver has insinuated itself into history, prophecy, character, culture, horror, mythology, and medicine!

History: Greek physician, Claudius Galen (130-200 CE), anointed liver as the principle organ of the body, teaching it as the primary source of blood and lymph (Anatomy Lesson #34, The Amazing Saga of Human Anatomy) – a status enjoyed for 1500 years! After this was disproven, liver fell from grace (sad face), only to have its stature revived in the 19th century by French physiologist, Claude Bernard. Bernard showed the liver serves many vital functions; indeed, we now know of at least 50 ways (TY, Paul Simon), to “love your liver” (Image A). But, counting all known liver functions, its duties approach 500!

Image A

Prophecy: Ever thought of a liver as a crystal ball? Believe it or not, livers were used for divination. Ancient Babylonians (19th century B.C.) studied sheep livers as a means to foresee the future. Such findings were documented on clay tablets in the shape of a sheep’s liver, complete with surface markings used for prophesying and instruction (Image B).

 

Image B

Character: The liver has the dubious honor of being used to symbolize a number of less savory human attributes, such as:

  • lily-livered (cowardice)
  • chopped liver (worthless)
  • white liver (cowardice)
  • hard liver (sensualist)
  • liver-hearted (craven)
  • liver-faced (mean-spirited)
  • liver-lipped (pale and feeble)
  • liver-sick (dropsy = cirrhosis or hepatitis)

Our beloved Outlander provides stellar examples of several such liver characteristics:

That lily-livered (coward), dastardly Duke (Starz, episode 110, By the Pricking of My Thumbs) peeks from behind a tree, leaving Jamie to battle three grumpy MacDonalds! Mayhap they only got haggis for brekky?

I think that I shall never see,

A more cowardly knave behind a tree!

From the same Outlander episode (Starz, episode 110, By the Pricking of My Thumbs), liver-faced (mean-spirited) Laoghaire spies Claire being arrested for witchcraft. She will happily sling the Heiland fling on Claire’s still-warm ashes!

I think that I shall never see,

A more wicked lass brimming with glee!

Now, please dinna fash, I affront the character, not the gifted and beautiful actress!

And before we leave Character-Assassination by liver, consider the hard-livered (sensualist), Black-Jack. A sociopathic-psychotic-sensualist if ever I saw one (Starz, episode 116, To Ransom a Man’s Soul)!

I think that I shall never see,

A more depraved voluptuary than HE!

Culture: Many cultures offer idioms about the liver. This “pointed” one is an ancient Tibetan Proverb: My enemy’s liver is the sheath of my sword!

Och! Jamie and his men present a perfect metaphor for this dire warning, with raised blades at the Battle of Prestonpans (Starz episode 210, Prestonpans). Redcoat livers: take care and beware – your livers willna be living long!

I think that I shall never see

a more deadly blade than…Owie!

Horror: The liver appears in a surprising number of “settings and upsettings” to convey horror!  Jonathan Demme’s 1991 horror film, The Silence of the Lambs offers a perfect example:

Check out this link to YouTube for a peek at this creepy scene!

Liver, fava beans, and a nice Chianti? Yuck. Well, maybe the nice Chianti. Hilarious Hannibal – the life of the party!

Anthony Hopkins as Dr. Hannibal “The Cannibal” Lecter in the 1991 film “Silence of the Lambs.” Photo Courtesy: MGM Home Entertainment

Mythology: Let’s not forget myths! Liver was immortalized in Theogony, a poem by Hesiod (8th – 7th century BCE), wherein the fate of the Titan, Prometheus (no relation to Ridley Scott), is recorded. Much to Zeus’s fury, Prometheus unwisely granted humans the gift of fire and the skill of metalworking. Zeus was so pissed, he chained Prometheus to a mountain rock. Immortalized in this stark painting (Image C), each day, Zeus sent an eagle to eat Prometheus’ liver and every night, his liver regenerated only to be devoured the next day. Eternal retribution (Prometheus eventually escapes)! Lesson learned: Yo mama always said, “dinna play with fire!”

Image C by Ruben and Snyders

 Medicine: Many cultures have used liver as medicaments. Even today, cod liver oil is taken to lower high triglycerides and high blood pressure, and to treat some symptoms of diabetic-related kidney disease (www.webmd.com).

An 1899 book titled “Animal Simples,” by W. T. Fernie, M.D., states:

Dr. Heffinger advocates the taking of crocodile liver oil for phthisis; which almost supersedes the use of cod-liver oil in Peru; being more nourishing and palatable.

I dinna ken Dr. Heffinger, but I assume and presume he was a renown practitioner of 19th century medical arts. Oh, and phthisis is an old term for pulmonary tuberculosis, although liver oil likely had zero effect on this diabolical disease.

We encounter crocodile oil at Master Raymond’s Paris apothecary shop (Starz, episode 204 La Dame Blanche)! This “little shop of horrors” (snort!) displays pretty much every oddity in gay Paree! There’s even a quote from Dragonfly in Amber book:

“My crocodile ? Oh, to be sure, madonna. Gives the customers confidence.” He jerked his head toward the shelf that ran along the wall just above eye height… Three of the jars closest to me were labeled in Latin, which I translated with some difficulty—crocodile’s blood, and the liver and bile of the same beast, presumably the one swinging sinisterly overhead in the draft from the main shop

“never smile at a crocodile…..”

Gross Anatomy: OK, enough  socializing – time for gross anatomy. Yay! Here, gross means visible with the naked eye (Anatomy Lesson #34, The Amazing Saga of Human Anatomy); it does not mean yucky!

Location: Where, oh where, does the liver dwell? It lives in the abdominal cavity along with most of the GI tract. Its location is best defined by dividing the abdominal wall/cavity into imaginary quadrants (Image D); vertical and horizontal lines intersect at the umbilicus (Anatomy Lesson #16, Jamie’s Belly or Scottish Six-Pack), dividing the area into RUQ, LUQ, RLQ, and LLQ.

Most of the liver resides in the RUQ although some extends into the LUQ. There’s another anatomical method dividing abdominal cavity and wall into 9 segments but the quadrant system works best for today.

Image D

Respiratory Diaphragm: What does respiratory diaphragm have to do with liver? Lots! Anatomy Lesson #15, Crouching Grants – Hidden Dagger, taught that the respiratory diaphragm is parachute-shaped, doming upwards such that it is largely surrounded by rib cage, sternum, and vertebrae (Image E).

Image E

Anchorage: Liver abuts the respiratory diaphragm (Image F – hooks) but it doesn’t flop around in the RUQ. Rather, it is anchored in place by membranes (Image F – red arrows), layers of peritoneum which bind liver tightly to the diaphragm.

Image F liver

Ribs and Sternum: Because the liver abuts the respiratory diaphragm, it too, enjoys the immediate and privileged protection of sternum, ribs and vertebrae (Image G). As such, a normal liver is challenging for a practitioner to palpate. To do so, a patient lies on the back and inspires deeply; the practitioner presses fingers under the right costal margin and, if skilled, may be able to feel the margin of the liver slip under the fingers. Normal liver is soft, smooth and slightly tender to palpation. An easily palpated liver is usually associated with one of several issues, the most dire being hepatitis or neoplasia (tumor).

Image G

Forensics: It’s Outlander Time. Yay! Ever wonder where Dougal met his Demise-by-Dirk (Starz, episode 213, Dragonfly in Amber)? No, not in the attic! I mean,  where was he stabbed? Did you think Claire and Jamie got him in the heart? Or, mayhap a lung? Forensic caps on!

Most likely, Dougal was stabbed in the liver! Yep. If ye look carefully, his wound is to the right of midline and above the costal margin. This means the dirk likely entered his RUQ, penetrating the right dome of respiratory diaphragm and piercing the right side of liver (Starz, episode 213, Dragonfly in Amber). No, Rupert, Jamie didn’t do the deed; or rather he didn’t do it alone!  It took four hands to finish Dougal off by Dirk-Deed! Dougal, man, we miss your sass!

As the heart lies mostly to the left of midline and right lower lung is to the right of the wound, neither of these organs were likely pierced. Good job, anatomy sleuths!

Physical Attributes: The adult liver is wedge-shaped, dense, and meaty, weighing 3-3.5 lb. Liver is our largest internal organ and the largest gland of the body, superseded in size only by our body’s largest organ, the skin (Anatomy Lesson #5, Claire’s Skin – Opals, Ivory and White Velvet). Ken the difference? Bonny!

Liver is solid in texture and deep red-purple-brown in color (Image H). Although liver mass constitutes only 2.5% of total body weight, the liver receives a whopping 25% of the cardiac output. Two and one-half pints of blood flow through a normal liver every minute of our lives!

Image H

Impressions: Front, back, and top surfaces of liver are relatively smooth; flip liver up-side-down, and its under-belly bears ridges and valleys. The depressions, named impressions, are created by contact with adjacent organs including stomach (gastric), duodenum, adrenal (suprarenal) gland, kidney (renal), and colon (Image I). Gallbladder also leaves an impression, but this is visible only after its removal. Ergo, liver is centrally-located in the upper abdominal cavity with many important organ contacts.

Image I

Anatomical Liver Lobes: Anatomists used landmarks to divide the liver into four anatomical lobes: right, left, caudate and quadrate (Image J). The large, right lobe (tan) is separated from the smaller left (yellow) by one of the membranes mentioned above, the falciform ligament. Only by viewing the undersurface are caudate (blue) and quadrate (green) lobes visible; caudate is nearer the spine and quadrate lies adjacent to gallbladder.

Image J

Blood Supply: Most organs receive blood via an artery and are drained by a vein. Not the liver! It is unique because it is the only organ receiving blood from both an artery and a vein; the hepatic vein delivers nutrient-rich blood derived from food digested in the gut, and the hepatic artery supplies oxygen-rich blood via the aorta. Three hepatic veins drain the liver (Image K).

Most organs are variations of a scarlet color because they receive oxygenated blood. Liver is a red-purple color because 75% of its blood supply is deoxygenated, nutrient-rich blood from the hepatic vein.

A dear long-time friend had a bit of trouble last year. Tests revealed that she had lost the blood supply to a segment of her liver with subsequent death of said segment! Cause unknown. She has given me permission to share this experience because it is unusual given she lacks any history of typical liver disorders or diseases. This is a wonderful example, though, of how dependent the liver is upon an intact blood supply!

Image K

Clinical Liver Segments: The next image looks scary, but bear with me here! Clinicians divide the liver into eight separate segments, numbered 1-8 or I-VIII (Image L); segment I (1) lies deep to IVa (4a) and IVb (4b), so it is not visible. Segments II and III lie to the left of the falciform ligament; all other segments lie to the right. Segmental divisions are determined by vascular supply and bile duct branching (see below) and are of great clinical import!

Image L

Clinical Liver Segments (cont.): Let’s say a cancer is found in liver segment IVb (4b). A competent surgeon determines the probable boundaries of IVb and resects only that segment, sparing remaining liver segments and minimizing blood loss. The surgeon performing these highly specialized surgeries must be thoroughly familiar with the segmental design as defined in Couinaud’s system (Image M).

Medical students have difficulty memorizing liver segments, but this fist mnemonic offers a useful visual. Note that the thumbnail (seen in ghost) represents the deep-lying, segment I.

Image M

Outlandish Lobes: Speaking of liver lobes… like you, I was deeply impressed by Master Raymond’s ministrations to Claire (and her liver) after her loss of Faith-faith (Starz episode 207, Faith). Her liver and other organs were infected; she probably had puerperal fever, a post-partum infection of the uterus that, if untreated, usually becomes systemic. Serious-Sobbing here (Dragonfly in Amber book)!

An odd feeling of warmth now emanated from those broad, square, workman’s hands. They moved with painstaking slowness over my body, and I could feel the tiny deaths of the bacteria that inhabited my blood, small explosions as each scintilla of infection disappeared. I could feel each interior organ, complete and three-dimensional, and see it as well, as though it sat on a table before me. There the hollow-walled stomach, here the lobed solidness of my liver, and each convolution and twist of intestine, turned in and on and around itself, neatly packed in the shining web of its mesentery membrane.

Bile Ducts and Gallbladder: Liver enjoys a robust working relationship with gallbladder and bile ducts. Why? Because, liver cells continuously produce bile, a dark green to yellowish-brown fluid. Bile is transported by a converging system of bile ducts from liver to gallbladder, a bag-like structure which stores and concentrates bile (Image N). Bile is then released in a controlled fashion after chyme (Anatomy Lesson #46, Splendid Stomach, Wobbly Wame) enters the duodenum. In folks lacking a gallbladder, bile ducts continuously release bile into the duodenum.

Bile: Two important purposes are served by bile:

  • Digestive aid: After eating a meal (especially high in fat), bile is released from gallbladder into duodenum (Anatomy Lesson #47, Brave Bowels – Gurgly Gut!) where it aids in lipid digestion by fats emulsification.
  • Excretory product: Specialized liver (Kupffer) cells devour effete red blood cells, breaking down hemoglobin into bilirubin, a waste component of bile that is eliminated with the stool.

Bile enjoys a long history in western medicine. From 500 B.C. to the early 19th century, standard practice adhered to a four humor system: black bile, yellow bile (liver bile), phlegm, and blood. Excesses of black and yellow biles were thought to produce depression and aggression and were treated accordingly (sometimes with phlebotomy). If only physiology/psychology were that simple!

Image N

Hepatocytes: The hepatocyte is the main functioning cell of the liver (there are other cell types, too). It’s prefix derives from the Greek word, hepar, meaning liver. Microscopically, the hepatocyte (image O – arrows point to hepatocyte cell membranes) is a large, round, bland-looking cell, but what a power-house it is!

Hepatocytes are arranged into 1-2.5mm cylinders, each known as a liver lobule. I will not teach liver lobule structure here as it is complex and difficult to understand for students lacking histology training – beyond the scope of this anatomy lesson. Suffice it to say that the liver is packed with millions of these tiny liver lobules. Their designs allows hepatocytes to have immediate access to blood vessels and bile channels. This allows ready access to substances in the blood stream and to release bile into bile channels for transport to the gallbladder.

Image O

Image P is a nice graphic summarizing a few liver functions – most are self-explanatory. Hepatocytes are responsible for almost all the ∼500 liver functions. Just a note about the Kupffer cell (Image O – arrowhead). a phagocyte, meaning “eating cell.” Kupffer cells ingest effete red blood cells (and other things), turning hemoglobin into bilirubin, a component of bile. Just consider: maintaining such a huge organ would be wasteful if it weren’t highly important – it wears many hats!

Image P

Liver Diseases: Liver is subject to a staggering array of diseases – from genetic disorders, autoimmunities, viral hepatitis, and parasitic liver flukes to cancer, chronic alcohol disease, poisoning, drug abuse, excessive use of over-the-counter pain relievers, etc. Although liver has a tremendous capacity to regenerate, long-term damage may result in the formation of scar tissue. A scarred liver is characteristically bumpy, a condition known as cirrhosis (Image Q). In the 18th century, Claire would have said the patient with a cirrhotic liver was liver-sick and cirrhotic livers were termed hobnailed livers. Just so you ken, hobnails are a short, heavy-headed nails used to reinforce the soles of boots. Bless Diana’s heart, she even wrote about cirrhotic livers (Dragonfly in Amber book)!

I knelt by the small traveling chest, unfolding the green velvet. Kneeling next to me, Jamie flipped back the lid of my medicine box, studying the layers of bottles and boxes and bits of gauze-wrapped herbs. “Have ye got anything in here for a verra vicious headache, Sassenach?” I peered over his shoulder, then reached in and touched one bottle. “Horehound might help, though it’s not the best. And willow-bark tea with sow fennel works fairly well, but it takes some time to brew. Tell you what—why don’t I make you up a recipe for hobnailed liver? Wonderful hangover cure.”

Liver dialysis can be used as a stop-gap treatment, but liver transplant is the only current option for complete liver failure. If all goes well, the transplant regenerates much of the original liver mass.

Image Q

Leaving that unhappy liver-note, let’s end on a happier liver quote!

Recall Starz, episode 105, Rent? One of my favs.

Intruder alert! With a massive candle stick, Claire goes after someone fussing outside her door!

Dashing outside, she encounters Jamie, sprawled on the filthy floor. “What are you doing here?” she demands (Outlander book), after stepping on his RUQ. Watch out lovely, lively liver! Crunch!

“What are you doing here?” I asked accusingly. At the same time Jamie asked, in a similarly accusatory tone, “How much do ye weigh, Sassenach?” Still a bit addled, I actually replied “Nine stone,” before thinking to ask “Why?” “Ye nearly crushed my liver,” he answered, gingerly prodding the affected area. “Not to mention scaring living hell out of me.”

Nurse Claire, in the hallway with a candlestick? <G> She almost brains Master Fraser! And her weight? What gently-bred Scottish lad asks a lass how much she weighs? Geez, at 126 lbs, Claire is a just wee thing!

And, Jamie, you drink Scotch whiskey so we all ken your liver can take a trashing! Uh oh, we’ve seen that look before. Run, Claire, run! Hah!

So, the liver may look boring, but is a bundle of life: 500 duties it performs to keep our bodies healthy and happy. We literally live in our liver!

Let’s end this lively liver lesson with a great quote from American physician and psychologist, William James:

Is Life worth living? It all depends on the liver.

And, from my own pen:

Liver the giver

makes us shiver and quiver

bound to deliver

It’s a major caregiver!

So, Love your Liver!

A deeply grateful,

Outlander Anatomist

Photo Creds: Starz, www.techmeanatomy.info (Image J), www.arthistorynewsreport.blogspot.com (Image C), www.cojs.org (Image B), www.commons.wikimedia.org (Image H), www.diets-usa.com (Image A), www.epomedicine.com (Image M), www.kenhub.com (Image F), www.medhealthdaily.com (Image G), www.medvizor.com (Image P), www.nature.com (Image L), www.ncbi.nlm.nih.gov (Image N), www.pathpedia.com (Image O), www.pinterest.com (Image I), www.skylerzarndt.com (Image E), www.vaxy.com (Image Q), www.wikipedia.org (Image D), www.24nurse.com (Image K)