Conclusion Caturday: Vince Vomits Valiantly (Case 7)

Photo of TA Douglas (Left) and Professor Pocky (Right) taken by Dr. Haus

 

Click For Explanation of Case Flow

 

Click for Test Case Tuesday:  Vince Vomits Valiantly

 

Click for Thoughtful Thursday:  Vince Vomits Valiantly

 

Quick Review

Diagnosis:

🦴Myasthenia Gravis🦴

 

Pathophysiological Point:

Myasthenia gravis is a disease where the acetylcholine receptors between nerves and muscles are destroyed or blocked.  Simply, nerves cannot conduct their signals to muscles.  Muscles are unable to contract (move) without the signals from the nerves.

 

 Questions, Answers, and Further Information:

 

Level 1 Questions, Answers, and Further Information:

1. Vince's communication between his nerves and muscles is disrupted, how does that affect the muscles of his body?  Why?
   
   If Vince's nerves cannot communicate with his muscles, his muscles will not be able to move.  The nerves tell the muscles to move and without this signaling he will not be able to contract his muscles easily leading to difficulty moving.
   
   
2. What part of Vince's history and physical exam findings support the diagnosis of a disease that affects communication between the nerves and muscles of his body?
   
   The history and physical exam findings that support his diagnosis are the generalized weakness and muscle loss.  These findings support the fact that Vince's nerves are not able to send their normal signals to the muscles.
   
   
3. Challenge question, why does Vince have megaesophagus?  How does this cause regurgitation after meals?  (HINT:  Think about Vince's disease and how it would affect the muscles of the esophagus)
   
   The esophagus is a muscle much like the other muscles of the body.  In order for food and fluid to get to the stomach, the esophagus must be able to contract.  With Vince's disease, he cannot use his esophageal muscles to push the food/fluid down to his stomach so the food and fluid accumulates in the esophagus causing it to expand and stretch causing megaesophagus.  As this food/fluid builds up in the esophagus it will comes out the mouth because the muscle contractions are not there to get the food and fluid to his stomach efficiently.
   
   

   Helpful Links:

   • VCA (dogs):  https://vcahospitals.com/know-your-pet/megaesophagus
     
     
   • Mayo Clinic (humans):    https://www.mayoclinic.org/diseases-conditions/myasthenia-gravis/symptoms-causes/syc-20352036
     
     
   • Cornell Vet School:  https://www.vet.cornell.edu/departments/riney-canine-health-center/canine-health-information/myasthenia-gravis
     

 

Level 2 Questions, Answers, and Further Information:

1. How does myasthenia gravis cause disease (i.e., megaesophagus) in a patient?  Be sure to mention the “normal” esophageal physiology in your answer and explain physiologically where the miscommunication is occurring.  (HINT:  Review normal neuromuscular junction physiology)
   
   Myasthenia gravis destroys/blocks the acetylcholine receptors on the muscle cells.  Neurons release acetylcholine into the synaptic cleft at the neuromuscular junctions.  This allows the muscle cell to begin to undergo the process of depolarization which will eventually lead to the muscle contracting.  The esophagus is a muscle that must contract to move food/fluid towards the stomach.  With the acetylcholine receptors of the esophageal muscles destroyed/blocked, the esophagus cannot move the food/fluid and the esophagus will expand to accommodate all the stuck food/fluid material.
   
   
2. How does megaesophagus lead to Vince’s major clinical sign (regurgitation)?  (HINT:  Think about what keeps us from floating away into space)
   
   Since Vince cannot contract his esophagus, the food/fluid will sit in the esophagus unable to move aborally.  This leads to the material falling back out the mouth especially when Vince puts his head down as gravity will cause the food/fluid to fall out of the mouth.
   
   
3. Challenge question, explain why Vince has pneumonia.  Be sure to explain how his underlying disease predisposed him to this condition.  Be sure to mention the anatomy involved.  (HINT:  Think about what structure sits right next to the esophagus)  
   
   Vince's pneumonia is likely due to his regurgitation from the megaesophagus.  Each time Vince regurgitates his food, he risks some of the food/fluid accidentally falling into the trachea which sits next to the esophagus.  When food/fluid enters the esophagus there is a risk that the material gets into the deeper lung tissues leading to pneumonia (inflammation of the alveoli).
   
   

   Helpful Links:
   

   • Merck Vet Manual:   https://www.merckvetmanual.com/nervous-system/congenital-and-inherited-anomalies-of-the-nervous-system/neuromuscular-disorders-in-animals 
     
     
   • Cornell Vet School:  https://www.vet.cornell.edu/departments/riney-canine-health-center/canine-health-information/myasthenia-gravis
     
     
   •  Merck Vet Megaesophagus:  https://www.merckvetmanual.com/digestive-system/diseases-of-the-esophagus-in-small-animals/dilatation-of-the-esophagus-in-small-animals
     
     

Level 3 Questions, Answers, and Further Information:

1. Describe the treatment plan you would recommend Vince and why you are recommending each part of your treatment plan.  Please answer this question as if you are speaking to a professional colleague.  .
   
   Vince's treatment plan will depend on the etiology of his disease.  If Vince's disease is due to a thymoma the thymoma needs to be surgically removed.  Otherwise, anti-acetylcholinesterase medications can be used to treat these patients.  Vince will also need to be treated for his pneumonia with antibiotics and other supportive care as needed.
   
   
2. Describe your recommended treatment plan and why you are recommending each part of your treatment plan.  Please answer this question as if you are explaining it to a client/patient without a scientific background.
   
   Vince has a disease that causes his nerves and muscles to not communicate correctly.  We will be starting Vince on a medication that will help his nerves and muscle communicate better while also starting him on antibiotics to treat his pneumonia.
   
   
3. Please describe the different ways Vince's owners could help manage his condition with environmental changes.
   
   There are a few ways Vince's owners can help increase Vince's quality of life at home.  Firstly, Vince should be fed and watered from dishes that are elevated off the floor (less gravitational effects).  The owners can also hold Vince up vertically after meals to help gravity "push" the food/fluid down to his stomach.  His owners should also feed him smaller, more nutrient dense meals to decrease his risk for regurgitation.
   
   

   Helpful Links:

   • Journal of Internal Veterinary Medicine:   https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8478050/  
     
     
   • Journal of Clinical Medicine:    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8196750/
   
   

Day 3 Conclusion

I hope you enjoyed the Vince's case!  Don't forget to...

📚 Review material related to the goats' case 

🤩 Get excited for upcoming cases

 

Thoughtful Thursday: Vince Vomits Valiantly (Case 7)

  

Photo of Professor Pocky taken by Dr. Haus

Click For Explanation of Case Flow

 

Click for Test Case Tuesday:  Vince Vomits Valiantly (Case 7)

 Vomiting or Regurgitation?

The MOST important determination to make in a vomiting patient's case is to make sure the patient is actually vomiting.  Vomiting is NOT the same as regurgitation.  Regurgitation is when food/fluid comes out of the mouth from any structure before the stomach (mouth, pharynx (throat), esophagus (food tube), etc.)  Vomiting is when food/fluid come out the mouth from the stomach or upper small intestines.

🤢

This distinction is extremely important because the causes of vomiting and regurgitation are different and the way we work up the two types of cases are completely different.  It is important to remember that an owner can say their pet is vomiting when they are in fact regurgitating food.  The ways you can differentiate vomiting and regurgitation are noted below:

Vomiting

• Abdominal push (abdominal muscles contract to push the vomitus out of the mouth)
  
• Bile present (green substance)
  
• Active process (you can see the whole body put in an effort to vomit)
  

🤮

Regurgitation

• No abdominal push
• No bile present
• Passive process (the mouth opens and the food/fluid comes out, no pushing seen)

 😵

An important aspect of any veterinary professional is to have your acting skills on point as it is common to see us acting out vomiting versus regurgitation.  The things that happen in an exam room are sometimes bananas (ask your vet med friends to act out reverse sneezing, you won't regret it).

 🎭

The owners describe Vince's "vomiting" as him eating his food and then immediately it "falls" back out of his mouth.  The owners do not see Vince actively retching or "pushing" when he has the "vomiting".  It is determined Vince is regurgitating, not vomiting!

 

Diagnostic Testing Results:

 

Radiographs: Severe megaesophagus (enlarged esophagus, food tube), signs of pneumonia 🩻

 

Specific Disease Testing - Acetylcholine Receptor Antibody Test: Positive ➕

 

🧪

Diagnosis:

🦴Myasthenia Gravis🦴

 

Pathophysiological Point:

Myasthenia gravis is a disease where the acetylcholine receptors between nerves and muscles are destroyed or blocked.  Simply, nerves cannot conduct their signals to muscles.  Muscles are unable to contract (move) without the signals from the nerves.

 

 Questions:

Level 1 Questions:

1. Vince's communication between his nerves and muscles is disrupted, how does that affect the muscles of his body?  Why?
   
   
2. What part of Vince's history and physical exam findings support the diagnosis of a disease that affects communication between the nerves and muscles of his body?
   
   
3. Challenge question, why does Vince have megaesophagus?  How does this cause regurgitation after meals?  (HINT:  Think about Vince's disease and how it would affect the muscles of the esophagus)
   

 

Level 2 Questions:

1. How does myasthenia gravis cause disease (i.e., megaesophagus) in a patient?  Be sure to mention the “normal” esophageal physiology in your answer and explain physiologically where the miscommunication is occurring.  (HINT:  Review normal neuromuscular junction physiology)
   
   
2. How does megaesophagus lead to Vince’s major clinical sign (regurgitation)?  (HINT:  Think about what keeps us from floating away into space)
   
   
3. Challenge question, explain why Vince has pneumonia.  Be sure to explain how his underlying disease predisposed him to this condition.  Be sure to mention the anatomy involved.  (HINT:  Think about what structure sits right next to the esophagus) 
   

    
   

Level 3 Questions:

1. Describe the treatment plan you would recommend Vince and why you are recommending each part of your treatment plan.  Please answer this question as if you are speaking to a professional colleague. 
   
   
2. Describe your recommended treatment plan and why you are recommending each part of your treatment plan.  Please answer this question as if you are explaining it to a client/patient without a scientific background.
   
   
3. Please describe the different ways Vince's owners could help manage his condition with environmental changes.
   

  

Day 2 Conclusion

Before Conclusion Caturday think about your...

❓Answers to the above questions

📚 Review Material Related to Vince's case

 

Conclusion Caturday: Vince Vomits Valiantly (link will go live Saturday, 02/17/2024)

 

Test Case Tuesday: Vince Vomits Valiantly (Case 7)

 

Picture of Professor Pocky taken by Dr. Haus

Click For Explanation of Case Flow

 

Signalment:

Vince is a 4-year-old male neutered Labrador Retriever Dog

🐶

History:

Vince is presenting for vomiting his food after every meal, generalized weakness, and lethargy.  His owners note that for the past few meals (even small ones) Vince will vomit immediately after he eats any food.  ​

Vince has a 2-year-old Labrador Retriever female spayed sister named Vanessa.  Vanessa is showing no signs of illness.

🤮

Physical Exam Findings:

Respiratory:  Raspy lung sounds​ 🫁

Musculoskeletal:  Generalized muscle weakness/atrophy (muscle wasting)​ 🏋️

 

🩺

 

🛑STOP and brainstorm what diagnostic tests you would like to perform on Vince 🛑

 

 

We will be stopping here today.  Before Thursday, think about what question(s) you need to ask Vince's owners to fully understand his history (Hint: Think about vomiting).  We will review an important distinction veterinarians need to make with vomiting patients and what diagnostic testing will be done based on that knowledge.

🧪

Day 1 Conclusion

Before Thoughtful Thursday think about your...

📋 Differentials List

🧪 Further Diagnostic Testing

📚 Review Material Related to Vince's case (i.e. what questions to ask owners of a vomiting patient, questions to ask a vomiting patient (if patient is a human that can communicate), specific diseases of interest, causes of vomiting, types of vomiting, personal interests, confusing points, etc.)

 

Thoughtful Thursday: Vince Vomits Valiantly (link will go live Thursday, 02/15/2024)

 

Conclusion Caturday: Janice is Jinxed (Case 6)

Photo of TA Douglas (Left) and Professor Pocky (Right) taken by Dr. Haus

 

Click For Explanation of Case Flow

 

Click for Test Case Tuesday:  Janice is Jinxed

 

Click for Thoughtful Thursday:  Janice is Jinxed 

 

Quick Review

Diagnosis:

🐮Ketosis🐮

 

Pathophysiological Point:

Ketosis is a condition where the body is breaking down fats at an extremely elevated rate due to a negative energy balance.  This energy imbalance occurs because the body is using more energy than it is taking in through eating.

 

 Questions, Answers, and Further Information:

 

Level 1 Questions, Answers, and Further Information:

1. Why do you think Janice is suddenly breaking down more fat?  In other words, why would Janice have a negative energy balance?  (HINT:  Think about Janice's history and physical exam findings)
   
   Janice is in a negative energy balance and breaking down more fat because she recently had her calf and is producing a large amount of milk.  In addition, Janice has a high body condition score (BCS) and thus has more fat in her body than an animal with a normal BCS.  It takes a lot of energy to make milk and Janice needs A LOT more energy to make milk for her baby (lactation).
   
   
2. What is the pathway that is occurring at an increased rate in Janice's body?  Please write out all the steps of the process and include what molecule there will be more of in Janice's bloodstream.  (HINT:  Click here)
   
   The process that is happening at an increased rate in Janice is gluconeogenesis of fats.  In this process, the body is breaking down the adipose tissue (fat tissue) into glycerol and fatty acids.  The glycerol is used to produce glucose for the body while the fatty acids accumulate and are converted to ketones.  Due to this, Janice will have more ketones in her bloodstream (her glucose will be taken out of the bloodstream very quickly to make more milk).
   
   
3. Challenge question, what information in Janice's history AND physical exam findings put her at increased risk for developing ketosis?  Why do those factors increase her risk for ketosis?  What ways could the farmer have reduced Janice's chance for developing ketosis?  (HINT:  Think about the underlying cause of the disease in Janice's case)
   
   Janice was at increased risk to develop ketosis due to her birthing a calf and because she was overweight before having the calf.  Having a calf puts Janice at increased risk for developing ketosis because after having the calf Janice needs to produce a large amount of milk.  This causes most of Janice's energy (glucose) to go to her milk and her body will start to break down fats to provide enough energy to produce milk and to keep herself alive.  Janice being overweight is another factor because since Janice is so overweight her body can/will break down a large amount of fat meaning she will produce a large amount of ketones.  The farmer should make sure their cows are not overweight prior to having their calves to decrease the risk of ketosis.
   
   

   Helpful Links:

   • Penn State Extension:  https://extension.psu.edu/preventing-dairy-cow-ketosis-nutritional-management-during-transition
     
     
   • Dairy NZ:    https://www.dairynz.co.nz/animal/animal-health/ketosis/
     
     
   • The Cattle Site:  https://www.thecattlesite.com/diseaseinfo/194/acetonaemia-ketosis/
     

 

Level 2 Questions, Answers, and Further Information:

1. Explain why Janice has low glucose concentrations and high ketone concentrations in her bloodstream.  Do not forget to name the process that is occurring at an increased rate in Janice's body and the steps of this process.  (HINT:  Click here)
   
   Janice has low glucose concentrations in her bloodstream because her body needs more energy than she is taking in by eating to undergo lactation.  In this case, her body is mobilizing fats through the process of gluconeogenesis.  In this process, her adipose tissue is broken down into fatty acids and glycerol.  That glycerol will be used in gluconeogenesis to produce the glucose Janice's body needs to produce the milk and keep her body functioning.  The fatty acids will accumulate and be processed into ketones.  This leads to the high ketone concentration in her bloodstream.  This process is called gluconeogenesis of fats.
   
   
2. High ketone concentrations in the bloodstream lead to inappetence.  How does this information affect Janice's disease process?  (HINT:  Think about how inappetence is affecting Janice's body and her ability to overcome this disease process)
   
   Janice has high ketones in her bloodstream and since ketones decrease appetite Janice does not feel like eating.  The less Janice eats, the more fats she needs to break down.  In this way, the ketones are causing her ketosis to become worse and worse as her body breaks down fats, makes her more inappetent, and thus makes her body break down even more fats.  Janice is stuck in a loop that is making her get more and more sick.
   
   
3. Challenge question, explain why ketosis is very common in dairy cattle, more common in dairy cattle that birth twins, and more common in dairy cattle that are overweight.  (HINT:  Think about what dairy cattle were bred to do and the underlying cause of this disease)   
   
   Ketosis is common in dairy cattle because they are bred to produce HUGE amounts of milk.  Due to this, a dairy cow's body will keep producing huge amounts of milk even if she is not eating enough food to sustain her body and milk production.  This process is also more common in dairy cattle that have twins because the birthing process of having twins uses much more energy than birthing one calf and more milk will be needed to support both calves.  Lastly, overweight dairy cattle are at an increased risk because they have a large amount of fat that can be broken down after they birth their calf and this will lead to them breaking down a higher amount of fat thus increasing the high ketone concentration in their bloodstream.
   
   

   Helpful Links:
   

   • Merck Vet Manual :     https://www.merckvetmanual.com/metabolic-disorders/ketosis-in-cattle/ketosis-in-cattle
     
     
   • Wisconsin Vet School:   https://heatherwhite.webhosting.cals.wisc.edu/wp-content/uploads/sites/164/2015/01/F-08872-15-Ketosis-Understanding-the-Biology1.pdf
     
     
   •  University of Kentucky:  https://afs.ca.uky.edu/content/treatments-dairy-cows-ketosis
     
     
     

Level 3 Questions, Answers, and Further Information:

1. Describe the treatment plan you would recommend Janice and why you are recommending each part of your treatment plan.  Please answer this question as if you are speaking to a professional colleague.
   
   Janice has ketosis and needs to be treated with intravenous glucose to start the process of getting enough glucose in her bloodstream to "break" the ketosis cycle.  After this first IV dose, Janice should be drenched with oral propylene glycol which will provide her extra glucose until her body adjusts to having enough energy for both mother and calf.
   
   
2. Describe your recommended treatment plan and why you are recommending each part of your treatment plan.  Please answer this question as if you are explaining it to a client/patient without a scientific background.
   
   Janice is suffering from a condition called ketosis.  Since Janice had her calf she has been needing a huge amount of extra energy to produce milk and started breaking down her fats for energy.  Unfortunately, Janice has broken down too much fat and it has caused her to get sick.  We need to give her extra energy/sugars in order to help her body adjust to producing milk and keeping her body healthy.
   
   
3. Please create and describe a ketosis prevention plan for this farm to decrease the incidence of ketosis on this farm (both clinical and subclinical ketosis).  Explain the importance of subclinical ketosis and why it is extremely important to prevent this disease process on dairy cattle farms.
   
   There are a lot of answers to this question and I will list some here.  The biggest factor to decrease the risk of ketosis in your herd is to ensure that you are not overfeeding your cows and to make sure they remain in the correct weight range before giving birth.  Additionally, cattle should be monitored closely for ketosis after they give birth.  Cows that recently calved should all be kept in a pen together (often called the fresh pen) to get examined everyday and to have their blood ketone levels tested on an as needed basis.  It is also important to ensure that you are feeding your cattle appropriate nutrition for each stage of their lifecycle to ensure they are getting the nutrition they need at each stage of their lives.
   
   

   Helpful Links:

   
   
   • Veterinary World:      https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8304442/   
     
     
   • Veterinary Medicine and Science:        https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9857124/
     
   
   

Day 3 Conclusion

I hope you enjoyed the Janice's case!  Don't forget to...

📚 Review material related to the goats' case 

🤩 Get excited for upcoming cases

Thoughtful Thursday: Janice is Jinxed (Case 6)

 

Photo of Professor Pocky taken by Dr. Haus

Click For Explanation of Case Flow

 

Click for Test Case Tuesday:  Janice is Jinxed (Case 6)

 

Diagnostic Testing Results Reminder:

 

Bloodwork:  Low glucose, high ketones

 

🧪

Diagnosis:

🐮Ketosis🐮

 

Pathophysiological Point:

Ketosis is a condition where the body is breaking down fats at an extremely elevated rate due to a negative energy balance.  This energy imbalance occurs because the body is using more energy than it is taking in through eating.

 

 Questions:

Level 1 Questions:

1. Why do you think Janice is suddenly breaking down more fat?  In other words, why would Janice have a negative energy balance?  (HINT:  Think about Janice's history and physical exam findings)
   
   
2. What is the pathway that is occurring at an increased rate in Janice's body?  Please write out all the steps of the process and include what molecule there will be more of in Janice's bloodstream.  (HINT:  Click here)
   
   
3. Challenge question, what information in Janice's history AND physical exam findings put her at increased risk for developing ketosis?  Why do those factors increase her risk for ketosis?  What ways could the farmer have reduced Janice's chance for developing ketosis?  (HINT:  Think about the underlying cause of the disease in Janice's case)
   

 

Level 2 Questions:

1. Explain why Janice has low glucose concentrations and high ketone concentrations in her bloodstream.  Do not forget to name the process that is occurring at an increased rate in Janice's body and the steps of this process.  (HINT:  Click here)
   
   
2. High ketone concentrations in the bloodstream lead to inappetence.  How does this information affect Janice's disease process?  (HINT:  Think about how inappetence is affecting Janice's body and her ability to overcome this disease process)
   
   
3. Challenge question, explain why ketosis is very common in dairy cattle, more common in dairy cattle that birth twins, and more common in dairy cattle that are overweight.  (HINT:  Think about what dairy cattle were bred to do and the underlying cause of this disease) 
   

    
   

Level 3 Questions:

1. Describe the treatment plan you would recommend Janice and why you are recommending each part of your treatment plan.  Please answer this question as if you are speaking to a professional colleague. 
   
   
2. Describe your recommended treatment plan and why you are recommending each part of your treatment plan.  Please answer this question as if you are explaining it to a client/patient without a scientific background.
   
   
3. Please create and describe a ketosis prevention plan for this farm to decrease the incidence of ketosis on this farm (both clinical and subclinical ketosis).  Explain the importance of subclinical ketosis and why it is extremely important to prevent this disease process on dairy cattle farms.
   

  

Day 2 Conclusion

Before Conclusion Caturday think about your...

❓Answers to the above questions

📚 Review Material Related to Janice's case

 

Conclusion Caturday:  Janice is Jinxed (link will go live Saturday, 02/10/2024)

Test Case Tuesday: Janice is Jinxed (Case 6)

 

Picture of Professor Pocky taken by Dr. Haus

Click For Explanation of Case Flow

 

Signalment:

Janice is a 5-year-old female intact Jersey dairy cow

Janice lives on Jersey Girl Farms which is a 100-cow Jersey dairy herd in rural Texas  

 

🐮

History:

The farmer on Jersey Girl Farms notes that Janice is off-feed (not eating) and is producing less milk than normal.  Janice had her calf, Janette, 5 nights ago with no issues.  Janice had been doing well since the birth of her calf (producing milk and eating okay).  Last night and this morning Janice did not eat any of her food and this morning she produced less milk than she has been producing the past few days.  The farmer wants you to come out and assess Janice to see what is ailing her.​

No other cows in the herd are showing signs of disease.​

🐄 

Physical Exam Findings:

Attitude:  QAR (quiet, alert, and responsive), lethargic​ 🙊

Body Condition Score:  4/5​ 🥩

Ocular:  Eyes sunken back into eye sockets (sign of dehydration) 👀

Abdomen:  Decreased rumen sounds🔈

Rectal Exam:  Decreased rumen fill 🍽️

 

🩺

 

🛑STOP and brainstorm what diagnostic tests you would like to perform on Janice 🛑

 

 

Diagnostic Testing Results:

 

Bloodwork:  Low glucose, high ketones

🧪

Day 1 Conclusion

Before Thoughtful Thursday think about your...

📋 Differentials List

🧪 Further Diagnostic Testing

📚 Review Material Related to Janice's case (i.e. specific diseases of interest, causes of high ketones in cattle, digestive tracts of cattle (ruminants), personal interests, confusing points, etc.)

 

Thoughtful Thursday: Janice is Jinxed (link will go live Thursday, 02/08/2024)

 

Ruminant Digestive Tract

 

Photo by Dr. Haus

Ruminant Digestive Tract

A ruminant is a category of animals that are able to digest plant-based, difficult to digest food sources that other animals cannot eat.  Ruminants include cattle, sheep, goats, giraffes, deer, and many other species of animals.  Ruminants do this with their extremely large stomach which is full of microorganisms that allow them to ferment these hard to digest plant-based foods.

🦒

Ruminants have ONE stomach that is separated into FOUR compartment.  The four compartments of the stomach are called the rumen, the omasum, the reticulum, and the abomasum.  The rumen is where the majority of the fermentation and breakdown of food materials occurs.  The omasum is where water and other nutrients are absorbed into the body.  The reticulum assists in determining when feed material is small enough to move forward in the digestive tract into the omasum.  If the feed material is too big, it will be funneled back into the rumen for further fermentation.  The abomasum is known as the "true" stomach and is similar to the stomach in other species (such as humans).

 

 

What are Ketones and Why are they Important?

 

Photo by Dr. Haus

What are Ketones?

Ketones are an acidic breakdown product of fats.  When the body is breaking down fats, ketones are one of the substances that are produced.  A normal amount of ketones can be used by the body for energy BUT as more and more fat is being broken down the ketones begin to accumulate.  The accumulation of ketones has SEVERE negative effects in an organism due to their highly acidic nature.

 

🍋

Why are they Important?

When there are too many ketones in the bloodstream an organism enters the state of ketosis (ketoacidosis).  This is a life threatening condition that leads to disorientation, confusion, aggressiveness, coma, and eventually death.  One example of such a state is diabetic ketoacidosis (DKA) which is a MEDICAL EMERGENCY.

😶‍🌫️

Gluconeogenesis of fats is the process where the body is using fats to produce the glucose the body needs to survive.  The steps of the breakdown of fats (adipose tissue) are noted below:

 

As noted in the above diagram, adipose tissue is broken down into fatty acids and glycerol.  The fatty acids accumulate in the bloodstream and are converted to ketones.  The glycerol is used in gluconeogenesis to produce more glucose for the body.  If this process is happening at too rapid of a rate, the organism risks entering a ketotic (ketoacidotic) state.

Carbohydrate Metabolism

 

Photo by Dr. Haus

Carbohydrate Metabolism

Carbohydrate metabolism refers to how the body breaks down, stores, and uses carbohydrates.  Carbohydrates are one of the four major sources of food and energy in a living organism.  Carbohydrates are the building blocks found in foods that the gastrointestinal organs (stomach, liver, intestines, etc.) need to break down, process, use, and store to allow the organism to survive.

🥖

When a meal is being digested, the body works to break down the carbohydrates into their smallest functional form called monosaccharides.  The majority of this digestion happens in the small intestines and the small intestines is the main location where the monosaccharides are absorbed into the body.

🍝

Glucose is the major monosaccharide that needs to remain in a homeostatic range in the bloodstream.  Homeostatic range is the value range a specific parameter must stay within to keep an organism healthy.  In the case of glucose, glucose concentrations HIGHER than the homeostatic range have severe negative consequences in an organism.  Glucose concentrations LOWER than the homeostatic range equally have severe negative consequences in an organism.  In a normal, healthy organism, the body works VERY HARD to maintain a parameter within its homeostatic range for optimal body functioning and health.

🍉

Glucose is a large and charged molecule that cannot move freely from the inside of the small intestines into the body and thus it relies on facilitated diffusion to be absorbed into the organism.  Facilitated diffusion is where a molecule needs help from a protein to move through the plasma membrane into the cell.  You can think about this like a tunnel that is only opened for the correct traveler.  A glucose transport protein will transport glucose DOWN its concentration gradient.  In the case of the body breaking down food after a meal, the concentration gradient "makes" the glucose want to move into the body and the glucose transport proteins help the glucose move from the small intestines into the body's bloodstream.

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Now, these glucose transport proteins are not always open (except for a variety in the brain, but that is a different blog post).  The signal that tells the glucose transport proteins that they can open to let the glucose pass is insulin.  WITHOUT INSULIN, THE BODY CANNOT ABSORB GLUCOSE INTO THE CELLS.  This is very important because EVERY cell in the body needs glucose to provide it the energy it needs to survive.

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The beta cells in the islets of Langerhans of the pancreas produce and release insulin into the bloodstream.  In a normal, healthy organism, insulin will increase shortly after a meal is eaten to allow the absorbed glucose to go from the bloodstream into the cells providing them the energy they need to survive.

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The opposite of insulin in the body is glucagon.  Glucagon is produced in the alpha cells in the islets of Langerhans of the pancreas to counteract the effects of insulin.  Insulin DECREASES the glucose concentration in the bloodstream by opening the glucose transport proteins so glucose moves INTO the cells of the body.  Glucagon INCREASES the amount of glucose in the bloodstream by causing the body to break down its energy stores to release glucose into the bloodstream.  This yin and yang process allows for the glucose concentration to remain in the homeostatic range and prevents fluctuations of glucose in the bloodstream.

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When glucose is absorbed into the body it will be used in one of three different ways:

1. Used immediately to produce energy for the cells (body)
2. Stored as glycogen (a quick energy source stored in large concentrations in the muscles and liver)
3. Stored as fat for later use
   

Remember, without glucose in the correct concentration in the bloodstream an organism won't be able to survive very long!