Ovarian Follicle

We are doing some more histology.  I hope those of you that do not understand the more technical details enjoy the pictures I've taken.

Today's Medical Topic:  Histology of The Ovarian Follicle

What Are We Looking For:  We're looking for oocytes, thecal cells, and granulosa cells among other histological landmarks.

The Tissue Sample:  Alrighty.  Let's take a look.

Particularly we are looking at an antral follicle.  That is, we are looking at an ovarian follicle in the critical preovulatory stage.   Basically, this follicle is about to spit out an oocyte.

So here is the what we are looking at:

(click for big)

Here we can identify a bunch of things:

Thecal cells:  These cells are identified by their wavy appearance.  These cells synthesize androgens which are sex hormones.

Oocyte:  This is the precursor to the "egg."  It remains suspended in prophase I until it is released during ovulation where it undergoes meiosis I in response to a lutenizing hormone surge.

Zona pellucida:  The thin, dark ring around the oocyte.  This is just a glycoprotein membrane surrounding the plasma membrane of an oocyte.  This is the structure that binds to incoming spern during fertilization.

Granulosa cells:  These are spotted/roundish cells that occur around the zona pellucida and the antrum.  These cells synthesize estrogen.

Antrum:  The large mostly empty space between the granulosa cell layers.  This area contains a nutritive liquor.

That was fun, right?  Histology is always awesome.

Send questions or comments to dudaday@gmail.com

Disclaimer:  I am not a health care provider, any information presented in this blog should not be considered advice it is mearly an outlet to slake my curiosity.  You should always consult your primary medical provider for any concerns or illness.  Unlike Tylenol, I am not approved by the FDA or American Medical Association to treat or provide relief for any ailment.

Histology of the Pancreas

We are doing some more histology.  I hope those of you that do not understand the more technical details enjoy the pictures I've taken.

Today's Medical Topic:  Histology of The Pancreas

What Are We Looking For:  Acinar cells and Islets of Langerhans.

The Tissue Sample:  Alrighty.  Let's take a look.

Just so we are clear here, the pancreas is that tadpole-shaped organ just posterior to your stomach.  The pancreas is a mixed gland composed of endocrine and exocrine glands.  Acinar cells make up most of the glands with Panceatic Islets or Islets of Langerhans sprinkled throughout.

So here is the what we are looking at:

100x Magnification (click for big)

So this is a cross section of part of the pancreas.  What you seeing is mostly acinar cells.  That little red line is pointing to an Islet of Langerhans.  We need to zoom in to really appreciate it.

(click for big)

That blurry little blob there in the middle is an Islet of Langerhans.  These islets contain two major populations of cells:

alpha cells:  These synthesize glucagon

beta cells:  These are much more numerous and synthesize insulin.

I am not able to identify which is which and it is my understanding that alpha and beta cells are very difficult to discern between.  Also it might not be possible with the dye used to stain this sample.

Insulin is needed for your cells to utilize glucose.  Which in turn is needed for ATP production.  And we all know that adenosine triphosphate is your body's energy currency.

I know this was super exciting.  Keep on keepin on and I'll keep on posting.

Send questions or comments to dudaday@gmail.com

Disclaimer:  I am not a health care provider, any information presented in this blog should not be considered advice it is mearly an outlet to slake my curiosity.  You should always consult your primary medical provider for any concerns or illness.  Unlike Tylenol, I am not approved by the FDA or American Medical Association to treat or provide relief for any ailment.

Histology of the Adrenal Gland

We are doing some more histology.  I hope those of you that do not understand the more technical details enjoy the pictures I've taken.

Today's Medical Topic:  Histology of The Adrenal Gland

What Are We Looking For:  The capsule that encloses the adrenal gland, the three major zones of the adrenal cortex, and the adrenal medulla.

The Tissue Sample:  Alrighty.  Let's take a look.

Adrenal Section at 100x.  (Click for big.)

So here is the whole section we are looking at.  For reference the bottom is the capsule and it goes up through all three layers of the adrenal cortex with the very top of this image being part of the adrenal medulla.

All the layers.  (click for big)

Here I have cut the image in half and identified the areas we are interested in.  From bottom to top:

The Capsule:  The adrenal glands are enclosed in a capsule of fibrous connective tissue.  This is turn is enclosed with a fatty cushion for protection.  This fatty cushion has been mostly dissected away for this slide and is not identified.

The next three sections compose the adrenal cortex:

Zona Glomerulosa:  The thinnest and most difficult to identify part of the adrenal cortex.  Only 5 to 6 cell layers thick this section looks indistinct and blurry.  I have magnified this section below.  This cells of this layer produce mineralcorticoids.

Zona Fasciculata:  The middle layer of the adrenal cortex and the thickest.  Microscopically it looks like cords of cells arranged linearly.  The cells in this layer produce metabolic hormones called glucocorticoids.

Zona Reticularis:  The inner most layer of the adrenal cortex.  Microscopically it is identifiable as a change from cords of lined up cells to a almost gravel-like appearance.  The boarder between this layer and the zona fasciculata are very indistinct but the change in overall appearance is unmistakable.  This layer produces adrenal sex hormones called gonadocorticoids.

Now the inner most section of the adrenal gland.

The Adrenal Medulla:  In the above image you can see about half of the adrenal medulla.  You can see it is quite a large section and also very different from any of the other areas.  The adrenal medulla synthesizes epinephrine and norepinephrine and acts as part of the sympathetic nervous system.

Because it is difficult to see the fibrous capsules and the zona glomerulosa in the above images here is a close up:

(click for big)

I have outlined part of the zona glomerulosa in red to highlight how it is sort of squares of cells.  You can also see the capsule and how the capsule becomes denser as it approaches the adrenal cortex.  I hope this helps those of you studying the endocrine system.  If you have any questions or comments then drop me a line at dudaday@gmail.com.

Send questions or comments to dudaday@gmail.com

Disclaimer:  I am not a health care provider, any information presented in this blog should not be considered advice it is mearly an outlet to slake my curiosity.  You should always consult your primary medical provider for any concerns or illness.  Unlike Tylenol, I am not approved by the FDA or American Medical Association to treat or provide relief for any ailment.

Clinical Case 1

This is a case study I am doing for my anatomy and physiology class.  Some of the terminology will be above the heads of average readers.

The Case:  A 28- year-old African-American man (of normal height & weight), was found unconscious in front of his door way. Upon arrival to hospital his wife was interviewed and stated that for two days he was frequently urinating in the middle of the night, vomiting, scratching his feet and started drinking grape juice 5-6 glasses a day. He also started running into walls and was constantly dropping his briefcase. When he entered the emergency department he appeared to be in a drunken stupor and emitted a sweat-fruity aroma from his breath, and he also experienced Kussmaul breather (a rapid, deep respiratory pattern).


Other clinical findings:

Blood glucose = 375 mg/dL (normal= 70 -
110mg/dL)
Positive urine glucose
Positive urine ketones
Blood pH = 6.95 (normal= 7.2 - 7.4)

He also has findings consistent with a deep ulceration to the plantar aspect of one of his great toes and retinal damage.


Analyzation and Plan: History of present illness, current symptoms, and diagnostic tests indicate that this 28 year-old African American male is suffering from newly onset or uncontrolled Type II diabetes.  It is possible he could be manifesting Type I but it would be really rare for new onset type I at his age.  His race and sex also put him at a higher risk for diabetes.

The frequent urination is common in uncontrolled diabetes as you are trying to dump excess glucose via diureses.  The influx of glucose in the blood also causes osmotic dehydration as water is pulled from cells and tissues to dilute glucose in the blood.  With type II diabetes the beta cells in his pancreas are producing deficient or ineffective insulin and he has become unable to maintain normal blood glucose levels.  All the fructose in the grape juice the patient is drinking to slate his extreme thirst is probably making things worse, continually elevating his blood glucose and worsening his dehydration.

Your cells need insulin to use glucose and essentially begin to starve without it.  Consequently your body begins breaking down large amounts of stored fatty acids in an attempt to utilize the energy to maintain ATP production.  This ineffcient process dumps large amounts of these fatty acids into general circulation.  His weak acid-base system is unable to manage the influx of fatty acids (ketones) in his blood and his blood is becomming acidic.  The fruity scent of his breath and his hyperventilation is typical in diabetics trying to blow off CO2 to lower blood pH.  He is also trying to dump ketones into his urine.  Between the ketones in his urine and the dehydration his kidneys are taking a real beating.

It is also possible he is in renal failure due to prolonged hyperglycemia.  The glucose can sort of clump up in the renal tubules and also cause diffuse microvascular damage causing nerve dysfunction and/or death.  In the patient's extremities this microvascular damage combined with atherosclerotic peripheral artery disease which diabetics are also prone to is causing peripheral neuropathy and the horrible foot ulcer.  He probably can’t feel that part of his foot.

The diabetic foot ulcer is a Wagner grade III since it is to the bone.  It looks like the ulcer is down to the joint between the distal and proximal phalanx of the hallux.  He’ll need broad spectrum IV antibiotic coverage especially something that covers Staph until a wound culture comes back.  If the lesion is down to the bone he will need a biopsy and a culture of the bone to rule out osteomyelitis and set up long-term management.

His confusion, weakness and discoordination is most likely the result of dehydration and diabetic ketoacidosis (DKA) and it could be causing a little cerebral edema.  Considering the blood chemistry his pH is becoming dangerously low.  Humans must maintain a very tight pH range to maintain homeostasis.  Almost every cellular interaction depends on stable pH.

A blood glucose of 375 isn’t super mega ultra high but some diabetics are extremely sensitive and this patient has probably had uncontrolled blood glucose levels for some time considering the foot ulcer and retinal damage.  He has most likely been floating a blood glucose above 180 for several months with some general malaise but no major ill effect until the scale tipped and the dehydration pushed him into DKA.  Meanwhile the disease was doing it's work.  Since he couldn't feel the ulcer he probably let it slide, same with the declining vision.  Most people don't want to believe they are sick and denial is a powerful and terrible master.

First and foremost this patient will need rehydration and an insulin regimen.  This patient requires admission to the hospital critical care unit where he can be closely monitored.  Provided he did not have any major brain swelling his mental faculties should return but he unfortunately probably lost a few IQ points.  He has a relatively high probability of surviving this incident but his long term outlook is poor.  The dialysis will take some of the load off of his kidneys but the damage is done.

Everyone’s physiology is a little different.  I’ve noticed that diabetics are either genetically inclined to tolerate or not tolerate the disease.  For some people diabetes hits them like a cement truck.  This patient is one of those people.  Renal failure, diabetic ulcers, and retinitis at age 28 is not good.  Even if he survives this he is not going to live very long.  He will need weekly dialysis, proper wound care with possible amputations, and frequent eye exams to see if he needs laser surgery to tack down his retina to avoid detachment.  

This sucks.  Especially when patients are this young.  I've seen this before working in the ER and knowing that a patient will probably never go back to a normal life despite your best efforts is depressing to say the least.  There is almost always a heavy price to pay when we cheat death.