Histology of Urinary System of Animal (Identification of Urinary System Organs under Microscope)
Hello and welcome again. Hope you are fine. If you are looking for the histology of the urinary system diagram, you are in the right place. Today, I will discuss the histology of the urinary system organs of animals (identification of urinary system organs under a microscope). I hope you have a basic idea on STRUCTURE OF CELL, LINING EPITHELIUM, CONNECTIVE TISSUE, and GENERAL STRUCTURAL PATTERN OF A TUBULAR ORGAN. If you don’t have basic knowledge about those topics, you may go through those links.
Histology of urinary system organs
I will discuss the important histological features necessary to identify the urinary system organs under a microscope. I will cover the histology of the following organs –
Histology of kidney cortex and medulla or histological features of kidney
Histological structure of ureter of animal or histology of ureter diagram
Histological structure of urinary bladder or histology slide of the urinary bladder
Histological structure of male urethra or histology slide of the male urethra
Now, I am going to discuss those organs in detail (histology of urinary system)
Histology of kidney cortex and medulla of animal
You should know the details histological description of the kidney. The following structures should be identified from kidney under the microscope –
Capsule of kidney
Renal corpuscle (glomerular epithelium, glomerulus, glomerular capsule)
Proximal convoluted tubule
Distal convoluted tubule
Thin tubules
Collecting ducts
Capillary and interstitium
You should also know about the juxtaglomerular apparatus
“If possible, I will make histology of urinary system ppt or histology of kidney pdf documents for you in future.”
Okay, let’s start identifying the structures from histology of the kidney cortex and medulla.
Capsule
A kidney is covered by a connective tissue capsule (more collagen fiber with few smooth muscles) on its external surface.
“You should have a better idea on gross anatomy of the kidney. You should know the dark red cortex and lighter medulla grossly.”
You will find different compact renal tubules – nephron (structural and functional units of the kidney) and collecting duct system in the kidney section.
“Please, know more about nephron for better understand. As I am going to identify important features of kidney cortex and medulla, so I am not going details on them”.
In the cortex, you will find a spherical structure called renal corpuscle. It comprises the glomerulus (branched and anastomosing capillaries) and glomerular capsule or Bowman’s capsule.
You will find two-pole in the renal vascular pole (towards afferent, efferent arteriole, the entry point of branched capillaries) and urinary pole (towards the proximal convoluted tubule).
Again, the glomerular or Bowman’s capsule has visceral and parietal layers. A parietal layer is lined by simple squamous epithelium, called the capsular epithelium, whereas the visceral layer is lined by specialized epithelium cells called the glomerular epithelium. They have the smallest foot process, and they are called podocytes.
The space between the visceral and parietal layer is called urinary space or Bowman’s space, or capsular space.
You should also know about the “Juxtaglomerular apparatus.”
It is located at the vascular pole of a renal corpuscle and composed of macula densa, extraglomerular mesangial cells, and juxtaglomerular cells.
Macula densa are densely packed cells located on distal straight tubules. Extraglomerular mesangial cells are found between macula densa and two arterioles (afferent and efferent) continuous with mesangial cells in the glomerulus.
Juxtaglomerular cells are located in media of afferent arteriole.
Proximal convoluted tubule
At the urinary pole of the renal corpuscle, the glomerular capsule opens into proximal convoluted tubules. You will find simple squamous lining epithelium (at the glomerular capsule end) to simple cuboidal with brush border.
Distal convoluted tubule
The distal convoluted tubule is shorter than the proximal convoluted tubule and lined by simple cuboidal lining epithelium (without any brush border on the cell surface).
In medical, you will also find distal convoluted tubule, thin tubule (lined by simple squamous epithelium), distal convoluted tubule, and collecting duct (lined by simple cuboidal epithelium).
Histological structure of ureter of animal or histology of ureter diagram
Here, it would be best if you had a basic idea of the general structural pattern of a tubular organ. Okay, we will identify the following structures or parts from ureter of animal –
Mucosal characteristic with lining epithelium
Characteristics of tunica muscularis layers
Characteristics of tunica adventitia
Okay, let’s identify those structures under a microscope –
The presence of longitudinal folds of the mucosa provided a stellate-shaped lumen (narrow also). It is lined by transitional epithelium.
Presence of more elastic fibers in lamina propria of the ureter
You will find two or three layers of smooth muscles layers in the tunica muscularis layer – inner longitudinal and outer circular (mainly); inner longitudinal, middle circular, and outer longitudinal layers (when three layers of smooth muscles)
Presence of loose connective tissue rich in blood vessels, lymphatic’s
Histological structure of urinary bladder or histology slide of the urinary bladder
We will cover the following structure of the urinary bladder under the microscope –
Characteristics of mucosa with lining epithelium
Characteristics of tunica muscularis layers
Characteristics of tunica adventitia
Okay, let’s start to identify –
Presence of thick mucosa layer (when the bladder is empty) which is lined by transitional epithelium (but if the bladder is distended condition; the mucosa fold disappears and then the epithelium becomes increasingly flattened)
Presence of distinct lamina muscular, lamina propria, and submucosa layers
Presence of well-layered (irregular shaped inter-weaving pattern) of smooth layers muscle
Presence of fibroelastic connective tissue with blood vessels, lymphatic’s in the tunica adventitia
Histological structure of male urethra or histology slide of the male urethra
I have already discussed the histology of male urethra in the histology of male genital organs. You may go through this link.
Okay, here we will identify the following structures of the male urethra under the microscope –
Characteristics of mucosa with lining epithelium
Characteristics of tunica muscularis
Characteristics of tunica adventitia
Okay, let’s start to identify –
The presence of a longitudinal mucosal fold gives the stellate-shaped appearance of the lumen. It is lined by transitional epithelium.
Presence of thick propria submucosa
Presence of three layers of the smooth muscle layer. You may also find skeletal muscle (longitudinal and circular orientation) mixed with smooth muscle layers.
Presence of loose connective tissue adventitia
Conclusion
I hope you have got an idea of the histology of the urinary system of animals (identification of urinary system organs under the microscope). You may also learn the basic histology of the organs from DIGESTIVE SYSTEM, RESPIRATORY SYSTEM, URINARY SYSTEM, MALE GENITAL SYSTEM, and FEMALE GENITAL SYSTEM. If you want to get more information on those topics, you should follow class lectures or go through the BOOK for more. Get the histology learning books list here.
If possible, I will update or enrich the information on this topic in the future.
If there is any mistake in the above information or if you have any suggestions for me, please, let me know in the comment box. Thank you so much.