1. Observe the location, morphology and peritoneum of the kidney.
2. Observe the gross anatomy of the kidney in frontal section, ureter and bladder.
3. Observe the microscopic structure of the kidney.
Operation method
Observational experiment on the urinary system
Materials and Instruments
Abdominal anatomy specimen and model Frontal section specimen of kidney Renal artery cast specimen Pelvic anatomy specimen Bladder anatomy specimen and model. Renal section Electroscopic picture of glomerular vascular cast Electroscopic picture of glomerulus Electroscopic picture of glomerular capillaries Electroscopic picture of filtration barrier Electroscopic picture of proximal tubular curvature Move I. Location, morphology and peritoneum of the kidney For more product details, please visit Aladdin Scientific website.
Dissecting Tray Dissecting Forceps Microscope
Observations were made with anatomical specimens and models of the abdominal cavity in which abdominal organs such as the stomach and intestines had been removed.
1. The location of the kidneys The kidneys are located on both sides of the spine, in the retroperitoneal space, close to the upper part of the posterior abdominal wall. The two kidneys are close to each other at the upper end and slightly away from each other at the lower end, which are slightly arranged in a figure of eight shape. The upper end of the left kidney is flat against the upper edge of the 12th thoracic vertebra and the lower end is flat against the upper edge of the 3rd lumbar vertebra; the upper end of the right kidney is flat against the lower edge of the 12th thoracic vertebra and the lower end is flat against the lower edge of the 3rd lumbar vertebra. Why is the left kidney higher than the right?
The shape of the kidney The kidney can be divided into the upper and lower ends, the medial and lateral margins, and the anterior and posterior parts. The middle part of the medial rim is more concave, which is the entry and exit point of blood vessels, nerves, lymphatic vessels and nephrons of the kidneys, and is called the renal hilum. The renal hilum depresses into the kidney to form a large cavity called the renal sinus.
The surface of the kidney is surrounded by three layers of membranes from the inside out, namely, the fibrous capsule, the fatty capsule and the renal fascia. What is the role of the peritoneum of the kidney?
The general anatomy of the kidney
A frontal cut specimen and model of the kidney were taken for observation. It can be seen that the renal parenchyma is divided into two parts: cortex and medulla. The renal cortex is mainly located in the superficial layer, rich in blood vessels, and the fresh specimen is reddish brown. The renal medulla was located in the deeper part of the renal parenchyma, which was lighter in color, dense and striated, forming 15-20 renal cones. The cortex extends into the part between the renal cones called the renal column. The white medulla extends radially into the cortex in stripes called medullary discharge lines. The tips of the cones extend into the renal sinuses and are called renal papillae. The short membranous tubes surrounding the papillae are called calyces, each of which may encircle 1 to 3 papillae. 2 to 3 calyces form a calyx. 2 to 3 calyces form a flattened funnel-shaped renal pelvis. The renal pelvis exits the renal hilum and continues into the ureter. Inside the renal sinus, there are renal monomer, renal calyces, renal calyces, renal arteries, renal veins and their main branches, lymphatics and nerves, etc., which are filled with adipose tissue.
Ureter
With abdominal and pelvic anatomical specimens and model observation, the ureter is a pair of long and thin muscular ducts, the upper continuation of the renal孟, along the anterior descent of the psoas major muscle, up to the entrance to the small pelvis, the left and right ureter respectively, over the left common iliac artery end and right external iliac artery in front of the beginning of the pelvic side wall, and then curved along the lateral wall of the pelvis, the bladder from the bladder floor of the outer upper corner of the bladder wall openings diagonally across the bladder in the bladder. There are three strictures in the full length of the ureter, where are they located?
IV. Bladder
Observe with pelvic dissection specimens and bladder dissection specimens. The bladder is triangular when empty and ovoid when full. The tip of the bladder is small and faces forward and upward, called the tip of the bladder. The base faces backward and downward in a triangular shape and is called the base of the bladder. The bulk of the bladder between the tip and the base is the body of the bladder. There is no clear demarcation between the various parts of the bladder. When empty, all of the bladder is located in the pelvis, and the bladder may be elevated above the pubic symphysis in full bladders and in children posterior to the pubic symphysis.
The inner wall of the bladder in emptiness, its mucosa forms many folds, but the bottom of the triangular cell that is the bladder bicorneal except the bladder within the three openings, the bottom of the bladder triangle on each side of the opening of the ureter, the tip of the bladder triangle has a urethral inlet.
Five, the microstructure of the kidney
Take a section of rabbit kidney (H-E staining) for observation. Focus on the structure of the renal microsomes, and identify the structural characteristics of the segments of the renal tubules and the structure of the dense spots.
(I) Visual observation
The dark red part of the surface is the cortex, and the light red part of the inner layer is the medulla.
(II) Low magnification observation
Identify the cortex and medulla, and within the cortex, identify the cortical labyrinth and medullary discharge line.
1. Cortical labyrinth This is a place where many spherical renal bodies are seen and many proximal tubular curvatures and distal tubular curvatures are seen in a variety of views.
2. Medullary radiolucent lines are located between the labyrinths and are many straight tubules. However, due to the different angles of cut, some tubules are cut into longitudinal, oblique and transverse sections. These tubules include the straight proximal tubule, the fine segment, the straight distal tubule, and the collecting duct.
3. The medulla can also be seen in various sections of the tubules, mainly the collecting tubules and fine segments. The straight parts of the proximal and distal tubules can also be seen in the subcortical portion.
(iii) High magnification observation
1. Cortex Identify the renal corpuscles, proximal tubule convolutions, distal tubule convolutions and dense spots.
(I) Renal corpuscle is a spherical structure composed of glomeruli and renal capsule. The glomerulus is a network of coiled capillaries. The glomerular epithelium was tightly adherent to the glomerulus, and the glomerular epithelium and capillary endothelial cells were tightly adherent to the glomerulus, so that the two were not easily distinguishable, and only a large number of nuclei were seen on the section, with unclear cellular boundaries. The glomerular epithelium was a single layer of flat epithelium. The narrow lumen seen between the glomerular epithelium and the renal capsule epithelium was the renal capsule lumen.
(2) Proximal tubular curvature Around the renal corpuscle, the tubular lumen is small and irregular. The tubular wall is composed of cone-shaped epithelial cells, with large, poorly demarcated cytosol; the nucleus is large and located at the base of the cell; the cytoplasm is stained crimson, and a reddish-stained brush border is visible on the free surface of the cell.
The straight and curved parts of the proximal tubule are similar in structure.
(3) Distal tubule curvilinear part The lumen was larger, the cells were smaller, tightly arranged and cubic. The cytoplasm was lighter in color. Distal tubule straight part I was similar to the curved part.
(4) Dense spots Looking for the distal tubular curvature at the vascular pole of the renal corpuscle, if you see that the epithelial cells on the side of the tube near the renal corpuscle become narrow and high, the cell boundaries are not clear, and the cells are obviously more and densely packed in the portion of the tubule, that is, the dense spots. The three-dimensional image of the dense spot should be understood in plan view as a disk.
2. medulla Identify collecting tubules and fine segments.
(1) Collecting tubules The epithelial cells of the tubular wall are unilayered and cuboidal or columnar, with clear cell demarcation, clear cytoplasm and light staining. The collecting tubules converge into larger papillary tubules near the renal papillae, which gradually change into migratory epithelium near the opening.
(2) Fine section The diameter of the tube is thin, and it is a single layer of flat epithelium, with rounded nuclei, deep staining, and protruding into the lumen of the tube. Must be careful not to be confused with capillaries, capillary diameter is also smaller, but the lumen is often blood cells, and the endothelial cells are more flat.
VI. Demonstrate the following ultrastructure
1. Scanning electron microscopy of glomerular vascular casts reveals thicker inlet microarterioles and thinner outlet microarterioles at the vascular pole, as well as a mass of capillaries between the two.
2. Glomerular surface view of the scanning electron microscope structure of the glomerulus is composed of coiled capillaries, foot cells and their protrusions covering the surface of the capillaries, forming the glomerular epithelium, glomerular epithelium and renal capsule epithelium of the interstices between the small capsular lumen called the small capsule.
3. The scanning electron microscopic structure of glomerular capillaries was cut along the long axis of the capillaries, showing the cross-sectional view of the filtration barrier and the luminal view of the endothelial cells, which could be seen as areas with pores and cytoplasmic and elevated cristae, and the junctions of the neighboring endothelial cells also appeared to be cristae-like elevations. There are also some irregular microprojections on the surface of endothelial cells.
4. Transmission electron microscopic structure of the filtration barrier In the filtration barrier section, the glomerular capillary lumen, endothelium, endothelial cell pores, basement membrane, peduncle cells, peduncle cell secondary protrusions, and lacunar septum were recognized.
5. Transverse section of the proximal tubule curvature structure can be seen in the middle of the tubular lumen, epithelial cells luminal surface with long and dense microvilli, epithelial cell nucleus is located in the near-basal part of the epithelial cell, the nucleus above the parietal plasma vesicles, the cytoplasm of the well-developed mitochondria and dense granules (secondary lysosomes), epithelial cells at the base of the plasmalemma internal folds.