200 THE ESSENTIALS OF HISTOLOGY. 



LESSON XXXVI. 



STRUCTURE OF THE URETER, BLADDER, AND MALE 

 GENERATIVE ORGANS. 



1. SECTION across the ureter. 



2. Section of the urinary bladder vertical to the surface. 



In the sections of the ureter and of the urinary bladder, notice the tran- 

 sitional epithelium resting on a mucous membrane, which is composed chiefly 

 of areolar tissue without glands, and the muscular coat outside this. In the 

 ureter there is some fibrous tissue outside the muscular coat, and at the upper 

 part of the bladder there is a layer of serous membrane covering the muscular 

 tissue. Sketch a section of the ureter under a low power, and the epithelium 

 of the bladder under the high power. 



3. Section across the penis. The blood-vessels of the organ should have 

 been injected with the hardening fluid so as the better to exhibit the arrange- 

 ment of the venous spaces which constitute the erectile tissue. Notice the 

 large venous sinuses of the corpora cavernosa and the smaller spaces of the 

 corpus spongiosum, in the middle of which is seen the tube of the urethra. 



4. Section across the testis and epididymis. The sections are best made 

 from a rat's testis which has been hardened in alcohol, and thin pieces of 

 which have been stained in bulk in hsematoxylin. In these sections notice 

 the strong capsule surrounding the gland, the substance of which consists of 

 tubules which are variously cut, and the epithelium in which is in different 

 conditions of development in the different tubules. Observe the strands of 

 polyhedral interstitial cells lying in the loose tissue between the tubules and 

 the lymphatic clefts in that tissue. Notice also in sections through the 

 epididymis the ciliated epithelium of that tube. 



Sketch carefully under a high power the contents of some of the semini- 

 ferous tubules so as to illustrate the mode of formation of the spermatozoa. 



5. Examination of spermatozoa. The spermatozoa may be obtained fresh 

 from the testis or seminal vesicles of a recently killed animal and examined 

 in saline solution. Their movements may be studied on the warm stage ; to 

 display their structure a very high power of the microscope is necessary. 

 Measure and sketch three or four spermatozoa. 



The ureter is a muscular tube lined by mucous membrane. The 

 muscular coat consists of two layers of plain muscular tissue, an outer 

 circular, and an inner longitudinal. In the lower part there are some 

 longitudinal bundles external to the circular. Outside the muscular 

 coat is a layer of fibrous tissue in which the blood-vessels and nerves 

 ramify before entering the muscular layer. 



