(3.05)

Now we'll take a further look at the bladder, first in the male, then in the female. Here's the bladder, here below it is the prostate. In this dissection the bladder has been filled slightly, which brings it just above the level of the pubic symphysis

When the bladder is full it rises up into the lower abdomen. When it's empty it flattens out. The bladder has a covering of peritoneum only on its upper surface.

Down here the bladder tapers towards its outlet, or neck. Here behind the bladder is the rectum. In this dissection the fatty connective tissue that lies between the bladder and the rectum has been removed.

To see the structures that are just behind the bladder we'll take the rectum out of the picture. We've also cut the ureter short. The ureter (here's its cut end) enters the bladder out to the side, passing through the bladder wall obliquely.

The ductus deferens comes around almost to the midline, widening to form the ampulla. Here lateral to the ampulla is the seminal vesicle. Here's the right ampulla and the right seminal vesicle.

On each side the ductus and the seminal vesicle join down here to form the ejaculatory duct, which passes through the prostate to enter the urethra, as we'll see when we look at the reproductive system.

To see the inside of the bladder we'll look at an isolated specimen that's been divided along this line.

The wall of the bladder consists of smooth muscle, lined with mucosa. On each side the ureter opens into the bladder obliquely at the ureteric ostium. Urine leaves the bladder through this opening, the internal urethal meatus, to enter the urethra.

This projection just above the urethral meatus is called the uvula. The mucosal lining of the bladder is thrown into irregular folds which flatten out as the bladder fills. The mucosal layer is relatively flat in this triangular area between the ureteric and urethral openings, which is called the trigone.

In the male the first part of the urethra passes downwards through the prostate. The prostate, or prostate gland, consists of smooth muscle, interlaced with glandular tissue which secretes a portion of the seminal fluid.

Down here at the apex of the prostate the urethra emerges. The proximal part of the urethra, the membranous urethra, passes downward through the sling of muscle that forms the pelvic diaphragm.

This part of the muscle sling is the levator prostatae: it's the most anterior and medial part of the pubococcygeus, which in turn is part of the levator ani muscle complex.