Stereocilia,
Epididymis,
Sperm
Observe a slide of the cross section of the epididymis
(Figure 10.7 and 10.8). Notice the abundant tubule cross-sections resulting
from the fact that the coiling epididymis tubule has been cut
through many times in the specimen. Look for sperm in the lumen
of the tubule. Identify the stereocilia of the
pseudostratified columnar epithelial lining. These non-motile
microvilli absorb excess fluid and pass nutrients to the sperm
in the lumen.
Spermatozoa (or sperm cells) from each testis
travel from tubules in the testis to the rete testis and into
the epididymis, where they are stored and mature. Each
epididymis has a blunt rounded head, an elongated body, and a
tapering tail that leads to the ductus deferens. Sperm
maturation, or capacitation, occurs in the epididymis. If
spermatozoa are removed from the testis proper, they are not
capable of fertilizing the female oocyte (egg). Spermatozoa move
slowly through coiled tubules of the epididymis.
D) Sperm
Sketch a sperm cell, label and identify the
following:
Head,
Acrosome,
Midpiece,
Flagellum
Examine an image of sperm (Figure 10.9). The structure
of an individual sperm cell consists of a head, midpiece and
tail. The head contains the genetic information (DNA) as well as
a cap known as the acrosome. The acrosome contains digestive
enzymes that digest the exterior covering of the female gamete.
The midpiece of the sperm contains mitochondria that provide ATP
to the sperm cell tail. The tail of the sperm is a flagellum
that propels the sperm forward
.
Figure 10.9
E) Male Contraception
Make a list of the different methods of male
contraception:
Use the link here to print a table for your list
TABLE
FOR MALE CONTRACEPTIVE LIST
The main goal in male contraception is the
prevention of spermatozoa from reaching the female gametes.
Abstention or refraining from sexual intercourse is the most
effective method. The next most effective method is male
sterilization, which is most commonly performed by a procedure
called a vasectomy. In a vasectomy an incision is made in the
side of the scrotal sac and both ductus deferens are cut. The
free ends of the cut ductus deferens are tied, preventing sperm
from traveling from the testes to the spermatic cords. Use of a
barrier, such as a condom, is relatively effective if used
properly, since it prevents ejaculated sperm from entering the
female reproductive tract. Coitus interrupts, or pre-ejaculatory
withdrawal is not a very effective method since sperm may be
present in seminal fluid prior or ejaculation and pregnancy can
result.
Figure 10.10
F) Questions (Male)
-
The testes are considered mixed glands
because they have both an endocrine and exocrine function.
Describe the endocrine and exocrine products that come from
the testes.
-
Male sterility can result from excessively
high temperatures around the testes. What mechanism occurs
in the scrotum to counteract the effects of high
temperature?
-
List all the structures involved in
producing semen.
-
How does spermatozoa differ from seminal
fluid?
-
A vasectomy is the cutting and tying of the
two ductus deferens at the level of the spermatic cords.
Review the percent of spermatozoa that composes semen and
determine what effect a vasectomy has on semen volume.
-
What is the organ in the male reproductive
system that functions as the gonad?
-
Where does sperm move after being in the
epididymis?
-
Name the three organs that produce seminal
fluid.
-
Name of the section of urethra that passes
through the prostate gland.
-
Where is spermatozoa produced in the testis?
-
What cells initiate spermatozoa production?
