Access over 20 million homework & study documents

ZOO 220 Biology & Physiology in Animals Reproductive System Notes

Content type
User Generated
Subject
Zoology
Type
Other
Rating
Showing Page:
1/42
1
ZOO 220 : DEVELOPMENTAL BIOLOGY AND PHYSIOLOGY IN ANIMALS
REPRODUCTIVE SYSTEM
The reproductive system or genital system is a system of sex organs within an organism which
work together for the purpose of sexual reproduction.
Male reproductive system
The male reproductive system has one function, and it is to produce and deposit sperm.
Humans have a high level of sexual differentiation. In addition to differences in nearly every
reproductive organ, numerous differences typically occur in secondary sexual characteristics.
The male reproductive system is a series of organs located outside of the body and around the
pelvis region of a male that contribute towards the reproduction process. The primary direct
function of the male reproductive system is to provide the male sperm for fertilization of the
ovum.
The major reproductive organs of the male can be grouped into three categories. The first
category is sperm production and storage. Production takes place in the testes which are housed
in the temperature regulating scrotum, immature sperm then travel to the epididymis for
development and storage. The second category is the ejaculatory fluid producing glands which
include the seminal vesicles, prostate, and the vas deferens. The final category are those used for
copulation, and deposition of the spermatozoa (sperm) within the male, these include the penis,
urethra, vas deferens, and Cowper's gland.
Major secondary sexual characteristics includes: larger, more muscular stature, deepened voice,
facial and body hair, broad shoulders, and development of an adam's apple. An important sexual
hormone of males is androgen, and particularly testosterone.
The testes release a hormone that controls the development of sperm. This hormone is also
responsible for the development of physical characteristics in men such as facial hair and a deep
voice
Anatomy of the Male Reproductive System
Scrotum
The scrotum is a sac-like organ made of skin and muscles that houses the testes. It is located
inferior to the penis in the pubic region. The scrotum is made up of 2 side-by-side pouches with a
testis located in each pouch. The smooth muscles that make up the scrotum allow it to regulate
the distance between the testes and the rest of the body. When the testes become too warm to
support spermatogenesis, the scrotum relaxes to move the testes away from the body’s heat.
Conversely, the scrotum contracts to move the testes closer to the body’s core heat when
temperatures drop below the ideal range for spermatogenesis.
Testes
The 2 testes, also known as testicles, are the male gonads responsible for the production of sperm
and testosterone. The testes are ellipsoid glandular organs around 1.5 to 2 inches long and an
inch in diameter. Each testis is found inside its own pouch on one side of the scrotum and is

Sign up to view the full document!

lock_open Sign Up
Showing Page:
2/42
2
connected to the abdomen by a spermatic cord and cremaster muscle. The cremaster muscles
contract and relax along with the scrotum to regulate the temperature of the testes. The inside of
the testes is divided into small compartments known as lobules. Each lobule contains a section of
seminiferous tubule lined with epithelial cells. These epithelial cells contain many stem cells that
divide and form sperm cells through the process of spermatogenesis.
Epididymis
The epididymis is a sperm storage area that wraps around the superior and posterior edge of the
testes. The epididymis is made up of several feet of long, thin tubules that are tightly coiled into
a small mass. Sperm produced in the testes moves into the epididymis to mature before being
passed on through the male reproductive organs. The length of the epididymis delays the release
of the sperm and allows them time to mature.
Spermatic Cords and Ductus Deferens
Within the scrotum, a pair of spermatic cords connects the testes to the abdominal cavity. The
spermatic cords contain the ductus deferens along with nerves, veins, arteries, and lymphatic
vessels that support the function of the testes.
The ductus deferens, also known as the vas deferens, is a muscular tube that carries sperm
superiorly from the epididymis into the abdominal cavity to the ejaculatory duct. The ductus
deferens is wider in diameter than the epididymis and uses its internal space to store mature
sperm. The smooth muscles of the walls of the ductus deferens are used to move sperm towards
the ejaculatory duct through peristalsis.
Seminal Vesicles
The seminal vesicles are a pair of lumpy exocrine glands that store and produce some of the
liquid portion of semen. The seminal vesicles are about 2 inches in length and located posterior
to the urinary bladder and anterior to the rectum. The liquid produced by the seminal vesicles
contains proteins and mucus and has an alkaline pH to help sperm survive in the acidic
environment of the vagina. The liquid also contains fructose to feed sperm cells so that they
survive long enough to fertilize the oocyte.
Ejaculatory Duct
The ductus deferens passes through the prostate and joins with the urethra at a structure known
as the ejaculatory duct. The ejaculatory duct contains the ducts from the seminal vesicles as
well. During ejaculation, the ejaculatory duct opens and expels sperm and the secretions from the
seminal vesicles into the urethra.
Urethra
Semen passes from the ejaculatory duct to the exterior of the body via the urethra, an 8 to 10 inch
long muscular tube. The urethra passes through the prostate and ends at the external urethral
orifice located at the tip of the penis. Urine exiting the body from the urinary bladder also passes
through the urethra.
Prostate
The prostate is a walnut-sized exocrine gland that borders the inferior end of the urinary bladder
and surrounds the urethra. The prostate produces a large portion of the fluid that makes up
semen. This fluid is milky white in color and contains enzymes, proteins, and other chemicals to
support and protect sperm during ejaculation. The prostate also contains smooth muscle tissue
that can constrict to prevent the flow of urine or semen.

Sign up to view the full document!

lock_open Sign Up
Showing Page:
3/42

Sign up to view the full document!

lock_open Sign Up
End of Preview - Want to read all 42 pages?
Access Now
Unformatted Attachment Preview
ZOO 220 : DEVELOPMENTAL BIOLOGY AND PHYSIOLOGY IN ANIMALS REPRODUCTIVE SYSTEM The reproductive system or genital system is a system of sex organs within an organism which work together for the purpose of sexual reproduction. Male reproductive system The male reproductive system has one function, and it is to produce and deposit sperm. Humans have a high level of sexual differentiation. In addition to differences in nearly every reproductive organ, numerous differences typically occur in secondary sexual characteristics. The male reproductive system is a series of organs located outside of the body and around the pelvis region of a male that contribute towards the reproduction process. The primary direct function of the male reproductive system is to provide the male sperm for fertilization of the ovum. The major reproductive organs of the male can be grouped into three categories. The first category is sperm production and storage. Production takes place in the testes which are housed in the temperature regulating scrotum, immature sperm then travel to the epididymis for development and storage. The second category is the ejaculatory fluid producing glands which include the seminal vesicles, prostate, and the vas deferens. The final category are those used for copulation, and deposition of the spermatozoa (sperm) within the male, these include the penis, urethra, vas deferens, and Cowper's gland. Major secondary sexual characteristics includes: larger, more muscular stature, ...
Purchase document to see full attachment
User generated content is uploaded by users for the purposes of learning and should be used following Studypool's honor code & terms of service.

Anonymous
Very useful material for studying!

Studypool
4.7
Trustpilot
4.5
Sitejabber
4.4

Similar Documents