Chapter 28 - The Reproductive System Flashcards
The male gamete is this cell?
Sperm
THe female gamete is this type of cell? aka?
egg cell / ovum
During fertilization a male and female gamete unite to form?
a zygote
Normally human gamete each have 23 chromosomes and are considered?
haploid
Each zygote normally has 46 chromosomes and is considered?
diploid
Most cells of the human body are haploid or diploid?
diploid
Most cells of the human body are what kind of cells?
somatic (Any cell of a living organism other than the reproductive cells)
These cells reproduce by dividing into two after doubling (replicating) their genetic material
somatic cells
This is the orderly division of the nucleus of a cell that ensures each new nucleus has the same number and kind of chromosomes as the original nucleus.
Mitosis
This is the division of the remainder of the cell after mitosis (division of the cytoplasm, organelles, etc)
Cytokinesis
If mitosis and cytokinesis occur together, these result from the division of one parent cell
two daughter cells
The daughter cells resulting from mitosis and cytokinesis normally contain the same chromosome number as what? Because?
Each parent / because of DNA replication
Mitosis + Cytokinesis = ???? (resulting in?)
cell division (resulting in 2 somatic cells with the diploid chromosome number of 46)
During sex cell formation, the number of chromosomes in the nucleus of a cell must be?
halved
This is the division of the nucleus of a cell during the formation of sex cells.
Meiosis
If a parent cell divides two times successfully (without DNA replication in between the divisions) what results? These cells are what kind?
four daughter cells / haploid
Meiosis + Cytokinesis = ?
gametogenesis
Gametogensis in males is called? In females?
spermatogensis / oogensis
These are the male gonads? The female gonads?
testis / ovaries
What are the two main functions of the reproductive organs: the testis and ovaries?
to produce sex cells and to secrete sex hormones
Within the seminiferoud tubules are several types of these cells which are involved in the formation of sperm.
spermatogenic cells
Spermatogenic cells develop progressively from the outer wall of a tubule inward toward the?
lumen
This is the hollow passageway part of the tubule?
lumen
In order of advancing maturity (and from the tubule wall inwards towards the lumen), what are the various spermatogenic cell types?
spermatogonia, primary spermatocytes, secondary spermatocytes, spermatids, sperm cells (spermatozons)
Embedded among the spermatogenic cells in the seminiferous tubules are large _____ cells which are the “nurse cells”
Sertoli
These cells produce inhibin
Sertoli cells
Sertoli cells protect the develop spermatogenic cells in what ways? (6)
How long does spermatogensis take in humans?
65-75 days
Spermatogensis begins with these cells which contain the diploid (2n) chromosome number
spermatogonia
Spermatogonia are what types of cells? When they divide by mitosis, what remains as a source of future spermatogonia?
stem cells / some of the daughter cells remain
During spermatogenesis, a spermatogonium (2n) matures and develops into a?
primary spermatocyte (2n)
The primary spermatocyte replicates its DNA and begins the first division of meiosis which is?
Meiosis 1
In meiosis 1, these line up at the equator or metaphase plate of the cell
homologous chromosomes
After homologous chromosomes line up at the equator, what occurs?
crossing over
After crossing-over occurs, what is formed? They enter this without replicating their DNA
secondary spermatocytes (n) / meiosis II
Each secondary spermatocyte divides in meiosis II resulting in 4 cells called?
spermatids (n)
The spermatids undergo the final stage of spermatogensis, called?
spermiogensis
During spermiogensis, the spermatids change form and become? They then enter?
sperm cells (n) / the lumens of the seminiferous tubules
This is the process by which the sperm become totally independent of the Sertoli cells, which have helped them up until the point in time.
spermiation
Each day, how many million sperm complete the process of spermatogenesis?
300 million
This part of the sperm cell is flattened, pointed, and contains a nucleus with 23 chromosomes
head
This part of the sperm cell is a structure that covers the anterior portion of the sperm head. It contains enzymes that help a sperm cell in fertilization (penetration)
acrosome
The tail of a sperm has this which enables the cell to move through the reproductive tract.
flagellum
This part of a sperm cell contains numerous cellular organelles called mitochondria which carry out? This produces ATP energy to power?
tail / cellular respiration / the sperm cells activities
Once ejaculated, most sperm do not survive more than how many hours in the female reproductive tract
48
This is the bag-like supporting structure for the testes
scrotum
The location of the scrotum helps to regulate?
the temperature of the testes
normal sperm production requires a temperature about how much below core body temperature?
2-3 degree celcius
Since the testes are suspended outside the pelvic cavity within the scrotum, they have what kind of temperature compared to the body?
lower
What two muscles within the scrotum contract and relax to help in the regulation of the temperature of the testes?
dartos and cremaster muscle
The dartos muscle is what kind of muscle?
smooth
The cremaster is what kind of muscle?
skeletal
The scrotum is separated internally by ____ which divides the scrotum into two sacs each containing one testis.
scrotal septum
These are oval glands each measuring about 2 inches long and 1 inch in diameter
testes
During embryological development, the testes develop?
within the pelvic cavity near the kidneys
Towards the end of the 7th month of dvelopment, the testis normally begin to descend into the scrotum through?
inguinal canals
passageways in the anterior abdominal wall
inguinal canals
This is a medical condition in which the testes do not descend into the scrotum
cryptorchidism
Cryptorchidism occurs in what percentage of full-term infants and this percentage in premature infants
3% / 30%
The tests of about what percentage of boys with cryptorchidism will descend during the first year of life.
18 months of age
If untreated, cryptorchidism can cause this in males; the cells involved in sperm production may be destroyed by the higher temperature of the pelvic cavity
sterility
In adition, the chance of testicular cancer is how many times greater in cryptorchid testes
30 - 50 times
The testes are divided into small internal compartments called?
lobules
Within each lobule are tightly coiled?
seminiferous tubules
Sperm are produced within these tubules by a process called?
spermatogenesis
Between the seminiferous tubules are clusters of?
interstitial cells (Leydig)
Interstitial (Leydig) cells produce?
testosterone
This is the main male sex hormone, or androgen?
Testosterone
Testosteron promotes the development of masculine characteristics and this?
libido
Pressure generated by the fluid secreted by Sertoli cells pushes sperm and fluid along the lumen of the seminiferous tubles and into?
straight tubules
The straight tubules lead into a network of ducts in the testis called?
the rete testis
From the rete testis, sperm move into a series of coiled? These are located?
efferent ducts / epididymis
After traveling into the efferent ducts in the epididymis, sperm is emptied into a single tube called?
ductus epididymis
This is a comma-shaped organ that lies along the posterior border of each testis
epididymis
The epididymis consists of tightly coiled?
ductus epididymis
The epididymis is the site of?
sperm maturation
This is the process by which sperm acquired motility and the ability to fertilize
sperm maturation
Sperm maturation occurs over a period of how many days?
14 days
At its distal end, the epididymis continues as the?
vas deferens or ductus deferens
Contractions of smooth muscle in the walls of the ductus epididymis during sexual arousal helps the epididymis to propel sperm into?
the vas deferens
This is a site for sperm storage
epididymis
Sperm may remain viable in the epdidymis for up to? What happens to any stored sperm that are not expelled by that time?
up to several months / reabsorbed
This is the main sperm duct
vas deferens
The vas deferens passes into the pelvic cavity from the testis through?
the inguinal canal
The vas deferens is about how long? It has an enlarged portion at the end called?
18 inches / ampulla
Like the epididymis, the vas deferens conveys sperm during sexual arousal by?
Contractions of smooth muscles in its walls
Like the epididymis, the vas deferens can also store sperm for how long?
up to several months
The main method of male sterilization is?
a vasectomy
During a vasectomy, an incision is made on either side of the? These are cuts and tied.
scrotum / vas deferens
After a vasectomy, sperm production and testosterone production continue, but the sperm cannot reach?
the exterior of the male reproductive tract
After a vasectomy, what happens to the sperm?
they degenerate and are destroyed by phagocytosis
consists of the vas deferens, the testicular artery, testicular veins, nerves, lymphatic vessels, and the cremaster muscle
spermatic cord
The spermatic cord passes through?
the inguinal canal from the testis into the pelvic cavity
Each ejaculatory duct is about how long?
1 inch
This is formed by the union of the duct from the seminal vesicle and the ampulla of the vas deferens.
ejaculatory ducts
The ejaculatory ducts pass through the prostate gland where they join?
the urethra
AFter the ejaculatory ducts join the urethra, what do they eject into the urethra?
sperm and secretions
In males, the urethra is the shared duct for what two system?
reproductive and urinary
This serves as a passage way for both semen and urine
urethra
The urethra ends at an opening to the outside of the body called?
External urethral orifice
The urethra is subdivided into what 3 parts?
prostatic, membranous, spongy (penile) urethras
The ducts of the male reproductive system store and transport sperm cells, but most of the liquid portion of semen is secreted by?
accessory sex glands
What are the accessory sex glands of the male reproductive system
seminal vesicles (2), prostate gland, bulbourethral (Cowper’s) glands (2)
The seminal vesicles are paired glands which are about how long?
2 inches
The seminal vesicles lie where?
At the posterior base of the urinary bladder
These secrete a thick alkaline fluid that contain fructose (a simple surgar), prostaglandins, and clotting proteins
seminal vesicles
What is the purpose of the alkaline fluid secreted by the seminal vesicles?
The pH of this fluid helped to neutralize the acidic environment of the male urethra and the female reproductive tract that would normally inactivate and kill sperm.
The fructose in the alkaline fluid secreted by the seminal vesicles is used for?
ATP production by sperm
This part of the alkaline fluid contributes to sperm motility and viability and may stimulate smooth muscle contractions within the female reproductive tract.
prostaglandins
What is the purpose of the clotting proteins found in the alkaline fluid secreted by the seminal vesicles?
help semen coagulate after ejaculation
Fluid secreted by the seminal vesicles normally contributes to about what percentage of the volume of semen?
60%
