male reproductive Flashcards
Somatic (body) cells have _________ chromosomes. This is referred to as being _________ (diploid or haploid).
46 chromosomes , diploid
Gametes (sex cells) have __________ chromosomes. This is referred to as being _________ (diploid or haploid).
23 chromosomes, haploid
have 23 chromosomes also called sex cells, haploid
gametes cells
have 46 chromosomes , diploid
somatic
Cell division that occurs in almost all cells in the body, 46 chromosomes in the body
mitosis
Cell division that occurs in sex cells
Involves 2 stages (meiosis I and meiosis II)
Produces 4 gametes with half the chromosomes
Only 23 chromosomes (haploid)
meiosis
sperm cells are also called
spermatozoa
egg cells also called
ovum, ova
-spermatozoa or sperm cells production
-Begins at puberty and does not stop with age
spermatogenesis
ovum creation
oogenesis
The Testes
Hang from body in the scrotum… why?
temperature
Allowing the testes to sit just outside the body cavity allows to remain slightly cooler and allows for sperm production to occur optimally. For example, when it is cold, the muscle contracts to bring the testes closer to the warm body. When it is hot, it relaxes to lower the testes and allow them to cool.
Site of sperm production “spermatogenesis”
outermost layer of seminiferous tubules , wall
cells that Produces androgens, dominant male sex hormones
Testosterone is the most important androgen
Large interstitial cells (Leydig cells)
the most important androgen
testosterone
also called the stem cells for spermatogenesis
spermatogonia
progression of spermatogenesis
- spermatogonia (mitosis)
- primary spermatocyte (meiosis 1)
- secondary spermatocyte (meiosis 2)
- spermatids ( 4 gametes) or 23 chromosomes
- spermatozoa
- spermiogenesis (fused)
- spermiation (unfused)
The last step of spermatogenesis
Spermiogenesis
Spermatogonia (stem cells) divide by mitosis to produce two daughter cells (_46___ Chromosomes)…what happens with the 2 daughter cells
1 remains as a spermatogonium
other 1 differentiates into a primary spermatocyte
Spermatozoa lose contact with wall of seminiferous tubule and enter fluid in lumen
spermiation
Functions of Nurse Cells
blood–testis barrier
mitosis and meiosis
spermiogenesis
inhibin
Secrete androgen-binding protein (ABP)
Secrete Müllerian-inhibiting factor (MIF)
Nurse cells are stimulated by:
Follicle-stimulating hormone, FSH (from Anterior Pituitary Gland)
Testosterone (from leydig cells)
Stimulated nurse cells promote:
Division of spermatogonia
Division of spermatocytes
Is a peptide hormone secreted by nurse cells in response to factors released by sperm
Depresses:
Pituitary production of FSH
Spermatogenesis
Inhibin
Regulation of FSH and GnRH by inhibin:
Gives nurse cells ______ control of spermatogenesis which will create an effect of
negative feedback
Sperm production, increased inhibin production, decreased FSH, GnRH, decreased sperm
decreases the production of FSH in the pituitary gland.
inhibin
FSH stimulates spermatogenesis so by decreasing FSH, inhibin decreases____
spermatogenesis
The release of inhibin gives nurse cells control of spermatogenesis. Cell division occurs, then the new sperm release factors that bind to nurse cells. Nurse cells increase inhibin. Inhibin decreases sperm production.
negative feedback
Its important to note that testosterone only stimulates sperm production when there is
FSH secretion
testosterone (androgen) is produced from
leydig cells
The _____ produce the components of semen (besides sperm).
accessory glands
The most important accessory glands for semen production
seminal glands
prostate gland
bulbo-urethral glands
____ is a vehicle for sperm transport out of the male reproductive tract and into the vagina. It is a mixture of secretions from many glands.
semen
____contains between 20 million and 100 million sperm per mL. It also contains______ from the aforementioned glands.
semen, seminal fluid
is a transportation medium for sperm.
seminal fluid
seminal fluid components
fructose (a sugar)
prostaglandins
seminogelin
component that is metabolized by the mitochondria in the sperm. This provides ATP energy for the sperm to “swim”.
fructose
stimulate smooth muscle contractions in the woman. These contractions help to spread the sperm.
Prostaglandins
a fibrin like protein that forms a temporary clot in the semen. The stickiness of the semen helps to keep the semen in the vagina to give the sperm a better chance of fertilizing an egg.
is secreted as the inactive proseminogelin. It gets activated when mixed with an enzyme from the prostate gland.
seminogelin
inactive proseminogelin is activated to seminogelin when mixed with an____ from the prostate gland.
enzyme
A rounded portion that contains the nucleus and chromosomes
head
A cap-like structure at tip of head
A membranous compartment that contains enzymes essential to fertilization of the egg
Made of fused saccules from spermatid’s Golgi apparatus
Acrosome
Attached to head by short neck
Contains mitochondria in spiral around microtubules
Provides ATP to move tail (flagellum)
Middle piece
Is the only flagellum in the human body
Is a whiplike organelle that moves cell from one place to another
Has complex, corkscrew motion
tail
