Regulation of Gonadal Activities Flashcards
Control of Spermatogenesis:
______ stimulates both steroidogenic ang gametogenic testicular function
LH
Control of Spermatogenesis:
LH indirectly influences spermatogenesis through
the action of testosterone produced by the Leydig cells
Control of Spermatogenesis:
_________ influences the activity of the Sertoli cells which aid in spermiogenesis
FSH
Control of Spermatogenesis:
there is a _____________ activity of Sertoli cells, in accordance with the requirements of spermatogenesis
cyclic variation activity
is also produced in a paracrine fashion by the Sertoli cells, for spermatocytes
undergoing meiosis
Insulin-like growth factor 1 (IGF-1)
Control of Spermatogenesis- Noxious agents:
Sensitivity of germinal cells of seminiferous tubules to harmful agents ______ as differentiation proceeds to ______
increases;
spermatid stage
Control of Spermatogenesis - Noxious agents:
Irraditation produces destructive effect on dividing cells, where _______ are more sensitive than ______
spermatogonia are more sensitive than spermatocytes
Control of Spermatogenesis - Noxious agents:
Irradiation causes mutations, translocations and deletions to the
spermatocyte DNA
Control of Spermatogenesis - Noxious agents:
_______ are sensitive to mutagenic effects of x-irradiation, while _______ are less sensitive and _______ are resistant
Spermatids,
Spermatozoa,
Spermatogonia
Control of Spermatogenesis - Noxious agents:
Interval between testicular damage and appearance of abnormal cells in semen depends on the
nature of the insult,
cell type affected,
duration of spermatogenesis,
epididymal migration time in species
Control of Spermatogenesis - Noxious agents:
If ________ are damaged, the semen is affected soon after application of noxious agent
Epididymal spermatozoa
Control of Spermatogenesis - Noxious agents:
If effect is on _______, damage will not be apparent in the semen for several weeks after the damage is done
Spermatogonia
Control of Spermatogenesis - Noxious agents:
Control of Spermatogenesis - Noxious agents:
Type of change in seminal quality is related to the_______
type of damage produced
Control of Spermatogenesis - Noxious agents: (Type of change in seminal quality is related to the type of damage produced)
Death of germinal cells causes ________
decreased number of spermatozoa
Control of Spermatogenesis - Noxious agents: (Type of change in seminal quality is related to the type of damage produced)
________ results to morphologic defects
Abnormal spermateliosis
Control of Spermatogenesis - Noxious agents: (Type of change in seminal quality is related to the type of damage produced)
Damage to spermatozoal genetic apparatus results in ________
embryonic and fetal death or teratogeny
Control of Spermatogenesis-Seasonal Variations:
Males show ____ seasonal variation in testicular function
less
Control of Spermatogenesis - Seasonal Variations:
The quality of ejaculate are optimal during the __________
reproductive season
Control of Spermatogenesis - Seasonal Variations:
Seasonal changes in LH, FSH, and testosterone are influenced by
photoperiod
Control of Spermatogenesis - Seasonal Variations:
____ and ______ are influenced by season and photoperiod
Testicular weight and male sexual behavior
Control of Spermatogenesis - Seasonal Variations:
In some species, during the hot summer months
seminal quality and male fertility tend to decline during the hot summer months
Control of Spermatogenesis - Scrotal Position:
Scrotal position is an indicator of ________ for spermatogenesis
optimal temperature
Control of Spermatogenesis - Scrotal Position:
Normal adult males of most domestic animals
scrotal testes which provides a lower intratesticular temperature essential for normal gametogenic function
Control of Spermatogenesis - Scrotal Position:
Scrotal descent
an evolutionary trait to maintain a temperature 2-4°C lower than the
abdomen
Control of Spermatogenesis - Scrotal Position:
Spermatogenesis is impaired when heat is applied to the scrotum or when the scrotum is insulated against heat loss
True
Control of Spermatogenesis - Scrotal Position:
Bilaterally cryptorchid males
sterile
Control of Spermatogenesis - Scrotal Position:
Unilaterally cryptorchid males
have lower testicular weight in undescended testes and display impaired spermatogenesis
Control of Spermatogenesis - Scrotal Position:
Fat
acts as an insulator, making it detrimental to spermatogenesis
Control of Spermatogenesis - Scrotal Position:
Constitute an effective thermoregulatory mechanism
Scrotum,
Cremaster muscle,
Spermatic vasculature
Control of Spermatogenesis - Scrotal Position:
Spermatic artery and pampiniform plexus
Provide a heat exchange
Control of Spermatogenesis - Scrotal Position:
Tunica dartos and cremaster muscle during hot weather
relax, so testes
is separated from the abdominal wall to allow maximum heat loss
Control of Spermatogenesis - Scrotal Position:
In cold weather
Muscles contract to reduce heat loss
Control of Spermatogenesis - Scrotal Position:
Homeothermy
Spermatogenesis depends on homeothermy
Control of Spermatogenesis - Scrotal Position:
Fever
increases testicular temperature, resulting in disturbed spermatogenesis
Control of Spermatogenesis - Scrotal Position:
Cooling vs Heat
Spermatogenesis is more resistant to cooling than heat, since the tunica dartos and
cremaster muscles contract to protect the testes
Control of Spermatogenesis - Nutrition:
Malnutrition in prepuberal males and postpubertal males
Malnutrition constitutes a greater stress to spermatogenesis in prepuberal males than in postpubertal males
Control of Spermatogenesis - Nutrition:
Energy-deficient diets
affects gonadotropin secretion, resulting to decline in libido, seminiferous epithelium damage, and low ejaculate volume
Control of Spermatogenesis - Nutrition:
Hypovitaminosis A
causes:
poor seminal quality, testicular atrophy,
hypoplasia of accessory sex glands,
delayed puberty
Control of Spermatogenesis - Nutrition:
Hypovitaminosis E
causes testicular damage
Control of Spermatogenesis - Nutrition:
Mineral deficiencies and feeding with phytoestrogens, goitrogens, and nitrates
associated with impaired reproductive performance in males
