characteristics of mature sperm
-presence of Y chromosome in half of sperm
-mitochondria spiraled around filaments
-acrosome produced by golgi apparatus &has hydrolytic enzymes
-Contain little cytoplasm/stored nutrients
-Sluggish in alkaline environments
target cells lose receptors in response to the hormone (happens w/ type 2 diabetes [mellitus])
-the ruptured follicle following the ejection of an oocyte from the ovary
-not a part of the proliferative phase of the female menstrual cycle
purpose of spermiogenesis?
-Turn non-mobile, immature spermatids mobile, mature spermatazoan
-Involves stripping away of superfluous cytoplasm
male secondary sex characteristics
-deepening of voice
-skin thickens/becomes oily
-bones grow & increase in density
-skeletal muscles increase in size & mass
-pubic, axillary & facial hair
-growth of chest
what cells produce testosterone in the testis?
Interstitial cells b/t seminiferous tubules [Leydig cells]
the testicular cells that construct the blood-testis barrier are called what?
Sustentacular cells [Sertoli cells]
whats included in the PNS reflex that results in erection?
during sexual arousal, PNS reflex promotes release of nitric oxide [NO] which is a vasodilator...opening blood vessels in the penis, which causes the spongy tissue in the penis to fill with blood, causing the penis to enlarge and become rigid.
basic difference between spermatogenesis and oogenesis.
in oogenesis, one mature ovum is produced, and in spermatogenesis four mature sperm are produced from the parent cell
What is the brain-testicular axis?
hormonal regulation of spermatogenesis and testicular androgen production, involving hypothalamus, anterior pituitary, & testes
low secretion of luteinizing hormone (LH) in the normal male adult would cause what?
decreased testosterone secretion
functional changes that sperm undergo in the female reproductive tract that allow them to fertilize a 2̊ oocyte
structure that maintains the integrity of the uterine lining during the first three months
[it secretes estrogen and progesterone which do this]
hyaluronidase and proteinase function in reproduction?
they breakdown the protective barriers around the egg, allowing sperm to penetrate
failure of the foramen ovale to close at birth may result in what?
mixing of oxygenated and deoxygenated blood
embedding of blastula in uterine wall
6-7 days after ovulation when the trophoblasts adhere to a properly prepared endometrium
correct sequence of the preembryonic structures from earliest
zygote, blastomere, morula, blastocyst
onset of labor is caused by what?
-rise of estrogen
-stimulates myometrial cells of uterus to form a lot of oxytocin receptors
-certain fetal cells begin to produce oxytocin
-causing the placenta to release prostaglandins
-both of these are powerful uterine muscle stimulants
-myometrium is now highly sensitive
-contractions become more frequent and vigorous.
major factor controlling the manner in which levers work?
difference in the positioning of the effort, load, and fulcrum
which cranial nerves are found on the pons and medulla?
pons - V, VI, VII, and VIII
medulla oblongata - IX, X, XI, XII