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])
trophoblast is responsible for forming which structure
umbilical arteries carry what?
deoxygenated blood and metabolic wastes from fetus to placenta
role of dartus and cremaster muscles
control temperature of the testes
ability of sperm cells to move along the ductus deferens is due to what?
gland is responsible for 60% of the synthesis of semen?
primary function of the uterus?
receive, retain, and nourish a fertilized ovum
Hormones control the release of anterior pituitary gonadotropins?
Gonadotropin releasing hormones
-the ruptured follicle following the ejection of an oocyte from the ovary
-not a part of the proliferative phase of the female menstrual cycle
structures that receive the ovulated oocyte, providing a site of fertilization.
structure constitutes the female counterpart of the male scrotum?
how are human egg and sperm similar?
have the same number of chromosomes (23)
maintains the constancy of the chromosome number from one generation to the next?
where fertilization occurs?
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]
erection of the penis results from what?
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
what does the brain-testicular axis involve?
FSH & LH release
low secretion of luteinizing hormone (LH) in the normal male adult would cause what?
decreased testosterone secretion
ectodermal cells migrate to form a raised groove known as what?
result of polyspermy in humans?
functional changes that sperm undergo in the female reproductive tract that allow them to fertilize a 2̊ oocyte
hormone is responsible for milk ejection or the let-down reflex?
structure that maintains the integrity of the uterine lining during the first three months
[it secretes estrogen and progesterone which do this]
fetal portion of placenta
function of relaxin in females
relax pubis symphysis
function of relaxin in males
fastens movement of sperm
hyaluronidase and proteinase function in reproduction?
they breakdown the protective barriers around the egg, allowing sperm to penetrate
three germ layers.
formation of the ectodermal and endodermal germ layers occurs when?
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
umbilical arteries carry what?
deoxygenated blood & metabolic wastes from fetus to placenta
correct sequence of the preembryonic structures from earliest
zygote, blastomere, morula, blastocyst
one sign of an infant's physical condition that is first noticed at birth is what?
provides nutrition of the young embryo after implantation occurs
digestion of the endometrial cells
muscle tissue is formed by which germ layer?
neural tissue is formed by which germ layer?
which stage of labor is the "afterbirth" expelled?
which stage of labor is the fetus delivered?
what passes through the placental barriers?
Nutrients, respiratory gases, wastes & alcohol
what is the deciduas basalis?
maternal portion of placenta
where is the deciduas basalis located?
b/t the chorionic villi & stratum basalis
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.
what affects the strength or force of skeletal muscle contraction?
multimotor unit summation
which molecules do calcium ions bind to in skeletal muscle cells?
regulatory sites on troponin
major factor controlling the manner in which levers work?
difference in the positioning of the effort, load, and fulcrum
function of the ependymal cells.
line the central cavities of the brain and spinal column
which cranial nerves are found on the pons and medulla?
pons - V, VI, VII, and VIII
medulla oblongata - IX, X, XI, XII
subdivisions of the brachial plexus.
roots, trunks, divisions, cords
really, tired, drink, coffee
neural connection with the hypothalamus
ability of a specific organ to respond to a hormone is dependent on what?