Ch 50 Flashcards
What does the reproductive system lack that every other physiological system has?
Homeostasis
What are the 6 types of asexual reproduction?
single cell division, fission, budding, specialized cells, fragmentation, and parthenogenesis
asexual reproduction
a single parent endows its offspring with genes identical to its own
What are the pros to asexual reproduction?
it’s energy efficient and is most successful in a stable environment
single cell division
this is the same thing as mitosis
budding
part of the parent’s body grows and separates from the rest of the body
fragmentation
the parent’s body breaks into pieces and each piece can grow into a new animal
parthenogenesis
‘virgin development’, a form of asexual reproduction in which an unfertilized egg develops into an adult animal, the adult is typically haploid, parthenogenesis is common among insects (typically honeybees and wasps) and crustaceans
Pros and cons of sexual reproduction
cons: it’s complicated, males may be wasted, cost of meiosis, and lack of founder effect; pros: variability
external fertilization
mating partners typically release eggs into the water simultaneously (ex. frogs or fish)
internal fertilization
male delivers sperm into the female’s body
hermaphroditism
single individual produces eggs and sperm (ex. earthworms), some hermaphrodites, such as tapeworms, are capable of self-fertilization, but typically, two animals come together and fertilize each other’s eggs and each animal inseminates the other
testes
tissues responsible for hormone and sperm production
sperm
travel through multiple male reproductive tissues
penis
houses urethra for urination and ejaculation of sperm
male sex hormone
testosterone
What are gametes?
gametes only have half of the DNA, so when they meet they form a full human set of DNA, gametes are eggs and sperm
Where is sperm formed and what are the organs, in order, that it must pass through to get out of the penis?
made in the testis, it is stored in the epididymis until it’s ready to be ejaculated, when ready it travels through the vas deferens, it goes through 3 glands (seminal vesicle, prostate, and bulbourethral) that add things to it, and then it goes through the ejaculatory duct and leaves via the urethra
Where are the testes located? What do they contain?
they are housed in the scrotum, the contain the seminiferous tubules, where sperm production takes place
What do interstitial cells secrete?
testosterone (males drive crazy on the INTERstate because of testosterone
What do sertoli cells produce?
produce signaling molecules and a fluid that nourishes sperm cells (Sertoli=Sperm)
seminiferous tubules
small, twisty tubes that are surrounded by sperm producing cells
penis
three columns of erectile tissue, two cavernous bodies, one spongy body that surrounds the urethra (erectile tissue becomes engorged with blood and causes erection)
flaccid penis vs erect
blood can flow in and out easily, in erect penis, the dorsal veins are constricted so the blood can’t get out (also the artery is dilated so more blood gets in)