Chapter 53- The Reproductive System Flashcards
2 types of asexual reproduction
- fragmentation
- budding
Oviparity
fertilized eggs are deposited outside mothers body to complete their development
Ovoviviparity
fertilized eggs are kept within mother to complete development, young obtain food from egg yolk
Viviparity
young develop within mother and obtain nourishment from her blood
bony fish fertilization
external
cartilaginous fish fertilization
internal
-viviparous
amphibian fertilization
external
fertilization in reptiles
internal
-amniotic egg
Bird fertilization
internal
-amniotic egg
menstration
females bleed when shedding inner lining of uterus
momotremes
oviparous-lay eggs
marsupials
viviparous
-give birth to incompletely developed fetus, matures in mothers pouch
placentals
viviparous
-retain young in uterus for long period of development
2 aspects of reproduction
- production of gametes
2. transfer of sperm into female
seminiferous tubules
sites of sperm production
gamete production in males
- 2N spermatogonuim divides by mitosis to produce 2 diploid cells
- primary spermatocyte-diploid cell that begins meiosis, undergoes meiosis 1 to produce 2 haplod
- each secondary spermatociyte undergoes second meiosis to produce 2 spermatids
- spermatids differentiate into sperm
Sperm Structure
- head-contains nucleus
- body-many mitochondria
- tail-flagellum
Epididymis
sperm maturation site
Semen
- mixture of seminal fluids and sperm
- made by seminal vesicles, prostate gland, bulbourethral glands
Hormonal Control
- begins at puberty
- Hypothalamus stimulates anterior pituitary to secrete FSH and LH
- FSH stimulates ertoli cells to make sperm
- LH stimulates leydig cells to secrete testosterone
Ovarian Follicles
- inside ovaries
- follicle contains a potential egg cell=primary oocyte and also granulosa cells
Granulosa cells
- secrete estrogen at puberty
- triggers mentrual cycle
Menstrual cycle
divided into follicular phase, ovulation, luteal phase
Follicular phase
- FSH stimulates several follicles to grow
- onlyo ne achieves full maturity
- primary oocyte competes meiosis one
- secondary oocyte begins meiosis 2
- arrested in metaphase 2 until fertilized
Ovulation
Stimulation by LH of follicle arrested in metaphase, released into fallopian tube
- if not fertilized, it disintigrates
- if fertilized, completes meiosis 2, makes ovum, makes zygote
Luteal Phase
- LH stimulation transforms graafian follicle into corpus luteum
- corpus luteum secretes estrogen and progesterone
- Exerts negative feedback on FSH and LH
- prepares embryo for implantation
- w/o fertilization, corpus luteum degenerates=menstration
- if fertilized, corpus luteum is maintained by hCG until placenta takes over
