Gamete Transport Flashcards
Oocyte
immature egg. a woman is born with millions. Only 100s are ovulated. Mature in a follicle
Sex cell production
a female can not make any more oocytes after birth. A male can produce sperm over his entire life, at a decreasing rate.
Follicle
oocyte + surrounding cells
Zona pellucida
a non-cellular membrane between the oocyte and follicle cells
Follicle maturation
Multiple follicles mature each cycle, and one becomes dominant, and releases its oocyte. It travels to the edge of the ovary, creating a bulge.
non-ovulated follicles degenerate and are absorbed
Ovulation
release of an oocyte. the dominant follicle ruptures, leaving the corona radiata around its oocyte. the oocyte is expelled into the body cavity.
Spotting
droplets of blood caused by blood vessels which were broken by follicle rupture during ovulation
Mittelschmerz
pain felt on the side of ovulation. May be caused by bulging follicle, or blood in body cavity.
Ovulation events
Physical: Spotting, Mittelschmerz
Female Psychological: other women less attractive, wears more revealing clothing
Male Psychological: Woman looks, sounds, and smells better. Increases testosterone levels
Oocyte transport aids
Fimbria(e), Corona radiata, Cilia. If one is missing, fertilization may still occur
Fimbriae
finger-like projections at end of uterine tubes. move towards ovary and sweep over the surface. captures oocyte and brings it into uterine tube
Corona radiata
covers non-adhesive zona pellucida. makes oocyte easier to bring into uterine tubes because of size and adhesion
Cilia
hair-like projections in uterine tubes that sweep the oocyte into the tube
Sperm Anatomy
Head, Midpiece, Tail
Sperm Head
front part of sperm containing acrosome and Nucleus with DNA
Acrosome
enzyme filled area that helps sperm integrate with oocyte
Sperm Nucleus
DNA wrapped around protamine instead of histone to allow it to be more densely packed
Histone
protein DNA is wrapped around in a normal cell
Protamine
protein DNA is wrapped around in a sperm cell
Sperm Midpiece
middle part of sperm, contains mitochondria
mitochondria
cell “organs” that produce energy
Sperm Tail
long, thin end of sperm that provides propulsion through a fluid
Sperm travel route
Vagina > Uterus > Uterine Tubes
Sperm Transport (Vagina)
100s of millions of sperm enter after ejaculation. 90% don’t make it past the vagina. In a few seconds seminal fluid neutralizes vagina acidity for a few minutes to give sperm time to reach cervix where they will have greater mobility.
Sperm Transport (Uterus)
Cervical mucus changes composition. either E or G. If muscular contractions are present (fast phase) sperm make journey in minutes. Otherwise it takes days.
E mucus
cervical mucus that helps keep sperm alive and move faster
G mucus
resistant to sperm penetration
Sperm Transport (Uterine Tubes)
Sperm bind to tube and undergo capacitation. Then 100s to 1000s meet oocyte at end of tube, travelling by contractions and swimming
Capacitation
alters the sperm head to allow it to be capable of doing an acrosomal reaction, allowing it to fertilize an oocyte
Sperm Guidance
heat gradient, “smell” (chemical detection), swim faster from progesterone