Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
34 Cards in this Set
- Front
- Back
|
Process of fertilization
|
1. Fusion of nucleus sperm and ovum
- Both sperm and ovum travel in female reproduction tract - Physiological changes to both sperm and ovum before fertilization |
|
|
Semen release
|
Epididymis, vasa differentia (storage and transport).
During ejaculation: sex accessory dutchs secrete seminal flasma -> semen 200 million sperm produced each day |
|
|
Stages semen release
|
1. Before orgasm small amount
2. During orgasm (majority of semen) 3. another small amount by seminal vesicle exuded |
|
|
Content of seminal plasma
|
1. Prostaglandin
2. Citric Acid + ascorbic acid 3. bicarbonates (buffer) 4. Fructose 5. Carnitine 6. Glycerylphosphocholine 7. Zinc 8. ATP |
|
|
Function of prostaglandin
|
Contributes to sperm motility in vasa deferentia by contracting SM.
(mainly secreted by seminal vescicles) |
|
|
Function of Fructose
|
Nutrient
|
|
|
Why is there a buffer present in fluid
|
To neutralize acidity in male urethra and vagina
|
|
|
Sperm number
|
40-500 million (average 180 million)
|
|
|
Percentage sperm abnormal
|
30%
|
|
|
Decrease in sperm count per year
|
1% for past 50 years
|
|
|
Average texture and volume
|
Texture: creamy, gray to yellow.
Volume: 2.5-3.5 ml |
|
|
Male fertility index
|
Minimum qualifications of male fertility
- >20 million sperm/ml - >40% able to swim - >60% normal shape and size |
|
|
Name structures and characteristics of sperm cell
|
Sperm head (Haploid DNA in membrane. Acrosome around it that contains digestive enzymes)
Neck Flagellum (midpiece with mitochondria and tail. 9-2 microtubules arrangement) |
|
|
Sperm in female reproductive tract
|
Vagina, cervix, uterus, urotubal junction, oviduct isthmus, amillary-isthmus junction.
|
|
|
Common location of fertilization
|
Ampillary-istmus junction
|
|
|
Sperm count in female
|
100-1000 reach oviduct
20-200 reach egg |
|
|
Vaginal sperm
|
- Semen raises pH to 7.2 -> aids motility.
- 1 min: semen coagulates (prevents sperm loss) - 20 min. sperm liquefies (aids motility and faster swimming towards cervix) |
|
|
How does female orgasm aid?
|
Vaginal wall contractions -> pressure vagina > pressure cervix
|
|
|
Cervical sperm
|
- Cervical canal: folds and crypts + blocked by sticky mass
- Around ovulation: estrogen > -> mucus more watery + gaps between cervical fibers wider and form channels - Fibration of cervical fibers in healthy sperm tail rythm: aids selection and propellation. |
|
|
Uterine sperm
|
- watery, but sparse mucous
- sperm climb way up - uterine muscle contractions and cilia beating aids |
|
|
How does oxytocin gets released and aids in uterus?
|
Penis movement induces oxytocin release.
Oxytocin stimulates uterine SM contractions |
|
|
Do sperm no to which oviduct to go?
|
No.
|
|
|
Sperm in oviduct
|
- 'wait' till ovulation (< tail beating)
- Ovulation: swim up to am-is junction. |
|
|
How does est/pro help?
|
- est: increase cillia number
- pro: increases cillia beating and ovum transport |
|
|
All cillia same direction?
|
No:
- recesses: towards ovary (sperm travells here) - ridges beat toward the uterus (ova) |
|
|
What is sperm capacitation?
|
During journey through female reproductive tract, the sperm matures and gains ability to fertilize eggs and increases tail movements of sperm.
|
|
|
What is the cumulus oophorus?
|
Sphere of loosely packed follicle cells
|
|
|
Process of fertilization?
|
1. Penetration of cumulus oophorus by sperm.
2. Zona pellucida 3. attachment to egg plasma membrane (ZP3/ZP2) 4. Cortical reaction 5. Completion of second meiotic division of ovum DNA 6. Formation/fusion of sperm and egg pronuclei |
|
|
What is the zona pellucida composed of?
|
ECM with 3 glycoproteins: ZP1, ZP2, ZP3.
|
|
|
Step 2 of fertilization: zona pellucida..
|
- Receptors sperm membrane attach to ZP3.
- Acrosomal reaction -> influx of Ca2+ -> rise in pH + cAMP -> exocytosis acrosomal vesicle 3. degradation of zona. |
|
|
How does the sperm cell maintain contact with ovum after release vescicles?
|
Inner sperm membrane exposed: ZP2 receptor
|
|
|
How egg prevents further fertilization?
|
Ca2+ influx triggers cortical granule release (and completion of 2nd meiosis) -> delibrate ZP2/3
|
|
|
Processes in egg activation?
|
- Cortical reaction
- Completion of meiosis - Increase in egg metabolism - Synthesis of protein, RNA, and DNA |
|
|
Steps of fusion haploid DNA
|
1. Upon entry sperm in ovum: nuclear membrane brak down -> DNA condenses + new membrane formed.
2. both pronuclei approach each other + their membranes break down 3. Syngamy 4. Diploid zygote -> mitosis -> blastomeres |
