Sperm Transport Flashcards
After sperm penetrates the zona, they must fuse with the oolemma how does this occur?
- Sperm enters the perivitelline space
- Sperm is engulfed by the oocyte plasma membrane (requires fusion of equatorial segment and oocyte plasma membrane)
Epididymal + Seminal plasma starts what? Then what does ejaculated + female tract start?
- Ejaculated
- Capacitated
How are sperm lost in the female tract after deposition?
- Through retrograde transport
- Phagocytosis by neutrophils (WBC)- vagina and uterus
How does the process of sperm transport go?
- Immediate Transport
- Cervix
- Uterus
- Oviduct
- Fertilization
How many phases make up the sperm transport?
Two phases:
1. Rapid phase
2. Sustained phase
In natural mating where is the cranial vagina the site of semen deposition for in which animals? Which animal has a different effect?
- The animals these apply under are:
cow, sheep,rabbit primates, dog,cat,rodents. - Rodents have a gel plug for vagina, prevents retrograde sperm loss
In sperm- oocyte fusion what occurs?
After passing the zona, sperm are surrounded by a bed of microvilli on the oocyte plasma membrane
1. The oolemma of the oocyte fuses with the equatorial segment of sperm and then the sperm is engulfed
2. Cortical granules are released into the perivitelline space.
What are some functions of the cervix?
- Barrier = non-motile, abnormal & dead sperm
- Mucous secretion (amount varies between species) = different viscosities of mucous help to filter sperm
What are the post capacitation events that lead to fertilization?
Hyperactive motility -> Binding to zona pellucida-> Acrosomal reaction-> Penetration of zona pellucida-> Sperm-oocye membrane fusion-> Sperm engulfed -> Decpndensation of sperm nucles-> Formation of male pronucleus
What are the sequence of events that follow semen deposition?
- Immediate transport
- Cervix
- Uterus
- Oviduct
What are the two types of mucous in the cow?
There are:
1. Sialomucin
2. Sulfomucin
What do these acronmys mean:?
1. OAM
2. IAM
3. ARPR
4. ZBR
- Outer acrosomal membrane
- Inner acrosomal membrane
- Acrosome reaction promoting region
- Zona binding region
What happens to the plasma membrane that protect the sperm?
Plasma membrane proteinsa re removed in the female tract, which allows sperm to interact with oocyte.
What initiates Phagocytosis by neutrophils? What occurs during this time?
- Requires elevated strogen
- Prevents microorganisms from colonizing in tract
- Digest some sperm (foreign to female)
(No real negative effect on fertility)
What is acrosin and proacrosin part of?
Part of the process when sperm releases enzymes to penetrate the zona
What is Acrosin?
- It is when the zona proteins hydrolyze
- Promotes sperm penetration through the zona
What is proacrosin?
It is the inactive form of acrosin, aids sperm binding to zona during hypermotility
What is sperm capacitation?
- Series of structural and biochemical events that prepares sperm for fertilization
- Capacitation of sperm occurs over time and not every sperm capacitates at the same rate.
- Ejaculated sperm are coated with proteins from seminal plasma
What is the Sulfomucin?
High viscocity, secreted by apical epithelial portions of crypts, sperm washed out of tract with contact.
What is the rapid phase?
- It is when sperm reaches the oviduct within minutes after deposition
- These sperm do not fertilize eggs
What is the Sialomucin?
Low viscocity, secreted by basal cells of crypts, “priviledged pathway” for sperm to swim.