Sperm Transport Flashcards
Retrograde loss of sperm
The backward movement of sperm away from the female reproductive tract.
Privileged pathways
Specialized routes within the female reproductive tract that facilitate sperm transport
Capacitation
The process by which sperm become capable of fertilizing an egg
Hyperactivation
-An increase in sperm motility characterized by vigorous, irregular movements
-Increased flagellar bend amplitude, Asymmetry, Lateral head displacement, and Velocity
Rapid transport phase
-The initial phase of sperm movement through the female reproductive tract.
-Inviable sperm
Sustained transport phase
-The slower, longer-lasting phase of sperm transport
-Trickle-like movement of sperm from reservoirs into the oviduct
-Viable sperm
Sialomucin
-Low viscosity mucus that helps forward movement of sperm through privileged pathways
-A type of mucin that contains sialic acid and is found in mucus
-low viscosity
Sulfomucin
-High viscosity mucus that traps sperm and is flushed out
-A type of mucin that contains sulfate groups
-High viscosity
Know methods by which sperm and oocyte recognition occur.
-Chemotaxis: Chemo-attractants that may be present in follicular fluid in the egg. The ability of sperm to move toward and recognize specific chemical signals from the egg.
-Thermotaxis: 2 degree C difference between isthmus and ampulla. The ability of sperm to navigate based on temperature gradients.
Be able to list and describe barriers to sperm transport.
-Vaginia
-Cervix
-Uterus
-Uterotubal junction
-Isthmus and sperm reservoir
How does the Viginia, cervix, and uterus act as a barrier to sperm?
-Low vaginal pH
-Retrograde flow of semen
-Long uterine body and horns
-Leukocytic infiltration of sperm cells
How does the Uterotubal junction act as a barrier to sperm?
-Folds in mucosa: Results in dead ends
-Viscous fluid
-Removal of seminal plasma
-Removal of defective, slow spermatozoa
How does the Isthmus and sperm reservoir act as a barrier to sperm?
-Capacitation: Only capacitated sperm can fertilize
-Capacitated sperm die quickly unless they undergo acrosome reaction
Be able to describe how the concentration, motility and morphology (normal vs abnormal) of sperm changes as it progresses through the female reproductive tract.
-Sperm concentration decreases as it progresses through the tract
-Percent of motile sperm increases
~50% at vagina
~99% at ampullary-isthmic junction
-Percent of normal sperm increases
~60% at vagina
~75% at ampullary-isthmic junction
Be able to describe the transport of sperm through the cervix.
-Spermatozoa migrate along the walls and fold: Not through the lumen
-Cervical mucus
-“Privileged” pathways
Cervical mucus
-Vehicle for sperm
-Filter for seminal plasma
~Sialomucin
~Sulfomucin
“Privileged” pathways
-Specialized routes within the female reproductive tract that facilitate sperm transport
-Low viscosity environment in the valley of the cervix that creates a privileged pathway for healthy spermatozoa.
-Removal of non-motile sperm
-Removal of some abnormalities
Know the 2 portions of the female reproductive tract where a great deal of the seminal plasma is removed.
Uterotubal junction
Uterus
Describe the uterine immune response following insemination including why it’s good and why it’s a challenge to fertility.
-Immune response to sperm is slightly delayed after insemination
-Gives the sperm cells a start to get through the tract
-Remaining sperm are destroyed by immune cells
How are sperm able to overcome the barriers made by the Viginia, cervix, and uterus?
-Alkaline pH of seminal plasma
-Cervical mucus moves sperm along
-Increased uterine contractions: Late follicular phase
-Immune response delayed
How are sperm able to overcome the barriers made by the uterotubal junction?
Waves of contractions
How are sperm able to overcome the barriers made by the Isthmus and sperm reservoir?
Hyperactivation
Be able to describe the purpose and characteristics of the oviductal sperm reservoir.
-Sperm bind to oviductal epithelium in the uterotubal junction or isthmus
-Functions:
~Maintenance of spermatozoa between the onset of oestrus and ovulation
~Synchronization of Sperm & Egg Transport In Oviduct
~Prevention of polyspermy
~Capacitation
~Hyperactivation
Be able to list the barriers to oocyte transport
-Follicle wall
-Infundibulum
-Ampulla
How does the follicle wall act as a barrier to oocyte transport?
Weakening of wall
How does the infundibulum act as a barrier to oocyte transport?
-Expanded cumulus
-Fimbria
-Mesosalpinx contractions
How does the ampulla act as a barrier to oocyte transport?
-Oviductal muscle contractions
-Cilia beat the oocyte to AIJ against flow of secretion
Be able to describe how the oocyte is captured by the infundibulum and then transported down the oviduct.
-Expanded cumulus keeps the oocyte moving along
-Fimbria
-Mesosalpinx contractions
-Oviductal muscle contractions
-Cilia beat the oocyte to AIJ against flow of secretion
-Infundibulum -> ampulla -> AIJ -> Isthmus -> UTJ
Know how ovum transport is controlled.
-Estrogen enhances alpha adrenergic receptors, Stimulatory, and Isthmus contractions increase
-Progesterone enhances beta adrenergic receptors, Inhibitory, and the Isthmus relaxes and allows embryo to go into the uterus
Know what the “AI compromise” is and what happens if we inseminate earlier than that time or later than that time.
Earlier AI reduced fertilization rates and increased embryo quality
Know how long it takes for sperm to be transported through the bovine tract to the oviduct.
4-16 hours
Capacitation
-The process by which sperm become capable of fertilizing an egg
-Strips the seminal plasma coating and some surface proteins so the parts needed to bind to the zona pellucida are exposed
-These sperm die quickly without binding
-NOT fully reversible
Hyperactivation
-An increase in sperm motility characterized by vigorous, irregular movements
-Increase sperm characteristics to move through cumulus cells
-Increase Flagellar bend amplitude, Asymmetry, Lateral head displacement, and Velocity
-Fully reversible
