Semen Deposition and Transport- Lecture 8 Flashcards Preview

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Flashcards in Semen Deposition and Transport- Lecture 8 Deck (23)
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1
Q

Sperm elimination

A

Only a small portion of ejaculated spermatozoa reach the oviduct. Due to physical barriers, retrograde loss of spermatozoa, breeding-induced inflammatory response.

2
Q

Fate of dead spermatozoa

A

Eliminated

3
Q

Breeding-induced endometritis causing sperm elimination

A

Spermatozoa induce inflammation and an influx of PMNs into the uterine lumen. Activated PMNs release PGF2alpha, which causes myometrial contractions. Reaction to clear the uterus from excess spermatozoa and bacterial contaminants.

4
Q

Ejaculate consists of…

A

Live spermatozoa- ready to fertilize. Live spermatozoa- unable to fertilize. Dead spermatozoa.

4
Q

Mechanism for PMN

A

Crisp-3. Lactoferrin. PMN’s.

5
Q

Ciliar activity

A

Cilia throughout the female tract aid in sperm transport.

6
Q

Physical barriers that cause sperm elimination

A

Cervix, uterus, UTJ- a sperm barrier, and selectively allows transport of morphologically normal spermatozoa.

7
Q

Before fertilization

A

Sperm transport to the oviduct. Sperm storage in the oviduct. Release from the oviduct. Capacitation. Binding and penetration of the oocyte.

8
Q

Uterine contractility

A

Oxytocin- ferguson’s reflex. PGF2alpha- seminal plasma. Estrogen- seminal plasma.

9
Q

Oviductal contractility

A

From the utero-tubal junction to the oviductal isthmus for storage. From the isthmus to the ampulla for fertilization.

9
Q

Retrograde loss of spermatozoa causing sperm elimination

A

Oxytocin and PGF2alpha. Contractions both ascending and descending. Major loss of spermatozoa through a relaxed cervix.

11
Q

Fate of live spermatozoa ready to fertilize

A

Transport to oviductal ampulla

12
Q

Cervix for sperm storage

A

Species with intravaginal deposition of semen. Spermatozoa stored in cervical crypts and released for transport to oviduct.

13
Q

Sperm transport

A

Sperm motility, uterine contractility, oviductal contractility, ciliar activity.

15
Q

Cryopreservation

A

Seminal plasma is removed

16
Q

Semen deposition in vagina

A

Cattle, sheep, dog, rabbit, primates.

17
Q

Semen deposition in uterus

A

Horse, pig, rodents

18
Q

Caudal oviductal isthmus for sperm storage

A

Main sperm reservoir in most species. Sperm attach to the epithelium. Selective mechanism for attachment of normal sperm. Prevent capacitation- maintain intracellular Ca levels. Increased viability. Sperm released by chemotactic signal associated with ovulation.

19
Q

Fate of live spermatozoa unable to fertilize

A

Stored within female tract or eliminated.

20
Q

Sperm motility

A

Progressive motility is correlated to fertility in fresh semen. Less correlation between motility and fertility in frozen/thawed semen.

21
Q

PMN

A

Polymorphonuclear nutrophils. Once PMNs reach the uterine lumen they bind to and phagocytose spermatozoa. They also release PGF2alpha, which causes more uterine contractions. This clears the uterus.

22
Q

Role of seminal plasma

A

Selective protection of viable spermatozoa. 70% dead spermatozoa binding in the presence of seminal plasma.

23
Q

Endometrail folds for sperm storage

A

Some evidence that endometrial folds can serve as a sperm reservoir.