C.1 Sperm Transport In The Female Reproducive Tract

Front 1

Why is passage of the sperm through the female reproductive tract regulated?

Back 1

To maximize the chance of fertilization and ensure that sperm with normal morphology and vigorous motility will be the ones to "succeed".

Front 2

What two inherent sperm characteristics are a disadvantage to their passage?

Back 2

1. They are terminally differentiated; they do not have the benefit of repair mechanisms like other cells.
2. They are allogenic to the female; thus they encounter female immune system

Front 3

What 2 vaginal defenses equipped for antimicrobial activity must the sperm overcome?

Back 3

1. Acidic pH
2. Immunological response

Front 4

What is the pH in the vagina and how is it maintained?

Back 4

pH of 5 which is microbicidal and it is maintained through lactic acid production by anaerobic lactobacilli that feed on glycogen present in shed vaginal epithelial cells.

Front 5

How do the sperm combat the vaginal pH?

Back 5

1. Limited exposure to the acid (don't spend much time in the vagina)
2. pH of the seminal plasma ranges from 7.3-7.7 so has the potential to neutralize vaginal acid (bicarb-rich due to male accessory sex glands)

Front 6

How do sperm combat neutrophil defense of the vagina?

Back 6

Seminal plasma contains inhibitors of immune responses:
1. Protection that coat the sperm when it is bathed in the seminal plasma
2. Inseminating many sperm having more sperm than neutrophils.

Front 7

What quality about leukocytes that is a disadvantage to stopping sperm from reaching the oviduct?

Back 7

the invasion of leukocutes takes time to build an effective level capable of ingesting sperm, by this time the sperm have may have already reached the oviducts.

Front 8

What cervical defense is thought to be a form of sperm selection?

Back 8

Cervical mucus
- characteristics changes throughout the menstrual cycle.
- Early mucus is thick, white, sticky and holds its shape=good barrier
- Transitional Mucus is thinner cloudy and stretchy=midpt easier for sperm to permeate
- High fertile mucus is thin, transparent and stretchy=easier for sperm to move

Front 9

Neutrophils can migrate through the mid-cycle cervical mucus but why would they not present a significant barrier to sperm?

Back 9

The number of leukocyte are less compared to in the vagina.

Front 10

What uterine features help aid and prevent the transport of sperm through the uterus.

Back 10

AID: The swimming of the sperm through the uterus is aided by contractions of the myometrium which is stimulated mechanically by the penis on the cervix causing the release of oxytoxin (which causes the contractions). Contractions can also aid sperm to pass the WBCs
PREVENT: presence of sperm initiates WBC (more in the vagina than the cervix)

Front 11

What is the role of prostaglandins from the seminal fluid?

Back 11

Once thought to produce the myometrial contractions but is now debated because there is very little seminal fluid that enters the uterus through the cervix.

Front 12

What type of barrier does the UT (uterine-tubal) junction present?

Back 12

1. This junction is muscular and tightly constricted region allowing only for slow gradual entrance of sperm into the oviduct.
2. Also contains a viscus mucus that may impede the progress of sperm.

Front 13

How many reach the right oviduct?

Back 13

Only half the sperm reach the right oviduct, since ovaries take turn ovulating each cycle.

Front 14

What type of barrier does the oviduct present for sperm?

Back 14

Oviducts present a haven for sperm. This region doesn't stimulate influx of leukocytes. The swimming motion of the sperm is very important in this region.

Front 15

What features of the oviduct that aid in the movement of the egg may also help in the movement of the sperm?

Back 15

Ciliated epithelium and muscularis contractions of the oviduct are postulated to help move the sperm but has limited evidence.