Semen

Seminal Fluid

complex fluid component that contains spermatozoa which is secreted by the male gonads and other sexual organs of male or hermaphroditic animals.

Spermatozoa

secreted by the male gonads and other sexual organs of male or hermaphroditic animals.

Clinical Applications

Fertility Testing

Post-vasectomy Semen Analysis

Forensic Analysis

Fertility Testing

male infertility evaluation

Post-vasectomy Semen Analysis

confirm azoospermia

Forensic Analysis

alleged rape, paternity testing

Composition of Semen

5% Spermatozoa

20-30% Prostate Fluid

5% Bulbuorethral Gland

5% Spermatozoa

provides fructose, the main energy source for sperm motility

20-30% Prostate Fluid

acidic fluid that contains ACP, zinc, citric acid and other enzymes; for coagulation & liquefaction

5% Bulbuorethral Gland

provide lubrication and neutralization of urethral acidity

Spermatogenesis and Sperm Maturation

90 days

Seminiferous Tubule

 site of spermatogenesis

Sertoli Cells

“nurse cells” that provide support and nutrition for developing cells

Leydig Cells

produce testosterone for spermatogenesis

Epididymis

site of sperm maturation (become motile)

Stages of Sperm Maturation

Spermatogonium → Primary spermatocyte (1°) → Secondary spermatocyte (2°) → Spermatid → Spermatozoon (mature sperm cell)

Abstinence Period Before Collection

2–3 days but not longer than 7 days.

Methods of Collection

Masturbation

Coitus interruptus

Condom method

Masturbation

preferred method of collection

Coitus Interruptus

not recommended due to loss of initial fraction of semen

Condom Method

only if plain, nonlubricated, non-spermicidal 

1 Hour

Deliver in lab in room temperature

Analysis

should be done after liquefaction (30-60 minutes)

Specinen Delayed for Analysis

should be kept at 37°C to preserve motility.

Odor of Semen

Musty or bleach odor

Normal Appearance of Semen

Gray, white translucent

Causes of White Turbidity

Presence of WBCs (infection).

Causes of Red or Brown Color

Increased RBCs (hematospermia or trauma).

Increased RBCs

hematospermia or trauma

Yellow Semen

Due to increased abstinence (flavin pigments).

Increased Abstinence

flavin pigments

Normal Volume of Semen

2–5 mL

Increased Semen Volume

overabstinence

Decreased Semen Volume

Incomplete collection, obstruction, or infertility.

Normal Viscosity of Semen

Pours in small droplets

Increased Viscosity (gel-like)

increased viscosity (gel-like) = decreased motility.

Normal pH

7.2-8.0

Increased pH

infection

Decreased pH

Increased prostatic fluid

Normal Sperm Concentration

>20 million sperm/mL

Improved Neubauer Counting Chamber

counting method

Dilution Used for Counting

1:20 using distilled water as diluent to immobilize sperm

Computation (2 WBC squares)

Number of sperm counted × 100,000

Computation (5 WBC squares)

number of sperm counted × 1,000,000

Normal Total Ejaculate Count

>40 million

Normal Sperm Motility

>50% motile within 1 hour

4.0 (a) Motility Grade

Rapid, straight line motility

3.0 (b) Motility Grade

Slower speed, some lateral movement

2.0 (b) Motility Grade

Slow forward progression, noticeable lateral movement

1.0 (c) Motility Grade

No forward progression

0 (d) Motility Grade

no movement

Routine Criteria Normal Morphology

>30% normal forms

Kruger’s Strict Criteria

>14% normal forms

Kruger’s Strict Criteria

Measures the head, neck and tails using a micrometer

Papanicolau’s Stain 

Stain used for Morphology

Head

oval shaped (normal);

poor ovum penetration (abnormal)

Acrosomal Cap

Covers 1/2 of the head and 2/3 of the nucleus

Midpiece of Sperm

Contains mitochondria for energy

Tail of Sperm

Varicocele45 µm in length; responsible for motility.

Varicocele

Hardening of veins that drain testes; most common cause of infertility; sperm head = tapered.

Sperm Viability Test

Modified Bloom’s test using Eosin & Nigrosin; living sperm = unstained bluish white; dead = red

Post-Vasectomy Semen Analysis

Sperm count should be zero within 12 weeks; any motile sperm = unsuccessful vasectomy.

Aspermia

No semen or ejaculate

Azoospermia

Absence of spermatozoa in the ejaculate

Hematospermia

Presence of blood in the ejaculate

Leukospermia

Presence of WBCs in the ejaculate.

Necrozoospermia

Increased number of immotile or dead spermatozoa.

Oligozoospermia

Decreased sperm concentration