# Sperm motility

> Mediated Wiki article. Canonical URL: https://mediated.wiki/wiki/page_0082
> Last updated: 2026-07-20T06:14:14.787Z

[Template:Short description](/mw/index.php?title=Template:Short_description&action=edit&redlink=1)

[File:Human sperm under microscope.webm](/mw/index.php/File:Human_sperm_under_microscope.webm)
Video of human sperm cells moving under a microscope

**Sperm motility** describes the ability of [sperm](/mw/index.php?title=Sperm&action=edit&redlink=1) to move properly through the female reproductive tract ([internal fertilization](/mw/index.php?title=Internal_fertilization&action=edit&redlink=1)) or through water ([external fertilization](/mw/index.php?title=External_fertilization&action=edit&redlink=1)) to reach the [egg](/mw/index.php?title=Ovum&action=edit&redlink=1). Sperm motility can also be thought of as the *[quality](/mw/index.php?title=Semen_quality&action=edit&redlink=1)*, which is a factor in successful [conception](/mw/index.php?title=Fertilisation&action=edit&redlink=1); sperm that do not "swim" properly will not reach the egg in order to [fertilize](/mw/index.php?title=Fertilisation&action=edit&redlink=1) it. Sperm motility in mammals also facilitates the passage of the sperm through the [cumulus oophorus](/mw/index.php?title=Cumulus_oophorus&action=edit&redlink=1) (a layer of cells) and the [zona pellucida](/mw/index.php?title=Zona_pellucida&action=edit&redlink=1) (a layer of [extracellular matrix](/mw/index.php?title=Extracellular_matrix&action=edit&redlink=1)), which surround the mammalian [oocyte](/mw/index.php?title=Oocyte&action=edit&redlink=1).

In the wood mouse *Apodemus sylvaticus*, sperm aggregate in 'trains' that are better able to fertilize eggs because they are more capable of navigating the viscous environment of the female reproductive tract. The trains move in a sinusoidal motion.

Sperm motility is also affected by certain factors released by eggs.[1]

Sperm movement is activated by changes in intracellular ion concentration.[2] The changes in ion concentration that provoke motility differ among species. In [marine invertebrates](/mw/index.php?title=Marine_invertebrates&action=edit&redlink=1) and [sea urchins](/mw/index.php?title=Sea_urchin&action=edit&redlink=1), the rise in pH to about 7.2\u20137.6 activates [ATPase](/mw/index.php?title=ATPase&action=edit&redlink=1), which leads to a decrease in intracellular potassium and thus induces membrane [hyperpolarization](/mw/index.php?title=Hyperpolarization_(biology)&action=edit&redlink=1). As a result, sperm movement is activated.[3] The change in cell volume that alters intracellular ion concentration can also contribute to the activation of sperm motility. In some [mammals](/mw/index.php?title=Mammals&action=edit&redlink=1), sperm motility is activated by an increase in pH, calcium ion and [cAMP](/mw/index.php?title=Cyclic_adenosine_monophosphate&action=edit&redlink=1), yet it is suppressed by low pH in the [epididymis](/mw/index.php?title=Epididymis&action=edit&redlink=1).

The tail of the sperm - the [flagellum](/mw/index.php?title=Flagellum&action=edit&redlink=1) - confers motility upon the sperm, and has three principal components:

1. a central skeleton constructed of 11 [microtubules](/mw/index.php?title=Microtubule&action=edit&redlink=1) collectively termed the [axoneme](/mw/index.php?title=Axoneme&action=edit&redlink=1) and similar to the equivalent structure found in [cilia](/mw/index.php?title=Cilium&action=edit&redlink=1)

1. a thin cell membrane covering the axoneme

1. mitochondria arranged spirally around the axoneme at the middle-piece

Back and forth movement of the tail results from a rhythmical longitudinal sliding motion between the anterior and posterior tubules that make up the axoneme. The energy for this process is supplied by [ATP](/mw/index.php?title=Adenosine_triphosphate&action=edit&redlink=1) produced by mitochondria. The velocity of a sperm in fluid medium is usually 1\u20134 mm/min. This allows the sperm to move towards an [ovum](/mw/index.php?title=Ovum&action=edit&redlink=1) in order to fertilize it.

The axoneme is attached at its base to a [centriole](/mw/index.php?title=Centriole&action=edit&redlink=1) known as the distal centriole and acts as a [basal body](/mw/index.php?title=Basal_body&action=edit&redlink=1).[4] In most animals, this distal centriole acts as a shock absorber, preventing the [microtubule](/mw/index.php?title=Microtubule&action=edit&redlink=1) filaments from moving at the axoneme base. In contrast, in mammals, the distal centriole evolved an atypical structure, known as the atypical distal centriole.[5] The atypical centriole is made of splayed [microtubules](/mw/index.php?title=Microtubule&action=edit&redlink=1) organized into left and right sides. During sperm movement, the two sides move relative to each other, helping to shape the waveform of the sperm tail.[5]

In mammals, [spermatozoa](/mw/index.php?title=Spermatozoa&action=edit&redlink=1) mature functionally through a process which is known as [capacitation](/mw/index.php?title=Capacitation&action=edit&redlink=1). When spermatozoa reach the isthmic [oviduct](/mw/index.php?title=Oviduct&action=edit&redlink=1), their motility has been reported to be reduced as they attach to epithelium. Near the time of ovulation, hyperactivation occurs. During this process, the flagella move with high curvature and long wavelength.[6] Hyperactivation is initiated by extracellular calcium; however, the factors that regulate the calcium level are unknown.[7]

Without technological intervention, a non-motile or abnormally motile sperm will not fertilize an egg. Therefore, the fraction of a sperm population that is motile is widely used as a measure of semen quality. Insufficient sperm motility is a common cause of [subfertility](/mw/index.php?title=Subfertility&action=edit&redlink=1) or [infertility](/mw/index.php?title=Infertility&action=edit&redlink=1). Several measures are available to improve sperm quality.

## Contents

- [1 Axoneme movement](#Axoneme_movement)

- [2 Sperm DNA damage](#Sperm_DNA_damage)

- [3 Sperm Motility and Age](#Sperm_Motility_and_Age)

- [4 Classifications of motility](#Classifications_of_motility)

- [5 References](#References)

- [6 External links](#External_links)

## Axoneme movement

Sperm motility is dependent on several metabolic pathways and regulatory mechanisms.

The axonemal bend movement is based on the active sliding of axonemal doublet microtubules by the molecular motor dynein, which is divided into an outer and an inner arm. The outer and inner arms play different roles in the production and regulation of flagellar motility: the outer arm increases the beat frequency, while the inner arm is involved in the propulsion and propagation of flagellar bending. The bending of the flagellum is due to subsequent cycles of dynein arm attachment, generation of force and detachment on the B subunit. The binding of the axoneme is the result of a resistance to the microtubule sliding generated by dynein.

Dyneins on the two sides of the central pair apparatus are regulated in an opposite way by an activation/deactivation process carried out by the radial spoke\u2013central pair apparatus, which regulates the flagellar bending. Sperm motility is regulated by several pathways, the most important of which are the calcium pathway and the PKA pathway. These pathways involve ions, adenylyl cyclase, cAMP, membrane channels and phosphorylations.

The first event is the activation of a *Na*+/HCO3 \u2212 (NBC) co-transporter and the regulation of HCO3 \u2212 /Cl\u2212 by SLC26 transporters, which leads to an increase in HCO3 \u2212 levels.

The second event is the activation of an *Na*+/H+ exchanger and of the proton channel Hv-1, which leads to an increase in pH levels.

These increases in HCO3 \u2212 and pH levels lead to the activation of the CatSper channel, a sperm-membrane-specific calcium channel. CatSper can also be activated by progesterone and albumin. CatSper, once activated, opens and allows free calcium to enter the cell, with a global increase in intracellular calcium levels.

Together, the increase in HCO3 \u2212 , pH and calcium leads to the activation of a soluble adenylyl cyclase (SAC or SACY), which increases the production of cAMP and leads to the activation of PKA, a protein kinase that phosphorylates several tyrosine kinases and produces a phosphorylation cascade that ends with the phosphorylation of the axonemal dynein and the start of flagellar movement.[8]

## Sperm DNA damage

Sperm [DNA damage](/mw/index.php?title=DNA_damage_(naturally_occurring)&action=edit&redlink=1) is common in [infertile men](/mw/index.php?title=Male_infertility&action=edit&redlink=1).[9] About 31% of men with sperm motility defects have high levels of sperm [DNA fragmentation](/mw/index.php?title=DNA_fragmentation&action=edit&redlink=1).[10]

## Sperm Motility and Age

Sperm motility increases from puberty through one's mid-thirties. Research shows that from the age of 36 onwards, sperm motility decreases from 40% Grade A+B to 31% in one's 50s. The effects of aging on semen quality are summarized below based on a study of 1,219 subjects:[11]

Age group (years) Number of subjects (n) Motility (% Grade A+B) [Min-Max] 21-28 57 47.5 \u00b1 25.4 [0-88] 29-35 450 48.1 \u00b1 30.4 [0-95] 36-42 532 40.0 \u00b1 27.1 [0-83] 43-49 165 33.1 \u00b1 25.1 [0-84] 50-60 15 31.3 \u00b1 23.9 [0-59]

## Classifications of motility

1. Rapid progressive motility(\u2265 25 \u03bcm/s)

1. Slow progressive motility(5-25 \u03bcm/s)

1. Non-progressive motility(<5 \u03bcm/s)

1. Non-motile

## References

[Template:Reflist](/mw/index.php?title=Template:Reflist&action=edit&redlink=1)

## External links

[Template:Commons category](/mw/index.php?title=Template:Commons_category&action=edit&redlink=1)

- [Sperm motility, Colorado State University](http://www.vivo.colostate.edu/hbooks/pathphys/reprod/semeneval/motility.html)

- [Semen analysis - how to interpret a semen analysis report, Malpani Infertility Clinic](http://drmalpani.com/book/chapter4b.html)

- [Sperm count analysis](http://fertilitylistings.com/articles/tests/sperm-count)

1. [↑](#cite_ref-1) [Template:Cite book](/mw/index.php?title=Template:Cite_book&action=edit&redlink=1)

1. [↑](#cite_ref-2) [Template:Cite journal](/mw/index.php?title=Template:Cite_journal&action=edit&redlink=1)

1. [↑](#cite_ref-3) [Template:Cite journal](/mw/index.php?title=Template:Cite_journal&action=edit&redlink=1)

1. [↑](#cite_ref-4) [Template:Cite journal](/mw/index.php?title=Template:Cite_journal&action=edit&redlink=1)

1. ↑ [5.0](#cite_ref-Fishman_et_al_2018_5-0) [5.1](#cite_ref-Fishman_et_al_2018_5-1) [Template:Cite journal](/mw/index.php?title=Template:Cite_journal&action=edit&redlink=1)

1. [↑](#cite_ref-6) [Template:Cite journal](/mw/index.php?title=Template:Cite_journal&action=edit&redlink=1)

1. [↑](#cite_ref-7) [Template:Cite book](/mw/index.php?title=Template:Cite_book&action=edit&redlink=1)[Template:ISBN missing](/mw/index.php?title=Template:ISBN_missing&action=edit&redlink=1)

1. [↑](#cite_ref-8) [Template:Cite journal](/mw/index.php?title=Template:Cite_journal&action=edit&redlink=1)

1. [↑](#cite_ref-pmid20864101_9-0) [Template:Cite journal](/mw/index.php?title=Template:Cite_journal&action=edit&redlink=1)

1. [↑](#cite_ref-pmid24566945_10-0) [Template:Cite journal](/mw/index.php?title=Template:Cite_journal&action=edit&redlink=1)

1. [↑](#cite_ref-11) [Template:Cite journal](/mw/index.php?title=Template:Cite_journal&action=edit&redlink=1)

---
Adapted from the Wikipedia article [Sperm motility](https://en.wikipedia.org/wiki/Sperm_motility) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Sperm_motility?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.