Friction Ridge Examination

Question 1

What are friction ridges?

Answer 1

• Appear on the palms, soles and ends of fingers and toe
• Begin forming in the 9th or 10th week of foetal development
• Become permanent and fixed in their patterns from about 17 weeks of embryonic development

Question 2

What are patent prints?

Answer 2

Prints visible with the naked eye

Question 3

What are latent prints?

Answer 3

Prints that are not visible to the naked eye, they require assistance to make them visible

Question 4

What are the three classes of fingerprints?

Answer 4

Loops, arches and whorls

Question 5

What are loops?

Answer 5

• Have one or more ridges entering from one side of the print, curving back on themselves and exiting the fingerprint on the same side
• The most common pattern
• Ulnar loop: loop enters and exits on the side of the finger toward the little finger
• Radial loop: loop enters and exits on the side of the finger towards the thumb

Question 6

What are arches?

Answer 6

• Plain arch: ridges entering one side of the finger gradually rising to a rounded peal and exiting the other side
• Tented arch: arches with a pronounced sharp peak
• The rarest of the three main classes of patterns
• Do not have type lines, cores or deltas

Question 7

What are whorls?

Answer 7

• All have type lines and at least two deltas
• Type line: one of the two diverging ridges around some feature of the print
• Delta: the point of divergence in ridges around some feature of the print
• Classified are plain, central pockets, double loops and accidentals