Fingerprints and Other Ridge Skin Impressions: Chapter 1

Biological

The basis of the permanence and uniqueness of friction ridge skin lies within _____ research.

To increase grip

What is postulated to be the essential function of having friction ridge skin?

15, 40

The dermis is __ to __ times thicker than the epidermis and constitutes the primary mass of the skin.

15, 20

The cornified layer of the epidermis exposed to the environment is made up of __ to __ layers of flat dead cells that are regularly shed through abrasion and replaced by keratinization. 

Do not, do

The basal cells (do/do not) migrate and (do/do not) remain firmly attached to the generating layer.

Basal

Only damage to the _____ layer will result in permanent scars on the epidermis.

5, 6

The hand starts to develop from __ to __ weeks EGA.

6, 7

The first fingers appear around __ to __ weeks, and volar pads appear on the palm.

Interdigital, thenar, hypothenar

The _____ volar pads appear first, followed by _____ and _____ pads.

7, 8, 10, 16

Volar pads appear on each finger at __ to __ weeks and remain clearly visible until __ weeks, when the growth of the hand overtakes the pads, rendering them not visible by week __ EGA

11, 20

It is between weeks __ and __ that the major development of friction ridge skin occurs.

10

At around __ weeks EGA, cells on the basal layer start to proliferate.

Periderm

The embryonic epidermal surface

Primary ridges

The first obvious manifestation of friction ridge skin is _____ _____ on the dermis with fully formed minutiae.

1. The apex of the volar pad (core of the fingerprint)

2. The distal periphery (tip of the finger)

3. The distal interphalangeal flexion crease area

When the surface of the dermis is examined at its various stages of development, ridges start to be visible from what three areas?

1. Shape (symmetry) and size of the volar pads

2. Timing between the regression of the volar pads and the onset of primary ridge formation

3. Relative speed of the three ridge development fronts

4. Bone morphology

The general pattern taken by the ridges seems to be dependent on what four interrelated factors?

Before

The basic form of the general pattern is set (before/after) the initial development of the primary dermal ridge.

Indirectly

The general pattern taken by ridges is (directly/indirectly) inherited.

Dermatoglyphics

The research area concerned with relative frequencies of general pattern types and their relation to chromosomal deficiencies and diseases

Hereditary

It appears that the number of minutiae is a _____ trait.

Sex, digit number

Studies tend to show that the frequency of bifurcation depends on the _____ and the _____ _____.

16

The friction ridge pattern is permanently set at __ weeks EGA

15, 17

Between 15 and 17 weeks EGA, secondary ridges commence to develop between primary ridges and mature until 24 weeks.

Secondary

_____ ridges increase the surface area of attachment to the dermis.

Dermal papillae

Sections of dermal ridges created by the formation of bridges between the apex of primary dermal ridges and secondary ridges

Dermal papillae

_____ _____ are formed for the purpose of increasing the anchorage, exchange, and surface area at the dermal-epidermal interface.

24

At __ weeks EGA, the development of the dermis is finalized

Dermis

The friction ridge pattern in its final stage is a projected image of the structure on the _____.

Age

Research has shown that dermal papillae evolve with ____, tending to multiply in order to anchor the skin structure.

Incipient

_____ ridges follow the same development process as friction ridges but, due to timing constraints, remain only partially developed.

Meissner corpuscles

It has been found that new incipient ridges that can develop during the course of a lifetime are associated with _____ _____.

7, 9

Development of flexion creases starts between __ and __ weeks EGA.

The fundamental premise of the individuality of friction ridge skin

The friction ridges are constructed of ridge units. The number of ridge units that make up a ridge is established at random. Where one ridge starts and stops, the factors that designate its length are completely dependent on differential growth. The location of the ridge unit where a branching develops is also established at random. Due to the plethora of genetic and physical variances the ridge units are subjected to during ridge formation and the number of units involved, the paths of friction ridges are unique to that area of friction skin.