Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

FIC 1-4 > Ridgeology > Flashcards

Ridgeology Flashcards

1
Q

Define Ridgeology

A

The study of the uniqueness of the friction skin and its use for personal identification

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the three layers of human skin?

A

Epidermis

Dermis

Hydrodermis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the types of skin and their characteristics?

A

Smooth skin - hair, sebaceous glands, sweat glands, and no friction ridges.

Friction (volar skin) - no sebaceous glands, sweat glands only, inner surface of fingers, hands and bottom of feet; less pigmentation; completely covered in friction ridges; increases grip.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the 5 layers of the epidermis?

A

Stratum Basale (basal layer)- single layer attached to the basement membrane

Stratum Spinosum- 2-4 layers thick
Stratum Granulosum- last of living cells
Stratum Lucidum- keratin fills inside of cell
Stratum Corneum- dead cells, can be 100 cells thick, large and flat, have accumulation of keratin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Basement membrane zone

A

Is a fibrous sheet that contains elements of epidermis and dermis. The fibres are interwoven and provide structural support for the epidermis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Cell Mitosis

A

Is the regeneration skin cells. Cells of the basal layer replicate their DNA and eventually separates into 2 cells with a complete copy of their DNA.

Cells are pushed into the stratum spinosum and continues with each new cell pushing older cells to surface.

Takes approximately 30 days for new cell to migrate to surface.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Dermal papillae

A

Critical peg like formations that keep the dermis and epidermis connected.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the two critical structures that keep the dermis and epidermis connected?

A

Basement membrane zone

Dermal papillae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Whose extensive research of fetal skin cross sections showed the development of dermis papillae?

A

Alfred Hale, 1952

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Whose research showed the dermal papillae are in 2 rows on the underside of the epidermis and break down into smaller pegs as people age?

A

Michigan Okajma, 1976

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe permanent scars vs temporary scars

A

Permanent occur when the damage is done to the basal layer or deeper. Can also occur as a result of a genetic condition/ disease

Temporary scars are superficial injuries that do not reach the basal layer.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the difference between a scar and a white line crease?

A

Scars - the ridges can’t be followed

White line crease- transient in nature and you can follow the ridge flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the factors that ensure the persistency of friction ridge structure?

A

Basal cell mitosis- the replacement of cells lost at the surface

Structural elements- desmosomes bound basal cells while they migrate to surface; basal cells are bound to the basement membrane; basement membrane is attached to the epidermis and dermis; dermal papillae on the dermis fit into pockets on the underside of the epidermis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Friction Ridge Development

3 weeks

A

The epidermis of the palms/ hands is approximately 1 cell thick and will thicken as the embryo grows

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Friction Ridge Development

6 weeks

A

Hand is flat and paddle like

Volar pads appear (11)

  • 5 fingers
  • 4 interdigital
  • thenar
  • hypothenar
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Friction Ridge Development

8 weeks

A

Digits have separated

Thumb has rotated

Major flexion creases appear. First in palm then fingers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Flexion Creases

A

Develop before friction ridges

Friction ridges do not cross over a flexion crease

18
Q

What are the three creases on the palm?

A

Distal transverse crease (top)

Proximal transverse crease (middle)

Thenar crease (bottom)

19
Q

Friction Ridge Development

10.5 to 12 weeks

A

Volar pads start to regress

Primary ridges develop in 2 directions. Down into the dermis and up from the basal layer.

Longest ridges and bifurcations are formed first

20
Q

Whose extensive research into friction ridge skin showed volar pad regression occurs almost concurrently with the beginning of primary ridge development?

A

Harold Cummins, 1929

21
Q

Friction Ridge Development

15 to 17 weeks

A

Primary ridge development ceases

Secondary ridges begin to appear between existing primary ridges

**Time of Differentiation **

22
Q

Whose study of this cross-sections of fetal skin determined the timing of the development of primary and secondary ridges?

A

Alfred Hale, 1952

23
Q

Friction Ridge Development

20 weeks

A

Secondary ridge locations are established

Friction ridges visible on surface

Friction ridge configuration is established and will not change by 20 weeks (maybe as early as 16 weeks)

24
Q

Friction Ridge Development

20 to 24 weeks

A

Secondary ridges continue to develop

Around 23 weeks dermal papillae begin to form

At 24 weeks entire system has matured

25
Q

Friction ridge flow

A

Ridges tend to grow across the finger

The bulges of the volar surface create create stresses in directions other than lengthwise cause the flow of ridges to change

26
Q

Who was the first to suggest these centres of disturbance of primate friction ridge formations represents the locations of volar pads?

A

Harrison Hawthorne Wilder, early 20th century

27
Q

How do volar pads affect patterns?

A

Size, shape and symmetry of volar pads direct ridge alignment, flow and pattern formation

Timing between the start of primary ridge development and volar pad regression affects ridge count (core to delta distance)

28
Q

Whose extensive research on friction ridge skin showed the size, location, growth, and configuration of the volar pads affect friction ridge development and overall fingerprint pattern?

A

Harold Cummins, 1929

29
Q

Ridge Formation on digits

A

First starts at apex of volar pad

Then the tip of finger

The the base (platform ridges) which can assist with orientation

30
Q

How do volar pads affect whorl patterns?

A

When the volar pad is large and evenly shaped

31
Q

How do volar pads affect loop pattern

A

Volar pad is off set to one side

Height of volar pad will dictate the core to delta distance

32
Q

How do volar pads affect arch patterns?

A

When primary ridge development occurs later in the process after the volar pads have fully regressed

33
Q

Minutiae

A

Friction ridges are made up of individual ridge units

Each ridge contains a pore, pore duct, sweat gland

Length of ridge unit is approximately same as width

34
Q

Who is credited with being the first to recognize that although specific friction ridge arrangements may be similar; they are never duplicated?

A

J.C.A, Meyer, 1785

35
Q

Incipient Ridges

A

Are immature ridges

Did not fully develop prior to the start of secondary ridge development ( by time if differentiation)

Not always recorded and not everyone has them.

36
Q

Who studied incipient ridges and determined they are primary ridges that didn’t fully develop?

A

Michigan Okajima, 1976

37
Q

Uniqueness

A

Chance events occur during development

Random Aspects

  • Random Timing
  • Random Growth
  • Random pressures
38
Q

Random Timing

A

The timing of onset of primary ridge development n conjunction with volar pad regression

Time differentiation- timing of onset of secondary ridge development

39
Q

Random Growth

A

Number of ridge units in friction ridge formation
Path of friction ridge and where starts/ stops
Ridge thickness/thinness
Ridge alignment, bifurcation or misalignment
Pore locations and shapes
Height of ridge as 3 dimensional

*** called Differential Growth **

40
Q

Whose research demonstrated that differential growth plays a major role in the establishment of the morphology of volar skin?

A

Alfred Hale, 1952

41
Q

Random Pressures

A

Stress on the skin due to shape and size of volar pads

Pressure from other ridges

Pressures in the womb

Numerous genetic and physical pressures

42
Q

Who observed that ridge patterns are affected by external forces and by neighboring ridges?

A

Inez Whipple, 1904

FIC 1-4 (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions