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Flashcards in The Integumentary System Deck (51)
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1
Q

What does the skin consist of?

A

The epidermis and the dermis.

2
Q

What kind of epithelium does the epidermis of the skin consist of?

A

Stratified squamous epithelium.

3
Q

What four cell types are found in the epidermis?

A
  1. Keratinocytes. 2. Merkel cells. 3. Langerhans cells. 4. Melanocytes.
4
Q

What are langerhans cells?

A

Wandering phagocytic cells that are important in triggering the body’s immune response.

5
Q

What is the most numerous cell type in the epidermis?

A

The keratinocytes.

6
Q

What is the outermost layer of the epidermis of thick skin?

A

The Stratum corneum.

7
Q

What are the epidermal layers of thick skin from outermost to innermost? (5)

A
  1. Stratum corneum. 2. Stratum lucidum. 3. Stratum granulosum. 4. Stratum spinodum. 5. Stratum basale.
8
Q

What are characteristics of the stratum corneum? (4)

A
  1. Contains multiple layers of flattened, dead, interlocking keratinocytes. 2. Relatively dry. 3. Water resistant, but not water proof. 4. Permits slow water loss by insensible perspiration.
9
Q

What is a characteristic of the stratum lucidum?

A

Appears as a glassy layer in thick skin only.

10
Q

What are characteristics of the stratum granulosum? (3)

A
  1. Keratinocytes produce keratin. 2. Keratin fibers develop as cells become thinner and flatter. 3. Gradually, the cell membranes thicken, the organelles disintegrate and the cells die.
11
Q

What is a characteristic of the stratum spinosum?

A

Langerhans cells and melanocytes are often present.

12
Q

What are characteristics of the stratum basale? (3)

A
  1. The deepest, basal layer. 2. Attaches to the basal lamina. 3. Contains epidermal basal (stem) cells, melanocytes, and Merkel cells.
13
Q

What are basal cells? What layer are they found in?

A

Large stem cells. They are found in the stratum basale.

14
Q

Skin surfaces that lack hair contain what specialized epithelial cells?

A

Merkel cells (Tactile cells).

15
Q

What are the functions of merkel cells (Tactile cells)?

A

They are sensitive to touch, and when compressed release chemicals that stimulate sensory nerve endings.

16
Q

Where are merkel (Tactile) cells abundant?

A

Where sensory perception is most acute, such as fingertips and lips.

17
Q

What do the terms thick and thin skin refer to?

A

They refer to the relative thickness of the epidermis, not to the thickness of the integument as a whole.

18
Q

Where is thick skin typically present? What creates thicker skin?

A

On the palms of the hands and the soles of the feet. All five layers are present and there are more layers of keratinized cells, resulting in an epidermis that is up to six times thicker.

19
Q

What do dermal ridges form and where are they formed?

A

They form friction ridges that result in a more secure grip. They are formed by the stratum basale.

20
Q

What is the papillary layer?

A

The superficial layer of the dermis.

21
Q

What two layers form the dermis?

A
  1. Papillary layer. 2. Reticular layer.
22
Q

What does the papillary layer consist of? What is its function?

A

It consists of loose connective tissue. It contains capillaries and axons of neurons. Capillaries supply the lower layers of the epidermis.

23
Q

What does the reticular layer consist of?

A

Fibers in an interwoven meshwork of dense irregular connective tissue that surrounds blood vessels, hair follicles, nerves, sweat glands, and sebaceous glands.

24
Q

Is the subcutaneous layer (hypodermis) part of the skin?

A

No.

25
Q

What determines skin color?

A

The amount of melanin in keratinocytes.

26
Q

Are there blood vessels in the epidermis? Where does blood diffuse into the epidermis?

A

No. Dermal papillae and epidermal ridges because it increases surface are.

27
Q

What are nails?

A

A modification of the stratum corneum.

28
Q

What is hair composed of?

A

Columns of keratinocytes.

29
Q

What are arrector pilli muscles?

A

Muscles that attach to the hair root.

30
Q

What do sebaceous glands do for hair?

A

They secrete oily sebum that softens and lubricates hair.

31
Q

What results in fingerprints?

A

Friction ridges.

32
Q

What are cleavage lines?

A

Collagen and elastin fibers organized in thin parallel bundles to resist stressors.

33
Q

What results in the formation of stretch marks?

A

The skin overstretching resulting in collagen fibers tearing to form, striae (stretch marks).

34
Q

What are the 3 kind of stimuli origins?

A
  1. Exteroceptors. 2. Interoceptors. 3. Proprioceptors.
35
Q

Where are exteroceptors found?

A

In the skin or mucous membranes.

36
Q

Where are interoceptors found? What is their function?

A

In the walls of viscera. They detect stretching, oxygen, temperature, and pressure.

37
Q

Where are proprioceptors found?

A

In muscles, tendons, joints. They detect body and limb movements.

38
Q

What are the three unencapsulated tactile receptors?

A
  1. Free nerve ending. 2. Tactile (merkel) disc. 3. Root hair plexus.
39
Q

What do tactile (merkel) disc cells sense?

A

Light touch.

40
Q

What do free nerve endings sense?

A

Pain and temperature.

41
Q

What does the root hair plexus sense?

A

Movement of hairs, light touch.

42
Q

What are the three types of encapsulated tactile receptors?

A
  1. Tactile (Melssner) corpuscles. 2. Lamellated (Padnian) corpuscles. 3. Bulbous (Ruffini) corpuscles.
43
Q

Where are tactile (melssner) corpuscles found?

A

In the tips of some dermal papillae.

44
Q

What do tactile (melssner) corpuscles sense?

A

Light touch, texture, shape.

45
Q

Where are Lamellated (Padnian) corpuscles found?

A

In dermis, subcutaneous tissue, synovial membrane, and some viscera.

46
Q

What do lamellated (Padnian) corpuscles sense?

A

Deep pressure.

47
Q

Where are bulbous (Ruffini) corpuscles found?

A

In dermis and subcutaneous layer.

48
Q

What do bulbous (Ruffini) corpuscles sense?

A

Continuous deep pressure. Force motion and skin distortion.

49
Q

What corpuscles are associated with the dorsal column media lemniscus (DCML) pathway? (2)

A
  1. Tactile disks/corpuscles. 2. Root hair plexus.
50
Q

What corpuscles are associated with the anteriolateral pathway?

A
  1. Bulbous. 2. Free nerve endings.
51
Q

What are dermatomes?

A

Specific segment of skin supplied by a single spinal nerve.