Brainscape's Knowledge GenomeTM

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


See full index

Human Anatomy > First half of Chapter 6 > Flashcards

First half of Chapter 6 Flashcards

1
Q

What is the integumentary system

A

(Fancy name for skin) consists of skin and accesory organs; hair, nails and cutaneous glands.

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

Inspection

A

Inspection of the skin, hair and nails is significant part of a physical exam. Skin is the most vulnerable organ. Relieves more medical treatment than any other organ. Largest organ in our body.

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

Skin Thickness : Thick and Thin

A

Thick skin covers front of hands, bottoms of feet, has sweat glands but no hair follicles or sebaceous (oil) glands. Thin skin covers the rest possesses hair follicles, sebaceous glands and sweat glands.

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

Functions of the skin: resistance to trauma and infection

A

Keratin(predominant in skin), Dermacidin and defensins. Acid mantle.

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

Functions of the skin: Other barrier functions(keep out)

A

Water, UV radiation and harmful chemicals.

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

Functions of the skin: Vitamin D synthesis

A

Skin carries out of first step, liver and kidneys complete process.

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

Functions of the skin: sensation

A

Sensation: skin is an extensive sense organ. Receptors for temperature, touch, pain and more.

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

Functions of the skin: Thermoregulation

A

Thermoregulation:

Thermoreceptors(cool and conserve heat), Vasoconstriction/vasodilation. Perspiration.

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

Functions of the skin: Nonverbal communication

A

Nonverbal communication:
Facial expression
Importance in social acceptance and self image.

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

The Epidermis

A

Epidermis—keratinized stratified squamous epithelium
(inside cells but dead cells)
Includes dead cells at skin surface packed with tough keratin protein
Lacks blood vessels
Depends on the diffusion of nutrients from underlying connective tissue
Contains sparse nerve endings for touch and pain

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

Cells of the Epidermis: Stem cells

A

Undifferentiated cells that give rise to keratinocytes

In deepest layer of epidermis (stratum basale)

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

Cells of the Epidermis: Keratinocytes

A

Great majority of epidermal cells

Synthesize keratin

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

Cells of the Epidermis: Melanocytes

A

Melanocytes
Synthesize pigment melanin that shields DNA from ultraviolet radiation
Occur only in stratum basale but have branched processes that spread among keratinocytes and distribute melanin

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

Cells of the Epidermis: Tactile cells

A

Tactile cells: Touch receptor cells associated with dermal nerve fibers
In basal layer of epidermis

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

Cells of the Epidermis: Dendritic cells

A

Dendritic cells
Macrophages originating in bone marrow that guard against pathogens
Found in stratum spinosum and granulosum. Special type of immune cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Stratum basale (deepest epidermal layer)Layers of the Epidermis

A

Thin skin contains four strata; thick skin contains five strata
Stratum basale (deepest epidermal layer):A single layer of stem cells and keratinocytes resting on the basement membrane
Stem cells divide and give rise to keratinocytes that migrate toward skin surface to replace lost cells
Also contains a few melanocytes and tactile cells

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

Stratum spinosum (Layers of the Epidermis)

A

Several layers of keratinocytes joined together by desmosomes and tight junctions
Named for appearance of cells after histological preparation (spiny)
Also contains some dendritic cells.(resist pulling apart)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Layers of the Epidermis,Stratum granulosum

A

Stratum granulosum
Three to five layers of flat keratinocytes
Cells contain dark-staining keratohyalin granules(related to keratin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Layers of Epidermis, Stratum lucidum

A

Thin, pale layer found only in thick skin

Keratinocytes packed with clear protein eleidin(only in thick skin)

20
Q

Layers of epidermis:Stratum corneum

A 
Stratum corneum (surface layer)
Several layers (up to 30) of dead, scaly, keratinized cells
Resists abrasion, penetration, water loss
21
Q

The Life History of a Keratinocyte:Keratinocytes

A

are produced by mitosis of stem cells in stratum basale or mitosis of keratinocytes in deepest part of stratum spinosum
Mitosis requires abundant oxygen and nutrients, so once cells migrate away from blood vessels of the dermis, mitosis cannot occur

22
Q

The Life History of a Keratinocyte:New keratinocytes

A

push older ones toward the surface
Over time, keratinocytes flatten, produce more keratin and membrane-coating vesicles
In 30 to 40 days a keratinocyte makes its way to the skin surface and flakes off (exfoliates) as dander
Slower in old age
Faster in injured or stressed skin
Calluses or corns—thick accumulations of dead keratinocytes on hands or feet.

23
Q

The Life History of a Keratinocyte:Four important events occur in stratum granulosum:

A

Keratohyalin granules release filaggrin—a protein that binds keratin into tough bundles
Cells produce tough envelope proteins beneath their membranes
Membrane-coating vesicles release lipid mixture that spreads out over cell surface and waterproofs it
Keratinocytes’ organelles degenerate and the cells die

24
Q

The Life History of a Keratinocyte: Epidermal water barrier

A

Epidermal water barrier:
Water retention is fostered by tight junctions between skin cells and the waterproofing that occurs in the stratum granulosum
Helps prevent dehydration
Does not prevent the absorption of water by the stratum corneum when we soak in a bath (“prune fingers”)

25
Q

Dermis

A

Dermis—connective tissue layer beneath epidermis.
Composed mainly of collagen
Well supplied with blood vessels, sweat glands, sebaceous glands, and nerve endings
Houses hair follicles and nail roots
Is the tissue of the facial skin to which skeletal muscles attach and cause facial expressions of emotion
Has a wavy, conspicuous boundary with the superficial epidermis

26
Q

Dermal papillae

A

are upward, finger-like extensions of dermis

27
Q

Epidermal ridges

A

are downward waves of epidermis

Prominent waves on fingers produce friction ridges of fingerprints.

28
Q

Hypodermis

A

Subcutaneous tissue
Has more areolar and adipose than dermis has
Pads body and binds skin to underlying tissues
Common site of drug injection since it has many blood vessels.

29
Q

Subcutaneous fat

A

Energy reservoir
Thermal insulation
Thicker in women
Thinner in infants, elderly

30
Q

Skin Color:Melanin

A

Melanin—most significant factor in skin color
Produced by melanocytes, accumulates in keratinocytes
Two forms of the pigment:
Eumelanin—brownish black
Pheomelanin—reddish yellow (sulfur-containing)

31
Q

People of different skin colors have the same number of melanocytes

A

Darker skinned people
Produce greater quantities of melanin
Melanin breaks down more slowly
Melanin granules more spread out in keratinocytes
Melanized cells seen throughout the epidermis
Lighter skinned people
Melanin clumped near keratinocyte nucleus
Little melanin seen beyond stratum basale

32
Q

Skin Color

A

This color fades as melanin is degraded and old cells are exfoliated. Exposure to UV light stimulates melanin secretion and darkens skin.

33
Q

Other pigments can influence skin color

A

Hemoglobin—pigment in red blood cells
Adds reddish to pinkish hue to skin
Carotene—yellow pigment acquired from egg yolks and yellow/orange vegetables
Concentrates in stratum corneum and subcutaneous fat.

34
Q

The Evolution of Skin Color

A

Variations in skin color result from multiple evolutionary selection pressures, especially differences in exposure to UV light (UV accounts for up to 77% of skin tone variation)
UV light has both harmful and beneficial effects
Adversely: it causes skin cancer, breaks down folic acid
Beneficially: it stimulates vitamin D synthesis
Populations that evolved in the tropics have well-melanized skin to protect against excessive UV

35
Q

The Evolution of Skin Color, continued

A

Populations that evolved in far northern and southern latitudes (weak sun) have light skin to allow adequate UV
Populations that evolved at high altitudes or dry climates (less UV filtering) also are darker skinned
Importance of vitamin D for calcium (crucial for pregnancy, lactation) might explain why women are lighter skinned than men

36
Q

Hair and Nails

A

Hair, nails, and cutaneous glands are accessory organs (appendages) of the skin. Hair and nails are composed of mostly dead, keratinized cells
Pliable soft keratin makes up stratum corneum of skin
Compact hard keratin makes up hair and nails
Tougher and more compact due to numerous cross-linkages between keratin molecules

37
Q

Pilus

A

Pilus—another name for a hair; pili—plural of pilus

38
Q

Hair

A

Hair—a slender filament of keratinized cells growing from a tube in the skin called a hair follicle

39
Q

Hair covers most of the body

A

Hair does not cover: palms, soles; palmar, plantar, and lateral surfaces and distal segments of fingers and toes; lips, nipples, and parts of genitals
Limbs and trunk have 55 to 70 hairs per cm2
Face has about 10 times as many
100,000 hairs on an average person’s scalp
Differences in hairiness across individuals is mainly due to differences in texture and pigment of hair

40
Q

Three types of hair-Lanugo

A

Lanugo: fine, downy, unpigmented hair that appears on the fetus in the last 3 months of development

41
Q

Three types of hair-Vellus

A

Vellus: fine, pale hair that replaces lanugo by time of birth
Two-thirds of the hair of women
One-tenth of the hair of men
All of hair of children except eyebrows, eyelashes, and hair of the scalp

42
Q

Three types of hair-Terminal

A

Terminal: longer, coarser, and more heavily pigmented
Forms eyebrows, eyelashes, and the hair of the scalp
After puberty, forms the axillary and pubic hair
Male facial hair and some of the hair on the trunk and limbs

43
Q

Structure of the Hair and Follicle:
Hair is divisible into three zones along its length
Bulb:

A

Bulb: a swelling at the base where hair originates in dermis or hypodermis
Only living hair cells are in or near bulb

44
Q

Structure of the Hair and Follicle:

Hair is divisible into three zones along its length:Root

A

Root-the remainder of the hair in the follicle

45
Q

Structure of the Hair and Follicle:

Hair is divisible into three zones along its length:Shaft

A

the portion above the skin surface

Human Anatomy (15 decks)

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