Skin, hairs, nails lab and lecture Flashcards
1
Q
Explain keratinization
A
As new keratinocytes move from the stratum basale to the skin surface, they accumulate more and more keratin, die, and form dead surface layers. This process takes 7-10 weeks.
2
Q
A
sebaceous glands
3
Q
What is the other name for the skin?
A
cutaneous membrane
4
Q
A
thin skin
5
Q
What are the two main parts of the skin?
A
epidermis and dermis
6
Q
What is the name of the muscle attached to the hair, where is it located, and what is its function?
A
arrector pili muscle of hair (smooth muscle)
extends from papillary dermis to the dermal rooth sheath around the base of the hair follicle
create goose bumps during cold or fright
7
Q
What are the functions of the stratum basale?
A
This is the only layer of the skin that undergoes mitosis and creates keratinocytes to replace the regularly shed ones from the top layer. The mitosis happens in the epidermal stem cells.
8
Q
What are the three layers of the root and shaft of the hair starting from the inside?
A
medulla, cortex, and cuticle
9
Q
What is the order of the layers of the epidermis starting from the most deep?
A
stratum basale, stratum spinosum, stratum granulosum, stratum lucidum (in thick skin), stratum corneum
10
Q
A
stratum basale or germinativum
11
Q
What is the average thickness of skin?
A
1-2mm
12
Q
A
Pacinian corpuscle
13
Q
What are two disorders that related to melanin production?
A
Albinism- complete lack of melanin production and genetic based
Vitaligo- parital or complete loss of melanocytes from patches of skin. Autoimmune based.
14
Q
What is contained in eccrine and apocrine sweat?
A
Ions, urea ,uric acid, ammonia, amino acids, glucose, and lactic acid
15
Q
A
dermal root sheath
16
Q
Define sebaceous glands?
A
Oil glands that are simple, branched acinar glands.
17
Q
A
nail bed or hyponychium
18
Q
define the cortex
A
forms the major part of the shaft and consists of elongated cells
19
Q
What are free nerve endings?
A
Dendrites that lack apparant structural specialization. Sense warmth, coolness, pain, tickling, and itching.
20
Q
A
hair bulb
21
Q
Structures?
A
dermal papillae
22
Q
What are the two types of granules found in the stratum granulosum?
A
keratohyalin and lamellar granules
23
Q
What do lamellar granules do?
A
release a water-repellent sealant that decreases water entry and loss and inhibits the entry of foreign materials
24
Q
A
eccrine sudoriferous gland
25
epidermis
26
How many layers of cells are in the stratum spinosum?
8-10 layers of keratinocytes
27
matrix
28
Pacinian corpuscle
29
What is type of tissue is the stratum basale made of?
single row of cuboidal or columnar keratinocytes
30
What are the two additional cells present in the stratum spinosum?
Langerhans cells and the projections of melanocytes
31
hair shaft
32
What are the four principal cells in the epidermis?
keratinocytes, melanocytes, Langerhans/dendritic cells, and tactile epithelial cells.
33
Which layer of skin is vascular?
dermis
34
apocrine sudoriferous gland
35
what are the two types of epidermis?
thin(hairy skin) and thick(hairless skin)
36
What do sebaceous glands secrete and what is it's function?
sebum which is a mixture of trigycerides, cholesterol, proteins, and inorganic salts. Coats the surface of hairs to keep them supple. Prevents excessive evaporation of water from skin, keeps skin soft, and inhibits the growth of some bacteria.
37
cortex
38
What is the inner/internal root sheath?
Produced by the matrix and forms a cellular tubular sheath of epithelium between the external root sheath and the hair. Provides a channel for the hair to grow in.
39
What is the integumentary system composed of?
skin, hair, oil and sweat glands, nails, and sensory receptors
40
What is in the subcutaneous tissue?
fat, large blood vessels that supply the skin, and pacinian corpuscles.
41
What is the other name for merkel cells?
tactile epithelial cells
42
cuticle
43
keratinocytes
44
How many layers does the stratum granulosum have?
3-5 layers of keratinocytes
45
texture of hair
straight
46
What is this in yellow?
medulla
47
Where is hair not located?
nipples, palms, palmar surfaces of digits, soles, plantar surfaces of feet, labia minora, and prepuce of the penis.
48
matrix cells
49
What are the three types of hair and what are their characteristics?
lanugo-fetal hair
terminal hair- coarse, heaily pigmented hair, often associated with secondary sexual characteristics at puberty
vellus hairs-peach fuzz
males have more terminal hair than females
50
What affects hair growth?
illness, radiation treatment, chemo, age, genetics, gender, and severe emotional stress. Extreme dieting, weightloss, and post partum.
51
nail body
52
hair follicle
53
Define apocrine sweat glands?
coiled tubular glands found mainly in the armpit, groin, areola, and beard areas. Release secretions via exocytosis NOT APOCRINE. Located in the reticular dermis and their ducts open into hair follicles.
54
Hair root
55
When do each type of sweat gland begin working?
Eccrine after birth
| Apocrine during puberty
56
What is the other name of langerhans cells?
dendritic cells
57
What are the two types of melanin?
Eumelanin and pheomelanin
58
What is alopecia?
partial or complete lack of hair caused my genetic factors, aging, endocrine disorders, chemo, or skin diseases
59
Label starting with top left.
eponychium (cuticle), lunula, nail body, hyponychium, nail matrix
60
dermis
61
eccrine sudoiferous gland
62
dense irregular connective tissue
63
What two structures are associted with hair?
sebaceous glands and smooth muscle fibers
64
What causes fingerprints?
papillary ridges?? epidermal ridges?? sources differ
65
arrector pili
66
Label starting at top right
67
hypodermis and subcutaneous tissue
68
Keratinized stratified squamous epithelium
69
Why is the stratum spinosum called that?
Spinelike projections made of keratin filaments insert into desmosomes
70
What are meissner corpuscles?
Nerve endings sensitive to fine touch and vibrations.
71
What things are in the reticular dermis?
Netlike structure of collagen fibers which resist skin stretching, blood vessels, nerves, hair follicles, sebaceous glands and sudoriferous glands.
72
What are the three stages of hair growth? What are they characterized by?
Growth- cells of the hair matrix divide and cause hair to grow longer 2-6 years
regression stage- hair matrix stops dividing 2-3 weeks
resting phase- hair root falls out 3 months
73
What are the functions of hair?
Protection and light touch sensation
74
What do the keratinocytes produces?
lamellar granules
75
stratum corneum
76
Define ceruminous glands?
modified sweat glands in the external ear that produce wax (cerumen). Are located in the subcutaneous layer. Provide a barrier against foreign bodies and insects. Waterproofs meatus and protects from bacteria and fungi.
77
define the hair cuticle
single layer of flat thin cells that are the most heavily kerotinized. Aranged like shingles on a house.
78
stratum corneum
79
texture of hair
wavy
80
What do merkel cells make contact with in the dermis that is important to their function?
They make contact with a neuron type cell called non encapsulated sensory corpuscle.
81
What is the description of the papillary dermis?
Superficial portion of the dermis (1/5) consisting of areolar connective tissue with thin collagen and fine elastic fibers, contains dermal ridges that house blood capillaries, tactile corpuscles, and free nerve endings.
82
What is the distinctive feature of cells in the stratum granulosum?
the dark staining granules of protein called keratohylin
83
Define the medulla
two to three rows of irregulary shaped cells that contain pigment granules
84
hari follicle
85
Label starting at the top right
86
What influences thickness and pattern of hair distributions?
genetics and hormones
87
what is the hair root plexus?
dendrites of neurons surrounding the hair follicle that are sensitive to touch
88
What type of cell junction is present in the stratum basale?
desmosomes and hemidesmosomes
89
What increases melanin production?
Esposure to UV
90
What is the main function of eccrine sweat glands?
thermoregulation via evaporative cooling
| also release sweat during emotional stress
91
Where do langerhans cells come from?
red bone marrow
92
What is the main function of melanocytes?
Produce melanin which gives skin pigment
93
What organ is carotene important for?
the eyes
94
What is the difference between the sweat released by eccrine glands and the one released by apocrine glands?
Apocrine contains lipids and protein and has a musky odor because of bacterial interaction.
95
Region?
papillary region
96
What is the external root sheath?
The outer root sheath (ORS) is an extension of the epidermal basal layer which envelopes the entire hair follicle (HF). In addition, the ORS contains a number of functional compartments: the bulge, which serves as a reservoir for hair stem cells, and the sebaceous gland, responsible for hair lubrication.
97
What are the accessory structures of the integumentary system?
hair, glands, and nails
98
What action stimulates increased cell production and keratin that forms a callus?
friction
99
Where are Merkel/tactile epithelial cells located?
deepest layer of the epidermis
100
How many layers does thin skin have?
4
101
What are the 6 functions of the integumentary system?
1. regulates body temp
2. stores blood
3. protects body from external environment
4. detects cutaneous sensations
5. excretes and absorbs substances
6. synthesizes vitamin D
102
How do nutrients and oxygen get to the nonvascular epidermis?
They diffuse from the blood vessels in the dermis. The stratum basale is closest to the dermis and receives most of this, allowing them to be more active and produce new cells.
103
What are the functions of merkel/tactile epithelial cells?
detect light touch sensations
104
What are the two layers of the dermis?
papillary dermis and reticular dermis
105
papilla of the hair
106
Besides keratinocytes, what two other cells are present in the stratum basale?
melanocytes and merkel/tactile epithelial cells with their sensory corpuscles.
107
external epithelial root sheath
108
Define eccrine glands
simple, coiled tubular glands located in the reticular dermis and end in a pore on the surface of the epidermis and produce sweat. They are merocrine-type secretion glands.
109
Where is the hair root located?
the dermis and sometimes the subcutanous tissue
110
internal epithelial root sheath
111
What are the three main substances that affect skin color?
Melanin, hemoglobin, and carotene.
112
What causes darker or lighter skin?
The amount of pigment the melanocytes produce. Everyone has roughly the same amount of melanocytes
113
Where are eccrine sweat glands
throughout the body and especially on the forehead, palms, and soles.
114
Where is the hair shaft located?
above the skin
115
areolar connective tissue
116
What process are keratinocytes undergoing in the stratum granulosum
apoptosis (cell death)
117
stratum spinosum
118
What are the functions of langerhans cells and what type of cell are they?
cell type: macrophage
participate in immune responses against microbes, they help other cells of the immune system recognize invading microbes
Easily damaged by UV light
119
What are dermal papillae and how are they identified?
small nipple shaped structures that project into the bottom of the dermis. Contain capillary loops, meissner corpuscles, and free nerve endings. Create finger prints.
120
How many layers are in the stratum corneum?
25-30 layers of flattened dead keratinocytes
121
What type of tissue is the epidermis made of?
| What type of tissue is the dermis made of?
epithelial
| connective tissue
122
Where are sebaceous glands located in the tissue and on the body?
Usually connected to hair follicles in the dermis and the opens up into the neck of the hair follicle
Located in lips, glans penis, labia minora. Small in trunk and limbs, large in breasts, face, neck, and superorior chest. Absent in palms and soles.
123
What is the dermis comprised of?
dense irregular connective and areolar tissue
124
How many layers of stratum lucidum are there?
4-6 layers of flattened clear, dead keratinocytes
125
stratum lucidum
126
What is below the dermis?
subcutaneous tissue
127
lunula
128
In what form does melanin come in?
granules
129
stratum granulosum
130
reticular region
131
What type of tissue makes up the epidermis?
keratinized stratified squamous epithelium
132
What is the subcutaneous tissue also know as?
hypodermis
133
What are the three main types of glands in the skin and what are the ones that fall under them if applicable?
```
Sebaceous
Sudoriferous
-eccrine
-apocrine
Ceruminous
```
134
What is the definition of the reticular dermis?
Deeper portion of the dermis (4/5), consists of dense irregular tissue with bundles of thick collagen and some coarse eleactice fibers. Spaces between fibers contain some adipose cells, hair follicles, nerves, sebaceous glands, and sudorferous glands.
135
What is the other name for stratum basale?
stratum germinativum
136
What is this?
hair cuticle
137
layer
external epithelial root sheath
138
Where is the hair follicle and what are the two layers of it?
Surrounding the hair root
| external root sheath and internal rooth sheath
139
thick skin
140
Which cell is most abundant in the epidermis?
keratinocytes
141
How does melanin protect cells from UV light?
Melanin granules cluster to form a protective veil over the nucleus of keratinocytes to shield nuclear DNA from UV light.
Melanocytes are very susceptible to UV damage.
142
What are capillary loops?
blood vessels
143
Specific layer
internal epithelial root sheath
144
What are sudoriferous glands?
sweat glands
145
How many layers does thick skin have?
5
146
texture of hair
curly
147
What is carotene a precursor to?
Vitamin A
148
eponychium or cuticle
149
Which skin contains epidermal ridges?
thick skin
150
What are nails made of?
keratinized epidermal cells
151
In which type of skin are sweat glands more numerous?
thick skin
152
In which type of skin are sebaceous glands absent?
thick skin
153
Which type of skin has more sensory receptors?
thick skin
154
How does the skin help with thermoregulation?
Sweat and blood flow to the dermis. dialation and constriction of blood vessels
155
What percentage of the blood is held in the dermis?
8-10%
156
How does the skin protect the body?
keratin, lipids released by lamella granules, sebum, acidic sweat, macrophages (langerhans cells)
157
What is the precursor molecule in vitamin D production?
calcitrol
158
Overview of epidermal wound healing
No blood lost/superficial
Stratum basale is activated by epithelial growth hormone to create more cells from the epidermal stem cells, these cells move up to replace the lost or damaged cells. Takes about 7 days to heal
159
Overview of deep wound healing
Blood involved, injury down to dermis
1. vasoconstriction to stop blood loss
2. platelets create clot
3. WBC go to injury, neutrophils then macrophages
4. cell mitosis to create new cells to replace damaged/lost ones
5. cell maturation
160
Six age associated changes
1. wrinkles
2. dehydration and cracking of skin
3. sweat production decreases
4. numbers of functional melanocytes go down
5. subcutaneous fat is lost and skin thickness decreases
6. nails become more brittle
161
Cause of skin cancer and the three major types
Excessive exposure to UV
| basal cell carcinoma, squamous cell carcinoma, and malignant melanoma
162
What causes burns?
Excessive heat, electricity, radioactivity, or corrosive chemicals that denature the proteins in the skin
163
How are burns graded?
```
By their severity
First degree(sunburn)- just epidermis
Second degree- down to dermis, blisters on the skin
Third-degree- down to hypodermis
```
164
What is the rule of nines?
A method for splitting up the body into percentages to calculate the % of the body that is burned.
Exam: Perineum is 1%
165
Define pressure ulcers (bed sores) and what type of patient has them often?
When shedding of epithelium caused by a deficiency of blood flow to tissues occurs, pressure ulcers can develop
Older patients and diabetic patients
166
What system does vitamin D work with besides the integumentary and skeletal system?
immune system
