Exam 2 Flashcards
1
Q
what does the integumentary system consist of
A
covers body and consists of skin and accessary tissues (nails, hair, sweat glands, sebaceous glands)
2
Q
integument =
A
skin
3
Q
what does the integumentary system provide
A
a barrier to the outside world and a visual indicator of our physiology and health
4
Q
dermatology
A
study of skin
5
Q
layers of the integument
A
epidermis and dermis
6
Q
what is the epidermis composed of
A
stratified squamous epithelium
7
Q
what is the dermis composed of
A
primarily dense irregular connective tissue
8
Q
is the hypodermis part of the integumentary system
A
no
9
Q
what is the hypodermis composed of
A
layer or areolar and adipose tissue
10
Q
what are the layers of the epidermis in order from deep to superficial
A
stratum basale
stratum spinosum
stratum granulosum
stratum lucidum
stratum corneum
11
Q
the layers in the epidermis are
A
keratinized
12
Q
what layers of the epidermis are composed of living keratinocytes
A
the first three layers
13
Q
what is stratum lucidum and stratum corneum composed of
A
dead cells
14
Q
what layer of the epidermis is the deepest
A
stratum basale
15
Q
stratum basale
A
has a single layer of cells as well as a germanitive layer with keratinocytes melanocytes and tactile cells
16
Q
whats the most abundant cell in the epidermis
A
keratinocytes
17
Q
keratinocytes are
A
found in all layers
large stem cells and have ability to regenerate new cells
18
Q
do keratinocytes always produce keratin
A
no, they CAN produce keratin but it doesn’t always mean that they are synthesizing it currently
19
Q
keratin
A
a protein that strengths epidermis and makes skin almost waterproof
20
Q
melanocytes
A
scattered among keratinocytes
21
Q
what do melanocytes produce and store
A
melanin in response to UV light
22
Q
melanocytes transfer _______ into keratinocytes
A
melanosomes
23
Q
how does melanin show in our skin color
A
pigment of melanosomes enter into the nucleus of keratinocytes create a dark pigement to protect the nucleus from UV radiation/sun
24
Q
tactile cells are also called
A
merkel cells
25
tactile cells
few in number
scattered within stratum basale
sensitive to TOUCH
when compressed, they release chemicals as a result of stimulation of sensory nerve endings
26
stratum spinosum
several layers of keratinocytes
daughter cells from stratum basale pushed into this layer
27
epidermal dendritic cells are also called
langerhans cells
28
where are epidermal dendritic cells found
in stratum spinosum and stratum granulosum
29
epidermal dendritic cells
initiate immune response when something enters the cells like a pathogen they are able to use phagocytosis to engulf the pathogen and break it down
30
phagocytosis
cells that are able to extend plasma membrane to engulf something and break it down
31
stratum granulosum contains how many layers of keratinocytes
3-5
32
where does keratinization start
within straum granulosum
33
keratinization
keratinocytes fill with keratin which caused nucleus and oragnelles to disintegrate
34
are fully keratinized cells living or dead
dead
35
is the process of keratinization done in stratum granulosum?
no it continues when cells rise to higher layers
36
are the cells in stratum granulosum dead
no because there isn't enough keratin in the production to kill the cell
37
stratum lucidum has how many layers
2-3
38
stratum lucidum contains
dead translucent cells due to a byproduct of keratinization that contains a translucent protein
39
what is the only kind of skin found on the palms and soles of feet
stratum lucidum
40
stratum corneum contains how many layers
20-30 dead interlocking keratinized cells
41
the cells within stratum lucidium are
anucleate meaning without a nucleus
42
migration of keratinocytes
originate from stem cells is stratum basale
migrate through strata to straum corneum over two weeks
remain in stratum corneum for two weeks
shed
43
what is the purpose of stratum corneum having a dry and thickened surface
it makes it unsuitable for microorganism growth and secretions help protect it
44
thick skin
found in palms of hands and soles of feet
exhibits all five layers of epidermal strata
houses sweat glands
no hair follicles or sebaceous glands
45
thin skin
covers most of body
lacks a stratum lucidum
contains sweat glands, hair follicles, and sebaceous glands
46
dermis is composed of
CT proper (collagen with elastic and reticular fibers), blood bessels, sweat glands, sebaceous glands, hair follicles, sensory nerve endings, arrector pili
47
what are the two layers of the dermis
papillary layer and deeper reticular layer
48
papillary layer is composed of
areolar connective tissue
49
dermal papillae
projections of epidermis (epidermal ridges) interdigitate with papillae which helps interlock and increase area of contact between layers
50
reticular layer is composed of
dense irregular connective tissue with large bundles of collagen fibers interwoven into meshwork surrounding structures
51
what three pigments contribute to skin color
hemoglobin
carotene
melanin
52
hemoglobin
oxygen binding protein in red blood cells
53
what gives blood vessels in dermis a reddish tint
hemoglobin
54
carotene
shows a yellow orange pigement that is acquired from yellow/orange vegetables
55
where does carotene accumulate
in subcutaneous fat and keratinocytes of stratum corneum
56
melanin
pigment produced and stored in melanocytes
57
what does the amount of keratin in somebodies skin depend on
heredity and light exposure
58
what stimulates melanin production
UV light
59
does everyone have the same number of melanocytes
yes except other produce more and darker melanin
60
subcutaneous layer/ hypodermis
areolar and adipose CT that isn't part of the integument that protects the body, acts as an energy reservoir, and provides thermal insulation
61
nails
scale-like modifications of stratum corneum
62
what is the function of nails
to protect distal tips of digits and assist in grasping objects
63
hair
pilus, shaped like slender filament that is composed of keratinized cells and grown from hair follicles
64
what are the three zones of hair
hairbulb, root, shaft
65
hair bulb
swelling at base where hair originates in dermis
surrounds hair papilla composed of CT
only region containing living epithelial cells
66
root
zone of hair from bulb to skin surface
67
shaft
portion of hair beyond skin surface
68
hair follicle
oblique tube surrounding hair root that extends to dermis
69
the outer connective tissue root sheath originates in the
dermis
70
the inner epithelial tissue root sheath orginates in the
epidermis
71
arrector pili
thin ribbons of smooth muscle that extend from hair follicle to dermal papillae
72
what does arrector pili do
elevates hair with contration "goosebumps"
73
what are the three phases of hair growth cycle
anagen
catagen
telogen
74
anagen
active phase where living cells in hair bulb rapidly grwoing dividing and transforming into hair
75
catagen
brief regression period where cell division ceases
76
telogen
resting phase where hair is shed
77
what is the longest phase of the hair cycle
anagen phase that is arround 18 months to 7 years depending on genetics
78
what percent of follicles are in anagen phase
80-95%
79
how long does the catagen phase last
3 to 4 weeks
80
how long does the telogen phase last
3 to 4 months
81
what happens after telogen phase
the hair bulb cells begin to regrow and the follicle re-renters anagen phase
82
what are the main functions of hair
protection, facial expression, heat retention, sensory reception, visual identification, chemical signal dispersal
83
phermones
chemical signals involved in attracting sexual partners
84
where are phermones secreted
specific sweat glands onto hairs in the axillary and pubic regions
85
sweat glands
coiled, tubular secretory portion in reticular dermis
86
myoepithelial cells
contract to squeeze gland and discharge secretions in response to sympathetic stimulation
87
how do sweat glands secrete
exocytosis
88
what is sweat composed of
99% water and 1% of other chemicals like electrolytes, metabolites, and waste products
89
what is the major function of a sweat gland
thermoregulation
90
thermoregulation
regulation of body temperature by fluid evaporation
91
what are some benefits of sweat
provides a means for loss of water and electrolytes
may help eliminate ingested drugs
antibacterial/antifungal
92
sebaceous glands
produce sebum which is a lubricant for skin and hair that helps kill bacteria
93
where does sebum dishcharge into
a hair follicle
94
the secretion of sebum is stimulated by hormones, mainly...
androgens
95
when is the secretion of sebum activated
during puberty
96
functions of the integument
protection
prevention of water loss/gain
secretion
absorption
temperature regulation
sensory reception
97
is the epidermis water resistant or waterproof
water resistant
98
what waste products are secreted onto skin surface when you sweat
urea, salts, water
99
secretion also assists with
electrolyte homeostasis
100
what helps make skin water resistant
the sebum of sebaceous glands lubricating skin surface and hair
101
skin is selectively permeable which allows for
the blocking of harmful things and absoption of certain chemicals or drugs
102
transdermal administration
some oil-soluble drugs delieverd by adhesive patch that slowly penetrate epidermis, and then are absorbed into blood vessels in dermis
103
epidermal dendritic cells are found in
stratum spinosum and initiate immune response against pathogens
104
temperature regulation
influenced by capillaries and sweat glands in dermis as well as dermal blood vessles
105
vasoconstriction
shunting of blood away from periphery of body toward depper structures
106
if the temperature is very cold what kind of regulation of heat would you see
vascoconstriction
107
vasolidation
more blood can travel close to the surface which results in a flushed face during exercise
108
skin has extensive innervation (distribution of nerve fibers) that helps to
monitor stimuli in dermis and epidermis
109
meissner's corpuscle responds to
light touch
110
ruffini corpuscle
deep pressure and skin distortion
111
pacinain corpuscle
deep pressure or vibration
112
free neuronal endings responds to
pain, itch, hot, and cold
113
hair follicles respond to
light touch and vibration
114
components of the skeletal system
bones
cartilage
ligaments
other CT (tendons; joint capsule)
115
bones are the
primary organs of the skeletal system
116
what are the two types of bone
compact and spongy bone
117
compact bone
referred to as dense or cortical bone that is composed of relatively dense CT that appears white, smooth, and solid
118
what percent of bone mass is compact bone
80%
119
spongy bone
referred to as cancellous or trabecular bone is loacted internal to compact bone and appears porous
120
what percent of bone mass is spongy bone
20%
121
cartilage
semirigid CT that is more flexible than bone
122
what are the three types of cartilage
hyaline
fibrocartilage
elastic
123
hyaline cartilage
provides model for formation of most bones in the body
124
where is hyaline cartilage found
within growth plates, at ends of ribs to connect to sternum, and covers the ends of some bones
125
what does the embryonic skeleton consist of
only cartilage
126
what cartilage is the strongest
fibrocartilage
127
fibrocartilage
weight bearing cartilage that withstands compression
128
where is fibrocartilage found
intervertebral discs, pubic symphysis, cartilage pads of knees (menisci)
129
ligaments
anchor bone to bone
130
tendons
connect muscle to bone
131
ligaments and tendons are comprised of
collagen fibers packed in a parallel fashion
132
general functions of the skeletal system
support and protection
movement
hemopoiesis
storage of mineral and energy reserves
133
how does the skeletal system function with support and protection
protects delicate tissues in the body like the rib cage protects the heart and lungs and the pelvis protect the urinary and reproductive organs and terminal end of GI tract
134
movement
bone serves as the attachment sites for skeletal muscles
135
hemopoiesis
refers to the production of blood cells
136
where does hemopoiesis occur
in red bone marrow which helps produce red blood cells, 5 white blood cells, and platelets
137
where are stem cells found
within bone
138
what elements does bone store
calcium and phosphate which is released into blood as needed
139
calcium is needed for
muscle contraction
blood clotting
nerve impulse transmission
140
phosphate is needed for
ATP utilization
plasma membranes
141
lipids are stored where
yellow bone marrow of adults
142
Diaphysis
elongated shaft of bone that provides leverage and weight support with compact bone on the outside and spongy bone on the inside
143
medullary cavity
hollow, cyndrilical space within the diaphysis that contains red bone marrow in children and yellow bone marrow in adults
144
epiphysis
knob like region at each end of long bone that is composed of outer thin layer of compact bone and an inner region of spongy bone
145
articular cartilage
covers joint surface with a thin layer of hyaline cartilage
146
what does articular cartilage help with
helps to reduce friction and absorb shock in moveable joints
147
metaphysis
region of mature bone between diaphysis and epiphysis
148
epiphyseal plate
also called a growth plate, found in metaphysis and is a thin layer of hyaline cartilage that provides for lengthwise bone growth
149
what happens to the epiphyseal plate in adults
it becomes the epiphyseal line once growth plate closes
150
periosteum
means around the bone, it is a thin layer of connective tissue that surrounds the bone
151
endosteum
layer of CT on the inside of the bone that lines the medullary cavity
152
bone marrow
soft CT tissue of bone; red or yellow
153
red bone marrow is also called
myeloid tissue
154
red bone marrow
hemopoietic (blood cell forming) reticular CT that contains immature blood cells and fat
155
where is red bone marrow found in children
spongy bone and medullary cavity of long bones
156
where is red bone marrow found in adults
in selected areas of axial skeleton like the skull vertebrae ribs or the proximal epiphyses of the humerus and femur
157
yellow bone marrow
a fatty substance that is a product of red bone marrow degeneration as children mature
158
what is bone composed of
cells and extracellular matrix
159
what are the four types of bone cells
osteoprogenitor cells
osteoblasts
osteocytes
osteoclasts
160
osteoprogenitor cells are
stem cells derived from mesenchyme
161
what do osteoprogenitor cells mature into
osteoblasts
162
where are osteoprogenitor cells found
the periosteum and endosteum
163
osteoblasts form from
osteoprogenitor stem cells
164
osteoblasts synthesize and secrete
osteoid
165
osteoid
initial semisolid organic form of bone matrix that later calcifies
166
osteoblasts become
entrapped within the matrix and then differentiate into osteocytes
167
osteoblasts become
osteocytes
168
osteocytes
mature bone cells derived from osteoblasts that don't have a bone forming ability
169
what is the function of osteocytes
to maintain bone matrix, detect mechanical stress of bone and then trigger a new bone matrix
170
osteoclasts
large, multinuclear, phagocytic cells that were derived from fused bone marrow cells (monocytes)
171
osteoclasts were derived from
fused monocytes or bone marrow cells
172
osteoclasts have an
increased surface area exposed to bone to help in bone resporption
173
bone formation
begins with the secretion of osteoid
calcification occurs which deposits hydroxyapatite crystals
174
what is required for bone formation
vitamin d - enhances calcium absorption from GI tract
vitamin c - required for collagen formation
calcium and phosphate for calcification
175
what is required for calification
phosphate and calcium to precepitate out and form hydroxyapatite crystals
176
Bone resorption/loss of bone
bone matrix is destroyed by substances released from osteoclasts
proteolytic enzymes released from lysosomes within osteoclasts chemically digest matrix components
calcium and phosphate dissolved by hydrochloric acid
calcium and phosphate ions enter the blood
177
when does bone resorption occur
when blood calcium levels are low
178
what is compact bone composed of
osteons
179
what is another name for osteons
haversian systems
180
osteons
basic functional and structural unit of mature compact bone that is oriented parallel to bone diaphysis
181
what are the 4 components of an osteon
central canal, concentric lamellae, osteocytes, canaliculi
182
central canal
cylindrical channel in center of osteon and parallel to it that has blood vessels ad nervves extend through the channel
183
concentric lamallae
rings of bone CT that surround the central canal
184
osteocytes
mature bone cells found in lacunae that help maintain the bone matrix
185
canaliculi
tiny interconnecting channels within bone CT that extend from each lacuna and travel through lamallae and connect to lacunae and central canal
186
canaliculi house
osteocyte projections that allow intercellular contact
187
canaliculi allows for exchange of
nutrients, minerals, gases, and wastes between blood vessels and osteocytes
188
ossification (osteogenesis)
formation and development of bone CT
189
where does ossification or osteogenesis begin
the embryo
190
how long does ossification occur
continues through childhood and adolescence
191
when does the skeleton begin forming in embryonic development
8-12 weeks
192
intramembranous ossification (dermal ossification)
bone growth within a membrane (thin layer of mesenchyme)
193
what does intermembranous ossification produce
flat bones of skull
some of the facial bones
mandible
central part of the clavicle
194
steps of intermembranous ossification
1. mesenchyme cells are going to give rise to osteoblasts and ossification centers form within thickened regions of mesenchyme
2. osteoid undergoes calcification
3. woven bone and surrounding periosteum form
4. lamellar bone replaces woven bone as compact and spongy bone form
195
endochorndral ossification
begins with a hyaline cartilage model and produces most bones in the skeleton like the upper and lower limbs, pelvis, vertebrae, ends of clavicle
196
steps of endochondral ossification
1. fetal hyaline cartilage model develops
2. cartilage calcifies and a periosteal bone collar forms around diaphysis
3. primary ossification center forms the diaphysis
4. secondary ossification centers form in epiphyses
5. bone replaces cartilage, except the articular cartilage and epiphyseal plates
6. epiphyseal plates ossify and form epiphyseal lines
197
interstitial growth
dependent upon cartilage growth in epiphyseal plate
198
five zones of epiphyseal plate
zone of resting cartilage
zone of proliferating cartilage
zone of hypertrophic cartilage
zone of calcified cartilage
zone of ossification
199
Zone 1: resting cartilage
closest to epiphysis
200
zone 2: proliferating cartilage
see lots of chondrocytes
201
zone 3: hypertrophic cartilage
not forming new cartilage but these cells are maturing and getting larger
202
zone 4: calcified cartilage
cartilage is getting calcified
203
zone 5: ossification
osteoblasts in the diaphyseal region are moving into calcified cartilage and osteoblasts are maturing into osteocytes
204
bone growth in length occurs specifically in what zones
zone 2 (proliferating cartilage) and zone 3 (hypertrophic cartilage)
205
bone growth in length occurs when
zone 2 and 3 pushes zone of resting cartilage toward epiphysis where hyaline cartilage permits growth and is then replaced by bone
206
epiphyseal plate
maintains thickness during childhood and once matured the rate of cartilage production slows
207
once the rate of cartilage production slows down _____ activity increases
osteoblastic
208
what is the remnant of the epiphyseal plate in adults
epiphyseal line
209
bone remodeling
continues throughout adulthood and occurs at different rates
210
what percent of the skeleton is replaced yearly
20%
211
bone remodeling is dependent on the coordinated activites of
osteoblasts, osteocytes, and osteoclasts
212
bone remodeling is influenced by
hormones and mechanical stress
213
what increases due to mechanical stress
bone mass
214
a decrease in bone mass from removal of mechanical stress causes
reduced collagen formation and demineralization
215
growth hormone is also called
somatotropin
216
growth hormone is produced by
anterior pituitary gland
217
how does the growth hormone work
stimulates liver to produce hormone somatomedin that directly stimulate growth of cartilage in epiphyseal plate
218
thyroid hormone
secreted by thyroid gland and influences basal metabolic rate of bone cells and regulates normal activity at epiphyseal plates
219
estrogen and testosterone
secreted in large amounts during puberty and dramatically accelerate bone growth
220
what is the relationship between bone formation and cartilage growth
bone formation rate is greater than cartilage growth
221
calcium is required for
muscle contraction
exocytosis of molecules from cells like neurons
stimulation of the heart by pacemaker cells
blood clotting
222
what primary hormones regulate blood calcium
calcitriol and parathyroid hormone
223
calcitriol production
UV radiation or dietary intake is combined with the precursor molecule and then converted to vitamin D3 (cholecalciferol)
vitamin d3 is transported to liver cells and then coverted to calcidiol (when an -OH group is added)
then it travels through the blood stream into the kidney where it is converted into calcitriol when another -OH group is added
224
parathryoid hormone (PTH)
secreted and released by parathyroid glands in response to reduced calcium levels
225
parathyroid hormone accelerates
conversion to calcitriol by kidney
226
PTH and calcitriol interact with major organs such as
bones, kidneys, and small intestine
227
PTH and calcitriol with bone
act synergistcally to increase release of calcium from the bone into the blood and increase osteoclast activity
228
PTH and calcitriol with kidneys
stimulate kidney to excrete less calcium in urine which increases calcium reabsorption in the kidney tubules
229
PTH and calcitriol with small intestene
only calcitriol increases absorption of calcium from small intestine into the blood
230
effects of parathyroid hormone and calcitriol on blood calcium levels
1.low blood calcium levels
2. parathyroid glands detect low blood calcium levels
3. prathyroid glands release parathyroid hormone
4. PTH and calcitriol act synergistically to increase activity in bone, decrease calcium in kindeys, and incease absorption of calcium in small intestine
5. blood calcium levels rise and return to normal homestatic range
231
calcitonin
has opposite stimulus and opposite effects of calcitrol that aids in regulating blood calcium levels
232
calcitonin is produced when
there is high blood calcium levels or hyperglycemia
233
what releases calcitonin
thyroid gland
234
calcitonin inhibits
osteoclast acitivty
235
calcitonin stimulates
kidneys to increase loss of calcium in the urine which reduces blood calcium levels and reduces bone reapsorption
