A&P Exam 2 Flashcards
tissues
a tissue is a group of cells that are similar in structure and perform a common or related function
how many types of tissues are there
there are 4 primary types of tissues
what are the 4 primary type of tissues
epithelial tissue
connective tissue
muscle tissue
nervous tissue
what is epithelial tissue
covering tissues
what is connective tissue
for support (variety)
what is muscle tissue
for movement
what is nervous tissue
for control
epithelial tissue
an epithelium is a sheet of cells that covers the body surface or lines a body cavity
what are the characteristics of epithelia
high capacity for repair and regeneration
is a vascular - no blood vessels in it
is innervated - served by neurons
dense cell packing - tissue contains many cells little room left for extracellular matrix
cells are joined by tight junctions and desmosomes
cells are usually polar in shape
classification of epithelia
each epithelium is given two names based on the number f cell layers and the shape of its cells
what are the two names epithelia is classified by
number of layers
and
cell shape
simple epithelia
one cell thick
stratified epithelia
two or more cell layers
cell shape
shape of nucleus is similar to cell shape
squamus
flat
cubadal
boxlike
collumnar
tall
stratified squamus
stratified tissues composed of different shapes but the name is based on superficial layer
how many types of epithelia are there
3
general types
pseudo stratified epithelium
transitional epithelium
6 general types of epithelia
simple squamus simple cubodial simple columnar stratified squamus stratified cuboidal stratified columnar
simple squamus
single layer of flattened cells
simple cubodial
single layer of boxlike cells
simple collumnar
single layer of tall cells
stratified squamus
multiple layer (flat cells at least on top layer)
stratified cuboidal
multiple layer (top layer at least is box like0
stratified collumnar
multiple layers (at least top layer is tall)
pseudostratified epithelium
cells originate from a single layer, but are different heights
so it’s only one layer but it seems like more than one because of this
(only tallest cells have cilia)
transitional epithelium
round cells that can stretch and flatten
cells are present stratified
only found in urinary system
glandular epithelia
specialized cells that are not used as part of covering or boundary
gland
produces and exports (secreted) a particular compound (different sizes of glands)
unicellular gland
one secreting cell found in an epithelial sheet
multicellular gland
large descrete structure built with many cells
exocrine glands
secrete product on to thee surface of the body
are more numerous than endocrine glands
how many major parts does the exocrine glands have
two secratory unit and duct
secratory unit
makes product of interest
duct
hallow passageway that carries product to surface
examples of exocrine glands
tears - mucus - sweat - oil - bile - saliva
unicellular exocrine gland
produce mucus
endocrine glands
secrete in to the body and ends up in the blood
do not have ducts (ductless glands)
release of product
two possible choices for release of secretion
continuously release product as it is formed
can accumulate product until gland bursts open
merocrine gland
salivary and sweat etc
holocrine gland / sebaceous gland
exocrine glands that secrete and oily or wavy matter
Where is connective tissue found
fills the spaces in the body between other major tissue types
4 major classes of connective tissue
bone
cartilage
blood
connective tissue proper
characteristics of connective tissue
all connective tissue share a common origin
most common type of tissue in the body
low cell density
mostly matrix of nonliving extracellular material
embryonic tissue - mesenchyme
common origin of all connective tissue
structural elements of connective tissue
all tissues are composed of cell and extracellular material
extracellular material
is a mix of ground substance and protein fibers
osteocytes
cells in bone
chondrocytes
cells in cartilage
blood
leykocytes (WBC) eythrocytes (RBC)
cells in proper - fibrocytes
general cells no special function
found in scar tissue
ground substance
name for the unstructured material that fills the space between cells
three major components of ground substance
interstitial fluid (water) adhesion proteins (small sticky proteins) proteologycans (protein cores with many sugar groups
fibers
strandlike proteins for structural support
elastin fibres
made from elastin thin and stretchy
collagen fibres
thick called collagen fibers
thin called reticular fibers
connective tissue proper
can be divided into loose and dense connective tissues
loose tissues
mostly composed of ground substance
can hold a variety of cell types
soft packing tissues
loose tissues examples
areolar and adipose
how many types of loose tissue does the body contain
and what are they and what for
two
white adipose tissue holds fat for long term storage
brown adipose tissues burn fat to produce body heat
cutaneous membrane
skin - forms our outer covering
only dry membrane in body
moccus membranes
also called mucosae
line body cavities that are open tooth outside -> respiratory tract -> gastrointestinal tract -> eurogenital tract wet membranes covered in mucus
Dense tissues
Mostly composed of protein fibers
Very mechanically resistant tissues
Mostly made of collagen
Dense tissues
Mostly composed of protein fibers
Very mechanically resistant tissues
Mostly made of collage.
Dense regular connective tissue
Fibers run parallel
Dense regular connective tissue examples
Tendons and ligaments
Dense irregular tissue
Fibers run in all directions and form a sac or a sheet
how much does the skin weigh
for an average adult it is 10 lbs
what are the functions of skin
protects underlying delicate tissues (chemical, physical, and biological barrier)
prevents dehydration
aids in heat loss
part of the process that activates vitamin D
what is the structure of the skin
it is composed of two major layers
epidermis and the dermis
epidermis
superficial portion of the skin
epithelial layer - stratified squamous epithelium
dermis
deeper portion of the skin
connective tissue layer - dense connective tissue
hypodermis
it is beneath the skin
not part of the skin
loose connective tissue mostly adipose
what is hypodermis connective tissue mostly made of
adipose tissue
thin skin
found over most of the body
how many layers of thin skin is there
4 epidermal layers
thick skin
found on the palms and soles of feet and hairless
how many layers of thick skin is there
5 epidermal layers
stratum basale
deepest layer of the epidermis
single layer of cells
cells in this layer undergo constant mitosis
producing new skin cells
how is new skin produced
older cells are pushed superficially (towards the surface of the skin)
stratum spinosum
Layer above the stratum basale Several cell layers thick of the epidermis
keratinocytes are filling intermediate filaments made of keratin -> cells start to look prickly
stratum granulosum
4-6 cell layers above the stratum spinosum
at this layer the morphology of keratinocytes change drastically - cells accumulate granules (helps to form keratin)
what forms when keratinocytes granule
keratin
what happens when keratinocytes change drastically
organelles disintegrate
cells flatten
plasma membrane thickens
what happens to cells at the stratum granulosum layer of skin
cells are avascular and starve to death due to being pushed too far away from dermis
stratum lucidum
additional layer found only in thick skin above the stratum granulosum
2-3 rows of cell layers thick
stratum corneum
most superficial layer of epidermis
20 to 30 cells thick
scale like remnants of keratinocytes called horny cells
what are keratinocytes in stratum corneum called
horny cells
What are keratinocytes
Produce keratin
Helps give the epidermis it’s protective properties
Tightly connected cells by desmosomes
most common epidermal cell
At the surface of the skin they are dead cells
where are keratinocytes produced
at the stratum basal (deepest layer of the skin)
how many keratinocytes are lost daily
millions of dead cells are lost daily
why are keratinocytes produced
they are produced in heavy wear areas in response to friction
What do melanocytes look like
spider shaped cells
where are melanocytes found
only in stratum basal
what is melanin for
color of skin
protects keratinocytes in the skin from UV radiation
what can UV radiation do
damage DNA
where does UV radiation come from
sunlight
what does melanin do to protect from UV radiation
absorbs and dissipates the energy so no damage occurs
what increases melanin production
constant UV exposure
langerhan’s cell
Aka dendric cells
immune cells that migrate to the epidermis
engulfs and destroys foreign substances
where are langerhan’s cells found
mostly in stratum spinosum
markel cells
Aka tactile cells
associated with a free nerve ending
Present at the epidermal-dermal junction
markel disc
sensory receptor for touch
where is a markel disc found
at the junction of epidermis and dermis
how many layers is the dermis composed of
two
Papillary and reticular layers
what kind of tissue is the dermis
Strong flexible connective tissue
papillary layer
superficial layer of the dermis
thin layer of areolar connective tissue (loose)
what does papillary layer produce
projections called dermal papillae
what does dermal papillae do
pushes epidermis upward to form epidermal ridges for palms and soles of feet
what are epidermal ridges good for
increase gripping ability
form fingerprints that are unique to each individual
reticular layer
deepest layer of the dermis
thick layer of dense fibrous connective tissue
what does reticular layer contain
accessory structures of skin like hair follicles and glands
what reasons can reticular layer be overstretched and or torn
pregnancy
excess body weight
stress pains
striae
stretch marks
light scarring produced from reticular layer
Different name for hypodermis
also called the superficial fascia
where is the hypodermic located
beneath the skin
what type of tissue is hypodermis
loose connective tissue
adipose tissue
what are the functions of the hypodermis
anchors skin
acts as a shock absorber
allows skin to slide
insulates agains heat loss
what does hypodermis become with age
thicker and accumulates weight
pigments
three pigments contribute to skin color
melanin colors
ranges from reddish-yellow to brownish-black
who produces more melanin
darker people
why do darker people produce more melanin
due to a darker melanin or melanin that lasts longer
what are moles or freckles due to
localized accumulation of melanin
carotene colors
range from yellow to orange
where is carotene found
pigment is found in vegetables (food)
most obviously found in palms and soles of feet
hemoglobin color
red pigment
where is hemoglobin found
erythrocytes / red blood cells
What is hemoglobin for
is 02 transporter protein
how does hemoglobin work
blood flows to the skin and adds pinking color
who is hemoglobin more common in
pale individuals
skin color disorders
reddness pallow jaundice cyanosis vitiligo
redness
also known as erythema
skin is flushed with blood
what is erythema due to
anger or embarrassment or inflammation
pallor
also known as blanching
skin is pale due to low blood content
when does pallor or blanching occur
during periods of intense emotions like fear or shock
jaundice
also known as yellow cast
due to accumulation of toxic pigment bilirubin
when does jaundice occur
when there is a liver dysfunction
cyanosis color and reason
bluing
blood in skin is poorly oxygenated
vitiligo
true skin pigmentation disorder
what is vitiligo due to
loss of melanocytes
what does vitiligo cause
uneven coloration of skin - forms light spots of unpigmented skin
eccrine sweat glands
most numerous typed of sweat glands
coiled tubular glands
Aka merocrine glands
what product do eccrine sweat glands produce
hypotonic
99% water
evaporates to cool the body
eccrine sweat glands are found all over the body except
red margin of lips
areolas (nipples)
hairless part of genitals
apocrine sweat glands
larger than eccrine sweat glands
what do apocrine sweat glands produce
viscous, milky, yellowish sweat
metabolized to produce body odor
where are apocrine sweat glands found
axillary region and anogenital region
when do apocrine sweat glands become active
during puberty
what are apocrine sweat glands stimulated by
stress pain or sexual arousal
ceruminous glands
modified apocrine glands only found along the external ear canal
what do ceruminous glands produce
sticky, yellow, bitter, waxy substance called cerumen
what is cerumen
earwax
mammary glands
specialized sweat glands in breast tissue
what can mammary glands secrete
milk
oil glands
also called sebaceous glands
what do oil glands produce
sebum
mix of lipids and dead cell fragments
where is sebum released to
hair follicles or onto the skin
what does sebum do
softens and lubricates skin and hair
Flexure lines
Reticular layer folds instead of slides
Flexure lines
Reticular layer folds instead of slides
Why does skin fold instead of slide in reticular layer
Due to dermis more firmly attached
hair follicles
deep end of hair follicle expands to form hair bulb
hair matrix
cells divide to produce new hair
hair follicle receptor
a knot sensory nerve endings associated with hair follicles
arrector pili
bundles of smooth muscle associated with hair follicles
what do arrector pili do
pull on hair follicle to make hair stand up when fearful or cold
produces goosebumps in skin
burns
tissue damage and cell death caused by intense heat, electricity, radiation, chemicals, or cold
initial short term danger in burns
fluid and electrolyte loss
long term danger in burns or prolonged
immune suppression and infections
rule of nines
system estimates body damage from burn
rule of nines numbers
head and neck 9% each arm 9% x 2 = 18% each leg is 18% x 2 = 36% body trunk is 36% perineum 1% all totals to 100%
first degree burn
only epidermis is damaged
second degree burn
epidermis and upper (superior) portion of dermis is damaged
what can second degree burns cause
epidermis and dermis separation
can form a fluid filled pocket called blisters
third degree burn
all epidermis and dermis is damaged
what is a third degree burn called
whole thickness
why are third degree burn areas pain free
neurons are all dead in area
skin cancer
overexposure to UV radiation (sunlight) damages DNA of skin cells
UV radiation mutations
is damage to DNA
P53
can inactivate tumor suppressor gene
sunburn skin
produces protein Fas
causes damaged cells to eliminate themselves and potentially cancerous cells
basal cell carcinoma
cells of stratum basal proliferate
begin to move down to the dermis and hypodermis
what is the most common type of skin cancer
basal cell carcinoma
what is the least malignant type of cancer
basal cell carcinoma
squamous cell carcinoma
grows rapidly and can metastasize if not removed
spread to other part of body
melanoma
melanocytes proliferate
- produce dark irregular spots
- can arise from moles
- metastasize very easily
ABCD rules for identifying melanoma
A - asymetry
B - borer irregularity
C - color variability
D - diameter
What is the only pigment produced in the skin
Melanin
What is the hair follicle receptor wrapped around
Hair bulb
What are hair follicle receptors for
To feel when hairs are being bent
What does Fas do
Eliminates cells on purpose
Why does skin peel in sheets
To get rid of all the damaged cells that may be cancerous
Where is squamous cell carcinoma found
In the stratum squanosum
What is Function of bones
Protect body tissues
Supports body weight - allows us to stand up
Allows body movements - with skeletal muscles
Stores Ca 2+
What is the human skeleton composed of.
Bone and cartilage
Long bone
A shaft with knobby ends
Like cartoon or dog bones
What kind of bone are limbs
Long bones
Long bones example
Radius, tibia, ulna
Short bones
Roughly cubed shaped
Where are short bones found
Carpals and tarsals (wrist and ankles )
sesmoid bones
short bone that forms in a tendon (example is patella)
flat bones
flat, thin, and usually curved
examples of flat bones
parietal temporal and occipital bones
bones in the cranium, ribs, sternum
irregular bones
vary in shape and size
example of irregular bones
vertebrae and coxals
structure of bone
there are several osseous tissues
what are the two different bone textures
compact bone and spongy bone
compact bone
structure unit is the osteon composed of central canal surrounded by hallow tubes of collagen
what does osteon do
carries blood vessels and nerves
bone cells
osteocytes
occupy open spaces in bone called lacunae
what are osteocytes trapped in
lacunae
canalicoli
tentacle like projections gap junctions in which bone cells connect to each other
why do bone cells connect to each other through canalicoli
to communicate and share nutrients
spongy bones
not composed of osteons
traburculae
cell fragments loosely organized in spongy bone and contains osteocytes
what are the open spaces between trabecular filled with
bone marrow
tissue arrangements
every bone has compact bone on surface and spongy bone on inside
what is the tissue arrangement of short bones
a plate of spongy bone surrounded by compact bone called diploe
chemical composition of bone
extracellular matrix of bone is a combination of organic and inorganic material
osteoid
produced by osteoblasts
organic component of bone matrix
composed of ground substance and protein fibers
hydroxyapitites
inorganic compound (unique to bone)
mineral salts like calcium phosphate
deposited around osteoid
makes bone hard (very resistant to mechanical forces)
diaphysis
tubular shaft that forms axis of long bone
thick collar of compact bone
hallow at center
madulary cavity
hallow center of long bone that holds bone marrow
epiphysis
two 1 proximal and 1 distal
knobby bone ends
positron contained in a join is covered with a hyaline cartilage
epiphyseal line
aka metaphysis
where is the epiphyseal line at
at meeting of diaphysis and epiphysis
remnants of the epiphyseal plate where growth used to occur
periosteum
white double layer that surrounds external bone surfaces
contains holes called nutrient foramen
anchored by perforating fibers
outer layer of periosteum
dense irregular connective tissue -> protective sac
inner layer of periosteum
osteogenic layer -> modified bone
what is a nutrient foramen for
passageway for blood vessels and herre fibers
endosteum
a single layered membrane covers internal bone surfaces
only osteogenic layer
how many types of bone marrow are there
two
red bone marrow
found in open spaces of spongy bone
deep in epiphysis
contains pluripotent hemotopoietic (adult) stem cells
produces all types of blood cells
yellow bone marrow
found in medullary cavity of the diaphysis
bone physiology
bone must maintain itself to remain a viable tissue
osteogenesis
process of producing new bone
intramembranous ossification
develops from a flat connective tissue membrane
what does intramembranous ossification produce
some flat bones like clavicles and bones of cranium
endochondral ossification
develops from cartilage
responsible for forming all other bones
responsible for long bone growth
bone growth in width
new bone is secreted on to the surface of old bone
why do bones get wider
to support more weight
can get wider at any age
bone growth in length
at the epiphyseal plate a thin layer of cartilage
what does older cartilage of the plate do
calcifies to become bone
when does growth in length stop
end of puberty
what happens to bone plate at the end of puberty
the plate seals shut cartilage becomes bone
what is the new name for sealed plate of cartilage
epiphyseal
bone remodeling
over 5% of total bone mass is recycled every week
how often is spongy bone replaced
every 3 years
how often does compact bone replace itself
about every 10 years
what does bone remodeling prevent
it prevents it from becoming old and brittle
osteoblasts
produce new bone
secrete osteoid
derived from osteogenic cells
osteoclasts
degrade away old bone
large multinucleate cells derived from bone marrow
secrete HCL and proteoses to digest bones
osteocytes
mature bone cell
where are osteocytes found
in lacunae
what do osteocytes do
monitor and maintain bone matrix (example of homeostasis)
hormones in bone
bone mineralization is affected by the amount of calcium levels in the blood
two hormones for bone
calcitonin and parathyroid hormone
calcitonin
released by thyroid gland
when blood levels are too high
what does calcitonin do when blood cels are too high
deposists excess calcium in to bones to make stronger more dense bones
pth
released by parathyroid gland when blood calcium levels are too low
what does parathyroid hormone do
causes calcium to be removed from bones
it is weaker less dense bones
osteomalacia
inadequate mineralization of bone
what is the issue with osteomalacia
lamellae are present but not enough calcium bones are soft and bend due to low dietary calcium and vitamin d
riketts
osteomalacia in children
more severe due to ongoing growth
what does rickets lead to
permanent skeletal malformation
osteoporosis
several diseases where bone removal is faster than bone deposited
bone fractures
despite their strength, bones can break when exposed to exceptional trauma
simple fracture
vs
compound fracture
broken bone does not penetrate skin (closed)
vs
bone penetrates skin (open)
nondisplaced fracture
vs
displaced fracture
broken bone ends retain proper shape of bone (remain in alignment)
vs
broken bone ends are forced out of alignment (must be reduced and realigned)
linear fracture
vs
transverse fracture
breaks along long axis of bone
vs
perpendicular to long axis
comminuted fracture
bone is broken in to 3 or more pieces
spinal fracture
excessive twisting
depressed fracture
piece is pressed inward
greenstick fracture
incomplete break of bone
compression fracture
bone is crushed
skeletal cartilage
a type of loose connective tissue
characteristics of cartilage
avascular aneural low cell content (protein + ground substance) holds A LOT of water resisten to mechanical forces found where flexible material is needed
hyaline cartilage
most common type of cartilage in body
extra cellular matrix contain thin collagen fibers
firm cartilage
hyaline cartilage examples
nasal, respiratory, articular, (found in joints)
elastic cartilage
elastin fibers
more strong and stretch but less firm
elastic cartilage examples
external ear
fibrocartilage
less firm but stronger than hyaline
very resisted to mechanical forces
thicker collagen fibers
fibrocartilage examples
in joints knee, hip, jaw
What are periosteums anchored by
Collagen fibers
structure of short, irregular and flat bones
they share a simple design
thin plates of spongy bone covered by compact bone
covered by connective tissue membranes
What does the osteogenic layer contain
Cells that modify bone
diploe
name of spongy bone in flat bones
Why does red bone marrow lose function
Due to age
What is appositional growth
New bone secreted on to the surface of old bone
Why does the epiphyseal plate shut
Cartilage becomes bone
What happens after the epiphyseal plate become bone
It becomes the epiphyseal line or metaphysis
What causes epiphyseal plate to shut
Sex hormones
Primary osteoporosis
Only seen in older women due to menopause
Osteoblasts begin to lose function
Secondary osteoporosis
Any other reason for osteoporosis
