EXAM 2 Flashcards
Histology
The study of tissue
tissue
a group of cells that are similar in structure and perform a common related function
Epithelial Tissue
found throughout the body- covers the body surface and organs
forms the inner lining of the body cavities and lines hollow organs
can cancer cells dissolve the basement membrane f epithelial tissue?
yes
what type of cell junction is found in epithelial tissue?
Tight junctions and desmosomes
is epithelial tissue vascular?
No it is avascular but innervated- lack of blood vessels- nourished by diffusion but has nerves
Cane the cells of epithelial regenerate themselves?
yes cells in this tissue divide
What are the functions of epithelial tissue?
- Protection- skin, digestive tract lining
- excretion-sweat from sweat glands
- absorption-nutrient uptake in small intestine, diffusion, filtration
- secretion-hormones, mucous, enzymes
How do epithelial tissues get their names?
First word- indicates the number of cells
second word- indicates the shape of the cells
simple epithelial
single layer of cells
stratified epithelial
two or more layers of cells- shape of cells can change in different layers
PSUDOSTRATIFIED epithelia
single layer of cells that look layered
transitional epithelia
transitions between one shape to another
squamous
oval/flat
cuboidal
square/hexagon like
columnar
tall/rectangular
Connective tissue
is prevalent in the body, its amount in particular organs varies.
characteristics of connective tissue
-most widely distributed type of tissue
Functions of connective tissue
- Movement
- insulation
- supports other tissues
- storage
- protects vital organs
- attachment of tissues/organs
- transports
- immunity
what type of connective tissue is involved in movement
cartilage
what type of connective tissue is involved in insulation
Adipose
what type of connective tissue is involved in supporting other tissues?
dense irregular and regular connective tissue and cartilage
what type of connective tissue is involved in storage
Adipose and bone
what type of connective tissue is involved in protecting vital organs?
bone, dense irregular connective tissue
what type of connective tissue is involved in attachment of tissues/organs
dense regular connective tissue and areolar connective tissue
what type of connective tissue is involved in transportation
blood
what type of connective tissue is involved in immunity
areolar, blood
What are the three structural elements of connective tissue?
Ground substance, fibers, cells
ground substance in connective tissue
unstructured material that fills interstitial space between fibers and cells.
what are the three types of fibers found in connective tissue?
collagen- strong fibers
elastin- strong but flexible
reticular- short branched fibers (spongey)
what are the two types of cells found in connective tissues?
blasts- and cyte
Blasts
used to develop tissue- chondroblasts, osteoblasts, fibroblast
cyte
cells used to maintain tissue - chondrocyte, osteocyte
Muscle Tissue
Highly cellular, well vascularized tissues that are responsible for most types of body movements
How are muscular tissues characterized?
by properties that allow movements- they respond to a stimulus
contractile
they can shorten and generate a pulling force
involuntary movement
under conscious control- conrraction of your pupil in bright light
What are the three types of muscle tissue? are they voluntary/involuntary
skelital- voluntary
cardiac- involuntary
smooth- involuntary
Nervous tissue
The main component of the nervous system- the brain, spinal crd, and nerves which regulates and control the body functions through signaling
irritability
easily stimulated
conductivity
easily transmit signal
Neuron
basic unit of structure of nervous tissue
neuroglia
when they occur in central nervous system- brain and spinal chord
Schwann cells
when they occur in peripheral nervous system- contain myelin
myelin
fatty substance which forms many layers around the fibers and functions to insulate and to increase the rate of transmission of impulses along the fibers.
Nodes of Ranvier
the myelin sheath I interrupted at regular intervals by openings called the nodes of ranvier-
impulses traveling along myelinated fibers jump from node to node, resulting in a tremendous increase in velocity of impulse, and also in saving energy by the sodium potassium pump.
what are the four types of tissue?
- Epithelial
- Connective
- Bone
- Nervous
simple squamous epithelium
single layer of flattened cells with disc shape central nuclei and space cytoplasm- simplest of epithelium
what is the function of simple squamous epithelium?
allows substances to pass by diffusion and filtration in sites where protection is not important
-also secretes lubricating substances in serosae.
where do you find simple squamous epithelium?
- kidney glomeruli
- air sacs f the lungs
- lining of the heart
- blood vessels
- lymphatic vessels
- lining of the ventral body cavity
Stratified squamous epithelium
thick membrane composed of several cell layers
- basal cells are cuboidal or columnar and metabolically active
- surface cells are flattened
- keratinized and non-keratinized types
- basil cells- active in mitosis and produce the cells of the more superficial layers.
What is the function of Keratinized stratified squamous epithelium
forms the epidermis of the skin, a dry membrane
what is the functions of non-keratinized stratified squamous epithelium?
forms the moist linings of the esophagus, mouth, and vagina
what is the functions of stratified squamous epithelium?
protection of underlying tissues in areas subject to abrasion
simple cuboidal epithelium
single layer of cube like cells with large spherical central nuclei
function of simple cuboidal epithelium
secretion and absorption
where would you find simple cuboidal epithelium?
- kidney tubes
- ducts and secretory portions of small glands
- ovary surface
simple columnar epithelium
single layer of tall cells with round to oval nuclei, some cells bear cilia, layer may contain mucus secreting unicellular glands also know as goblet cells
what is the function of simple columnar epithelium?
absorption, secretion of mucus, enzymes and other substances
ciliated types propels mucus or reproductive cells by ciliary action.
where do you find simple columnar epithelium
non-ciliated- lines most of the digestive tract from the stomach to the rectum, gallbladder, and excretory ducts of some glands
ciliated- small bronchi, uterine tubes, some regions of the uterus.
stratified cuboidal epithelium
typically two cell layers thick, square or cube like shaped cells.
what is the function of stratified cuboidal epithelium
excretion and secretion
where do you find stratified cuboidal epithelium
rare- found ins some sweat and mammary glands
stratified columnar epithelium
layered column like shape
what function does stratified columnar epithelium possess
occurs at a transition between two types of epitheloa
where does stratified columnar epithelium occur
small amounts in the pharynx, male urethra and lining of some glandular ducts
pseudostratified columnar epithelium
single layer of cells differing in heights, some not reaching the free surface. Nuclei seen at different levels, may contain mucus secreting cells and bear cilia
what is the function of pseudostraified columnar epithelium
non-ciliated- male’s sperm carrying ducts and ducts of large glands
ciliated- lines the trachea, most of the upper respiratory tract
transitional epithelium
resembles both stratified squamous and stratified cuboidal.
basal c
what is the functions of transitional epithelium
stretched readily, permits stored urine to distend the urinary organ
where can you find transitional epithelium
lines the ureters, bladder, art of the urethra
Goblet cells
produce mucin a complex glycoprotein that dissolves in water when secreted.
once dissolved, mucin forms mucus a slimy coating that protects and lubricates surfaces.
where do you find goblet cells?
sprinkled in the epithelial lining of the intestinal and respiratory tracts amid columnar cells with other functions.
cilia
tiny hair like projections that propel substances along their free surface
what are cancers originating in epithelium called?
Carcinoma
what percentage of cancers are carcinoma?
90%
What are the three characteristics of carcinoma cells
- usually continually divide- and do not die
- do not specialize so they do not have characteristics of their starting tissue
- loose their ability for cell adhesion and can penetrate through tissue layers including the basement membrane of epithelial tissues
where do most carcinomas begin
on the surfaces that contact the external environments such as skin, lining of the respiratory tract and digestive tract.
what does the fact that carcinoma is found o the surfaces that contact the external environments say about cancer causing agents?
cancer causing agents are found in external environments that come into contact with the epithelial tissues that cover or line our body surfaces.
glands
one or more cells that produce and secrete a specific product. this product is always a water based fluid and usually contains proteins- product is referred to as a secretion.
glandular epithelium
the one gland that is endocrine and exocrine
-is composed of cells, specialized to produce and secrete substances into ducts or into body fluids
exocrine glands
glands that secrete their products int ducts that open onto the surfaces
endocrine glands
glands that secrete their products into tissues fluid or blood as product is needed by a target organ or ductless
what is the difference between simple and compound exocrine glands?
-simple have one duct and compound have branched ducts
what is the difference between tubular and alveolar exocrine glands?
tubular are cylindrical and alveolar are sac like dilations
tubuloalveolal
both cylindrical and sa like dilations
what are the three types of secretion?
Merocrine, Holocrine, and apocrine
What is an example of simple tubular secretory structure
intestinal glands
What is an example of simple branched tubular secretory structure
stomach glands
What is an example of simple branched alveolar secretory structure
sebaceous oil glands
What is an example of compound tubular secretory structure
duodenal glands of small intestine
What is an example of compound alveolar secretory structures
mammary glands
What is an example of compound tubualveolar secretory structures
salivary glands
merocrine glandular secreting cells
are not altered by the secretory pathway- most common type of glandular epithelium secretion.
Describe Merocrine Secretion
- secretory granules gather at the apical region of the cell
- the granule’s limiting membrane fuses with the apical membrane
- the contents of the granule ae opened and released
- this type of fusion and release is referred to as expcytosis
- the secretory granules lease the cell with no loss of other cellular material
what type of cell exhibit merocrine secretion
Mucous and serous cells
Apocrine glandular secreting cells
slightly damaged as part of the cell is released with the secretion cells are able to repair the lost part.
-rare type of secretion dependent on sex hormones
Describe Apocrine Secrition
- decretory granules within th cytoplasm gather at the apical region of the cell
- a portion of the cytoplasm of the cell simply pinches off enclosing the granules.
- within the lumen this small secretory vesicle breaks down and releases the glands products.
when do apocrine glands become functional
at puberty
what do apocrine glands respond to?
emotional or sensory stimuli not to heat
what are some examples of apocrine glands
- Lactating mammary glands
- apocrine glands of the skin in the pubic and axillary regions
- ciliary (Molly’s) glands of the eyelid
- the verminous glands of the external aquatic meatus
Holocrine glandular secreting cells
are destroyed, but new cells are replaces after secretion
describe what happens in holocrine secretion
- disintegrated cells of the gland itself
- granules fill the cell until the entire cell becomes bloated with secretory products
- instead of being released or pinched off the whole cell is discharged into the lumen
- Once inside the lumen the cell degenerates and the secretory products are released.
what are some examples of holocrine secretion
primarily occurs in sebaceous glands within the skin but also the tarsal glands of the eyelid.
What is the composition of connective tissue?
Ground elements, fibers, cells
what type of ground substance is found in connective tissue
unstructured material that fills interstitial space between fibers and cells
what type of fibers are found in connective tissue
collagen- strong
elastin- strong but flexable
reticular-short branched fibers- spongey
what type of cells are found in connective tissue
blasts- used to develop tissue
chondroblasts, osteoblasts, fibroblasts
cyte- cells to help maintain tissue
chondrocyte, osteocyte
what are some of the functions of connective tissue where is it found in the body
- movement- cartilage
- insulation- adipose
- supports other tissues- dense irregular/regular CT
- protects vital organs- bones dense irregular CT
- storage-adipose/bone
- attachment of tissues/ organs- dense regular, adipose
- transports- blood
- immunity- areolar, blood
what are the different types of connective tissue
areolar loose connective tissue, adipose loose connective tissue, reticular loose connective tissue, dense regular connective tissue, dense regular CT, Dense Elastic CT, hyaline cartilage , elastic cartilage, fibrocartilage, bone, blood
areolar Connective tissue
universal packing material
what cells and fibers does areolar CT contain
fibroblasts, macrophages, mast cells, and some white blood cells
collagen, elastin, reticular
what is the function of Areolar CT
- wraps and cushions organs
- phagocytize bacteria
- important role in inflammation
- holds and conveys tissue fluid
where do you find areolar CT
- widely distributed under the epithelia of the body
- forms lamina propria of mucous membranes
- packages organs
- surrounds capillaries
adipose CT
closely packaged adipocytes, have the nucleus pushed to the side of the fat droplet
Function of adipose CT
FUEL FROM RESERVED FOOD, PROTECTS AGAINST HEATT LOSS, SUPPORTS AND PROTECTS ORGANS
where do you find adipose CT
under the skin in subcutaneous tissue, around the kidneys, and eyeball, within abdomen and breast
Reticular CT
reticular fibers in a lose groundwork substance
reticular cells lie on the network-looks like grapes and grapevines
what are the functions of reticular CT
fibers form a soft internal skeleton (stoma) that supports other cell types including white blood cells, mast cells and macrophages
where do you find reticular CT
lymphoid organs- lymph nodes, bone marrow, and spleen
dense regular connective tissue
primarily parallel collagen fibers, a few elastic fibers, major cell type is fibroblast
what are the functions of dense regular connective tissue
attaches muscle to bones muscles to muscles bless to bones -withstands great tensile stress when pulling force is applied in one direction
Dense irregular connective tissue
Primary irregular arranged collagen fibers with some elastic fibers, fibroblast is a major sale type
What are the functions of dense irregular connective tissue
- With stands tension exerted in many directions
- Provide structural strength
Where can you find dense irregular connective tissue
Fibrous capsule of organs and joints, dermis of the skin, submucosa the digestive track
Dense elastic connective tissue
Dense regular connective tissue containing hi portions of elastic fibers
What are the functions of dense elastic connective tissue
- Allows tissue to recoil after stretching
- Maintains pulsating flow of blood through the arteries
- Aids and passive recoil of the lungs following inspiration
Where can you find dense elastic connective tissue
(Aorta) walls of large arteries, within certain ligaments associated with the vertebral column, within the walls of the bronchial tubes
Hyaline Cartridge
Amorphous but for Matrix, collagen fibers form an impeccable network, chondroblasts produce the Matrix and Nguyen mature countryside lie in the lacunae
What are the functions of hyaline cartilage
Supports and reinforces
Serves as a cushion, resists compressive stress
Where can you find hyaline Cartlidge
Most of the embryonic Skeleton, covers the end of a long bone and joint cavities, forms coastal cartilages of the ribs, nose, trachea, and larynx
Elastic cartilage
Similar to hyaline but more elastic fibers in the matrix
What are the functions of elastic cartilage
Maintains the shape of a structure while allowing great flexibility
Where can you find elastic cartilage
Supports external ear, epiglottis
Fibrocartilage
Similar to but less firm then highland cartilage, the collagen fibers predominant
What are the functions of fibrocartilage
Tensile strength allows it to absorb compressive shock
Where can you find fibrocartilage?
Intravertebral disc, pubic synthesis, disc of the knee joint
Bone
Hard calcified matrix containing many collagen fibers, osteocytes lie and the lacunae very well vascularized
What are the functions of bone
- supports and protects
- Provides levers-for muscles to act on
- Stores calcium, fat and other minerals
- marrow inside bones is the site for blood cell formation
Blood
Red and white blood cells in the fluid matrix called plasma
What is the function of blood
Transports respiratory gases, nutrients, waste and other substances
Where can you find blood
Contained within the blood vessels
Blasts
Used to develop tissues – chondroblast osteoblast, fibroblast
Cyte
Cells to maintain tissues chondrocyte, osteocyte
How is connective tissue classified?
Into proper and non-proper connective tissues
What is proper connective tissue
- Loose connective tissue
- areolar
- adipose
- Reticular - Dense connective tissue
- regular
- irregular
- elastic
What is non-proper connective tissues
- Cartledge
- hyaline
- elastic cartilage
- fibrocartilage - bone
- compact
- spongey - blood
What are the three different types of Cartlidge
Hyaline,Elastic cartilage, fibrocartilage
How do Cartlidge is heal? Why?
They heal slowly because the lack of blood flow to them
What are the three different types of muscles?
Skeletal, cardiac, smooth
What types of muscles are voluntary
Skeletal muscles
What types of muscles are involuntary
Cardiac and smooth muscle
Where are skeletal muscle tissue found
Found in the skeletal muscle
Where are cardiac muscle tissues found
In the walls of the heart
Where is smooth muscle tissue found
Mainly in the walls of hollow organs other than the heart
Muscle tissue
Characterized by properties that allow movement, muscle tissues are excitable, they respond to a stimulus, they are contractile meaning they shorten and generate a pulling force one attached between two movable object
What type of muscle tissue has intercalated discs
Cardiac muscle
What are the cells that make up the nervous tissue
Neurons and neuroglia
Nervous tissue
Main component of the nervous system – brain, spinal cord, nerves
What is the function of the nervous tissue
Specialize nerve cells that generate and Conduct nerve impulses
Irritability
Easily stimulated
Conductivity
Easily transmit signals
Neurons
Specialize nerve cell that generates and conducts nerve impulses
Nuroglia
Supporting cells that support, insulate and protect neurons
What are the tissues in a membrane covering?
Cutaneous membrane, mucous membrane, Serous membrane, synovial membranes
Cutaneous membrane’s
The skin serves a number of important functions and it’s associated with a number of structures that are divided from it. The skin forms the integumentary system made up of both epithelial and connective tissues
Functions of the skin
Protection – the skin protects us in a variety of ways
Thermoregulation
Excretion
Synthesis of vitamin D
Sensation
What are the six types of protection the skin provides
Mechanical, chemical, protection against disease agents, ultraviolet radiation, thermal damage, desiccation
Mechanical protection from the skin
The skin physically protects the tissue that it covers
Chemical protection from the skin
Skin offer some protection against chemical damage
Invasion of disease agents
The skin presents a barrier against invasion by a variety of pathogens
Xeroderma pigmentations
Demonstrates the destructive energy of UV radiation
Thermal damage
The skin provides protection against the extremes of temperature
Desiccation
The skin provide waterproofing that protects against excessive water loss
Thermoregulation in the skin
The skin contributes to our ability to maintain a consistent ideal body temperature by mechanisms that retain heat and cold environments and loose he and hot environment
Excretion in the skin
The skin aids in the secretion of urea and uric acid in sweat
Synthesis of vitamin D in the skin
Exposure of sunlight enables the skin to participate in the conversion of cholesterol into vitamin D
Sensation in the skin
The skin contains a variety of sensory receptors that provide information about touch he called and tissue damage
Structure of the skin
- Epidermis – the epithelium on the surface
- Dermis – the underlying connective tissue
- Subcontinuous tissue-also known as hypodermis – attaches the skin to the underlying organs
Mucous membranes
I found where outside invaders are able to get in our bodies
What is the function of mucous membranes
They secrete mucus as protection from potentially harmful invaders such as bacteria, viruses or outside matter that can mess up our systems
The mucus from these layers can trap and remove invaders, some mucus can’t even contain antibodies to help detect the different viruses and bacteria and send her back up from the bodies immune system
Where do you find mucous membranes?
Find the cavities and tubes are open to the outside of the body, oral and nasal cavities, tubes of the digestive tract, urinary and reproductive systems
What type of tissue makes up mucous membranes
Consist of epithelium overlaying a layer of Areolar connective tissue
Serous membrane
Lines body cavities that do not open to the outside and reduce friction between organs and cavity walls
Consist of Single layer of Flattened mesothelial cells applied to the service of a thin layer of collagenous tissue
Composed of both epithelial and connective tissue
Mesothelium
I was serous membrane forms the lining of a closed serious membrane cavity
What is the function of the serous membrane
Secretes serous fluid which helps lubricate membrane surfaces
What are the serous membranes
Peritoneum, Pleura, Pericardium, vaginal tunics
Peritoneum
Cavity is found within the abdominal and pelvic cavity’s. Connecting peritoneum forms the mesentery and ligament
Pleura
Tupelo cavities – separated by mediastinum are found within the thoracic cavity
Parietal pleura Is divided into what three sections
- Coastal pleura
- Diaphragmatic pleura
- Mediastinal pleura
Pericardium
The pericardial cavity is found within the mediastinum of the thoracic chest
Vaginal tunics
The cavity of the vaginal process begins at the vaginal ring and extends into the scrotum around the spermatic cord and testes
What does connecting the vaginal tonight form
Mesorchium
Mesoductus deferens
Synovial membranes
Find the joints and secrete synovial fluid for lubrication of certain joints – not covered in the book at this point but want to introduce it
Inflammatory response
Is a relatively nonspecific reaction that develops quickly wherever tissues are injured, while other immune responses are extremely specific but take longer to swing into action
What occurs during an inflammatory response
Tissue trauma causes injured tissue cells – macrophages, mast cells and other to release inflammatory chemicals.
Blood vessels become more permeable
Allowing WBC, fluid, clotting proteins and other plasma proteins to sweep into the injured area
What are the beneficial effects of inflammation
- Prevents spread of damaging agents to near bag tissues.
- Disposes of cell debris and pathogens.
- It alerts the adaptive immune system.
- It sets the stage for repair.
What symptoms are associated with inflammation
Heat, redness, pain, swelling
What are the three stages of tissue repair
- Inflammation sets the stage
- Organization restores blood supply
- Regeneration and fibrosis
Tissue repair-What is it and what is the main goal of tissue repair?
Wound healing and the process by which the skin, or any injured Oregon, repairs itself after Injury. The main aim of wound healing is to prevent or limit further damage, to clean and seal the wound against infection, to restore tissue strength, and if possible tissue function
Step one inflammation set the stage
- Release of inflammatory chemicals
- dilation of blood vessels
- which increases vessel permeability
- Cording occurs, service drive and forms a scab
What does dilation of the blood vessels allow during the inflammation stage of tissue repair
Local blood vessels become more permeable allowing white blood cells, fluid, clotting proteins, and other plasma proteins to sweep in to the injured area
What happens during step two- organization restores blood supply
- The blood clot is replaced with granulation tissue which restores the vascularity supply.
- Fibroblast produce collagen fibers that bridge the gap
- Macrophages phagocytize dead and dying cells and other debris
- Epithelium begins to regenerate – service epithelial cells multiply and migrate over the granulation tissue
What happens during step three regeneration of fibrosis
- The scab detaches
- Fibrous tissue matures, epithelium thickens and it begins to resemble adjacent tissue
- Results in a fully regenerated epithelium with underlying scar tissue
What is regeneration?
The ability of the skin to repair itself after injury is vital to human survival, and the process of cutaneous wound healing is complex, requiring a coordinated response by immune cells, hematopoietic cells, and resident cells of the skin. While skin wounds heal, they do not regenerate normal human skin.
Are some tissues better at regeneration than others?
Yes
What tissues regenerate extremely well?
Epithelial tissue, bone, areolar connective tissue, dense a regular connective tissue, blood forming tissue
What tissues are moderate at regenerating?
Smooth muscle and dance regular connective tissue
What tissues have virtually no functional regenerative capacity
Cardiac muscle, nervous tissue
-Brain and spinal cord – new research shows cell division does occur efforts underway to coax them to regenerate better
What is the integumentary organ system made up of
Hair, skin, nails
What are the functions of the skin?
HIPPIE RV
- House is sensory receptors
- insulation
- protective covering
- epidermal dendritic cells- Phagocytized micro organisms
- excrete waste
- regulates water loss
- vitamin D precursor
Why does the skin regulate water loss
To regulate body temperature
Why is vitamin D precursor important?
Because it becomes activated in the liver and the kidneys which is necessary for calcium absorption
What are the layers that make up the skin?
- Epidermis
- dermis
- sub continuous layer- AKA hypodermis
What is Tru skin
Has two distinct layers referred to as the continuous membrane one being the epidermis and two being the dermis
Epidermis
Outer most layer of the skin composed of stratified squamous epithelium
Dermis
Composed of dense regular connective tissue, smooth muscle, nervous tissue, and blood
Sup continuous layer
Hypodermis Dash masses of areolar and adipose tissue find the skin to underlying organs
Where would you get an interdermal injection
Just below the epidermis, this has the longest absorption time as compared to sub continuous injections an intramuscular injections. As a result it is used for sensitivity test like TB, allergy test, and local anesthesia
Where would you get a sub continuous injection
The drugs need to be injected into fatty tissue just below the skin on either side of your arms, front of your thighs, or abdomen
What are the four layers of the epidermis and order from the outside in
- Stratum corneum
- stratum lucidum (only thick skin)
- stratum granulosum
- Stratum spinosum
Stratum corneum
Provide a thick layer of dead cells filled with Charitan that provide a waterproof barrier for underlying tissue
-Usually 15 to 30 layers of cells
What does the dry dead later in the stratum corneum help prevent
Helps prevent the penetration of microbes, the dehydration of underlying tissues, and provides mechanical protection against abrasion for the more delicate, underlying tissues.
How did the cells in the stratum corneum shed?
Cells in his lower shed periodically and are replaced by cells pushed up from the stratum granulosum. Or stratum lucidum in the case of the palms and soles of your feet.
How long does it take to replace the entire layer of the stratum corneum
The entire layer is replaced during a period of about four weeks
-Cosmetic procedures such as Microderm ablation help remove some of the dry, upper layer and aim to keep the skin looking refreshed and healthy.
What happens in healthy skin, the rate of cells produced in the stratum basal vs. the loss of dead cells
the rate of cells produced is closely balanced to the loss of dead cells.
Stratum Lucidum
Only thick skin
- soles, palms, digits
- keratinocytes are dead and flattened
- cells are densely packed with eleiden
Eleiden
a clear protein rich in lipids which gives these cells their transparent appearance and provides a barrier to water.
Stratum Granulosum
- Second layer (third in thick skin)
- five layers of flattened dying cells(squamous)
- generate large amounts of keratin
what two types of keratin proteins is the stratum granulosum mostly made up of? What do they do?
fibrous and keratohyalin
-accumulate as lamellar granules within the cells, gives this layer its grainy appearance
What happens in the stratum granulosum
the nuclei and other cell organelles disintegrate as the cells die, leaving behind the keratin, keratohyalin, and cl membranes that will form the stratum lucid/corneum and the accessory structures of hair and nails.
Stratum spinosum
composed of 8-10 layers of keratinocytes formed as a result o cell division in the stratum basale.
Langerhans cell
- interspersed among the keratinocytes in the stratum spinosum
- functions as a macrophage by engulfing bacteria, foreign particles, and damaged cells that occur in this layer.
what is the appearance of the stratum spinosum`
spiny- due to the protruding cell processes that join the cells via a structure called a desmosome
-unstained epidermis samples do not exhibit this characterizing appearance
What is the function of a desmosome?
interlock with each other and strengthen the bond between cells
what is the function of the stratum spinosum?
- cells undergo keratinization and accumulate desmosomes.
- keratinocytes in the stratum spinosum begin the synthesis of keratin and release a water repelling glycolipid that help prevent water loss from the body
- As new keratinocytes are produced atop the stratum basale the keratinocytes of the stratum spinosum are pushed into the stratum granulosum
Stratum Basale
- Deepest layer
- single layer of cells mostly basal cells
how do the cells in the stratum basale bond to the dermis
via intertwining collagen fibers referred to as the basement membrane
Dermal papillae
finger like projections or folds found in the superficial portion of the dermis
- increases the strength of the connection between the epidermis and dermis.
- the greater the folding the stronger the connections made
what is the function of the stratum basale?
Active mitosis because they receive nutrients from blood vessels nearby
Basal cell
a cuboidal shaped stem cell that is a precursor of the keratinocyte of the epidermis
keratinocyte
all of them are produced from the basal cell which are constantly going through mitosis to produce new cells.
-as new cells are formed the existing cells are pushed superficially away from the stratum basale.
What are the cells found in the stratum basale
basal cell, keratinocytes, Markel cell, melanocyte
Merkel cell
functions as a receptor and is responsible for stimulating sensory nerves that the brain perceives as touch.
melanocyte
cells that produce the pigment in Melanin
Melanin
gives hair and skin its color and helps to protect the living cells of the epidermis from uv radiation damage.
what are melanocytes , what do they produce and why?
in the stratum basale contain specialized organelles called melanosomes that produce Melin pigment
Functions-
- provide skin color
- absorbs uv radiation
- transferred to other cells by cytocrine secretion.
cytocrine secretion
the transfer of melanin granules from neighboring epidermal cells
How is skin color determined
by heredity as well as by environmental and physiological factors.
what are the heredity factors in skin color
- determined by he amount of melanin produced which is regulated by several genes and the presence of carotene and hemoglobin
Do all people have the same number of melanocytes in stratum basale?
yes
What do people with mutations in melanin genes have?
albinism
what environmental factors come into play in skin color?
sunlight, uv radiation, x rays
-they darken the existing Melin, stimulate melanocytes to produce more pigment and undergo cytocrine secretion
What are physiological factors that come into play with the skin color?
erythema, cyanosis, paleness, jaundice
Erythema
increased blood flow to the skin causes pink color
cyanosis
lack of blood flow to the skin, causes blue color
paleness
conditions that constrict blood flout the skin, causes white color
jaundice
liver malfunction causes the skin to turn yellow
In the dermis one finds lines of tension what are these lines made of?
Clevage lines made of collagen fibers that run parallel to the skin
externally invisible
are cleavage lines beneficial to surgeons
yes, lines gap less and heal more readily
Dermis
strong, flexible connective tissue
- thickest layer of skin
- made of fibrous and elastic tissue
role of the dermis
to support the epidermis and enable the skin to thrive
what cell types are found in the dermis?
fibroblasts, macrophages, and occasionally mast cells and white blood cells.
Alloderm
used to replace epithelial tissue in reconstructive surgery
what are the contents of the dermis
nerve fibers, blood and lymphatic vessels, epidermal hair follicles, oil and sweat glands
what are the two layers of the epidermis
papillary and Reticular
Papillary layer of the epidermis
superficial layer of the dermis, projects into the stratum basale of the epidermis to form the finger-like dermal papillae
- fibroblasts, small number of fat cells, abundance of small blood vessels
- phagocytes to help fight bacteria and other infections that have breached the skin
components of the papillary layer
capillaries, elastin fibers, reticular fibers, collagen
Dermal Papillae
superficial peg like projections- most contain capillary loops some contain messiner’s corpuscles and lamellar
- some contain free nerve endings (pain receptors)
- In skin lie atop dermal ridges the cause epidermal ridges.
meissner corpuses
touch receptors
lamellar
pacinian pressure receptors
friction ridges
enhance gripping, contribute to sense of touch, pattern is fingerprints
Reticular layer
deeper and thicker layer of the dermis
lies above subcutaneous layer of the skin
80% of the dermal thickness
what is the reticular layer made of?
- dense fibrous connective tissue
- elastic fibers- stretch/recoil
- collagen fibers- strength and bind water
- cleavage lines
What is the reticular layer composed of
dense irregular connective tissue, well vascularized, as a rich sensory and sympathetic nerve supply, the reticular layer appears reticulated (net like)
what gives the reticular layer a mesh like appearance
network of fibers
- elastin
- collagen
- retin-a
what are the nerve endings in the dermis able to do?
detect touch, temperature, pressure, pain stimuli
what are the sweat glands in the dermis responsible for
- production of sweat in response to certain conditions such as heat and stress
- as sweat evaporates off the skin it can help in cooling the body dwn to maintain homeostasis
apocrine sweat glands
specific type of sweat gland present in the armpits and genital region
-product a thick oily sweat that treats body odor when bacteria on the skin digest it
sebaceous glands
responsible for the secretion of sebum
sebum
an oily substance that helps to keep the skin moist and helps to prevent the entry of foreign substances
hair follicle
produces the hair around the body
what is hair important for
regulation of body temps, protection from injury and the enhancement of sensation
blood vessels
-carry nutrients and discard waste products created by metabolism within the dermis and epidermis in addition to helping to regulate temps of the body
Decubitus ulcer
Disease affecting the epidermis of the skin
What causes a decubitus ulcer
prolonged pressure to an area of skin can cut off blood flow from the dermis telling the dividing cells in the stratum basil which will break down the epidermal tissue resulting in the ulcreatiin of the skin- open wound
What can cause a decubitus ulcer
A person who has been bed ridden
Where are you most likely to see a decubitus ulcer
Most common in areas of skin overlying bony projections, such as hip, elbow, heel, shoulder
How many stages are there in a decubitus ulcer
4
What are the 4 stages on a decubitus ulcer
- Reddened , inflamed area on the skin that doesn’t Blanche upon touch. 2. It blistered or open sore with redness surrounding the area.
- Crater legs sore that spans the thickness of the skin to the sub continuous layer.
- Full thickness wound that exposes underlying bone and muscle.
How can decubitus ulcers be prevented
By frequently changing the body position of bedridden patients
What are the parts of the hair itself?
- Hair shaft
- hair route
- hair follicle
- hair bulb
- hair Papilla
Hair shaft
- Found above the surface of the epidermis
- Keratinization complete
Hair root
Found below the surface of the epidermis
-Where keratinization takes place
Hair follicle
Has two layers, epidermal and dermal that surround the hair route located at a slight angel
Explain what happened and the two different layers of the hair follicle
The hair route is created from the epidermal layers of the follicle and is nourished by the dermal layers within the hair papilla
Hair bulb
The hair in bedded in the skin is the hair follicle and at the bottom of the follicle is the hair papilla
Hair papilla
Nourishes hair route and houses sensory receptors
Root hair plexus
For touch
Why is hair curly?
The shape of the follicle determine the shape of the shaft
What shape follicle does curly, wavy, straight hair have
- curly- elliptical shape which can be near linear…The more narrow the shape the curly or the hair.
- Wavy – oval shape follicle
- Straight – round shape follicle
Why is hair course?
The diameter of the follicle determines the coarseness, the wider the diameter the more course the hair is
What is the process of hair growth
- The epidermal cells in the hair bulb or nourished by the dermal blood vessels in the hair papilla.
- As the cells in the hairball grow and divide they push older sells toward the service.
- These cells become keratinized and die. 4. There remains make up the hair shaft.
What is the average hair growth rate
2.25 mm per week
What is the average hair loss
90 Scalp hairs a day
What are the two types of hair you have on your body
- Vellus
2. Terminal hair
Vellus
Hell, Finehair of children and adult females
Terminal hair
Course, long hair of eyebrows, scalp
What happens with your terminal here at puberty?
Appear and ask Larry and pubic region of both sexes and on the face and neck’s of males
What is your hair made of
Dead keratinized cells with hard keratin – harder than your skin cells
What color is your hair? Why?
Melanin- Produces light, brown and black hair. Read is produced from another pigment. The absence of melon produces gray and white hair.
What are the areas you have hair on your body and why those hairs there
- Body-warns off insects
- Head-Reduce heat loss and prevent burning on the scalp from the sun
- eyes-Eyelashes shield the eye
- nose- Filter large particles
What causes goosebumps
Arrector pili muscle attached to the hair follicle – used in humans to produce goosebumps and a form Seabrook out of the sebaceous gland to lubricate the skin
Hair thinning and baldness
Alopecia and true balding
Alopecia
Hair thinning and both sexes after the age of 40, auto immune disease affects 2.5 million in the US
True baldness
- Effects 1.4 billion people in the world.
- Genetically determined and sex influence condition.
- Male pattern baldness caused by follicle response to DHT
What are treatments to true baldness
Minoxidil (rogaine) and finastride(propecia)
Sebaceous glands
Secrete sebum and located near the hair follicle In most areas of the skin but not on the palms or souls
Example of a holocrine gland
Secretes contents as a wholesale that disintegrate to release sebum
Example of a simple branched alveolar gland
Looks like a clove
Acne vulgaris
A disease that runs from the access of Sebum
Sweat gland (sudoriferous gland)
- 2.5 million Sweat glands that can release up to 12 quarts of water
- Each Glenn originate as a bell shaped coil in the deepest part of the dermis and extends one tube to the surface
What are the two types of sweat glands
Eccrine and apocrine glands
Eccerine gland
Squeeze fluid through a pore
Merocrine gland
Fluid released by exocytosis, abundant in the neck, four head, and back some on the palms and soles.
Produce odorless fluid that is mostly water
Apocrine glands
Secrete fluid near the hair follicle
Releases fluid at the hair root
When does an apocrine gland become active? Where does it’s a creek? And where is it located?
At puberty Dash secrete during pain, emotional change, stress and sexual arousal.
Located in the armpits-axillary region in the growing- anogenetal region
What does the Apocrine gland produce
So that does have an odor because of bacteria
Where do nails Grow from
The most active side of growth is at the
-lunula region where the cells quickly become keratinized and therefore dead cells and resemble scales that become part of the nail plate as a grown, the nail plate is push forward over the nail bed
Nail-pitting
Autoimmune disease such as psoriasis and connective tissue disorder
Nail clubbing
May indicate disease of the liver, heart, lungs
Spoon nails
anemia, heart disease, thyroid problems
Terry’s nails
Aging but also diabetes
Beau’s lines
Horizontal lines in the nails – may indicate a period of serious illness or indicate malnutrition
Onycholysis
Fungal infection
Yellow nail syndrome
Chronic bronchitis or lymphedema
Pigmented spot
Melanoma
Red streaks
May indicate rheumatoid arthritis, ulcers or hypertension
First-degree burn
Superficial partial thickness burn – minor sunburn
What happens to the skin and a first-degree burnHow long does it take to heal?
Skin becomes red and as blood vessels dilate, some swelling
Top layer of skin may peel within 48 hours
healing takes a few days up to two weeks with no scarring
Second-degree burns
Deep – partial thickness burn, destroy some of the epidermis and dermis
What happens during a second-degree burn
Fluid escapes from damage capillaries and may form blisters, skin becomes moist and firm and may vary in color from dark red to waxy white
How long does it take a second-degree burn to heal
Healing may require stem cells and accessory organs made out of epithelial tissue. Longer period of recovery with no scarring and less infection occurs
Third-degree burns
Full thickness – destroys the epidermis, dermis and accessory structures
What happens during a third-degree burn
Immersion and hot liquids or a long exposure to a hot object or flames Dash skin becomes dry leathery and may vary from dark red to black or white.
What does healing of a third-degree burn require
Epidermal cells nearby to extend in over the burn. Grafting may be necessary using an autographed, skin substitutes – scarring is usually evident
What is the burn assessment
Rule of nine
Rule of nine
- Is for the treatment of second and third-degree burns.
- Subdivide the body in regions of 9% surface areas to estimate the damage associated with Burns.
- Important for treatment in order to replace lost body fluids and electrolytes for covering the burned area with skin or graphs
What is considered to be a crucial burn?
- Greater than 25% of the body has second-degree burns
- greater than 10% of the body has third-degree burns.
- Face, hands, or feet bear third-degree burns
What is the treatment for Crucial Burns
- Debris removal of burnt skin
- Antibiotics
- temporary covering
- skin graphs
What are the two most common types of skin cancer
Cutaneous carcinoma and cutaneous melanoma
Cutaneous carcinoma
Cancer originating from epithelial cells
What are the two types of cutaneous carcinoma
Basal cell carcinoma and squamous cell carcinoma
What is the most common type of skin cancer?
Cutaneous carcinoma
Who is at risk for cutaneous carcinoma
People over 40, light skin, regularly exposed to sunlight
What does cutaneous carcinoma look like?
Hard, dry, Skelly growth with a reddish base that appears most often on the neck, face or scalp
Cutaneous melanoma
Cancer that originates in melanocytes associated with Moles
What is the ABC DE role as it applies to Cutaneous melanoma
A-Asymmetry
B-Border-irregular
C-color change
D-diameter - Anything bigger than a pencil eraser- 6mm
E- Evolving – if the mole changes significantly in any of the other, or becomes elevated above the skin, itchiness or scaling
Who is at risk for cutaneous melanoma
People of any age can get melanoma but light skin people are at risk
What causes cutaneous melanoma
- Caused by short, intermittent exposure to high intensity sunlight such as a person who gets blistering sunburn.
- Usually appears on the trunk of the body especially on the back or limbs from an existing mold and spreads horizontally.
How frequent do we see cases of melanoma?
Accounts for only 4% of skin cancers but 80% of the people die because it metastasizes
Boil
A skin infection that starts in a hair follicle or oil gland – starts out read and turns into a white pustules with a red ring
Vesicles
Fluid bumps that look like bubbles on the skin – blister
Cyst
Information in the dermal area of the skin that never comes to the surface but forms a lump under the skin
Wart
Neoplasm Caused by a virus living in deepest part of the epidermis
Urticaria
Hives
Peuritus
Itchiness of the skin
Cyanosis
Skin turns blue
Alopecia
Hair thinning and both sexes after age 40
Pustule
A small blister or pimple on the skin containing pus
Ulcer
Skin ulcers can be caused by prolonged periods of poor blood flow to an area of the body. This can occur as a result of infection, immobility, or conditions affecting the blood vessels like diabetes
