Study guide lecture exam 2 Flashcards
Five layers of the epidermis
stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, stratum basale
Stratum corneum
-outermost layer of epidermis
-composed of 20 to 30 layers of dead, interlocking, anucleate, keratinized cells
-dry, thickened surface is protective against abrasion and infection
stratum basale
-deepest layer of epidermis
- single layer of cuboidal to low columnar cells
stratum spinosum
-spiny layer
-several layers of polygonal keratinocytes
new cells from basale pushed into this layer
-nondividing keratinocytes attached by desmosomes
stratum granulosum
-granular layer
-3 to 5 layers of keratinocytes
Stratum lucidum
-only in thick skin
-translucent layer, 2 to 3 cell layers thick
Epidermal cells found in stratum lucidum
dead skin cells
Epidermal cells found in stratum corneum
dead keratinocytes
Epidermal cells found in stratum basale
merkel cells
Epidermal cells found in stratum spinosum
dendritic (langerhans) cells
Epidermal cells found in stratum granulosum
diamond shaped cells with keratohyalin granules and lamellar granules
What is the difference between thin skin and thick skin?
- thin skin has thinner epidermis
- think skin has no stratum lucidum
- think skin CONTAINS HAIR FOLLICLES
Describe thick skin
Thick skin is only found in areas where there is a lot of abrasion - fingertips, palms and the soles of your feet
- on palms of hands and soles of feet
- thick epidermis with a thick outer layer of keratin
- high dermal papillae enhance adhesion of dermis and epidermis
- ridges and grooves present - responsible for fingerprints
- numerous sweat glands
Describe thin skin
-covers the remainder of the body
- thin epidermis and keratin layer
- contains hair follicles
- fewer sweat glands and no ridges and grooves
Compare and contrast the papillary versus reticular dermis in terms of tissue type and structures
they contain (glands, muscle)
The dermis has two layers. The upper papillary layer has papillae extending upward into the epidermis and loose connective tissues. The lower reticular layer has denser connective tissues and structures, such as glands and hair follicles.
What is indicated by the lines of cleavage in the skin, and why is this medically important?
Lines of cleavage indicate predominant orientation of collagen within the dense irregular tissue of the dermis. Surgical or accidental cuts that run perpendicular to the lines of cleavage take longer to heal.
Functions of the integumentary system
body temperature regulation, cell fluid maintenance, synthesis of Vitamin D, and detection of stimuli.
integumentary system protects the body
protects the body from bacteria, infection, injury ad sunlight.
integumentary system controls body temperature
Sweat glands in the skin allow the skin surface to cool when the body gets overheated. Thermoregulation is also accomplished by the dilation or constriction of heat-carrying blood vessels in the skin.
Types of hair disorders
-male/female pattern baldness
-telogen effluvium
-Anagen Effluvium
-Alopecia areata
-Tinea Capitis
-Cicatricial alopecia
-Lichen Planopilaris
-Discoid Lupus Erthematosus
-folliculitis Decalvans
-Disssecting Cellulitis of the Scalp
-Frontal fibrosing alopecia
-Central centrifugal cicatricial alopecia
-Hypotrichosis
Androgenetic alopecia (male pattern baldness)
Hair is lost in a well-defined pattern, beginning above both temples.
telogen effluvium
It is characterized by an abrupt onset of diffuse hair loss usually seen 2-3 months after a triggering event.
Anagen Effluvium
-a form of nonscarring alopecia commonly associated with chemotherapy.
-In this disorder, affected anagen hairs suffer a toxic or inflammatory insult, resulting in fracture of the hair shaft.
Alopecia areata
autoimmune disorder that causes your hair to come out, often in clumps the size and shape of a quarter.
Tinea Capitis
-scalp ringworm
- fungal infection of the scalp that’s a common cause of hair loss in children.
-This condition causes hair to fall out in patches, sometimes circular, leading to bald spots that may get bigger over time.
Cicatricial Alopecia
scarring alopecia, is a rare type of hair loss in which inflammation destroys hair follicles and causes scar tissue to form in their place. After scar tissue forms, hair doesn’t regrow.
Lichen Planopilaris
-may cause a dry, flaky rash to appear on the skin that causes hair on the scalp to fall out in clumps.
-The scalp may also become red, irritated, and covered in small white or red itchy, painful, or burning bumps.
Discoid Lupus Erythematosus
type of cutaneous lupus, an autoimmune disease that affects the skin. It can lead to inflamed sores and scarring on the ears, face, and scalp. Hair loss is one symptom of the disease. When scar tissue forms on the scalp, hair can no longer grow in that area.
Folliculitis Decalvans
an inflammatory disorder that leads to the destruction of hair follicles, is often accompanied by redness, swelling, and lesions on the scalp that may be itchy or contain pus, known as pustules.
Dissecting Cellulitis of the Scalp
Dissecting cellulitis of the scalp, a rare condition, causes pustules or lumps to form on the scalp.
This condition may also cause scar tissue to develop, destroying hair follicles and causing hair loss. Medications may help control symptoms.
Frontal Fibrosing Alopecia
occurs in a receding hairline pattern and may also result in hair loss in the eyebrows and underarms.
most commonly affects postmenopausal women
Central Centrifugal Cicatricial Alopecia
occur as a result of hair products or styling techniques that damage hair follicles.
The use of hair relaxers, blow dryers, curling irons, and hair extensions can cause central centrifugal cicatricial alopecia, as can the process of creating a permanent wave, or a “perm.”
Hypotrichosis
rare genetic condition in which very little hair grows on the scalp and body. Babies born with this condition may have typical hair growth at first; however, their hair falls out a few months later and is replaced with sparse hair.
distinguish the apocrine vs. merocrine (eccrine) sweat glands in terms of location,
secretions, and function
Apocrine sweat glands are found associated with hair follicles and only become active at puberty. Merocrine sweat glands are found throughout the skin and produce a watery sweat from birth.
regeneration vs. fibrosis
regeneration involves replacing injured cells with cells of the same type while fibrosis involves replacing parenchyma tissue with connective tissues, leading to the formation of permanent scar tissue.
process of a wound healing
Wound healing is classically divided into 4 stages: (A) hemostasis, (B) inflammation, (C) proliferation, and (D) remodeling.
Hemostasis
Hemostasis is the process of the wound being closed by clotting. Hemostasis starts when blood leaks out of the body. The first step of hemostasis is when blood vessels constrict to restrict the blood flow. Next, platelets stick together in order to seal the break in the wall of the blood vessel.
Inflammation
Inflammation, the next stage of wound healing occurs within the first 24 hours after injury and can last for up to 2 weeks in normal wounds and significantly longer in chronic non-healing wounds
proliferation
the provisional wound matrix formed during hemostasis is replaced by granulation tissue, consisting of a large amount of fibroblasts, granulocytes, macrophages, blood vessels, in complex with collagen bundles, which partially recovers the structure and function of the wounded skin
remodeling
begins two to three weeks after the onset of the lesion and can last for one year or more. The core aim of the remodeling stage is to achieve the maximum tensile strength through reorganization, degradation, and resynthesis of the extracellular matrix.
First degree burns
mild (like most sunburns). The top layer of skin (epidermis) turns red and is painful but doesn’t typically blister.
second degree burns
affect skin’s top and lower layers (dermis). You may experience pain, redness, swelling and blistering.
third degree burns
affect all three skin layers: epidermis, dermis and fat. The burn also destroys hair follicles and sweat glands. Because third-degree burns damage nerve endings, you probably won’t feel pain in the area of the burn itself, rather adjacent to it. Burned skin may be black, white or red with a leathery appearance.
first degree burn treatment
Run cool water over the burn. Don’t apply ice. For sunburns, apply aloe vera gel. For thermal burns, apply antibiotic cream and cover lightly with gauze. You can also take over-the-counter pain medication.
second degree burn treatment
Treatment for second- and first-degree burns is similar. Your healthcare provider may prescribe a stronger antibiotic cream that contains silver, such as silver sulfadiazine, to kill bacteria.
third degree burn treatment
Third-degree burns can be life-threatening and often require skin grafts. Skin grafts replace damaged tissue with healthy skin from another of the uninjured part of the person’s body.
The area where the skin graft is taken from generally heals on its own. If the person does not have enough skin available for a graft at the time of injury, a temporary source of graft can come from a deceased donor or a human-made (artificial) source but these will eventually need to be replace by the person’s own skin.
Treatment also includes extra fluids (usually given intravenously, with an IV) to keep blood pressure steady and prevent shock and dehydration.
Rule of nines
The front and back of the head and neck equal 9% of the body’s surface area. The front and back of each arm and hand equal 9% of the body’s surface area.
effect of UV radiation on skin aging, and skin cancer
Unprotected exposure to UVA and UVB damages the DNA in skin cells, producing genetic defects, or mutations, that can lead to skin cancer and premature aging. UV rays can also cause eye damage, including cataracts and eyelid cancers.
compact bone
dense bone in which the bony matrix is solidly filled with organic ground substance and inorganic salts, leaving only tiny spaces (lacunae) that contain the osteocytes, or bone cells.
found under the periosteum and in the diaphyses of long bones
spongy bone
Spongy (cancellous) bone is lighter and less dense than compact bone.
Spongy bone consists of plates (trabeculae) and bars of bone adjacent to small, irregular cavities that contain red bone marrow.
The canaliculi connect to the adjacent cavities, instead of a central haversian canal, to receive their blood supply.
-located at the core of vertebral bones in the spine and the ends of the long bones (such as the femur or thigh bone).
hyaline cartilage
a translucent bluish-white type of cartilage present in the joints, the respiratory tract, and the immature skeleton.
slippery and smooth which helps your bones move smoothly past each other in your joints. It’s flexible but strong enough to help your joints hold their shape.
fibrocartilage
Fibrocartilage provides the tough material of the intervertebral discs; the intraarticular cartilages of the knee, wrist and temporo-mandibular joints;
the articular cartilage of the temporo-mandibular joint and of the joint between the clavicle and the sternum.
Fibrocartilage is a dense, whitish tissue with a distinct fibrous texture.
Function of bones
support, protection, movement, mineral storage, blood cell formation
Classifications of bones
long, short, flat, irregular
Long bone examples
femur, humerus
short bone example
wrist and ankle bones
flat bone example
skull, ribs, sternum
irregular bone example
vertebrae and hip bones
Gross anatomy of the long bone
A long bone has 2 parts, the diaphysis and the epiphysis.
Microscopic anatomy of the long bone
an osteon or Haversian system that contains lamellae of compact tissue surrounding a central canal.
functions of bone cells
to protect the internal organs, to create a rigid frame for muscular movement, and to store minerals such as calcium and phosphorous.
Bone Matrix components
Non-cellular (secreted by bone cells)
collagen fibers
calcium salts.
2 . cellular (bone cells)
matrix originally produced by osteoblasts,
matrix maintained by osteocytes (osteoblasts that continue to deposit bone matrix a lower levels),
matrix dissolved by osteoclasts
Major components of an osteon
The osteon consists of a central canal called the osteonic (haversian) canal, which is surrounded by concentric rings (lamellae) of matrix.
Between the rings of matrix, the bone cells (osteocytes) are located in spaces called lacunae.
Hyaline cartilage vs. bone
Cartilage is thin, avascular, flexible and resistant to compressive forces.
Bone is highly vascularised, and its calcified matrix makes it very strong.
red vs yellow bone marrow
Red bone marrow is the bone marrow that produces red blood cells, white blood cells, and platelets
the yellow bone marrow produces fat cells
Red bone marrow helps the body in its everyday functions
yellow bone marrow helps the body survive extreme cases of hunger and blood loss.
red marrow location
Spongy bone of skull, ribs, sternum, clavicles, vertebrae, hip bones in adults … most bones in infant
functions in formation of red/white blood cells, blood platelets
Yellow marrow location
in the medullary cavity in the shaft of long bones and is often surrounded by a layer of red bone marrow.
produce cartilage, fat and bone.
Difference of two types of bone growth
Intramembranous ossification - bone is formed by direct replacement of mesenchyme.
Endochondral ossification - cartilage model serves as the precursor of bone.
intramembranous ossification
Bone develops from fibrous membrane
Bones called membrane bones
Forms flat bones, e.g. clavicles and cranial bones
endochondral ossification
process in which bone forms by replacing hyaline cartilage
forms all long bones of the axial skeleton (vertebrae and ribs) and the appendicular skeleton (limbs).
hormonal activities on bone tissue
Bone modeling and remodeling require osteoclasts to resorb unneeded, damaged, or old bone, and osteoblasts to lay down new bone.
Two hormones that affect the osteoclasts are parathyroid hormone (PTH) and calcitonin. PTH stimulates osteoclast proliferation and activity.
What hormones play a role in bone growth?
The pituitary gland secretes growth hormone (GH), which, as its name implies, controls bone growth in several ways.
It triggers chondrocyte proliferation in epiphyseal plates, resulting in the increasing length of long bones.
How does parathyroid hormone maintain calcium homeostasis?
The parathyroid glands’ function is to maintain serum calcium homeostasis through synthesis and release of PTH.
At the bone, PTH inhibits osteoblast activity and stimulates osteoclast activity leading to bone breakdown and calcium release.
What is the process of calcium homeostasis?
Calcium homeostasis is controlled by bidirectional calcium fluxes, occurring at the levels of intestine, bone and kidney.
The latter organ plays a central role in regulating the extracellular calcium concentration.
What is osteoporosis and how is it treated?
Osteoporosis is a condition in which your bones break down faster than they rebuild.
Treatment usually includes a combination of medications and lifestyle changes.
The most aggressive way to prevent additional bone loss is to take prescription medications.
four steps of fracture repair
1) hematoma formation due to broken blood vessels that cause a blood clot
2) fibrocartilage callus forms
3) bony callus forms
4) bone remodeling in response to mechanical stress
describe the axial versus appendicular skeleton in terms of bone components
and their functions
Functionally, the axial skeleton supports the head and the bones of the upper limbs, and it protects vital organs in the chest, back, and head.
The appendicular skeleton includes three main parts: the pectoral girdle, the bones of the appendages, and the pelvic girdle.
axial skeleton function
protects brain, spinal cord, sense organs, and soft tissues of thoracic cavity; supports the body weight over lower limbs
appendicular skeleton function
provides internal support and positioning of the limbs; supports and moves axial skeleton
