exam 2 skeletal integumentary

epidermis

keratinized epithelium, protect against water loss and abrasion

dermis

dense connective tissue, contains exocrine glands, hair follicles, sense receptors, blood vessels

hypodermis

adipose tissue for padding and insulation

dermal appendages

nails and hair

blood supply to skin

papillary capillaries, for thermoregulation

sebaceous glands

oil producing glands to keep our skin moisturized

eccrine sweat glands

greatest in palms, sole, and forehead, important for thermoregulation

apocrine

fewer in number but produce more sweat, in armpits, face, abdomen

lesions

a region in an organ or tissue which has suffered damage through injury or disease

primary lesions

skin changes that develop directly due to condition

secondary lesions

skin changes that develop from primary lesions

pressure ulcers

lesion resulting from unrelieved pressure on the skin that leads to underlying tissue damage

pressure ulcer causes

pressure, shearing forces, friction, moisture

where does pressure ulcer typically develop

bony prominences, occluding blood supply

preventative techniques for pressure ulcers

frequent skin assessment, repositioning, pressure reduction, elimination of moisture

basal cell carcinoma

most common, slow growing with numerous subtypes, develops crusts, metastasis is rare

squamous cell sarcoma

tumor of the epidermis, second most common

cutaneous melanoma

malignant tumor of skin, originate in melanocytes, basal layer

changes in the skin with aging

repair decreases, fewer melanocytes, atrophy of glands

bone function

give form/structure to body, permit movement, protect organs, site for blood cell formation

how many bones do we have

206

axial skeleton

80 bones, skull, vertebral column, thorax

appendicular skeleton

126, shoulder, pelvic, upper and lower extremities

long bone

diaphysis, metaphysis, epiphysis, epiphyseal plate, medullary cavity, endosteum

flat bones

only 2, ribs and scapulae, parallel plates of compact bone

short bones

wrist and ankles, spongy bone covered by thin layer of compact bone

irregular bones

various shapes, vertebrae, mandible, facial bones

bone cells

osteoblasts, osteoclasts, osteocytes

what does bone cells do

enable bone to grow, repair, change shape, synthesize new bone tissue and resorb old tissue

ground substance

gel like component of bone matrix

calcification

minerals are deposited and then crystalized

osteoblasts are derived from

mesenchymal stem cells

osteoblasts

primary bone producing cells

osteoblasts responds to

parathyroid hormone

osteoblasts produce

osteocalcin, helps with matrix mineralization, and RANKL

RANKL

promotes osteoclast formation and activity

proteoglycans

strengthen bone, bone calcium deposition and calcification

glycoproteins

control collagen interactions

bone minerals have 2 phases of mineralization

formation of mineral deposit, proliferations of additional mineral crystals

how much does compact cortical bone take up

85% of skeleton

compact cortical bone

highly organized, solid and strong, have haversian system

haversian system

basic structural unit in compact bone

spongy bone

less complex, don’t have haversian systems, have trabeculae

trabeculae

irregular mesh network of plates or bars

periosteum

double layered connective tissue that covers bones

three phases of bone

activation of the remodeling cycle, resorption, formation of new bone, takes 4-6 months

osteomalacia

remodeling cycle proceeds through osteoid formation but calcification does not occur, results in soft bones, vitamin D deficiency

paget disease of bone

chronic accelerated remodeling of bone, enlarges and softens bones

paget disease mostly affects

vertebrae, skull, sacrum, sternum, pelvis, femur

osteoporosis

porous bone, low bone mineral content and density

why does osteoporosis happen

old bone resorbed faster than new bone made

potential causes

endocrine dysfunction, medications, vitamin D deficiency, underlying diseases, low physical activity, abnormal BMI

post menopausal osteoporosis

middle ages and older women, from estrogen deficiency

secondary osteoporosis

from hormone imbalances, medications and disease

regional osteoporosis

confined to seg ment of skeleton, associated with disuse, may be short term

glucocorticoid induced osteoporosis

glucocorticoids improve osteoclast survival, inhibits osteoblast formation and function

kyphosis

curve caused by vertebral collapse

DXA

gold standard for detecting and monitoring osteoporosis

+1 -1

normal bone density

-1 -2.5

osteopenia

lower than -2.5

osteoporosis

risk factors of osteoporosis

caucasian, asian, family history female, sedentary lifestyle, alcohol use

what determines a bone’s load bearing capacity

strength of its material and how bone tissue is distributed

how do daily activities and exercise affect bone strength

forces placed on bones help develop and maintain their strength