Skeletal System (PP5) Flashcards
Function of skeletal system
Support
movement
protection
mineral storage
hematopoiesis
What is hematopoiesis and where does it occur?
The production of RBC
Occurs in red bone marrow
What controls hematopoiesis?
EPO- erythropoietin hormone
produced by the kidneys
When is EPO released?
decrease of O2
Where is red bone marrow found?
Kids: every single damn bone
Adults: skull, ribs, femur head, sternum, vertebrae
Osteoprogenitor cell
stem cells that make osteoblasts
Osteoblasts
immature cells that produce the matrix, new bone in childhood, remodeling, and repair broken bone
Osteocytes
Mature cell in the lacunae that performs daily tasks
Osteoclasts
Breaks down bone in remodeling
Reabsorbs matrix to release minerals
What is remodeling?
Starting at age 30, all bone in your body is broken down and rebuilt over the course of 10 years, and the process repeats once completed
Sesamoid bone
round (patella)
Long bone
includes shaft (diaphysis) and 2 knobby ends (epiphyses)
Irregular bone
vertebrae
need I say more?
Short bone
lil square things
carpals and tarsals
Flat bone
skull bones
Compact bone
dense and smooth
outer surface of bone
Spongy
Looks like a dry sponge
In middle
Osteon
weight baring pillars running parallel to the axis of the long bone
Lamella
rings of the osteon
Haversian Canal
conduit for small BV and nerves for osteon cells
center of osteon
Volkmann’s Canal
connects vascular and nerves of haversian canals
Lacunae
cavities between lamella
Canaliculi
connect lacunae
tie all osteocytes in an osteon together.
nutrient and waste transport
Trabiculae
Irregularly organized lamella and osteocytes interconnected by canaliculi
no osteons
arranged for max stress resistance
What cartilage is in epiphyses?
hyaline cartilage
What does the endosteum cover
trabeculae
When does ossification occur
Starts at week 6/7 in utero and continues into puberty
Remodeling in 30s
Where is intramembranous ossification?
bone formed within fibrous CT membrane
What bones are made from intramembranous ossification
skull, mandibles, scapula (flat bones)
What are the steps of intramembranous ossificaiton?
Mesenchymal cells collect
Change to osteoprogenitor cells
Change to osteoblasts, which help create the matrix
The matrix hardens, forming trabeculae
Internal space turns into red bone marrow
Mesenchyme outside turns into periosteum
What bones are made from endochondral ossification?
All bones below the head excluding the clavicle
Where is endochondral ossification performed?
formed within the cartilage model
Describe endochondral ossification
Chondroblasts secrete hyaline cartilage model
chondrocytes become trapped in lacunae and form outer membrane
What are the steps of endochondral ossification
Mesenchymal cells change into chondrocytes to form the long bone shape and start the periosteum
Chondrocytes divide, secrete more matrix to harden, killing the hyaline cartilage cells, and vessels invade midshaft
Periosteum is developed, osteoprogenitor cells change into osteoblasts and form the bone collar around cartilage matrix, cavity fills with RBM, 2nd ossification center forms in epiphyses as vessels spread- mostly make the spongey bone
Hyaline cartilage remains at the end, divided from the shaft by the growth plate
What is remodeling?
old, worn out, injured bone replaced with new tissue
allows bone to store Ca
What happens to the bone diameter after remodeling?
increases bone diameter
What are the requirements for remodeling?
Sufficient Ca & P in diet
Vit D, C, & A
HGH
Estrogen/Test
Calcitonin
PTH
What is Vit D’s role in remodeling?
needed for Ca absorption
What conditions may arise if Vit D deficient?
rickets and osteomalacia (weak bones)
What is Vit C role in remodeling
maintain bone matrix
What is Vit A role in remodeling
regulates cell function
What is Human Growth Hormone’s role in remodeling?
(HGH)
helps generate bone growth
What is Estrogen and Testosterone’s role in remodeling?
Helps osteoblasts make matrix and remove cartilage
What is calcitonin’s role in remodeling?
Positive feedback loop!
decreases Ca levels in blood to inhibit osteoclast f(x) if not much broken bone
What is PTH’s role in remodeling?
(Parathyroid hormone)
Negative feedback loop
increases osteoclast activity by slowing Ca absorption in urine & stimulate kidney release of calcitriol
What does calcitriol do?
converts Vit D absorbed by skin into active form
What happens to repair a broken bone?
cartilagenous patch forms in break, causing cells in area to die
w/in 24 hours, endosteal stem cells differentiate into chondrocytes & secrete matrix
Matrix from both ends come together
Fixed within weeks
What effects bone remodeling and bone strength?
more exercise and gravity increases bone mass via matrix production
aging decreases d/t demineralization as sex hormone levels decrease
Osteoporosis
mostly effects spongey bone
remodeling doesn’t keep up with breakdown
What factors impact osteoporosis?
age
lots of pregnancy and breast feeding
poor nutrition
2nd to alcoholism, cushings, hyperthyroid, hyperparathyroidism,
Symptoms of osteoporosis
loss in height via kyphosis or lordosis
Kyphosis
T12 body broken, incomplete, absent or flattening
(humpback)
Lordosis
Anterior curvature greater than 50 degrees
(swayback)
Paget’s Disease
Metabolic disorder
Bone grows back thickened and enlarged
cartilage replaced with fibrous tissue
Paget’s Disease Signs/Symptoms
severe/persistent pain esp. when weight baring
enlarged head
barrel chest
asymmetric bowing of tibia &/or femur
Osteogenesis Imperfecta
genetic disorder
mutated collagen production genes
Osteogenesis Imperfecta signs/symptoms
fractures easily, doesn’t fully heal
short d/t fractures
thin skin
deaf (misshapen ear bones)
Synovial Joint
capsilar fluid around area surrounded by ligaments
Cartilagenous Joint
hyaline and fibrocartilage
Fibrous Joint
adjacent bones united by fibrous CT which fills gap between bones
Gomphosis
fibrous joint from jaw to tooth
Suture Joint
Fibrous joint with diathrosis, no movement
Amphiarthrosis
flexible and stretches
Pivot Joint
1 articulated bone with round surface fits into ring made by ligament and other bone
(axis/atlas, radius/ulna)
Ball & Socket Joint
multi-axial joint- injured easily, highly moveable
rounded head fits into 2nd bone socket
Hinge Joint
2 bones fit together in depression
1 plane motion
knee, fingers, elbows
Condylar joint
oval surface articulates with concave surface
side-side movement
knuckles
Sadle Joint
convex & concave articulation
opposition
thumb
Plane/gliding JOint
articular surface flat side-side
How is Arthritis Categorized?
Degenerative
Anomaly
Metabolic
Neoplasia
Immune mediated
Trauma
Rheumatoid Arthritis
Autoimmune Disorder
Osteoarthritis
wear and tear
Bursitis
Inflammation of bursa
effects elbow, hip, knee and heel
What are the common signs and symptoms of a joint disorder?
Irritation, Inflammation, and pain
What are the common treatments for joint disorders?
Rest
Ice
Corticosteroids
Ehhhh idk
Carpal Tunnel
Nerve entrapment syndrome
effects women 30-60 yrs old
Tendenous sheath inflammes, compress median nerve and changes sensory and motor to fingers 1-3
Diagnostic tests for carpal tunnel
Tinel’s sign: pins & needles when tapping over nerve
See if symptoms erupt when decreasing blood to area
Primary Gout
Metabolic
effects the big toe
effects overweight ppl, alcoholics, no exercise, lots of protein
urate acid forms crystals
Secondary Gout
Metabolic
effects the big toe
W/in another dz
urate acid gets stuck in CT
Gout Tx
Increase fluid, allopurinol, colchicine
Strain
tear to tendon/muscle unit via sudden forceful contraction
can appear bruised
occurs in muscles that cross 2 joints (calf, biceps, hams, quads)
Sprain
Tear to ligament
graded 1-3
w/in days collagen form and fibers org parallel to stress lines
Sx needed if Gr 3 (full tear)
