Unit 2 Lecture Notes

types of cartilage

hyalin, elastic, fibrocartilage

whats in cartilage?

chondrocytes (maintain and support cartilage without making new matrix), abundant ECM, Lacuna (where chondrocytes live)

hyaline cartilage

l: ends of bones in synovial joints (articular cartilage), costal cartilages between ribs and sternum (sternal cartilage), along portions of respiratory tract, part of septum

f: stiff but flexible support

*resists compression due to large amounts of water

elastic cartilage

l: epiglottis, ear, voice box/auditory tube

f: provide support while tolerating distortion

*collagen AND elastic fibers

fibrocartilage

l: menisci, pubic symphysis, intervertebral discs

f: resists compression, prevents bone on bone friction (articular discs- wrist, jaw, knee), limits relative movement

*thick collagen fiber

*torsion is bad

functions of bones

1. support

2. movement

3. protection

4. mineral storage

5. blood cell and fat storage

6. energy metabolism

kinds of bones

long, short, flat, irregular, sutural

sesamoid bone

grows inside of a tendon creating power

1. big toe

2. thumb

3. patella

compact bone histology

• osteon - ringed cylinder

  • central canal with veins, arteries, and nerves

• perferating canal - 90 angles connecting central canals

• lacunae - ECM

• canaliculi - links osteocytes together, spreading nutrients

• circumferential lamellae - holds osteons together

spongy bone

holds red marrow (red blood cell production), inside linings and ends

organic and inorganic composition of bones

organic - collagen made by osteoblasts (bending + flexibility)

inorganic - calcium phosphate (hard + resists compression)

cell types found in bones

1. osteogenic cell - bone stem cell, becomes osteoblasts

2. osteoblast - builds

3. osteocyte - mature osteoblast

4. osteoclast - reshapes

when does ossification begin? whats the two types?

8 weeks

intramembranous + endochondral

intramembranous ossifcation

• bone formed by fibrous membrane

• fibrous connective tissue turns to bone

• skull and clavicle

endochondral ossification

• bone formed by hyaline cartilage

• bone grows from inside out

• interstitial - grows length wise

• appositional - grows in thickness

kinds of fractures

1. comminuted - 3+ pieces

2. compression - vertebrae, crushed bone

3. spiral - torsion, sports fracture

4. epiphyseal - through epiphyseal plate, stunting growth (kids)

5. depressed - skull fracture

6. greenstick - partial break partial bend (kids)

1 & 2 = common in elderly w/ osteoporosis

osteoporosis

• low bone mass → brittle, porous, thin bones

• vulnerable in lumbar region and neck of femur

• women over 65, caucasians and asians, men with bad diets

• dexascan for diagnosis (body composition)

• treated with medicine (osteoblast stimulant or osteoclast inhibitor), calcium supplements, diet change, and restrictive exercises (stress turns on osteoblasts)

pagets disease

chronic bone disease, too much osteoblast work means thick bones

rickets disease

• form of osteomalacia in kids

• bones arent fully calcified → soft bones → cant hold weight

• why? 1- low vit D 2 - low calcium phosphate

joints

1. bone on bone

2. bone on muscle

3. bone on teeth

*stability and mobility! (inversely related)

functional joint classification

1. synarthrosis (no moving)

2. amphiarthrosis (some moving)

3. diarthrosis (free moving)

structural joint classification

1. fibrous

2. cartilaginous

3. synovial

fibrous joint

• connected by fibrous CT

• no joint cavity

• synarthrotic + amphiarthrotic

1. sutures - only in skull; synostoses = closed sutures

2. syndesmosis - ligaments only, motion depends on ligament length

3. gomphosis - tooth in socket, periodontal ligament

cartilaginous joint

• bones united by cartilage

• no joint cavity

• synarthrotic + amphiarthrotic

1. synchondroses - hylaine cartilage (epiphyseal plates and first rib x manubrium)

2. symphyses - fibrocartilage (pubic symphysis and intervertebral discs)

synovial joint

• diarthrotic

• fluid filled joint cavity

• joint cavity!

  • fibrous outside - dense irregular ct

  • synovial inside - hyalin cartilage

• some have additional articular discs (TMJ, wrist, knee)

• busae (fluid-filled cushion) + tendon sheaths decrease friction

• types: plantar, hinge, pivot, condyloid, saddle, ball and socket

when are fontanelles closed by?

2 years

plantar synovial joint

• nonaxial

• intercarpal joints, intertarsal joints, joints between articular surfaces

hinge synovial joint

• uniaxial

• elbow joints, interphalangeal joints

pivot synovial joint

• uniaxial

• proximal radioulnar joints, atlantoaxial joint

condyloid synovial joint

• biaxial

• metaphalangeal joints, wrist joints

saddle synovial joint

• biaxial

• carpometacarpal joints of the thumbs

ball and socket synovial joint

• multiaxial

• shoulder joints and hip bones

angular movement

• flexion/extension - dec/inc joint angle

• abduction/adduction - away/towards midline

• circumduction - propeller

rotation movement

• turning around long axis

• external vs internal

protraction and retraction

forward and back/ anterior and posterior

opposition movement

putting your thumb to each finger

dorsiflexion and plantar flexion

inversion and eversion

knee joint

• largest joint

• hinge joint

• ligaments

  • patellar

  • fibular/lateral collateral

  • tibial/medial collateral

  • anterior cruciate - prevents anterior sliding of tibia

  • posterior cruciate - prevents posterior sliding of tibia

sinuses

• frontal, ethmoid, sphenoid, maxillary

• lined with mucus membrane

• lighten skull

• sound resonation

cleft palate

• left and right parts of palate don’t join medially

• food can aspirate into nasal cavity → pneumonia

• fixed surgically

spinal curvature

cervical and lumbar → anertior; develops with gravity/after walking

thoracic → posterior; present at birth

spinal curve abnormalities

• scoliosis → s-shape or c-shaped; treatment: nothing, physical therapy, brace, rods

• kyphosis → hunched over

• lordosis → cervical & lumbar curvatures are too extreme, compresses facets, pregnancy + obesity

pectoral girdle

clavicle + scapula

high mobility & shallow glenoid cavity = unstable

pelvic girdle

two hip bones

pelvis (& F vs M)

hip bones & sacrum

F: rounded pubic arch, wide and shallow outlet/inlet

M: narrow heart-shaped inlet/outlet

transverse ligament of atlas

holds c1 and c2 together (risk of serverence by dens)

condyles + c1 =

nodding

c1 + c2 =

shaking

hip dysplasia

femur head not in acetabulum → bracing, PT, surgery

club feet

foot inversion

foot arches

1. medial longitudinal

2. lateral longitudinal

3. transverse