Lect 3: Skeletal and Articular System

What are 3 distinct physical attributes of long bones?

greater length than width
mostly dense, compact bone
curved to absorb stress

What are distinct physical attributes of short bones?

cube shaped
spongy bone surrounded by compact bone

What is the role of flat bones in the body?

protect + muscle attachments

What is the function of sesamoid bones?

protect tendons

Label

periosteum- outer layer of bone

endosteum- inner lining of bone

What 3 “ingredients” compose bone?

collagen

protein

minerals

When does ossification begin? When does it end?

6th-7th week (embryonic)

continues through adulthood

What is the process by which bone is formed called?

ossification

What is heterotropic ossification?

abnormal bone growth in soft tissue that negatively impacts mobility/function

Where does bone remodeling occur?

along lines of mechanical stress

Bone replacement (remodeling) is a balance between what two things?

Osteoclast (cat break down)

Osteoblast (build- ‘boom ur bone‘)

What law can also be described as remodeling?

Wolff’s law

An imbalance in bone remodeling in which deposits are greater can result in what?

spurs / bumps

that interfere with joint movements

Imbalanced bone remodeling with greater resorption can lead to what?

weak / brittle bones (osteoporosis)

What are the components of bones vascular supply?

• periosteal arteries

• nutrient arteries

• veins (accompany arteries through nutrient foramina)

What types of nerves go to bone?

periosteal nerves (sensory > periosteum)

vasomotor nerves (reg blood flow thru bone marrow)

Periosteal nerves

innervate the pereosteum of bones

Vasomotor nerves in bone

regulate BF through bone marrow

What are the steps in bone repair after a fracture?

1) hematoma: 6-8hr post injury

2) fibrous/cartilaginous callus formation: several weeks

3) bony callus formation: lasts 3-4 months

can takeup to a year

What terms are used to describe the 6 “sides” of bones?

anterior / posterior

medial / lateral

superior / inferior

Name the elevation:

small, raised, rounded

tubercle

Name the elevation:

swelling, knob, rounded

protuberance

Name the elevation:

large, blunt, rounded

trochanter

Name the elevation:

large, rounded

Tuberosity

Name the elevation:

rounded, articular

condyle

Name the elevation:

superior to condyle

epicondyle

Name the elevation:

slender, tooth-like

process

Name the elevation:

hammerhead-like

malleolus

Name the elevation:

large, linear ridge

crest

Name the elevation:

sharp, slender

spine

Name the depression:

pit like

sinus

Name the depression:

circumscribed, lare or small

fossa

Name the depression:

trough-like

sulcus

Name the opening:

hole in bone

foramen

Name the opening:

long narrow opening

canal / groove

Name the opening:

indentation at bone’s edge

notch

Name the opening:

enters but does not pass through structure

meatus

What is the name for bone to bone smooth areas of contact?

articular facets

What do you call a flat articular surface of bone?

Plateau

Cartilage

dense network of collagen and elastic fibers embedded in chondroitin sulfate (ground substance)

Cartilage gets its strength from ___ and resiliency from ____

collagen

ground substance (chondroitin sulfate)

What are the 3 types of cartilage?

• fibrocartilage

• hyaline

• elastic

What is the strongest vs weakest cartilage?

strongest- fibrocartilage

weakest- hyaline

Fibrocartilage

strongest

support + fusion

ex: pubic symphysis, menisci, intervertebral discs

Pubic symphysis, menisci, intervertebral discs

are all made of what?

Fibrocartilage

Hyaline cartilage

weakest cartilage

no intrinsic blood/nerve supply

smooth surfaces for joints

What type of cartilage provides smooth surfaces for joints?

hyaline

Elastic cartilage

suppport + shape

ex: epiglottis, ear, nares

What type of cartilage makes up the epiglottis, ear, and nares?

elastic

Joints are points of contact between what?

• bones

• cartilage + joints

• teeth + bones

What do we classify joints base on?

structure and function

What are the 3 functional classifications of joints?

• synarthrosis (immoveable)

• amphiarthosis (slightly moveable)

• diarthrosis (freely moveable)

What are the 3 structural classification of joints?

• fibrous: nocavity/space between bones -skull

• cartilaginous: tightly join but allow slight movement - vertebrae

• synovial: space between bones allows for movement - knee

What are the components of a synovial joint?

Articular Capsule

• fibrous capsule: outer layer, dense/irregular connective tissue, prevent dyslocation but allow movement

• Synovial membrain: inner layer, synovial fluid nourish/lubrical joint

• Articular cartilage: hyaline (no BF/N) lines articulating surfaces of bones

• reinforced by accessory ligaments

What are the 4 classifications of synovial joints?

1) Uniaxle: hinge, pivot/trochiod

2) biaxial: conyloid, saddle

3) triaxial: ball and socket

4) nonacial: plane/gluiding

Hinge joint

uniaxial synovial

convex into concave

only move in one plane

Pivot joint is also called what?

trochoid

Condyloid (joint)

oval shape body fits in elliptical cavity

biaxial

Saddle joint

modified condyloid

provide more movement

biaxial

How many degrees of freedom do ball and socket joints have?

3

and permits circumduction

Glenohumeral vs Acetabulofemoral joint

shoulder: ↑mobility but ↓ stability

hip: ↑stability but ↓ mobility

Do plane/gluiding joints themselves permit rotation?

no

Intrinsic / intracapsular ligaments

in joint capsule

anterior/posterior cruciate ligaments (ACL/PCL)

Extrinsic (Extracapsular) ligaments

outside joint capsule

medial/lateral collateral ligaments (MCL/LCL)

Study of movement in the body

Kinematics

bones, liggaments, and muscles form ____ rotating around a joint to do what?

levers

generate force to propel body through space

Majority of the levers in the body are what class?

3rd class

3rd class lever

• force (muscle) is between the axis and the resistance

Torque

the ability of force to create rotation abt an axis

determines how successful a muscle can create movement

1st class lever

ex: head

(Lever) Equilibrium =

effort x force arm = resistance x resistance

Mechanical advantage (lever)

force arm > resistance arm

2nd class lever

resistance is in the middle

ROM sacrificed to gain force

2nd class lever

3rd class lever

effort is closer to pivot than resistance (effort in middle)

*majority of muscle

*sacrifice force for inc ROM with minimal muscle shortening

3rd class level

2nd class levers in the body are rare. One example is:

plantarflexing the foot