Exam1 Flashcards
Biomechanics
Application of mechanical physics to human motion
Anatomical position
Standing upright posture, facing straight ahead, feet parallel and close, palms facing forward
5 types of bones
Long, short, flat, irregular, sesamoid
Long bones
Shaft contains the medullary canal:
Phalanges, metatarsals, metacarpals, tibia, fibula, femur, radius, ulna, and humerus
Short bones
Small, cubical shaped, solid bones:
Carpals & tarsals
Flat bones
Usually have a curved surface and vary from thick tendons attach to very thin:
Ilium, ribs, sternum, clavicle & scapula
Irregular bones
Bones throughout the spine & ischium, pubis and maxilla
Sesamoid bones
Small bones embedded within go tendon of a musclelotendinous:
Patella, 1st metarsophalangeal,
1st metacarpophalangeal
Diaphysis
Long cylindrical shaft
Cortex
Hard, dense compact bone forming walls of diaphysis
Periosteum
Dense, fibrous membrane covering outer surface of diaphysis
Endosteum
Fibrous membrane that lines the inside of the cortex
Medullary (marrow) cavity:
Between walls of diaphysis, containing yellow or fatty marrow
Epiphysis
Ends of long bones formed from cancellous (spongy or trabecular) bone
Epiphyseal plate
Thin cartilage plate separates diaphysis & epiphyses
Articular (hyaline) cartilage
Covering of epiphysis to provide cushioning effects and reduce friction
Endochodral bones
Develop from hyaline cartilage
Hyaline cartilage masses at embryonic stage
Bone growth
- Longitudinal growth continues as long as epiphyseal plates are open.
- Shortly after adolescent plates disappear & close.
- Most close by age 18 but some may be present until 25.
- growth in diameter continues throughout life.
Osteoblasts
Cells that form new bone
Osteoclasts
Cells that resort old bone
Cortical bone
- Low porosity 5-30% non mineralized tissue
- Cortical is stiffer & can withstand greater stress, but less strain than cancellous
Cancellous
- Spongy and high porosity, 30-90%
- Cancellous is spongier and can undergo greater strain before fracturing
Wolff’s law
- Bone size & shape are influenced by the direction and magnitude of forces that are habitually applied to them
- bones reshape themselves based upon the stresses placed upon them
- bone mass increases over time with increased stress
Synarthrodial
Immovable joint
- suture: found in structures of cranial bones
- gomphosis: socket of teeth
Amphiarthrodial
Slightly movable joints
- syndesmosis:joint held together by strong ligamentous (tibiofibular)
- symphysis: separated by fibrocartilage pad (intervertebral disk)
- synchondross: separated by hyaline cartilage
Diarthrodial
Freely moveable joint (synovial joints) joint capsule sounds bony ends forming joints -arthrodial -ginglymus -trochoid -condyloid -enarthrodial -sellar
Arthrodial
Gliding joint
Ginglymus
Hinge joint
Trochoid
Pivot, screw joint
Condyloid
Knuckle joint
Enarthrodial
Ball and socket joint
Sellar
Saddle joint
How are muscles named?
Visual appearance
Anastomotic location
Function
2 major types of fiber arrangements
Parallel: to length of muscle, produce greater range of motion (flat,fusiform,strap,radiate,sphincter)
pennate: usually thin and broad, originate from broad, fibrous sheet like aponeuroses (unipennate,bi pennate,multipennate)
Skeletal muscle tissue properties
Irritability
Contractility
Extensibility
Elasticity
Intrinsic
Muscles within or belonging solely to body part upon which they act
Extrinsic
Muscles that arise or originate outside of body part upon which they act
Innervation
Segment of nervous system responsible for providing stimulus to muscle fibers within a specific muscle or portion of a muscle
Amplitude
Range of muscle fiber length between maximal and minimal lengthening
Gaster
Belly or body of muscle the contractile portion of muscle
Origin
The proximal attachment of a muscle or the part that attaches closest to midline ( the least moveable part)
Insertion
The distill attachment or part that attaches farthest from midline( most movable part)
Agonist muscle
Cause joint motion through a specified plane of motion (primary movers)
Antagonist muscles
Located opposite side of joint from agonist
Contralateral muscles
Kinesiology defined
Study of motion or human movement
Stabilizers
Surround joint or body part
Contract to fixate or stabilize the area (enable another body part to exert force& move)
Synergist
Assist In action of agonist
Not necessary prime movers for action
Know as guiding muscles
Neutralizes
Contract to neutralize the action of another muscle to prevent undesirable movements
Neural control of voluntary movement
Cerebral cortex Basal ganglia Cerebellum Brain stem Spinal cord
Cerebral cortex
Highest level of control
Provides for creation of voluntary movement
Basal ganglia
Controls maintenance of postures and equilibrium
Controls learned movement such as driving a car
Cerebellum
Major integrator of sensory impulses
Provides feedback relative to motion
Brain stem
Functions in arousal or maintaining wakeful state
Spinal cord
Common pathway between CNS and PNS
Most specific control
Proprioceptors
Work in combination with other sense organs to accomplish kinesthesis
Kinesthesis
Conscious awareness of position and movement of body in space
Golgi tendon organ
Protects us from An excessive contraction by causing its muscle to relax
Uniarticular muscle
Cross and act directly only on the joint that they cross
Ex. Brachialis can only pull humerus and ulna closer together
Biarricular muscle
Cross and act on two different joints
Multiarticular muscle
Acts on three or more joints due to the line of pull between the origin and insertion crossing multiple joints
Levers
Cannot be changed but can be utilized more efficiently
- levers are ridged bar that turns about on an axis or rotation or a fulcrum
- axis is a point of rotation about which lever moves
1st class Lever
Axis is between force and resistance
F-—A——R
2nd class lever
Resistance is between force and axis
F—-R——A
3rd class lever
Force is between Axis and Resistance
A——F—-R
Axis,point of Force, point of Resistance
Axis: The point of rotation
Point of Force: usually the muscle
Point of resistance: body weight plus any added weight
Mechanical advantage
Force/Resistance or
length of force arm/ Length of Resistance arm
Torque
The turning effect of an eccentric force
Eccentric force
Forced applied off center of any direction not in line with the center of rotation of an object with a fixed axis
Short lever arm
Best for quickness
Wheels and axis
Used primarily to enhance range of motion and speed of movement in the muscleosketal system
-if wheel radius is greater than radius of axle then longer force arm takes place resulting in mechanical advantage
Pulleys
Single pulleys function to change effective direction of force application
Law of motion
- Body in motion is produced by or started by some action of muscular system
- motion can not occur without force
Types of motion
- linear
- angular motion
Angular displacement
Change in location of a rotating body
Linear displacement
Distance that a system moves in a straight line
Speed
How fast an object in moving or distance in an amount of time
Velocity
Includes the direction and describes the rate of displacement
Law of inertia
A body in motion tends to remain in motion at the same speed in a straight line unless acted on by force; A body at rest tends to remain at the rear unless acted on by a force
Inertia
Resistance to action or change
The greater the objects mass the greater the inertia
Law of acceleration
A change in the acceleration of body occurs int the same direction as the force that caused it
Acceleration
The rate of change in velocity
Mass
The amount of matter in the body
Law of reaction
For every action the is an opposite and equal reaction
Friction
Force that results from resistance been tween surfaces of two objects from moving upon one snother
Force formula
Force =mass x acceleration