Kinesiology Test 1

Kinematics vs Kinetics

-kinematics - study of the form, pattern, or sequence of movement without regard for the forces that produce that movement

-kinetics - study of the effects of internal and external forces on the body

axial vs appendicular skeleton

axial = head neck down to pelvic bones

appendicular = appendages

Bone tissue Function

- Supports and protects organs

- Provides levers and attachment site for muscles

- Stores calcium and other minerals

- Stores fat

- Marrow is site for blood cell formation

Lever systems

lever, fulcrum, effort, load

1st class lever

fulcrum in the middle; see-saw, hammer, scissors (mechanical advantage varies)

2nd class lever

fulcrum at the end, load in the middle; wheel barrow, car-jack (mechanical advantage is always greater than 1, movement same side as fulcrum)

3rd class lever

fulcrum at the end, effort in the middle; tweezers, baseball bat (mechanical advantage is always less than 1, movement arm same side as fulcrum)

Bone composition

collagen

inorganic salts (do not contain carbon)

water

osteocytes

Cortical Bone vs Trabecula bone

Cortical

- compact

- 80%

- Porosity less than 15%

- Lamella

Trabecula

- spongy

- porosity over 70%

- Trabecula

Long Bones

- diaphysis

- epiphysis

longer than they are wide

- diaphysis: shaft of bone

- epiphysis: end of bone

Short bones

carpals and tarsals

flat bones

bones of the ribs, shoulder blades, pelvis, and skull

irregular bones

bones of the vertebrae and face

stress strain curve

The relationship between the stress and strain that a particular material displays

anisotropic

exhibiting different mechanical properties in response to loads from different directions

viscoelastic

having the ability to stretch or shorten over time

hyaline cartilage

Most common type of cartilage; it is found on the ends of long bones, ribs, and nose

Fibrous Joints: synarthroses

bones of joints fit together closely, thereby allowing little or no movement

who is most at risk for osteoporosis

-Smaller stature of women that have not been active

- steroid users for a prolonged time

Cartilaginous Joints: symphyses, amphiarthroses

sternocostal joints, with little movement

synovial joints; diarthroses

Also called movable joints

At ends of long bones

Within articular capsules

Lined with synovial membrane

types of synovial joints

plane, hinge, pivot, condyloid, saddle, ball and socket

Muscle tissue properties

Irritability (respond to stimuli)

Contractility (ability to shorten)

Extensibility (ability to lengthen)

Elastic (ability to return back to resting length)

Muscle functions

Movement

Posture and Position

Stabilize Joints

Other functions (thermogenesis, communication)

Skeletal Muscle Structure

Parallel Fiber Arrangement

Flat

Fusiform (bicep brachii)

Convergent

Circular

Penniform Fiber arrangement

Unipennate (form at the same angle

Bipennate (2 different angles)

Multipennate (multiple angles greater than 2)

Individual muscle structure

Sarcolemma

Sarcoplasm

Myofibrils

Muscle FIber

Fasciscles

superficial to deep muscle

Epimysium

Perimysium (binds fibers)

Endomysium

microstructure

Myofilaments

Sarcomere

Z-line (anchor the actin)

A-Band (contain myosin and actin)

I- Band (contain actin)

H-Zone (small region that only contains myosin)

sliding filament theory

theory that actin filaments slide toward each other during muscle contraction, while the myosin filaments are still

Force generation (excitation- contraction coupling)

Troponin (really high affinity for calcium)

Tropomyosin (covering the actin sites)

Acetylcholine (name of neurotransmitter for communication for neuron in cell membrane)

Steps of EC Coupling

1. Action potential travels down axon, reach acetylcholine release binds Nicotinic receptors on the sarco level

2. Action potential generated on sarcolevel enters the fiber by way of the t tubules

3. DHP receptor communicators Ryanadine receptor that there is a charge change

4. Opens calcium channels on the sarcoplasmic reticulum and is released

5. Calcium binds troponin

6. Active sites are exposed and cross bridges are formed

7. Cross bridge cycle occurs

8. To stop the cycle calcium is pumped back in too SR, ACH esterase occurs and the process stops

pure fiber types

Type 1a (slow twitch oxidative)

- Smaller

- Slower velocity

- Fatigue resistant

Type 11a (fast twitch oxidative glycolytic)

- More fatigue resistant

- More aerobic activity

Type 11x (Fast twitch glycolytic)

- Fatigue easily

- Strongest, biggest, and fastest

Mechanical model of Musculotendinous

Contractile component

Parallel Elastic Component

Series Elastic component

Net Muscle Actions

isometric, concentric, eccentric

Biarticulate Muscles

muscles that cross two joints

Limitations of biarticulate muscles

Passive (stress)and active (contract) insufficiency (cannot maximally contract or stress) across two joints)

Length Tension Relationship

The resting length of a muscle and the tension the muscle can produce at this resting length.

Factors influencing force production

Cross-bridge formation

Muscle Length

Fiber Type

Neural activation

Factors influencing velocity shortening

Muscle length

Shortening rate

Muscle fiber arrangement

Fiber type

open vs closed kinetic chain

Open kinetic chain

- Hands and feet are not fixed and you can throw the weight

Closed kinetic chain

- Hands and feet are fixed more safe

gray matter vs white matter

-White matter is myelinated axons and Glia

Gray matter is the cell bodies, dendrites, axons and glia

All or none principle

Refers to the fact that the action potential in the axon occurs either full-blown or not at all.

rate coding (summation of tension)

15-50 impulses/sec

80-120 impulses/sec

Sensory receptors and reflexes

Muscle spiders

Stretch reflex (recruit more fibers)

Autogeneic facilitation

Reciprocal inhibition