Exercise Science Exam 3

Lab equipment used for:

Ground reaction forces

joint angles

movement of limbs

Force plate

goniometer

motion capture system

Kinetics vs Kinematics

Kinetics: forces that cause or change motion

Kinematics: description of motion independent of the causes

Momentum

def: quantity of motion of an object in motion

equation = mass*velocity

Impulse

def: overall effect of a force acting over time

Power

def: amount of work(energy transferred t/from object) done over a period of time

equation = force*displacement

Torque

def: measure of force that causes an object to rotate about an axis(angular equivalent of force)

equation: force*perpendicular distance

Force

def: influence that can cause an object to change its velocity

equation = mass*acceleration

units: newtons(N)

Inertia

def: tendency to resist change in state of motion(proportional to mass)

mass

def: quantity of matter within/what makes up an object

units: kg

weight

def: force exerted on an object due to gravity

units: Newtons(N) or kg*m/s²

anatomical position

standing

body erect

palms facing forward

feet shoulder-width apartsuperior

superior vs inferior

superior: closer to the head

inferior: closer to the feet

medial vs lateral

medial: closer to the center of the body

lateral: away from the center of the body

proximal vs distal

proximal: closer to the base of the limb/trunk

distal: away from the base of the limb/trunk

sagittal plane

divides body into right and left

relates to flexion and extension

medial lateral axis

frontal plane

divides body into front and back

relates to abduction and adduction

anterior posterior axis

transverse plane

relates body into top and bottom

relates to rotation

longitudinal axis

pronation vs supination

pronation: turning towards body/midline

supination: turning away from body/midline

plantar flexion vs dorsiflexion

plantar flexion: movement of the foot downward and away from the body

dorsiflexion: backward or upward motion of a part of the body

Newton’s 1st Law

Law of inertia/momentum

An object in motion stays in motion unless acted upon by an outside force

Newton’s 2nd Law

Law of acceleration

acceleration of an object depends on the mass and force applied

Newton’s 3rd Law

Law of action/reaction

every action has an equal and opposite reaction

Ground reaction forces

forces made by the ground in reaction to a force made by a body on the ground

Types of muscle contractions

Twitch: a single contraction and relaxation of a muscle after a single stimulation

Summation: additive effect of frequent contractions where a muscle fiber is stimulated again before it has relaxed completely from prior contraction

Tetanus: a sustained contraction without relaxation, resulting from a series of rapid nerve impulses that stimulate a muscle before it has time to relax

Steps of Excitation-Contraction coupling

1. AP travels down motor neuron axon to neuromuscular junction and releases neurotransmitters(acetylcholine)

2. ACh binds to ACh channels on muscle fiber sarcolemma allowing Na+ to enter cell, initiating AP

3. AP travels down T-tubule releasing Ca2+

4. Ca binds to troponin exposing binding site on actin

5. Myosin binds to actin (forming the cross-bridge formation)

Order of motor skill development

Cephalocaudal- head to toes

proximodistal- midline to extremities

Main motor control centers

1. Motor cortex(frontal lobe): voluntary control of movement

2. Basal nuclei(ganglia): organize motor signal and modify if needed, inhibit and disinhibit

3. Cerebellum: incorporation of sensory information to fine-tune movement for proper balance and coordination; transmits info to thalamus to relay to motor cortex(relay station); important in “learning” motor behaviors

4. Thalamus: relay station for sensory and motor info

3 stages of motor learning

Cognitive: full focus on understanding task, relies on visual and verbal cues

Associative: focus on refining/improving the skill, skill becomes more proprioceptive

Autonomous: mastery of skill, requires little thought, greater external focus

Pivot joint

allows for rotation and pronation/supination

ex: upper forearm

Hinge joint

allows for flexion/extension only

ex: knee

Condyloid joint

allows for flexion/extension and abduction/adduction

ex: wrist, knuckles

Ball and socket joint

allows for flexion/extension, abduction/adduction, and rotation

ex: shoulders and hips

Saddle joint

allows for flexion/extension, abduction/adduction, and rotation

ex: thumb

PNS neurons

afferent: sensory neurons, carries info into the spinal cord

efferent: motor neurons, carries info to the muscles

types of neurons

multipolar: 1 axon and several dendrites, most abundant, motor neurons and interneurons

unipolar: single axon coming from cell body with dendrites at the end of the axon, sensory neurons

Stages of Transtheoretical Model

1. Precontemplation

2. Contemplation

3. Preparation

4. Action

5. Maintenance

Types of skills

Closed skill: doesn’t change, not affected by outside factors, ex: free-throws

Open skills: changes each time, heavily affected by outside factors, ex: jump shot

2 types of proprioceptors

Golgi tendon organ: located in junction of muscle and tendon, monitors tension(force of contraction)

Muscle spindle: located inside the muscle, monitors stretch of muscle

Synapse vs neuromuscular junction

Synapse: junction between neuron and next cell(typically another neuron)

NMJ: type of synapse between motor neuron and muscle cell

Exercise participation motivation

refers to the direction component

knowledge, attitude, and beliefs influence motivation

exercise adherence motivation

refers to the persistence component

influenced by biological, psychological, sensory, and situational factors

psychological benefits to exercise

enhanced psychological well-being

reduced state anxiety

decreased depression

improved cognitive performance

explicit vs implicit learning

explicit: external source, better for error correction, worse for retaining info in the long run

implicit: derived from within the body, better for retaining info long term, worse for technique/habits

Neuron signaling

neurons use chemical messengers and changes in electric signal to quickly send signals across the body

Graded vs action potentials

Graded: weak signals, signals that try to activate or inhibit neurons

action: strong signals, an all or none signal that travels down the whole length of the axon

AP propagation

Continuous: unmyelinated neurons, Na/K channels open all along the neuron, travels straight down axon, channels open

Saltatory: myelinated neurons, ions only move in Nodes of Ranvier(jump over Schwann cells), much faster

Joint types

fibrous: bones are joined by fibrous tissue(skull)

cartilaginous: bones are joined by cartilage(spine)

synovial: fluid-filled joint cavity contained with in a fibrous capsule, freely moveable, most common