Module 3

Question 1

What are the main parts of the Nervous system?

Answer 1

1-Central nervous system:
- brain
-spinal cord
->protected by boney structures (skull, spine)

2- peripheral nervous system:
- nerves outside the CNS
-somatic component->sensory and motor nerve
-> reacts to senses and movement respectively

3- Autonomic nervous system:
- control system of body functions (breathing, cardiovascular function, digestion etc)
- sympathetic (responding to danger) and parasympathetic (relax after stressful period)

Question 2

What are the parts of the brain?

Answer 2

1-Brain:
Cerebrum- hippocampus, cerebral cortex, amygdala
Cerebellum
Diencephalon- thalamus, hypothalamus
Brain stem- midbrain, pons, medulla

2-Spinal cord

Note: the rigid/grooves in the brain increase surface area
Rigid : gyri
Groove : sulci

Question 3

White vs Grey Matter

Answer 3

White (lighter pink) : Axons, Pathways between grey

Grey(darker pink) : cell bodies, dendrites, axon terminals, areas of synaptic connections

Question 4

Peripheral Nerves

Answer 4

-nerves pointing out at every vertebrae form the peripheral nervous system
- nerves in limbs
- a nerve is a collection of many neurons (cells)

2 types:
1- motor nerves:
-efferent neurons: control effectors such as skeletal muscles
2- Sensory nerves:
-afferent neurons: detect stimuli and relay information to the CNS

Question 5

Neurons

Answer 5

• basic information processing units->recieves input, processes info and provides output
• send action potential or stops sending action potential

Membrane potential:
- negative at rest (-70mmol)
-depolarization=membrane potential becomes positive
-repolarization/hyperpolarization=membrane potential becomes negaitive

Question 6

How do Neurons work? What are the steps?

Answer 6

1. Dendrites recieves signal from other neurons
2. Axon transmit the signal over a certain distance
3. Axon terminal transmits single to their neuron dendrites or tissues
4. Myelin sheaths speeds up the transmission of the signal
5. When the signal reaches another neuron a synapse occurs

• axon hillock determines if action potential is fired
  The soma is the cell boddy

Question 7

What are Glial cells?

Answer 7

• cells that provide support to neuron function (helps with structure, metabolism and repair)
  -“helper cells”

Question 8

What is a synapse?

Answer 8

• structure permitting communication between two neurons

Question 9

What is action potential?

Answer 9

-change in electrical potential that can travel along a cell membrane

Question 10

What are neurotransmitters?

Answer 10

-chemical messenger that transmits a message between cells

Question 11

What are the basic steps of cell communication?

Answer 11

1. Action potential travels down an axon
2. Neurotransmitter crosses the synapse
3. Neurotransmitter binds to neuroreceptors
4. Trigger signal in post-synaptic neuron

Question 12

Methods of measuring the nervous system

Answer 12

1. Structure: structural imaging
2. Function(behaving):
   - neuronal activity
   
   • functional imaging
   • EEG (electroencephalographs)
   • electrophysiology
3. Behaviour
   -timed (reaction time)
   -non-timed (errors, response)

Question 13

What is bio potential?

Answer 13

• electric potential that is measured between two points in living cells, tissues, and organs
• electrodes, amplifiers and electrical activity

Question 14

What is EEG?

Answer 14

Electroencephalographs
- measures electrical activity (bio potentials) arising rom the central nervous system
- neuronal activity is being measured
Depolarization/repolarization 9action potentials) is being measured

Question 15

What are the different types of muscle structure?

Answer 15

Muscle: tissue made up of many muscle cells and associated connective tissue. There are 3 main muscle types( skeletal, cardiac and smooth)

Skeletal: (muscle fibre or myocyte) individual cell that when activated produces force that can lead to motion

Sacromere: fundamental unit of skeletal and cardiac muscle. Many , many sacromeres are arranged in sequence within a single myofibril and many myofibrils make up a muscle cell

Myofilaments: sarcomeres are composed of highly organized arrangement of myofibrils that interact with each other to generate force

Question 16

Overall structure of a muscle fibre

Answer 16

• muscle is made up of fascicle
  -fascicle are made up of muscle fibres
• Muscle fibres are full of structures needed to generate force/strength
  ->myofibrils, sarcolemma, satellite cell, sarcoplasma
• myofibrils are filled with sacromeres which are composed of thin and thick filaments or actin and myosin respectively
  
  • z lines determine the end of the sacromere

Question 17

What is a cross bridge?

Answer 17

-The binding of actin to myosin myofilaments and change in the confirmation of myosin
-the cross bridge cycle is the process involving attachments, conformational change and detachment (with ATP) that generates force

Question 18

What is the sliding filament theory

Answer 18

Theory that explains the mechanism of muscle contraction associated with the gross bridge cycling and sliding of myofilaments past each other to generate force

Question 19

What is a motor neuron?

Answer 19

Neuron that synapses with skeletal muscle cells
- can interact with millions of cells

Question 20

What is a motor unit?

Answer 20

Motor neuron and all muscles cells that interact together

Question 21

What is a neuromuscular junction?

Answer 21

Synapse between motor neuron and skeletal muscle

Question 22

What is a muscle action potential?

Answer 22

Action potential on the membrane of a skeletal muscle

Question 23

What are the steps to neuromscular activation?

Answer 23

1. Depolarization of motor neuron-electrical
2. Neurotransmitter release at neuromuscular junction-chemical
3. Depolarization of muscle fibre-electrical
4. Cross-bridge formation and sacromere shorten-mechanical

This occurs every couple of milliseconds

Question 24

How can you control the amount of force a whole muscle generates?

Answer 24

2 ways:
1. Motor neuron recruitment- # of neurons activating or producing force
2. Action potential frequency
in general increase AP frequency =I increase in force

Question 25

What determines the maximum isometric force a whole muscle could generate ?

Answer 25

- cross sectional area determines the max isometric force a muscle produces - more cross bridges = more sarcomeres=more cells=more force

Question 26

What is EMG?

Answer 26

Electromyography - measures electrical activity produced by a muscle 2 types: 1. Surface(in the lab) - need skin prep -need to know muscle fibre direction -limited by surface muscle = less accurate 2. Intramuscular - small needle inserted into a muscle - invasive but more accurate - need to trained Graph: X axis - time Y axis - mV An increase in force = an increase in EMG *cant compare EMG between muscle and people

Question 27

What is stimuli response?

Answer 27

The neural information is processed 4 steps: 1. Efferent neurons determine that a desired output is needed 2. Muscle are activated to perform task 3. Stimulus is presented in computer screen 4. Specialized cells detect the light on the screen by afferent neurons

Question 28

What is reaction time dependent on?

Answer 28

1. Stimulus intensity and modality 2. Simple reaction time_only one stimulus and one response 3. Choice reaction time-number of different stimuli presented each requiring different response.

Question 29

What is dual-task interference?

Answer 29

Simultaneous performance of two tasks often leads to performance deficits in the component tasks. This effect is known as dual-task interference, is thought to be a prof of capacity limitation on cognition.

Question 30

Antagonist vs Agonist

Answer 30

Antagonist id the muscle that relaxes during a movement Agonist is the muscle that activists during a movement

Question 31

Types of contractions

Answer 31

1. Co-contraction: When both the agonist and antagonist activate at the same time 2. Reciprocal contraction: When the agonist and antagonist contract one after the other

Question 32

What’s is biomechanics?

Answer 32

The study of the effects and control of forces that act on and are produced by living beings

Question 33

WHat is kinematic?

Answer 33

The study of the motion of objects (without reference to the forces that caused the motion)

Question 34

What is kinetics?

Answer 34

The study of forces that cause motion 2 types: Linear - displacement(m) Velocity(m/s) -acceleration(m/s^2) Angular motion Angular displacement (rad) Angular velocity (rad/s) Angular acceleration (rad/s^2)

Question 35

What is force?

Answer 35

An action or influence that moves the body or influences the movement of the body - internal forces are created primarily by skeletal muscles - external forces are created by the ground external loads, other individuals and from passive sources (wind force) -units in N F= m x a

Question 36

What is the definition of moment?

Answer 36

A force that tends to change the rotational motion of an object -units are Nm Moment arm is the perpindicular distance to the application of force - distance between point of rotation and application of force M= Fx d F=force D=perpendicular distance between axis of rotation and line of force

Question 37

What id the COM?

Answer 37

Centre of mass - point in an object where the mass of the object is equally distributed in all directions - the force of gravity is equal to mass(acceleration) due to gravity F=mxa = m (9.8 m/s^2)

Question 38

How can kinematic be measured?

Answer 38

Visual observation Goinometer->measure joint angle - hand held and electric Inertial sensors( Apple Watch sensory devices) optical or magnetic motion capture - gold standard for measuring kinematic - expensive - requires knowledge of software - best technique, reliable and accurate

Question 39

What are the ways to measure kinetics?

Answer 39

Manual assessment - do anywhere, by anyone, need training Dynamometer-device measures force, moment of power - hand held-> accurate - electronic (isokinetic)->measure force produced by grip, expensive, control variable, speed of contractions, joint angle Force plates - gold standard of measuring kinetics - super accurate - very pricey

Question 40

What do you need to picture the movement

Answer 40

-EMG -Kinetic data(forces) - kinematic (movement data)