Functional Anatomy

Question 1

explain key events off the sliding Filament theory

Answer 1

1. action potential is met at end of axon triggering release of acetylcholine into synaptic cleft causing muscle too become more positively charged end plate potential
2. Once the threshold is Matt the muscle contracts and Depolarises causing a release of calcium
3. Neuromuscular stimulation causes calcium to be released into sarcomere
4. Calcium prompts reaction between actin and Myosin filaments by binding to acting as long as there is a sufficient amount of adenosine triphosphate present
5. Acton is pulled along the myosin via cross bridges this is known as a power stroke
6. Once totally contracted actin filaments overlap and the H zones signs will disappear
7. When stimulation Caesars cross bridges release aceteylcholine is removed and the muscle slides back to resting length

Question 2

list the order in the structures of skeletal muscle

Answer 2

epimysium (outer layer of the muscle) muscle belly made up so many fascicles the fascicle is covered in perimysium a fascicle is made off muscle fibre which will then split too microfibrils which will then split into microfilaments a microfilament will then be made of the proteins myosin and actin

Question 3

explain the relationship between concentric and eccentric moment

Answer 3

concentric: the angle will decrease during the moment
eccentric: when the angle will increase during the exercise

Question 4

explain the relationship between force and velocity

Answer 4

• muscle can create a large force when there is a decrease in velocity during concentric contraction ( when the decreases during the movement )

Question 5

explain the relationship between force and length

Answer 5

MAX muscle tension is is obtained when a muscle is at its normal resting tension as this is when there is an increase off cross bridges that are attached too the myosin and actin

muscle generates less force when the muscle is contracted or lengthened between its optimal length

the greater number off cross bridges the grater force generated

Question 6

What are the three purposes of the nervous system

Answer 6

1: to receive Messages from receptors which detect changes in the body and the external environment
2: to process information
3: to use the effectors to carry out the bodies response

Question 7

Explain the four structural classifications of neurons

Answer 7

Bipolar has two extensions one axon and one dendrite

Multipolar has one axon and many dendrites

Unipolar only one single extension leading away from the cell body

Axonic sonic has many dendrites button no axon

Question 8

Outlined explain what the two functional classifications off neurons

Answer 8

Sensory or afferent these neurons send a messages from receptors towards the central nervous system

Efector or motor neurons send a messages from central nervous system to muscles or glands

Question 9

Explain the difference between an effector and a receptor

Answer 9

Effector response to nerve impulse and Can be a muscle or gland it contracts or secretes when it receives information

Receptor and organ with the nerve endings which response to stimuli

Question 10

Outline the difference between the central nervous system and the peripheral nervous system

Answer 10

The central nervous system consists of the brain and the spinal cord

The peripheral nervous system consist of nerves and Gangai and is split into the sensory and the motor division

Question 11

Explain what a motor unit is

Answer 11

Motor neuron and all of the fibres it attaches to

Question 12

What is an inter-neuron

Answer 12

Send messages between sensory and motor neurons their store and retrieve information and decide how we respond to stimuli

Question 13

isometric training involves……

Answer 13

Developing tension in muscles without creating movement

Question 14

dentify 5 distinct phases to assist you in describing the ‘Sliding filament theory’

Answer 14

1. A nerve impulse from the CNS travels to the MOTOR NEURON
2. CALCIUM CHANNELS are flooded at the NEUROMUSCULAR JUNCTION
3. ACETYCHOLINE is released into the neuromuscular junction.
4. SODIUM increases and POTASSIUM decreases at the muscle fibre membrane.
5. CALCIUM is then released unblocking the binding sites.
6. MYOSIN HEADS bind to the ‘binding sites’ = ‘POWER STROKE’
7. The muscle fibre contracts as the filaments slide over each other.
8. ATP is released and the myofilaments relax.
9. Calcium causes the MYOSIN heads to bind to the ACTIN.

Question 15

With respect to neural impulses, identify 3 ways in which maximum force can be generated?

Answer 15

FREQUENCY, AMOUNT, COORDINATION of nerve impulse. EXCITABILITY of muscle fibre

Question 16

Use an example to explain the relationship between force and velocity?

Answer 16

INVERSELY PROPORTIONAL, HIGH VELOCITY = LOW FORCE

LIFTING A WEIGHT QUICKLY

Question 17

Identify at least one characteristic of the relationship between force and muscle length?

Answer 17

RESTING LENGTH = MAXIMUN FORCE/STRENGTH

SARCOMERES ARE AT THEIR MAXINAL POSITION – i.e. Not too overlapped nor not overlapped enough

Question 18

Define the ‘all or none’ principle and describe how the basketball player is able to control the forcefulness of her skeletal muscle contractions to perform a fast, penetrating pass.

Answer 18

Provides a definition of the all or none principle such as:
When motor unit receives stimulation/impulses/action potential to threshold.
and
All the muscle fibres associated with a motor unit will contract to their maximum level (all the same time).
Describes:
The number of motor units/muscle fibres recruited is related to the amount of speed/force produced.
And
Answers a correct reference to passing the ball with increased speed/force.

Question 19

Identify the five main structures in a motor unit and explain their respective functions?

Answer 19

DENDRITE – picks up messages from the body / other nuerons
CELL BODY – control the neuron
AXON – conduit for the message sent
MYELIN SHEATH – speeds up and insulates the axon
MOTOR END PLATES – passes message on to muscle fibre for contraction

Question 20

list six characteristics of Type IIB.

Answer 20

Larger diameter/bigger fibre 
Larger motor neuron 
Low capillary density/oxidative density 
Greater force can be generated 
Fast contraction speed 
Low number of mitochondria 
Low resistance to fatigue/fatigues quickly 
Uses the anaerobic energy system 
White in colour/low myoglobin content 
Fast glycolytic (anaerobic glycolysis)/ATP-PC Energy system 
•Fuel source is phosphocreatine

Question 21

Identify the components of the neuromuscular system and their function in enabling athletes to produce a fast start.

Answer 21

Sensory neuron
Ears receive sound and pass information from the sensory receptors to the cell body of the sensory neuron/brain.
Brain
Interprets/decides on the information and sends signals/impulse/action potential for movement to occur
Motor neuron
Transmit electrical information/signals away from cell body to the muscle fibres.
Spinal cord
Transmits electrical messages from the brain to parts of the body.
Motor unit
The motor neuron receives signal to cause contraction (innervation/stimulation) of the associated muscle fibres.

Question 22

explain what a neuromuscular suction is

Answer 22

The nerve fibre meets the target muscle fibre the nerve fibre and the target do not touch this gap is known as the synaptic cleft the Shawn cell will surround the whole neuromuscular junction to separate it from the fluid around it

Question 23

list at least 5 functions for each muscle type

Answer 23

Type one
Contraction speed: slow
Force of contraction: low 
Resistance to fatigue: high
Aerobic capacity : very high 
energy pathway used: Aerobic 
recruitment order: first 
fatigue level: low 
activity suited: endurance
anaerobic capacity: low 

type II A
Contraction speed: Medium 
force of contraction: Medium 
resistance to fatigue: Medium 
aerobic capacity: Medium 
energy pathway used: aerobic and anaerobic 
recruitment order: second
fatigue level: medium 
activity suited: sprinting
anaerobic capacity: high

type II B
Contraction speed: high 
force of contraction: high 
resistance to fatigue: low
aerobic capacity: low 
energy pathway used: anaerobic 
recruitment order: third
fatigue level: high 
activity suited:high intensity/ rapid 
anaerobic capacity: high

Question 24

Explain the structure of each muscle type

Answer 24

type 1
Fibre diameter: small
Myoglobin content: high
Phospho creatin content: low 
Ability to generate ATP: high
motor neuron size: small
Triglyceride store: high
Mitochondrial density: high

type II A

Fibre diameter: medium 
Myoglobin content: medium 
Phospho creatin content: high
Ability to generate ATP: medium 
motor neuron size: large 
Triglyceride store: medium 
Mitochondrial density: high

type II B
Fibre diameter: large
Myoglobin content: low
Phospho creatin content: high
Ability to generate ATP: low
motor neuron size: large 
Triglyceride store:low
Mitochondrial density; low