functional anatomy

Question 1

epimysium:

Answer 1

a layer of connective tissue which covers the entire muscle belly.

Question 2

fascicle:

Answer 2

the bundle of skeletal muscle fibres. this bundle is surrounded by connective tissue called perimysium.

Question 3

perimysium:

Answer 3

the connective tissue that surrounds an individual fascicle

Question 4

muscle fibre:

Answer 4

Cylindrical shape cells that form along the length of the muscle. Bundled with many others to form fascicle/myofibrils.

Question 5

myofibril:

Answer 5

The part of the muscle in casing the actin and myosin filaments. Long filaments within muscle fibre

Question 6

myosin:

Answer 6

thick protein filament within the sarcomere

Question 7

actin:

Answer 7

the protein filament within the sarcomere

Question 8

sarcomere:

Answer 8

smallest functional unit and their contraction change the muscles length and forces it to shorten.

Question 9

what are the 10 steps of the sliding filament theory?

Answer 9

1. motoneuron stimulans muscle fibre with neural impulse
2. calcium ions released from sarcoplasmic reticulum and enters sarcomere
3. actin binding sites revealed, for myosin heads to attach
4. myosin attaches to actin, creating cross bridges
5. ATP broken down at site, stimulates cross bridges
6. myosin heads pull actin in, in power strokes causing muscle contractions
7. sarcomere shortens as z line comes closer
8. H zone and I band decrease in size
9. neural impulse stops, calcium goes back to sarcoplasmic reticulum
10. myosin heads detach from actin, muscle relaxes

Question 10

isometric contraction:

Answer 10

the muscle does not change length even though it does produce force. the joint angle also remains the same.

Question 11

isotonic concentric contactions:

Answer 11

the muscle shortens while developing tension or force and the angle of the joint decreases.

Question 12

isotonic esentric contentions:

Answer 12

the muscle lengthens as it develops tension or force and the angle of the joint increases.

Question 13

force length relationship:

Answer 13

The amount of force produced by muscle depends on the length of the muscle. Differing lengths produce differing forces.

Question 14

Resting length/midpoint of joint angle/optimal length:

Answer 14

Force at this length is the greatest due to optimal overlap of myosin heads and actin binding site.

Question 15

Full lengthened:

Answer 15

Muscle force generation is low due to minimal overlap of myosin heads and actin binding sites

Question 16

Fully contracted:

Answer 16

Muscle force generation is low due to the Z line not being able to move any further inwards. No more actin binding sites available to form cross bridges

Question 17

order of function of nerves, spinal cord, motor unit:

Answer 17

1. sensory neuron
2. brain
3. spinal cord
4. motor neuron
5. motor unit

Question 18

sensory neuron:

Answer 18

Receive stimulus via the dendrites of the sensory neuron and pass information on to the cell body of the sensory neuron, onwards towards the brain via axon

Question 19

brain:

Answer 19

Interpret message or impulse from the sensory neuron and then decides on the action to take. Sends impulse through to spinal cord for movement

Question 20

spinal cord:

Answer 20

Receives impulse from the brain and passes message onto motor neuron and muscles

Question 21

motor neuron:

Answer 21

Receives impulse via dendrites at spinal cord processes it at its cell body, suns onto muscle fibres via axon

Question 22

motor unit:

Answer 22

Motor neuron and all of the muscle fibres that it innovates, motor neuron receives electrical impulse, sends down axon towards muscle fibre for physical movement.

Question 23

dendrite of sensory neuron:

Answer 23

Receives information from sense receptors and passes it onto cell body of sensory neuron

Question 24

axon of motor neuron:

Answer 24

Transmits impulses from one cell body and send it to muscle fibres

Question 25

all of none principle:

Answer 25

When a motor neuron unit receives stimulation/action potential at or above its threshold, all muscle fibres associated with that unit will contract to maximum level at the same time