Physiology

Question 1

physiological functions of skeletal muscle?

Answer 1

purposeful movement 
metabolism 
heat production 
posture maintenance 
respiratory movement

Question 2

what causes the striation in skeletal muscle

Answer 2

dark myosin filaments

light actin filaments

Question 3

what nervous system innervates skeletal muscles and what control are they under

Answer 3

somatic

voluntary

Question 4

what is a motor unit

Answer 4

single alpha motor neuron and all of the skeletal muscle fibres it innervates

Question 5

true/false - muscles doing finer tasks have more muscles per motor unit

Answer 5

false - they have less

Question 6

what is a myofibril

Answer 6

part of skeletal muscle cell containing actin and myosin filaments arranged into sarcomeres

Question 7

what is the Z line

Answer 7

line connecting two sarcomeres

Question 8

what is the A band

Answer 8

thick myosin filaments with strands of actin filaments overlapping

Question 9

what is the H zone

Answer 9

middle of A band where actin filaments do not reach

Question 10

what is the M line

Answer 10

runs down middle of A band within centre of H zone

Question 11

what is the I band

Answer 11

remaining portion of actin filaments that do not project into the A band

Question 12

during skeletal muscle contraction, when is ATP required?

Answer 12

during contraction and relaxation of the myosin cross bridge

Question 13

describe the events of skeletal muscle contraction within the sarcomere

Answer 13

AP is carried down T tubules and causes calcium release
calcium binds to tropomyosin to expose myosin cross bridge binding site. myosin cross bridge binds after ATP phosphorylation and contracts
AP disappears, calcium reuptake by SR and tropomyosin covers binding site. cross bridge detaches

Question 14

what are the 2 factors skeletal muscle tension are dependent on

Answer 14

tension developed by each contracting fibre

number of muscle fibres contracting

Question 15

what is motor unit recruitment

Answer 15

stronger contraction achieved by stimulation of many motor units

Question 16

true/false - the more APs to a muscle, the stronger the contraction

Answer 16

true

Question 17

what is tetanus (physiologically)

Answer 17

maximal sustained contraction without rest

Question 18

maximal tetanic contraction is achieved when muscle is ___

Answer 18

at optimal length

Question 19

what is isotonic contraction and examples

Answer 19

muscle tension is constant but length varies

body movement and moving objects

Question 20

what is isometric contraction and examples

Answer 20

tension varies but length remains constant

posture, supporting objects in a fixed position

Question 21

state the 3 main differences in skeletal muscles

Answer 21

enzyme pathways for ATP synthesis
activity of myosin ATPase
resistance to fatigue

Question 22

describe slow oxidative muscle fibres and examples

Answer 22

low work, aerobic activities

posture maintenance, walking

Question 23

describe fast oxidative muscle fibres and examples

Answer 23

aerobic and anaerobic metabolism, prolonged moderate work

jogging

Question 24

describe fast glycolic muscle fibres and examples

Answer 24

anaerobic metabolism for short term, high intensity activities
jumping

Question 25

describe the stretch reflex arc

Answer 25

muscle spindle activated by stretch afferent neuron firing increased, synapse in cord alpha motor neuron innervate stretched muscle to contract

Question 26

what is a muscle spindle

Answer 26

sensory receptor for stretch reflex

Question 27

what is an intrafusal fibre

Answer 27

muscle spindle

Question 28

what is an extrafusal fibre

Answer 28

ordinary muscle fibres

Question 29

what do gamma motor neurons do

Answer 29

adjust tension within the muscle spindle as the muscle itself contracts

Question 30

what muscle and tendon is activated in the knee-jerk reflex

Answer 30

patellar tendon | contraction of quadriceps femoris

Question 31

describe cartilagenous joint and examples

Answer 31

limited movement, united by cartilage | IV discs, pubic symphesis, costochondral joints, part of sacroiliac joint

Question 32

describe fibrous joint and attachment

Answer 32

fibrous tissue, no movement | fissures in skull

Question 33

what is the synovial membrane and what makes it up

Answer 33

inner aspect of fibrous capsule | vascular connective tissue and synovial cells producing synovial fluid

Question 34

what is a simple synovial joint

Answer 34

one pair of articular surfaces

Question 35

what is a complex synovial joint

Answer 35

more than one pair of articular surfaces

Question 36

how does a joint remain stable

Answer 36

shape of joint ligaments synovial fluid

Question 37

functions of synovial fluid

Answer 37

``` lubricates joint facilitates joint movement minimise wear/tear nutrition of articular cartilage supplies chondrocytes with o2 and nutrients and removes co2 and waste ```

Question 38

true/false - synovial fluid is a static pool

Answer 38

false

Question 39

true/false - rapid joint movement decreases fluid viscosity and increases elasticity

Answer 39

true

Question 40

true/false - synovial fluid is rich in WBC

Answer 40

false - unless there is an inflammatory process or septic arthritis

Question 41

what type of cartilage is articular cartilage

Answer 41

usually hyaline

Question 42

describe layers of cartilage

Answer 42

articular surface with shallow superficial zone, deeper middle and deep zone

Question 43

what is the ECM made up of in articular cartilage

Answer 43

mainly water type II collagen proteoglycan

Question 44

true/false- water in ECM is evenly distributed

Answer 44

false

Question 45

what maintains ECM

Answer 45

chondrocytes

Question 46

what does collagen do in ECM

Answer 46

stiffness/stength

Question 47

what does proteoglycan do in ECM

Answer 47

compressive properties

Question 48

artricular cartilage is vascular/avascular

Answer 48

avascular - receives nutrient by synovial fluid

Question 49

describe the balance of synthesis/degradation in normal and pathological joints

Answer 49

synthesis/degradation should be balanced, degradation exceeds synthesis in pathology

Question 50

anabolic factors for cartilage matrix turnover

Answer 50

stimulates proteoglycan synthesis TGF-B IGF-1

Question 51

catabolic factors for cartilage matrix turnover

Answer 51

inhibits proteoglycan synthesis TNFa IL-1

Question 52

define pain

Answer 52

unpleasant sensory or emotional experience, associated with actual tissue damage or described in terms of such damage

Question 53

describe the 4 physiological steps of pain processing

Answer 53

transduction of stimulant to nociceptor transmission through CNS modulation in nervous system perception

Question 54

describe nociceptor activation and what it does

Answer 54

sense noxious stimulus and run through afferent 1st order neuron to CNS synapse with 2nd order in spinal cord to carry to thalmus relay to thrid order to carry to primary sensory cortex

Question 55

what is the function of the spinothalmic tract

Answer 55

pain perception

Question 56

what is the function of the spinoreticular tract

Answer 56

response to pain, arousal, emotional response

Question 57

what are Agamma fibres

Answer 57

thin myelinated nociceptor subtype to carry pain quickly | only mechanical and thermal

Question 58

what are C fibres

Answer 58

unmyelinated nociceptor subtype mediating slower pain to all noxious stimuli

Question 59

describe nociceptive pain

Answer 59

normal response to tissue injury pain is adaptive early warning

Question 60

describe inflammatory pain

Answer 60

activation of immune system due to tissue injury/infection heightened pain sensitivity and sensitivity to innoculous stimuli adaptive discourage movement

Question 61

what is allodynia

Answer 61

heightened sensitivity to non-noxious stimuli

Question 62

what is hyperalgesia

Answer 62

heightened pain sensitivity

Question 63

describe neuropathic pain

Answer 63

pain due to neural tissue damage simple analgesia not enough, pain is maladaptive manage antidepressants/antiepileptics neuropathies, phantom limb, central pain

Question 64

describe dysfunctional pain

Answer 64

``` no identifyable damage/inflammation IBS, tension headache not fully understood simple analgesia not enough, pain is maladaptive manage antidepressants/antiepileptics ```

Question 65

describe referred pain

Answer 65

pain felt in body not related to cause | convergence of nociceptive visceral/skin afferents on same spinal level