Physiology

Question 1

name the 3 types of muscle

Answer 1

cardiac, smooth, skeletal

Question 2

T/F: cardiac muscle is voluntary

Answer 2

fales..

innervated by the ANS and is involuntary

Question 3

what are the 2 types of muscles that are striated

Answer 3

cardiac and skeletal

Question 4

smooth muscle is…

Answer 4

unstriated and involuntary

Question 5

T/F: skeletal muscle is voluntary

Answer 5

true, innervated by somatic nervous system

Question 6

the excitation for cardiac muscle is?

Answer 6

Ca++ and extra cellular fluid

Question 7

excitation for skeletal muscle is?

Answer 7

neuromuscular junction

Question 8

how does strength of contraction mechanisms vary in cardiac and skeletal muscle?

Answer 8

cardiac: pre-load
skeletal: motor unit recruitment and summation

Question 9

what is the NT for skeletal muscle?

Answer 9

Ach

Question 10

breakdown a motor neurone complex?

Answer 10

1 alpha motor unti and parallel skeletal muscle fibres attached to skeleton via tendon

Question 11

there are 2 types of skeletal muscle contractions; what are they?

Answer 11

isotonic- muscle tension constant, muscle length changes

isometric- muscle length constant, muscle tension develops

Question 12

give an example for isotonic movement…

Answer 12

body movement or object movement

Question 13

isometric contraction example…

Answer 13

posture

Question 14

what are the 3 skeletal muscle fibres and what they’re best suited for?

Answer 14

T1: slow oxidative- long low aerobic
T2a- fast oxidative- long moderate aerobic
T2b- fast glycolytic- short anaerobic

Question 15

what determines speed of contraction?

Answer 15

activity of myosin ATPase

Question 16

T/F: 1 motor unit can contain multiple fibre types

Answer 16

F: can only contain 1 type

Question 17

muscle organisation…

sarcomere>

Answer 17

sarcomere> myofibril> muscle fibre> muscle

Question 18

what actually is a sarcomere and how it creates muscle tension?

Answer 18

arrangement of myosin and actin- actin slides on myosin

Question 19

define a sarcomere…

Answer 19

the most basic contractile unit of muscle

Question 20

fill in the gaps…

sarcomere is found between 2 _ ____ and have 4 zones- A and _ bands, _ zone and _-___.

Answer 20

found between 2 Z-lines and have 4 zones- A and I bands, H zone and M-line

Question 21

what is the main power that causes actin over myosin sliding?

Answer 21

ATP which powers cross bridge formation and relaxation

Question 22

what is the mineral component that drives cross-bridge formation?

Answer 22

Ca++

Question 23

what is the action of Ca++ in cross-bridge formation?

Answer 23

bind to troponin pulling troponin-tropomyosin complex aside revealing cross-bridge site.

Question 24

where is Ca++ released from and how

Answer 24

released from sarcoplasmic reticulum when AP spreads down t-tubules

Question 25

where does ATP come from for AP production resulting in cross-bridge formation?

Answer 25

oxidative phosphorylation (aerobic) and glycolysis (anaerobic)

Question 26

what determines grade of muscle contraction?

Answer 26

no of muscle fibres and tension developed by each contracting fibre (further determines by its length, freq of stimulation etc)

Question 27

inc no of APs results in..

Answer 27

longer muscle twitch

Question 28

what are 2 types of skeletal muscle activity?

Answer 28

excitatory/inhibitory and reflex

Question 29

what is reason for reflex?

Answer 29

maintains optimal muscle resting length

Question 30

what are the sensory receptors for stretch reflex and where are they located in the muscle?

Answer 30

muscle spindles found in belly of muscle

Question 31

what are the 4 mechanisms of action for pain?

Answer 31

transduction, transmission, modulation, perception

Question 32

pathway for nociceptors?

Answer 32

sensory afferents activated by noxious stimuli > 2nd order neurones which ascend spinal cord > reaches thalamus and synapses with 3rd order neurones > sensory cortex of brain

Question 33

what are the 4 types of pain

Answer 33

nociceptive: provoked by intense nociceptor stimulation inflammatory: immune system provoked referred: caused by convergence of visceral and skin afferents at same spinal level pathological

Question 34

pathological pain is subdivided into...

Answer 34

neuropathic: damage to neural tissue dysfunctional: no damage or infection

Question 35

T/F: neuropathic pathological pain is localised, sharp pain

Answer 35

false: more general- burning, shooting, numbness

Question 36

what are the 3 types of joints

Answer 36

synovial, fibrous and cartilaginous

Question 37

what are synovial joints?

Answer 37

joints filled with synovial fluid and bones are united by a fibrous capsule

Question 38

what are fibrous joints?

Answer 38

bones united by fibrous tissue

Question 39

what are cartilaginous joints?

Answer 39

bones united by cartilage

Question 40

T/F: synovial joints are the least mobile

Answer 40

False: fibrous are the least mobile > cartilaginous > synovial

Question 41

how do joints support motion

Answer 41

stress distribution and synovial fluid (lubrication)

Question 42

give 3 functions of synovial fluid?

Answer 42

lubricates joint, aids nutrition of articular cartilage and supplies chondrocytes with nutrients

Question 43

T/F: synovial fluid is viscous

Answer 43

true: viscosity changes during movement- rapid movement= dec viscosity

Question 44

what is the function of articular cartilage?

Answer 44

distributes contact pressure to subchondral bone

Question 45

what is the structure of articular cartilage?

Answer 45

``` superficial zone middle zone deep zone calcified zone - made up of chondrocytes ```

Question 46

which is the most common type of articular cartilage?

Answer 46

hyaline

Question 47

which cartilage is sponge like and has extra-cellular membrane (water, T2 collagen, proteoglycans)?

Answer 47

hyaline

Question 48

extracellular matrix is synthesised by which cells?

Answer 48

chondrocytes

Question 49

what is responsible for the breakdown of extracellular matrix?

Answer 49

IL 1 & TNF-a

Question 50

what 2 features can be used in a synovial tap to detect degradation?

Answer 50

1. serum and synovial keratin sulphate | 2. T2 collagen in synovial fluid

Question 51

describe the innervation of muscle with reference to the NMJ...

Answer 51

a-motor neurones divide into unmyelinated branches to reach individual muscle fibres > then further divide into fn branches > these end at terminal bouton which synapses with muscle membrane (NMJ)

Question 52

NMJ transmission...

Answer 52

1. Ach synthesised in cytoplasm of bouton (choline + acetyl CoA) 2. ach uptake into vesicles for storage 3. Ca++ dependent release of Ach into synaptic cleft 4. Ach binds to nicotinic Ach receptors opening gates causing Na+ influx and K+ efflux 5. once certain no of gates opened end plate potential reached and triggers AP 6. AP propagates over sarcolemma and down t-tubules causing Ca++ release switching on cross-bridge formation and contraction occurs

Question 53

how does NMJ transmission terminate?

Answer 53

hydrolysis of Ach by acetylcholinesterase