unit 5 - nervous system, the heart, muscles

Question 1

which nervous systems speeds up the heart?

Answer 1

sympathetic nervous system

Question 2

which nervous systems slows down the heart?

Answer 2

parasympathetic nervous system

Question 3

what des the parasympathetic nervous system release to slow down the heart?

Answer 3

acetylcholine (neurotransmitter)

Question 4

what does the sympathetic nervous system release to speed up heart

Answer 4

noradrenaline (neurotransmitter)

Question 5

ECG: what does part P represent?

Answer 5

atrial depolarisation (atrial systole)

Question 6

ECG: what does part R represent?

Answer 6

ventricular depolarisation (ventricular systole)

Question 7

ECG: what does part T represent?

Answer 7

repolarisation (atria + ventricular diastole)

Question 8

does myoglobin do cooperative binding?

Answer 8

no

Question 9

what curve is myoglobin’s affinity represented in?

Answer 9

hyperbolic curve

Question 10

what are slow twitch muscles used for

Answer 10

maintain body posture

Question 11

do slow twitch muscles contain myoglobin?

Answer 11

yes

Question 12

how do slow twitch muscles respire?

Answer 12

mainly aerobically

Question 13

what do slow twitch muscles use for fuel?

Answer 13

glucose mainly

Question 15

what do slow twitch muscles contain a lot of?

Answer 15

mitochondria

Question 16

what are fast twitch muscles used for?

Answer 16

sudden rapid activity

Question 17

how do fast twitch muscles respire mainly?

Answer 17

anaerobicallly

Question 18

what colour are the 2 types of muscles

Answer 18

fast - pale
slow- red (myoglobin)

Question 19

what do fast twitch muscles have high levels of?

Answer 19

creatine

Question 20

how are the myofibrils packed in fast twitch?

Answer 20

close together

Question 21

what are the 3 types of muscle?

Answer 21

cardiac
skeletal
smooth

Question 22

how do skeletal muscles appear under miscoscope?

Answer 22

striped

Question 23

what is a myofibril?

Answer 23

several muscle cells

Question 24

what do u call a muscle cell?

Answer 24

sarcomere

Question 25

what does myogenic mean? example?

Answer 25

contract by itself w/o external stimuli e.g. cardiac muscle

Question 26

what is released from sarcoplasmic reticulum? what do they bind to? causing what?

Answer 26

calcium ions bind to troponin, this causes troponin to change shape and pull of the tropomyosin

Question 27

what does the movement of tropomyosin do?

Answer 27

exposes the myosin binding site

Question 28

what is released from myosin head once bonded to myosin binding site>

Answer 28

ADP + Pi

Question 29

what does release of ADP + Pi cause?

Answer 29

causes myosin to change shape, and head bends forwards pushing actin along 10nm

Question 30

what does free ATP do? what does it cause?

Answer 30

ATP bind to myosin head, cause change in shape, cross bridge between myosin + binding site broken

Question 31

what does the presence of calcium ions activate?

Answer 31

ATPase enzyme, ATP is hydrolysed and energy is released, this is used to return myosin to original position