Animal responses

Question 1

what is the CNS made up of ?

Answer 1

brain and spinal cord

Question 2

what is the peripheral nervous system made up of ?

Answer 2

rest of neurones that connect CNS to rest of body

Question 3

what does somatic nervous system control ?

Answer 3

conscious activities

Question 4

what are the two functional systems of PNS ?

Answer 4

somatic and autonomic

Question 5

what are the two divisions of the autonomic nervous system ?

Answer 5

sympathetic and parasympathetic

Question 6

what is the role of the sympathetic nervous system ?

Answer 6

gets body ready for ‘fight or flight’

Question 7

what is the role of the parasympathetic nervous system ?

Answer 7

puts body into a constant normal state (rest and digest)

Question 8

what neurotransmitter released from sympathetic nervous system neurones ?

Answer 8

noradrenaline

Question 9

what neurotransmitter released from parasympathetic nervous system neurones ?

Answer 9

acetylcholine

Question 10

state the function of pituitary gland

Answer 10

releases hormones and stimulates other glands (e.g. adrenal)

Question 11

state function of medulla oblongata

Answer 11

controls breathing and heart rate

Question 12

state the function of cerebellum

Answer 12

coordinates muscles, balance and posture

Question 13

state the function of cerebrum

Answer 13

involved in hearing, seeing, learning and thinking

Question 14

outline the process of blinking reflex

Answer 14

• sensory neurones (in cornea) stimulated by touch
• impulse sent sensory -> relay -> motor
• motor carries impulse to effector (orbicularis oculi muscles)
• muscle contracts, closing eye

Question 15

what is beneficial of knee jerk reflex ?

Answer 15

maintains balance and posture

Question 16

outline the process of knee jerk reflex

Answer 16

• stretch receptors in quadriceps detect muscle stretch
• impulse passed sensory -> motor in spinal cord
• motor carries to effector (quadriceps muscles)
• muscle contracts, leg moves forward

Question 17

how is fight or flight response initiated ?

Answer 17

• nerve impulses from sensory neurones arrive at hypothalamus
• hormonal and sympathetic nervous system activated

Question 18

how is hormonal system involved in the initiation of fight or flight response ?

Answer 18

• pituitary gland releases hormone ACTH

- ACTH causes cortex of adrenal gland to release steroidal hormones

Question 19

how is sympathetic nervous system involved in the initiation of fight or flight response ?

Answer 19

triggers release of adrenaline from medulla of adrenal gland

Question 20

state and explain 5 effects of adrenaline

Answer 20

1. heart rate increased (more blood pumped)
2. smooth muscle in airways relaxes (more oxygen)
3. glycogenolysis (more energy)
4. blood diverted to muscles/heart/lungs (smooth muscle contracting/relaxing)
5. erector pili muscles contract so hairs stand (animal looks bigger)

Question 21

involving the heart, where are baroreceptors based and what is their function

Answer 21

• based in aorta and vena cava

- detect high / low pressure

Question 22

involving the heart, where are chemoreceptors based and what is their function

Answer 22

• aorta / carotid artery / medulla

- monitors oxygen / carbon dioxide / pH levels in blood

Question 23

how does adrenaline affect the heart ?

Answer 23

• binds to receptors in heart

- causes cardiac muscle to contract more freq. w/ more force

Question 24

Describe how high blood pressure is brought back to normal

Answer 24

• baroreceptors detect high blood pressure
• impulses sent -> medulla -> vagus nerve
• acetylcholine secreted, which binds to receptors on SAN
• heart rate slows

Question 25

Describe how low blood pressure is brought back to normal

Answer 25

- baroreceptors detect low blood pressure - impulses sent -> medulla -> accelerator nerve - noradrenaline secreted, which binds to receptors on SAN - heart rate increases

Question 26

Describe how high p(O2) / pH or low p(CO2) is brought back to normal

Answer 26

- chemoreceptors detect chemical changes - impulse sent -> medulla -> vagus nerve - ACh secreted, which binds to SAN - heart rate decreases

Question 27

Describe how low p(O2) / pH or high p(CO2) is brought back to normal

Answer 27

- chemoreceptors detect chemical changes - impulse sent -> medulla -> accelerator nerve - noradrenaline secreted, which binds to SAN - heart rate increases

Question 28

describe / name structures of a muscle fibre

Answer 28

- sarcolemma is the cell membrane - transverse tubules are folded parts of sarcolemma - sarcoplasm is cytoplasm - internal network of membranes called sarcoplasmic reticulum runs through sarcoplasm - lots of ATP and nuclei

Question 29

what is function of T tubules ?

Answer 29

spreads electrical impulses throughout sarcoplasm

Question 30

what is the function of sarcoplasmic reticulum ?

Answer 30

stores and releases calcium ions (voltage gated)

Question 31

what are thick myofibrils made from ?

Answer 31

protein myosin

Question 32

what are thin myofibrils made from ?

Answer 32

protein actin

Question 33

what is A-band ?

Answer 33

dark band containing thick myosin filaments w/ some overlapping thin actin filaments

Question 34

what is I band ?

Answer 34

light band containing only thin actin filaments

Question 35

what is a sarcomere ?

Answer 35

short unit of a myofibril containing A band and 2 I bands

Question 36

what is H zone ?

Answer 36

area around M line, contains only thick filaments

Question 37

describe the change in lengths of a contracted sarcomere

Answer 37

- sarcomere shortens - A bands stay same - I bands shorten - H zones shorten

Question 38

what occurs w/ the filaments to cause sarcomere to contract ?

Answer 38

the filaments slide over one another

Question 39

describe binding sites of sarcomere at rest...

Answer 39

actin-myosin binding site in actin filament blocked by tropomyosin, which is held in place by troponin

Question 40

outline the process of muscle contraction (6)

Answer 40

1. depolarisation of sarcoplasmic reticulum releases Ca ions 2. Ca ions bind to troponin, causing shape change 3. tropomyosin pulled out of binding site 4. myosin head binds, forming actin-myosin cross bridge 5. Ca ion activated ATPase breaks down ATP, releasing energy, which moves myosin head, pulling actin filament along 6. myosin reattaches to diff binding site ...

Question 41

state the three uses of energy from ATP in muscle contraction

Answer 41

1. moves myosin head 2. breaks actin-myosin cross bridge 3. pumping calcium ions back into sarcoplasmic reticulum

Question 42

describe how muscle stops contracting

Answer 42

Ca ions leave binding site and are pumped back to sarcoplasmic reticulum --- troponin return to shape --- tropomyosin pulled back to block binding site --- no myosin heads attached to actin filaments --- actin filaments slide back to relaxed position --- sarcomeres lengthen

Question 43

what other process (other than an/aerobic respiration) generates ATP ?

Answer 43

ATP - Creatine Phosphate (CP) system

Question 44

state the equation for CP system

Answer 44

ADP + CP --> ATP + C

Question 45

what is CP system ? what is it used for ?

Answer 45

- phosphorylating ADP w/ phosphate group from CP - very fast process but CP runs out fast so used for short bursts of vigorous exercise - anaerobic and alactic (no lactate formed)

Question 46

what is a neuromuscular junction ?

Answer 46

synapse between motor neurone and muscle cell

Question 47

what neurotransmitter is used at neuromuscular junction and what does it bind to ?

Answer 47

ACh binds to nicotinic cholinergic receptors

Question 48

describe structure of skeletal muscle

Answer 48

- made up from many muscle fibres w/ lots of nuclei | - regular cross-striations visible under microscope

Question 49

where is smooth muscle found ?

Answer 49

lining of gut, airways, blood vessels

Question 50

describe the contraction of skeletal muscle

Answer 50

- some contract quickly (speed and strength) but fatigue fast - some contract slowly and fatigue slow (endurance and posture) - in one direction

Question 51

describe the structure of smooth muscle

Answer 51

- one nucleus for each muscle fibre | - spindle shaped w/ pointed ends

Question 52

describe the contraction of smooth muscle

Answer 52

contract slowly so don't fatigue

Question 53

describe the structure of cardiac muscle

Answer 53

- muscle fibres connected by intercalated discs - muscle fibres branched to spread impulses - muscle fibres are cylinder shaped and have one nucleus - many mitochondrion so don't fatigue

Question 54

describe the contraction of cardiac muscle

Answer 54

- myogenic so contracts without nervous system | - contracts rhythmically and relatively fast

Question 55

what measures muscle fatigue ?

Answer 55

electromyogram