animal responses

Question 1

Describe the peripheral nervous system

Answer 1

Made up of neurons that connect CNS to the rest of the body

Question 2

What is the somatic nervous system

Answer 2

Controls conscious activities like running

Question 3

What is the autonomic nervous system

Answer 3

Controls unconscious activities like digestion

Question 4

What is the sympathetic nervous system

Answer 4

Gets body ready for fight or flight response

Releases noradrenaline

Question 5

What is the parasympathetic nervous system

Answer 5

Calms body down

Rest and digest system

Releases acetylcholine

Question 6

Where is the hypothalamus located

Answer 6

Beneath the middle part of brain

Question 7

Roles of hypothalamus

Answer 7

Maintains body temperature

Produces hormones that control pituitary gland

Question 8

Where is the pituitary gland located

Answer 8

Beneath hypothalamus

Question 9

Role of pituitary gland

Answer 9

Releases hormones and stimulates other glands like the adrenal gland

Question 10

What is a reflex

Answer 10

The body responds to stimulus without making a conscious decision

Question 11

describe the blinking reflex

Answer 11

sensory nerve in cornea is stimulated by touch

nerve impulse is sent along sensory neurone to relay neurone in CNS

impulse goes to motor neurone

motor neurones send impulse to effectors (orbicularis oculi muscles that move eyelid)

Question 12

Describe the knee jerk reflex

Answer 12

stretch receptors in quadriceps detect stretch motion

impulse passed along sensory neurone to motor neurone in spinal cord

motor neurone carries impulse to effector muscle causing it to contract

Question 13

describe process of fight or flight response

Answer 13

impulse from sensory neurone arrive at hypothalamus

pituitary gland releases ACTH

ACTH causes cortex of adrenal gland to release steroidal hormones

sympathetic nervous system is activated which releases adrenaline from medulla region

Question 14

What are the effects of adrenaline

Answer 14

increased heart rate

breathing is deeper

glycogen converted to glucose (more respiration)

hairs stand on end to make animal look aggressive and bigger

Question 15

How does the nervous system help to control heart rate

Answer 15

SAN generates electrical impulses

causes cardiac muscle to contract

rate at which SAN fires is controlled by medulla

Question 16

What are chemoreceptors

Answer 16

chemical receptors

found in aorta, carotid artery and medulla

monitors o2 level and co2 level

Question 17

What are baroreceptors

Answer 17

pressure receptors

found in aorta and vena cava

stimulated by high and low blood pressure

Question 18

Describe structure of skeletal muscle

Answer 18

made up of muscle fibres

membrane is called sarcolemma

sarcolemma fold inwards to form transverse tubules(this allows impulses to spread around the membrane)

have lots of mitochondria ( which provides more ATP)

Question 19

describe the structure of myofibrils

Answer 19

contain bundles of thick and thin filaments

made up of sarcomeres

Question 20

what are the thick filament made of

Answer 20

myosin

Question 21

what are the thin filaments made of

Answer 21

actin

Question 22

describe the light and dark bands in myofibrils

Answer 22

Dark bands contain thick myosin filaments ( called A bands)

Light bands contain thin actin filaments (called I bands)

Question 23

describe the structure of the sarcomere

Answer 23

end of sarcomere marked with Z line

middle of sarcomere is M line

Around sarcomere is H zone ( only contains myosin filaments)

Question 24

describe muscle contraction in regards to filaments

Answer 24

Myosin and actin filaments slide over one another

this causes sarcomeres to contract

myofibrils contract

sarcomeres return to original length when relaxed

Question 25

describe the structure of myosin filaments

Answer 25

have globular heads that are hinged( allows movement back and forth) Each head has binding site for actin

Question 26

Describe structure of actin

Answer 26

have binding sites of myosin heads ( called actin myosin binding sites)

Question 27

What happens to muscles in resting phase

Answer 27

actin myosin binding site is blocked by tropomyosin( held by troponin) myofilaments cant slide past each other

Question 28

describe muscle contraction via action potential

Answer 28

action potential stimulates muscle cell sarcolemma is depolarised T-tubules are spread to sarcoplasmic reticulum causes sarcoplasmic reticulum to release stored ca ions ca binds to troponin troponin changes shape pulls out tropomyosin so that myosin can bind

Question 29

How does the myosin head move

Answer 29

Calcium ions activate ATPase ATPase breaks down ATP into ADP and P this releases energy which moves the myosin head

Question 30

What happens when excitation stops

Answer 30

Ca leaves binding sites on troponin by active transport ca goes to sarcoplasmic reticulum

Question 31

What is a neuromuscular junction

Answer 31

Synapse between motor neurone and muscle cell

Question 32

How do neuromuscular junctions work

Answer 32

ACh binds to nicotinic cholinergic receptors neuromuscular junctions releases neurotransmitter triggers depolarisation in muscle muscle contracts AChE is stored in clefts of postsynaptic membrane

Question 33

What are the three types of msucle

Answer 33

Skeletal Smooth muscle Heart muscle/cardiac muscle

Question 34

describe the structure and function of skeletal muscles

Answer 34

controlled consciously made up of muscle fibres (have many nuclei) some contract very quickly- used for speed and strength but you get tired quickly some contract slowly and fatigue slowly-used for endurance and posture

Question 35

describe the structure and function of smooth muscles

Answer 35

controlled unconsciously found in the walls of hollow organs e.g gut and blood vessels each muscle fibre has one nucleus contract slowly and doesn't fatigue

Question 36

describe the structure and function of cardiac muscles

Answer 36

contracts on its own (myogenic) found in the walls of the heart branched allow nerve impulses to spread quickly through muscle each muscle has one nucleus contract rhythmically and doesn't contract