Animal responses - Miss Parry

Question 1

Which nervous system is without consious thought? ANS or SNS?

Answer 1

ANS (autonomic nervous system)

Question 2

What are the transmitter substances for both the sympathetic and parasympathetic nervous systems?

Answer 2

Sympathetic = Noradrenaline
Parasympathetic = Acetylcholine

Question 3

What type of nervous system leads to an increased heart rate?

Answer 3

Sympathetic

Question 4

What are the three areas that are in the Cerebral cortex?

Answer 4

Sensory
Association
Motor

Question 5

What part of the brain links the two sides of the brain together?

Answer 5

Corpus callosum

Question 6

What part of the brain works with higher order processes such as language, thinking and emotions?

Answer 6

Cerebrum / Cerebral Cortex

Question 7

What do neuromuscular junctions connect?

Answer 7

A motor neurone to muscle fibres

Question 8

Explain how a neuromuscular junction works

Answer 8

An impulse causes an influx of Ca2+ ions, which cause vesicles with ACh to fuse with the post synaptic membrane
ACh binds to receptors on the sarcolemma
The membrane becomes depolarised
The depolarisation causes the t-tubules to become depolarised, causing Ca2+ to be released from the sarcoplasmic reticulum
This causes muscular contraction

Question 9

What are the 3 types of muscle?

Answer 9

Cardiac
Involuntary (smooth muscle)
Stirated (voluntary / skeletal)

Question 10

What is the structure of involuntary muscle? And what are two of its functions?

Answer 10

Small bundles of actin + myosin with a single nucleus

Allow contraction of blood vessels, and the iris of the eye

Question 11

During muscular contraction, which bands/zones in the myofibril get smaller?

Answer 11

H zone

I band

Question 12

Explain the mechanism of muscular contraction (starting at influx of Ca2+ in the t-tubules)

Answer 12

Influx of Ca2+ in the t-tubules
Ca2+ bind to the troponin which causes the troponin and tropomyosin to change shape (away from the binding site)
Myosin head binds to the actin
Myosin head changes shape, pulling the myosin fibril across the actin fibril (releasing ADP + P)
ATP binds to the myosin head, it is then hydrolysed to provide the energy for the myosin head to detatch from the actin

Question 13

Explain how Cortisol is produced

Answer 13

The hypothalamus releases CRF (corticosteroid releasing factor)
This passes along neurosecretory cells to the pituitary gland
The pituitary gland then releases the hormone ACTH
ACTH acts on the cortex of the adrenal gland, causing it to release cortisol and other hormones