Test 1

Question 1

Alzheimer’s happens because:

Answer 1

Neurons in brain shrink or disappear.
Abnormal material builds up, neurofibrillary tangles inside neurons, amyloid plaques around remaining neurons.
Disrupts messages, damages connections between neurons -> death

Question 2

Parkinson’s happens because:

Answer 2

Deficiency in neurotransmitter dopamine.
Caused by progressive degeneration of nerve cells in brain’s basal ganglia.

Question 3

A nerve impulse is an electrochemical change:

Answer 3

• a change in electrical voltage
• is bought about by change in chemicals.

Question 4

When the impulse reaches the axon terminal:

Answer 4

Activates the voltage-gated calcium ion channels, and so the calcium enters the cell at the pre-synaptic axon terminal following the concentration gradient.
This causes:
Synaptic vesicles to fuse with the membrane, which releases neurotransmitters by exocytosis.
These diffuse the gap, and bind to the next neuron’s receptors, and the process repeats.

Question 5

Conduction along unmyelinated

Answer 5

maximum of 2 m/s

Question 6

Conduction along myelinated

Answer 6

maximum of 140 m/s

Question 7

Sensory areas

Answer 7

interprets impulses from receptors.

Question 8

Motor areas

Answer 8

controls muscular movements.

Question 9

Association areas

Answer 9

interprets information from senses and makes it useful, emotional processes.

Question 10

Three track types in white matter:

Answer 10

• Connects various areas of the cortex within same hemisphere.
• Carries impulses between left and right hemispheres.
• Connects cortex to other parts of the brain/spinal cord.

Question 11

Basal ganglia

Answer 11

• Grey matter deep inside cerebrum.
• Consists of nerve cell bodies associated with skeletal muscle control.
• Helps initiate desired movements and inhibiting unwanted movement.

Question 12

Dura mater in spinal cord

Answer 12

not joined to bone, instead to a space containing fat, connective tissue and blood vessels to serve as padding and allows bending.

Question 13

Mechanoreceptors

Answer 13

Senses pressure

Question 14

Osmoreceptors

Answer 14

Detects solute concentrations in blood

Question 15

Somatic sensory neurons

Answer 15

brings impulses from skin and muscles.

Question 16

Visceral sensory neurons

Answer 16

brings impulses from internal organs.

Question 17

Autonomic pathway:

Answer 17

• Goes across two neurons to an organ controlled by ANS.
• First neuron myelinated, second is unmyelinated.
• Has a ganglion.
• Sympathetic and parasympathetic nerves.
• Acetylcholine or noradrenaline neurotransmitters at effector.

Question 18

Somatic pathway:

Answer 18

• Goes across one neuron to a skeletal muscle.
• Neuron is myelinated, no ganglion or synapse.
• Only acetylcholine.
• Either sympathetic or parasympathetic, not both.

Question 19

Sympathetic neurotransmitter vs parasympathetic neurotransmitter

Answer 19

Parasympathetic is acetylcholine and sympathetic is noradrenaline.

Question 20

Alter cell activity by:

Answer 20

• Activating certain genes in nucleus so that a particular enzyme or structural protein is produced.
• Changing the shape or structure of an enzyme so it is ‘off’ or ‘on’.
• Changing enzyme/structural protein production rate by changing transcription or translation rate during protein synthesis.

Question 21

Explain why hyperpolarisation reduces the likelihood of a new action potential being created.

Answer 21

As the inside of the membrane is more negative than at resting potential, more sodium ions must enter in order for the potential difference to hit the threshold for an action potential to be created.

Question 22

Describe the metabolic effects of growth hormone.

Answer 22

Stimulates the production of bone cells and bone tissue development.
Stimulates muscle growth through protein synthesis.