CNS & Behaviour

Question 1

Thalamus

2

Answer 1

Relay system

Receives info. from various senses and passes it on to the appropriate area of the cerebral cortex

Question 2

Hypothalamus

3

Answer 2

Controls motivational behaviours (Hunger, sex etc.)
Fight or flight
Homeostasis (Temp.)

Question 3

Limbic System

2

Answer 3

Consists of several structures e.g. Amygdala

Regulates emotional responses

Question 4

Cerebellum

2

Answer 4

Coordinates posture, balance and movement by receiving info. from the spinal cord
Contains 50% of the brains neurons

Question 5

Corpus Callosum

2

Answer 5

Connects the two hemispheres

Allows signals to pass between the two

Question 6

Frontal Lobes

Answer 6

Controls high-level cognitive functions (thinking, problem-solving etc.

Question 7

Parietal Lobes

Answer 7

Contains somatosensory cortex which processes sensory info. from the skin

Question 8

Temporal Lobes

Answer 8

Contains an auditory cortex which deals with sound info.

Contains Wernicke’s Area

Question 9

Occipital Lobes

Answer 9

Contains the visual cortex

Question 10

Broca’s Area

3

Answer 10

Located in the left frontal lobe
Responsible for speech production
Damage causes Broca’s Aphasia, which causes slow laborious speech

Question 11

Wernicke’s Area

Answer 11

Located in the left temporal lobe
Understands language
Damage causes Wernicke’s Aphasia, which causes fluent but meaningless speech

Question 12

Cell Body (Soma)

Answer 12

Includes the nucleus

Question 13

Dendrites

2

Answer 13

Branch-like structures protruding from the cell body

Carry impulses from neighbouring neurons to the cell body

Question 14

Axon

Answer 14

Tube-like structure that carries impulses away from the cell body

Question 15

Myelin Sheath

Answer 15

Wraps around the axon, protecting it and speeding up electrical impulses

Question 16

Nodes of Ranvier

Answer 16

Gaps in the myelin sheath that speed up transmission by forcing the signal to ‘jump’ across

Question 17

Terminal Buttons

2

Answer 17

At the end of the axon

Involved in communication across the synapse

Question 18

3 Types of Neuron

Answer 18

Sensory - Carries messages from sensory receptors along the PNS to the CNS. Long dendrites & short axons
Motor - Carry messages from the CNS along nerves in the PNS to effectors (muscles & glands). Short dendrites & long axons
Relay - Connect sensory & motor neurons together, also connect other relay neurons. Short dendrites & short axons. Only found in the CNS

Question 19

Synaptic Transmission

3 Steps

Answer 19

Neurons are separated by a tiny gap called a Synaptic Cleft
Signals BETWEEN neurons are passed chemically
1. When the Action Potential reaches the end of the neuron it triggers the release of neurotransmitters from Synaptic vesicles.
2. NTs diffuse across the Synaptic cleft and fit into matching receptor sites on the post-synaptic neuron.
3. NTs that remain in the synapse are reabsorbed, this is called REUPTAKE

Question 20

Excitatory or Inhibitory

Answer 20

Excitatory NTs increase the positive charge of the neuron, making it more likely to fire
Inhibitory NTs decrease the positive charge, making it less likely to fire

Question 21

Limbic System Evaluation *

Answer 21

S - Charles Whitman (1966), killed his family, himself and 12 others in a shooting. Suicide note states he has ‘been a victim of irrational thoughts’. Autopsy revealed he had a tumour on his amygdala.
Egger & Flynn (1963) Cat doesn’t kill a rat in its cage, instantly does when the amygdala is stimulated

Question 22

Pre-frontal cortex Evaluation *

Answer 22

S - Phineas Gage (1848) Rod passes through his skull & pre-frontal cortex, his doctor stated he had ‘little deferance’ and was ‘impatient’ when it came to his desires.