CNS & Behaviour Flashcards
Thalamus
2
Relay system
Receives info. from various senses and passes it on to the appropriate area of the cerebral cortex
Hypothalamus
3
Controls motivational behaviours (Hunger, sex etc.)
Fight or flight
Homeostasis (Temp.)
Limbic System
2
Consists of several structures e.g. Amygdala
Regulates emotional responses
Cerebellum
2
Coordinates posture, balance and movement by receiving info. from the spinal cord
Contains 50% of the brains neurons
Corpus Callosum
2
Connects the two hemispheres
Allows signals to pass between the two
Frontal Lobes
Controls high-level cognitive functions (thinking, problem-solving etc.
Parietal Lobes
Contains somatosensory cortex which processes sensory info. from the skin
Temporal Lobes
Contains an auditory cortex which deals with sound info.
Contains Wernicke’s Area
Occipital Lobes
Contains the visual cortex
Broca’s Area
3
Located in the left frontal lobe
Responsible for speech production
Damage causes Broca’s Aphasia, which causes slow laborious speech
Wernicke’s Area
Located in the left temporal lobe
Understands language
Damage causes Wernicke’s Aphasia, which causes fluent but meaningless speech
Cell Body (Soma)
Includes the nucleus
Dendrites
2
Branch-like structures protruding from the cell body
Carry impulses from neighbouring neurons to the cell body
Axon
Tube-like structure that carries impulses away from the cell body
Myelin Sheath
Wraps around the axon, protecting it and speeding up electrical impulses
Nodes of Ranvier
Gaps in the myelin sheath that speed up transmission by forcing the signal to ‘jump’ across
Terminal Buttons
2
At the end of the axon
Involved in communication across the synapse
3 Types of Neuron
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
Synaptic Transmission
3 Steps
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
Excitatory or Inhibitory
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
Limbic System Evaluation *
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
Pre-frontal cortex Evaluation *
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.
