basal ganglia
several nuclei located deep within cerebral white matter
fucntions of basal ganglia
what is parkinsons caused by
degeneration of dopaminergic neurons in substantia nigra in midbrain which synapse onto neurons in basal ganglia- important for smooth movement
features of parkinsons
-inc muscle tone and rigidity
- involuntary useless movements at rest. tremors
-difficulty in initiating and carrying out movement
what causes huntingtons disease
degeneration of cuadate nucleus
symptoms of huntingtons
some motor circuits become overactive
-chorea- rapid uncontrolled jerky movements
- memory movements
where is the thalamus
deep in the brain near basal ganglia
function of thalamus
relay station and synaptic integrating centre for sensory input
helps direct attention to stimuli of interest
capable of crude awareness of sensations but cant distinguish location or intensity
function of hypothalamus
integrating centre for homeostatic functions
regulates internal enviroment
body temp and food intake
thirst and urine output
anterior pituitary hormone secretion
posterior pituitary hormone
five functions of brain stem
cerebellum function
integration of motor output and sensory perception
balance and planning of movement
what are the three functionally distinct parts of the cerebellum
RAS
Reticular activating system- behavioural state system- diffuse modulatory system
where do neurons originate
in the RAS and project to various areas in brain
what does RAS influence
attention, motivation, wakefulness, memory, motor control, mood and metabolic homeostatis, overall degree of cortical awareness
what effect do general anaesthetics do to reticular formation
depress transmission in RAS
what does blocking the ascending pathways between the reticular formation and the cerebral cortex create
state of unconsciousness
limbic sysem
surrounds brain not seperate structure. interconnected ring of forebrain structures
what does the limbic system include
poritons of the cerebral lobes, basal nuclei, thalamus, and hypothalamus
what neurotransmitters does the limbic system use
serotonin, dopamine, norepinephrine
defects in the limbic system cause
depression
what parts of our behaviour is related to limbic system
emotions, basic survival, sociosexual behaviour, motivation and learning
limbic system functions
cortical structures of limbic system
medial prefrontal cortex: decision making, control of emotion and impulses
cingulate cortex: motivation, drive, mood, decreased avitivity correlates with depression
medial temporal lobes: episodic memory formation of recent event sequences