Oct5

Oct 5 The nervous system

Central Nervous system (CNS): consists of neurons in the brain and the spinal cord.

Peripheral Nervous system (PNS): consists of neurons connection CNS with muscles, glands, and sensory receptors

PNS contains: somatic nervous system and autonomic nervous system

Somatic Nervous system: related to voluntary behaviours

Autonomic nervous system: related to involuntary behaviours

Brain: 2% total body weight yet accounts for 20% of oxygen used, relatively constant energy metabolism

Spinal cord: most nerves enter/leave the CNS via this

Spinal reflexes: simple stimulus response behaviours that result in motor output without any communication from the brain (doctor hammering knee, leg kicks)

Somatic division contains: sensory nerves and motor nerves

Sensory nerves: groups of sensory neurons

Motor nerves: group of motor nerves

Autonomic division controls: body's internal environment, respiration, circulation, digestion, motivation, emotion, stress, etc.

Autonomic system subdivisions: Parasympathetic and sympathetic

Parasympathetic: inhibits/calms

Sympathetic: excites/activates.

Neuropsychological tests

Various kinds of neuropsychological tests can be used to measure verbal and non-verbal behaviours. This is commonly used for clinical evaluations. Can allow inferences about things like cognition, brain function, etc.

Destruction and stimulation

Destruction and stimulation: Can examine known areas of damage, can also stimulate areas with electricity/chemicals, Wilder Penfield stimulated the cortex with mild electrical current, patients were awake and could describe the experience which allowed motor and sensory areas to be mapped.

Neuroimaging

Electroencephalogram (EEG): records electrical activity of thousands of neurons, can be used to study event-related potentials

Event-related potentials (ERP): neural response to specific events (being shown a picture of something)

Some EEG patterns correspond to particular states of consciousness (ex. REM sleep)

There are alpha and beta brain patterns. fucking hilarious

Computerized tomography (CT): uses multiple x rays taken of narrow slices of brain that are then put together to form a highly detailed anatomical image

Positron Emission Tomography (PET): person is injected with a harmless radioactive tracer which can be tracked to provide a measure of blood flow, changes in blood flow are used to infer changes in brain activity and it can measure metabolism and neurotransmitter activity.

Magnetic Resonance imaging (MRI): used to measure biological structures by measuring response to magnetic pulses, and is more sensitive than CT or PET for producing anatomical images

Functional Magentic Resonance Imaging (fMRI): attempts to measure neural activity by detecting changes in the magnetic response of hemoglobin Functional images are superims

The brain stem contains: Medulla, pons

Medulla: heart and respiration, thoroughfare for sensory/motor nerve tracts

Pons: Regulate sleep, dreaming, respiration

Cerebellum: muscular movement (particularily reflexive/ automatic/rapid), coordination, learning/memory

The midbrain: sensory relay station, consciousness

Reticular formation: important for consciousness and attention

Ascending portion sends input to higher regions

Decsending portion admits or block