AQA A-level Psychology Biopsychology notes

Biopsychology

, THE NERVOUS SYSTEM
(CNS) CENTRAL NERVOUS SYSTEM PHERIPHERAL NERVOUS SYSTEM

BRAIN SPINAL CORD SOMATIC AUTONOMIC
NERVOUS NERVOUS
SYSTEM SYSTEM
(Voluntary muscle movements (involuntary body, functions)
E.g: ..

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transmit sensory information
to CNS)

SYMPATHETIC PARASYMPATHETIC
NERVOUS SYSTEM NERVOUS SYSTEM
(Arouses body to expend (calms body to conserve
energy) and maintain energy)
E.g: F or F E.g:
• HR + dig • decr HR + dig

Central Nervous Syem
• brain
• Spinal cord
• Origin of all conscious commands and decisions




Peripheral nervous syem
• sends info from internal and external environments to CNS
• Transmits messages from CNS to effectors via neurons E
• All other neurons not part of CNS (Muscles/glands)

Somatic nervous syem
• transmits info, for Receptor cells in the sense organs to CNS
• received info from CNS, which directs effecters to act
• Sensory and motor pathways
• Skeletal muscle + movement

Autonomic nervous syem

• transmit info to, and from internal bodily organs
• Automatic system operates in voluntarily
• Two main divisions: (sympathetic)(para sympathetic )
• Only motor pathways
• Controls internal organs + gland

, Sensory Neurons

• transmit nervous impulses from receptors cells to relay /
motor neuron
• Many dendrites converge onto one dendron
• Dendron carries impulses towards cell body
• Axon carries impulses away from the cell body and ends
with terminal buttons
• Terminal buttons connect with other neutrons


↑ TERMINAL BUTTONS




Relay Neuron

• (intermediate)

• transmits impulses between neurons
• E.g. from sensory neurons to motoneurons
• Short dendrites
• Short Axon
• Many terminal buttons
• mainly CNS
• analysis of sensation



Motor Neuron

• transmit impulses from relay/intermediate neuron to effector
• Short dendrites
• Long axon
• Many connections with effectors

* how to identify from drawing:
1. Sensory neurons = connect to receptors
2. Relay neurons short
3. Motoneurons cell body inside




*sensory + motor enable reflex actions

, Myelin Sheath

MYELIN SHEATH: the fatty layer that insulates the axon, protecting it, and speeding up the
electrical transmission of impulses

*STEPS VS LEAPS
• segmented by gaps (nodes of Ranvier)
—> speed up impulse - forces to jump acr gaps along axon

• Relay - alr short - impulse sent fast anyway




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