BIOSPYCHOLOGY
, THE NERVOUS SYSTEM
Central Nervous System
o Processes, interprets, and
stores information and
issues orders to muscles,
glands, and organs
o Brain: has two hemispheres
and is the centre of
consciousness. The cerebral
cortex (outer layer) is 3mm
thick and controls functions
like decision making.
o Spinal cord: responsible for
reflexes and passes messages
to and from the brain,
connecting nerves to the
PNS
Peripheral Nervous System
o Transports information to and from the CNS
Somatic: sensory neurons relay messages to the CNS, motor neurons relay information
from the CNS to the body and is involved in reflex actions without involvement of the
CNS
o Made up of 12 pairs of cranial nerves and 31 pairs of spinal nerves
Autonomic: regulates glands, blood vessels, and organs and carries out involuntary,
subconscious actions
Sympathetic: uses noradrenaline which has stimulating effects
o Pupils dilate o Lungs dilate o Stimulates adrenaline
o Dry mouth o Inhibits digestion o Inhibits peristalsis
o Increased heart rate o Bladder relaxes
Parasympathetic: uses acetylcholine which has inhibiting effects
o Eyes constrict pupil o Stimulates digestion o Stimulates bile reflex
o Stimulates salivation o Constricts bladder o Stimulates peristalsis
o Slows heartbeat o Constricts bronchi
, NEURONS
o Brain contains 100billion neurons each connected to 1000 other neurons
(ranging from mm-m in length
o Cells that are specialised to carry neural information throughout the body
Dendrites: receive signals from other neurons or sensory receptors
Cell body: control centre of the neuron
Axon: impulse carried along and terminates at the axon terminal
Myelin sheath: insulating layer around the axon to make transmission more rapid
Sensory Neuron
o Carries impulses from the PNS receptors
o Reflex actions don’t travel all the way to the brain
o Impulses translate into sensations so they can respond appropriately
Relay Neuron
o Carries impulses from sensory neurons to motor neurons
o Short dendrites, short axons
Motor Neurons
o Carries impulses from the CNS to effector
o Short dendrites, long axons
, THE NERVOUS SYSTEM
Central Nervous System
o Processes, interprets, and
stores information and
issues orders to muscles,
glands, and organs
o Brain: has two hemispheres
and is the centre of
consciousness. The cerebral
cortex (outer layer) is 3mm
thick and controls functions
like decision making.
o Spinal cord: responsible for
reflexes and passes messages
to and from the brain,
connecting nerves to the
PNS
Peripheral Nervous System
o Transports information to and from the CNS
Somatic: sensory neurons relay messages to the CNS, motor neurons relay information
from the CNS to the body and is involved in reflex actions without involvement of the
CNS
o Made up of 12 pairs of cranial nerves and 31 pairs of spinal nerves
Autonomic: regulates glands, blood vessels, and organs and carries out involuntary,
subconscious actions
Sympathetic: uses noradrenaline which has stimulating effects
o Pupils dilate o Lungs dilate o Stimulates adrenaline
o Dry mouth o Inhibits digestion o Inhibits peristalsis
o Increased heart rate o Bladder relaxes
Parasympathetic: uses acetylcholine which has inhibiting effects
o Eyes constrict pupil o Stimulates digestion o Stimulates bile reflex
o Stimulates salivation o Constricts bladder o Stimulates peristalsis
o Slows heartbeat o Constricts bronchi
, NEURONS
o Brain contains 100billion neurons each connected to 1000 other neurons
(ranging from mm-m in length
o Cells that are specialised to carry neural information throughout the body
Dendrites: receive signals from other neurons or sensory receptors
Cell body: control centre of the neuron
Axon: impulse carried along and terminates at the axon terminal
Myelin sheath: insulating layer around the axon to make transmission more rapid
Sensory Neuron
o Carries impulses from the PNS receptors
o Reflex actions don’t travel all the way to the brain
o Impulses translate into sensations so they can respond appropriately
Relay Neuron
o Carries impulses from sensory neurons to motor neurons
o Short dendrites, short axons
Motor Neurons
o Carries impulses from the CNS to effector
o Short dendrites, long axons
