Biopsychology Flashcards
The Nervous System
A specialized network of cells, fast-acting and electrical (and chemical) internal communication system.
Central Nervous System (CNS)
Brain - divided into hemispheres, cerebral cortex (outer layer), 3mm thick.
Spinal cord - connects brain to PNS, reflexes.
Peripheral Nervous System (PNS)
Autonomic nervous system (ANS) - governs vital functions.
Somatic nervous system (SNS) - muscle movement, sensory information.
Glands
Produce hormones
Pituitary is master gland
Hormones
Hormones distributed in bloodstream, e.g. thyroid gland produces thyroxine.
Fight or flight
Sympathetic arousal: hypothalamus + pituitary > adrenal gland > adrenaline.
Adrenaline leads to increased heart rate, faster breathing, sweating, inhibits digestion.
Immediate and automatic.
Parasympathetic state - once threat has passed, body returns to rest and digest.
Sensory neuron
PNS to CNS, long dendrites - short axons.
Relay neuron
Sensory to motor or other, short dendrites - short axons.
Motor neuron
CNS to effectors, short dendrites - long axons.
Structure of a neuron
Cell body contains a nucleus, has dendrites.
Axon covered in myelin sheath divided by nodes of Ranvier.
Electrical transmission
Positive charge leads to action potential.
Synapse
Neurons are separated by very tiny gaps.
Chemical transmission
Neurotransmitter released from synaptic vesicle into synapse, taken up by postsynaptic receptor site on receiving dendrite.
Neurotransmitters
Specialist functions e.g. acetylcholine for muscle contraction.
Excitation and inhibition
Adrenaline is excitatory, serotonin is inhibitory.
