Biopsychology Flashcards
The nervous system
A specialised network of cells in the human body, a primary internal communication system. It collects, processes and responds to information in the environment and also co ordinates the working of different organs and cells in the body.
The nervous system
Divided into two sub systems:
Central nervous system (CNS)
Peripheral nervous system (PNS)
The central nervous system
Made up of the brain and spinal cord.
The brain is the centre of all conscious awareness.
The spinal cord is an extension of the brain. It is responsible for reflex actions such as pulling your hand away from a hot plate.
The peripheral nervous system
The PNS transmits messages, via millions of neurons to and from the central nervous system. The peripheral nervous system splits into: the autonomic nervous system (ANS) and the somatic nervous system (SNS).
Somatic nervous system
Transmits information from receptor cells in the sense organs to the CNS. It also receives information from the CNS that directs muscles.
Autonomic nervous system (ANS)
Transmits information to and from the internal bodily organs (breathing, heart rate, digestion). It is automatic. It has two main divisions, the sympathetic and parasympathetic nervous systems.
The endocrine system
The body’s major information system that instructs glands to release hormones directly into the bloodstream. These hormones are carried towards target organs in the body. Works alongside the nervous system.
Glands and hormones (endocrine system)
Various glands in the body, eg. Thyroid/ pituitary gland, produce hormones. The pituitary gland is in the brain and it controls the release of hormones from all the other endocrine glands in the body. (Adrenals, ovaries, testes).
Gland
An organ in the body that synthesises substances such as hormones.
Hormones
Chemical substances that circulate in the bloodstream and only affect target organs. They are produced in large quantities but disappear quickly. Their effects are very powerful.
Fight or flight
The way an animal responds when stressed. The body becomes physiologically aroused in readiness to fight an aggressor or in some cases, run.
Endocrine and ANS working together fight of flight
When a stressor is perceived, the hypothalamus triggers activity in the sympathetic branch of the ANS. The stress hormone adrenaline is released from the adrenal gland into the blood. This increases heart rate and other physiological changes needed for fight or flight.
Sympathetic state
Increases heart rate Increases breathing rate Dilates pupils Inhibits digestion Inhibits saliva Contracts rectum
Parasympathetic state
Decreases heart rate Decreases breathing rate Constricts pupils Stimulates digestion Stimulates saliva production Relaxes rectum
Neuron
The basic building blocks of the nervous system. They are nerve cells that process and transmit messages through electrical and chemical signals.
Sensory neurons
Carry messages from the PNS to the CNS. Long dendrites and short axons.
Relay neurons
Connect the sensory neurons to the motor or the other relay neurons. Short dendrites and short axons.
Motor neurons
Connect CNS to effectors such as muscles and glands. Short dendrites and long axons.
Structure of a neuron
Cell body includes a nucleus.
Axon carries the impulses away from the cell body.
Dendrites carry nerve impulses from neighbouring neurons towards the cell body.
Axon is covered by a myelin sheath, a fatty layer that protects it.
Nodes of ranvier leave gaps in the myelin sheath to speed it up as it jumps across.
Electric transmission
At resting state the inside of the cell is negatively charged compared to the outside. When its activated by a stimulus it becomes positively charged causing an action potential to occur. This creates an electrical impulse.
Synaptic transmission
When neighbouring neurons communicate with each other by sending chemical messages across the synaptic gap that separated them.
Neurotransmitter
Brain chemicals released from the synaptic vesicles that relay signals across the gap. Can be divided into excitatory and inhibitory function.
Excitation
When a neurotransmitter increases the positive charge of the post synaptic neuron. Neuron will fire and pass on the electrical impulse.
Inhibiton
When a neurotransmitter makes the charge of the postsynaptic neuron more negative. Decreases the likelihood that the neuron will fire and pass on the electrical impulse.
Chemical transmissions - synapses
Each neuron is separated from the next by a synapse. Signals within neurons are transmitted electrically, however signals between neurons are transmitted chemically by synaptic transmission.
When the electrical impulse reaches the end of the neuron, it triggers the release of neurotransmitter from tiny sacs, synaptic vesicles.
Excitation and inhibition
The neurotransmitter serotonin causes inhibition.
The neurotransmitter adrenaline causes excitation.
Localisation of function
Theory that different areas of the brain are responsible for different behaviours, processes or activities.
Brain - motor area
In frontal lobe regulating movement.
Brain - somatosensory area
In the parietal lobe that processes sensory information such as touch.
Brain - visual area
Part of the occipital lobe that receives and processes visual information.
Brain - auditory area
In the temperal lobe and concerned with the analysis of speech based information.
Brain - broca’s area
In frontal lobe in the left hemisphere responsible for speech production.
Brain - wernicke’s area
In the temporal lobe in the left hemisphere responsible for language comprehension.
