Psychology - Biopsycholgy Flashcards
The nervous system
is the main system that controls the mind and body. It takes in information from the environment and elsewhere in the body (transmitted across neurons) and co-ordinates a wide range of conscious functions such as thinking and movement, as well as unconscious functions like the control of organs (e.g. heart rate, digestion) and glands.
Central nervous system
Main control system for life functions, plus conscious psychological processes
CNS - Two parts
Brain and spinal cord
Brain
Higher psychological processes (e.g. thinking, behaviour), and regulates bodily processes based on information from peripheral nervous system
Spinal cord
Transmits information between the brain and peripheral nervous system
Peripheral nervous system
Transmits information between the CNS and external world/organs
PNS - two parts
Autonomic and somatic
Autonomic
Transmits information betwen organs and CNS responsible for involuntary bodily activities e.g. heart rate
Somatic
Transmits information between senses and CNS directs voluntary movement e.g. walking
Autonomic - two parts
sympathetic and parasympathetic
Parasympathetic
Decreases bodily functions to conserve energy (calm and rest)
Sympathetic
Increases bodily functions to prepare for action (fight or flight)
Brain - functions
Perception (i.e. translating information from the senses so it can be understood and processed)
Motor control (i.e. sending commands to muscles to move)
Regulating bodily processes and maintaining homeostasis (e.g. maintaining temperature and hormone levels based on information from the peripheral nervous system)
Sleep
Spinal cord -functions
The spinal cord connects the brain with the peripheral nervous system. In other words, it connects the brain with the rest of the body and with the external world. The spinal cord is also responsible for some unconscious movements, such as reflexes (e.g. the one where you get hit on the knee and your leg kicks).
PERIPHERAL NERVOUS SYSTEM - function
The peripheral nervous system goes beyond the central nervous system to connect it with the rest of the body and the external world. It consists of two parts: the somatic nervous system and the autonomic nervous system.
Somatic - function
It transmits information between the central nervous system and the senses (i.e. it connects the brain to the external world) and is under conscious control.
Autonomic - functions
The autonomic nervous system is responsible for transmitting information between the central nervous system and the internal organs (i.e. it connects the brain to the rest of the body). Unlike the somatic nervous system, it is involuntary and not under conscious control.
Organ - Heart - Sympathetic
Increase heart rate
Organ - Digestive system - Sympathetic
Decrease stomach acid and digestion
Organ - Eyes (iris) - Sympathetic
Dilate pupils
Organ -Lungs -Sympathetic
Dilate bronchioles
Organ - Heart - Parasympathetic
Decrease heart rate
Organ - Digestive system - Parasympathetic
Increase stomach acid and digestion
Organ - Eyes (iris) -Parasympathetic
Constrict pupils
Organ -Lungs -Parasympathetic
Constrict bronchioles
Neurons
Are the main components of the nervous system. They are how information is transmitted from one part of the nervous system to another. There are around 100 billion neurons in the brain and another 1 billion in the spinal cord.
General structure of a neuron
The dendrite (receptor) receives a signal
The signal is carried towards a cell body (which contains the nucleus)
The signal travels along an axon (which is protected by myelin sheaths) towards the axon terminal
Terminal boutons at the end of the axon pass the electrical signal to the next neuron in the chain
Direction of impulse
Signals are passed within neurons electrically. At rest, the neuron is negatively charged but becomes positively charged when activated, which sends an electrical impulse through the axon. Once this electrical signal reaches the axon terminal, synaptic transmission enables the signal to pass along to the next neuron in the chain.
SYNAPTIC TRANSMISSION
Neurons are separated by small gaps called synapses, and synaptic transmission is the process of sending information from one neuron to another. The gap between two neurons is called the synaptic cleft (or synapse). When the electrical signal within a neuron reaches the axon terminal of that neuron, neurotransmitters are released from vesicles and cross over the synapse where they are taken up by receptors in the dendrites of the other neuron.
Whereas signals within neurons are transmitted electrically, signals between neurons are transmitted chemically. In other words, neurotransmitters are chemicals. When a neurotransmitter is taken up by the receptor of the next neuron, it is converted back to an electrical signal which passes along the axon of that neuron until it reaches the axon terminal where the chain can continue.