WEEK 5- Biological Psychology. Flashcards
Caffeine, alcohol and nicotine changes the way you feel because they:
Change the chemistry of the brain.
Biological Psychology
Is the study of the cells and organs of the body, and the physical and chemical changes involved in behavior and mental processes.
The nervous system contains billions of cells that make up the brain, spinal cord and other nerve fibres. The combined activity of these cells tells you:
what is going on inside and outside your body and allows you to make appropriate responses.
The nervous system
- Is the combination of the Central Nervous System and the Peripheral Nervous System.
- Detects information and execute responses.
- Is made up of cells that communicate with each other.
The key function of the nervous system and body is:
The processing of information.
The nervous system’s three main functions are:
To receive information and gather information from the environment (input), integrate that information with past experiences (processing) and guide actions (output).
The nervous system is made up of two cells:
Neurons and Glial Cells.
Neurons
- Are cells that are specialized to rapidly respond to signals and to quickly send signals of their own, are anatomical structures.
- Nurons contains organelles such as mitochondria, ribosomes, endoplasmic reticulum, Golgi apparatus that support the daily functioning of the cell. Neurons are a special type of cell for neurotransmission.
Glial Cells
Are non-neuronal cells that performs important communication too, they are also specialized cells. They provide essential nutrients and growth factors needed for neurogenesis, as well as neuronal repair and maintenance. So, without glial cells, neurons could not function. Furthermore, glial cells are capable of the signature functions of neurons, including releasing chemicals that influence neurons, responding to chemicals from neurons, and changing in response to experience.
The human brain contains:
86 billion neurons
Soma
- Is the neuron cell body which is surrounded by a permeable cell wall and a nucleus holding the hosts DNA.
- All the information goes first to the soma (cell body) then it decides whether that neuron is sending information through the axon into its terminals.
Glial cells produce
Myelin.
There are 3 features that neurons share with almost every other kind of cell in the body which are:
- Neurons have an outer membrane that acts like a fine screen, letting some substances pass in and out while blocking others.
- Nervous system cells have a cell body which contains a nucleus (only red blood cells have no nucleus). The nucleus carries the genetic information that determines how a cell will function.
- Nervous system cells contain mitochondria, which are structures that turn oxygen and glucose into energy. This process is especially vital to brain cells.
Both neurons and glial cells are in charge of:
Processing chemical and electrical transmission of information within the nervous system.
The neuron structure comprises:
- Cell
- Cell membrane
- Dendrites
- Axons
- Ogliodendrocyte
- Node of Ranvier
- Myelin sheath
- Synapses
Axons
Tube-like structure that propagates the integrated signal away from the cell body and towards specialised endings called axon terminals. Each neuron has only one axon leaving the cell body, but one axon may have many branches.
Axon Terminal
Is where synapses with neighbouring neuron occurs. Located the end of an axon and typically synapse on other neurons, muscles or target organs. Axon terminals contain tiny parcels (vesicles) of neurotransmitters that are released in synapse.
Dendrites
Are fibers that receive signals from the axons of other neurons and carry those signals to the cell body. A neuron can have many dentrites. The dentrites have many branches.
Axons carry signals _____ from the cell body, whereas dendrites _________ from other cells.
Away; detect signals
Axon Hillock
Integrate signals from multiple synapses and serves as a junction between the cell body and an axon.
Synapses
Specialized junctions where transfer of signals occur, usually between the axon of one cell and the dendrite of another.
Neuronal membrane
A barrier that separates the inside of the neuron from the outside, which in cases the entire neuron
Action potential
Is an electrical impulse that travels down the axon and allows neurons to communicate.
Presynaptic neuron
The neuron transmitting the signal
Postsynaptic neuron
The neuron receiving the signal
The release of neurotransmitters which are chemical signals received by dendrites into the synapse is a process called:
Action potentials
The speed of the action potential depends on the
Diameter of the axon (larger ones are faster) and on weather myelin is present.
Myelin
Is a fatty substance that wraps around some axons and increases the speed of action potentials. Larger myelinated cells are usually found in parts of the nervous system that carry the most urgently needed information.
The disease Multiple Sclerosis is based on damaged
Myelin
A neurological disease affecting the output stage of processing is:
Parkinson disease
Nodes of Ranvier
Are gaps in the myelin sheath that allow the action potential to be propagated and regenerated (this is called saltatory conduction), here the signal is recharged as it travels along the axon.
The Saltatory Conduction
Allows for the action potential to travel extremely quickly along the axon – much faster than without the myelin sheath, where the action potential is required to be regenerated the whole way along the axon and is therefore slower and less energy-efficient
Refractory period
Is a short rest period between action potentials.
For communication to occur between cells, a signal must be transmitted across
The synapse, or gap, between neurons.
Neurotransmitters
Specialised neural chemicals released by neurons that are designed to cross the synaptic gap and bind onto cell receptors on another cell. These chemicals that assist in the transfer of signals from one neuron to another. These chemicals are stored in little bags called “vesicles“ at the tip of the axons.
Neural receptors
Cell surface proteins located within the cell wall that receive chemical signals.
______________ are involved in every aspect of behaviour and mental processes.
Neurotransmitters
Postsynaptic potential
Is the change in the membrane potential of a neuron that has received stimulation from another neuron.
Excitatory postsynaptic potential
Is a postsynaptic potential that depolarises the neuronal membrane, making the cell more likely to fire an action potential.
Inhibitory postsynaptic potential
Is a postsynaptic potential that hyperpolarises the neuronal membrane, making a cell less likely to fire an action potential.
For one neuron to communicate with another, a _____________has to cross the ____________between them.
Neurotransmitter; synapse.
In the brain and spinal cord, neurons are organized into groups called
Neural networks
Sensory system or senses
The groups of neurons in the nervous system that provide information about the environment (hearing, vision, taste, smell and touch).
Motor systems
Are parts of the nervous system that the brain uses to influence muscles and other organs to respond to the environment.
Central Nervous System (CNS) is composed of:
The brain and the Spinal Cord.
Brain in the CNS:
Interprets and stores information and send orders to muscles, glands and organs.
Spinal Cord in the CNS:
- Connects the brain and the Peripheral Nervous System.
- Relays signals from peripheral senses to the brain and conveys messages from the brain to the rest of the body
Cells of the spinal cord can direct some simple behaviours without instructions from the brain, these behaviours are called:
Reflexes, which are simple involuntary and unlearned. Ex, withdrawal of heat and knee jerk.
The surface of the brain is called:
Cerebral cortex
Parallel distributed processing
Is when information is processed by a number of brain regions at the same time.
A feedback system
- Are series of processes in which information about the consequences of an action goes back to the source of the action so that adjustments can be made. Ex, when you touch something hot, the arm contracts, if this does not happen, the feedback system appears.
- It also serves in the endocrine system as it regulates hormone secretion to keep it within a certain range. If a hormone rises above a certain level, feedback about this situation signals the brain and pituitary to stop stimulating that hormone’s secretion.
Limbic system
Is a complex set of brain structures that lies on both sides of the thalamus, just under the cerebrum. It deals with 3 key functions that are: emotions, memories and arousal (or stimulation).
The brain divides in:
Forebrain, Midbrain and Hindbrain.
Forebrain
Is the most highly developed part of the brain; it is responsible for the most complex aspects of behaviour and mental life. The forebrain has grown out of proportion to the rest of the brain as well as the cerebellum. The forebrain is a sensory relay for the brain. All of our senses, with the exception of smell, are routed through the thalamus before being directed to other areas of the brain for continued processing.
The major structures of the Forebrain are:
- Hypothalamus
- Corpus callosum
- Cerebral Cortex
- Striatum
- Thalamus
- Septum
- Amygdala
- Hippocampus
Midbrain
Is a small structure between the hindbrain and forebrain that relays information from the eyes, ears and skin an that controls certain types of automatic behaviors that control simple movements
The major structures of the Mindbrain are:
- Brain Stem
- Substantia nigra
Hindbrain
Lies just inside the skull and is actually a continuation of the spinal cord. So, signals coming from the spinal cord reach the hindbrain first. Blood pressure, heart rate, breathing and many other vital autonomic functions are controlled by nuclei in the hindbrain.
The major structures of the Hindbrain are:
- Reticular formation
- Locus coeruleus
- Cerebellum
- Medula oblongata
Thalamus
Is a brain structure responsible for relaying motor and sensory signals to other parts of the brain. Also, It relays pain signals from the spinal cord, as well as signals from the eyes and most other sense organs, to upper levels in the brain.
Hypothalamus
The hypothalamus regulates a number of homeostatic processes, including the regulation of body temperature and blood pressure. It regulates hunger, thirst and sex drive.