Week 2 Flashcards
Define analgesia
Absence of pain
Define hypoalgesia
Diminished sensitivity to pain
Exercise induced hypoalgesia
- induced with aerobic,
- resistance and isometric exercise
- Cold, heat, and pressure pain methods
Dorsal view of the brain
looking down at the brain from above
Lateral view of the brain
looking at the brain from the side.
Ventral view of the brain
looking at the brain as if from underneath
Rostral view of the brain
looking at the brain as if from in front
Brain stem
- connects the brain to the body
- sustains basic life functions
The Cerebrum
- Seat of complex thought
- responsible for complex mental activities such as learning, remembering, thinking and consciousness
The Cerebral Cortex
The convoluted area outside edge of the brain
The Cerebral Hemispheres
- the cerebrum is divided into right and left halves called hemispheres
- each hemisphere contains four lobes
The Corpus Callosum
a broad band of nerve fibres joining the two hemispheres of the brain.
The four lobes of the Cerebrum
- Frontal Lobe
- Parietal Lobe
- Occipital Lobe
- Temporal Lobe
Occipital Lobe
Includes the primary visual cortex-the cortical area where most visual signals are sent and processed
Parietal Lobe
Includes the primary somatosensory cortex-the area that registers the sense of touch
Temporal Lobe
Includes the primary auditory cortex-the cortical area devoted to auditory processing
Frontal Lobe
- Includes the primary motor cortex-the area devoted to the control of various muscles and limbs
- Includes the pre frontal cortex-area responsible for higher order cognitions such as working memory, reasoning and decision making
Cerebellum
- responsible for motor control, attention and language
- Critical to coordinate movement, equilibrium and balance.
- Damage here damages fine motor skills like writing or typing
Medulla
- Attaches spinal cord
- manages the unconscious and instinct driven responses
- breathing, maintaining muscle tone and regulating circulation
Pons
- Regulate sleep and arousal
- Above Brain Stem
- In Front of Cerebellum
Midbrain
- Controls sensory processes like spatial awareness
- controls sleep/wake cycle
- Makes dopamine releasing axons
- Dopamine regulates voluntary movements
- damage here is related to Parkinson’s Disease
Forebrain
largest part of the brain and is the most complex
- thalamus
- Cerebrum
- Limbic system
- hypothalamus
The Forebrain – Thalamus
- Relay centre of the cortex
- distributes incoming stimulus (not smell)
The Forebrain – Cerebrum
Complex mental activities, senses, learning, thinking and planning
The Forebrain - Limbic System
Loosely connected network and contributes to emotion, memory and motivation
The Forebrain – Hypothalamus
- Regulates basic biological needs
- Four F’s Fight, Flight, Feed, Mating
Central Nervous System (CNS)
- Lies within the skull and spinal column
- Is the command centre of the CNS
Peripheral nervous system (PNS)
- Controls nerves outside the brain and spine
- Somatic Nervous System
- Autonomic Nervous System
Peripheral nervous system (PNS)
- Controls nerves outside the brain and spine
- Somatic Nervous System
- Autonomic Nervous System
Somatic Nervous System (SNS)
- Connection of nerves to voluntary muscles and sensory organisms
- Afferent Pathways (towards the CNS; sensory)
- Efferent Pathways (away from the CNS; motor)
Autonomic Nervous System (ANS)
Nerves to heart, blood vessels, smooth muscles, glands
Neuron Anatomy
- Dendrites
- Axon
- Cell Body
- Neural impulse
- Myelin Sheath
- Terminal branches of axon
Terminal branches of axon
Form junctions with other cells
Myelin Sheath
covers the axon of some neurons and helps speed neural impulses
Neural impulse
electrical signal travelling down the axon
Axon
Passes messages away from the cell body to other neurons, muscles or glands
Dendrites
Receives messages from other cells
Cell Body
The Cell’s life support centre
Electrical communication within a cell
- small but measurable electrical impulse present everytime you move or have a thought
- Direction of potential travels from cell to terminal button
Action Potential
- Converts chemical energy to electrical energy and carries this down the nerve
- make this decision by combining inputs that arrive at each dendrite
Excitatory Input
information entering a neuron that gives it the signal to respond and fire
Inhibitory input
Information entering a neuron that tells it not to respond or fire
Neurotransmitters
- Chemicals released by one cell that binds to the receptors on another cell
- Tell the next cell to fire or not to fire its own action potential
Receptors
- Proteins on the cell membrane that receive chemical signals
- Recognise specific NTs
Chemical Communication - Graded Potentials
- Signals have different strengths
- Signals come from communication between synapses from the number of neurotransmitters present in the synaptic cleft.
Major Neurotransmitters
- serotonin
- dopamine
- acetylcholine
- norepinephrine
- GABA
- Glutamate
Function of Serotonin
Affects mood, sleep, impulsivity, aggression, appetite.
Function of Dopamine
Affect learning, attention, movement, reinforcement, pleasure
Function of Acetylcholine
Affects movement, learning, memory, REM Sleep
Function of Norepinephrine
Affects eating, alertness, wakefulness
Function of GABA (gamma-aminobutyric acid)
Facilitates neural inhibition in the CNS
Function of Glutamate
Active in areas of the brain involved in learning, thought and emotion
Neurotransmitter associated disorders - Acetylcholine (ACh)
Alzheimer’s Disease
Neurotransmitter associated disorders - Dopamine
- Parkinson’s Disease
- Schizophrenic Disorders
- Addictive Disorders
Neurotransmitter associated disorders - Glutamate
Schizophrenia
Neurotransmitter associated disorders - Norepinephrine
Depressive Disorders
Neurotransmitter associated disorders - GABA (gamma-aminobutyric acid)
Anxiety Disorders
Neurotransmitter associated disorders - Seratonin
- Depressive Disorders
- Obsessive-Compulsive Disorders
- Eating Disorders
Endorphins
- Inhibition or blocking of pain
- Regulation of pleasurable sensations.
Electroencephalograph (EEG)
Monitors the electrical activity of the brain over time by means of recording electrodes attached to the surface of the scalp
Lesioning
- Destroys a small peice of the brain
- Inserts an electrode into the brain, then passing a high-frequency electric current through it.
- Looks at the difference in behaviour before and after the brain damage to determine how the brain works.
Electrical Stimulation of Brain (ESB)
Sends a weak current into the brain to stimulate it.
Transcranial Magnetic Stimulation (TMS)
- Temporarily enhances or depresses activity in a specific area of the brain
- Pulsed magnetic field 2cm
- Strong results for treatment of addiction, depression and autism
Dual Process Model
- Behavior is the dynamic result of combining Automatic and Controlling processes
- Compulsive Behaviour affects affects Biology and Biology is linked to Compulsive Behaviour
Propreoception
awareness of where our body is in space
Gyrus or Gyri
A ridge or fold between two clefts on the cerebral surface in the brain.
Sulcus or sulci
a groove or furrow, especially one on the surface of the brain
Sensory Integration
- The process by which we receive information through our senses
- Organises this information
- Use information to take action
eg: See a car, hear high revving engine, stop at the kerb and allow the car to pass.
Contralateral projections
When sensory info (other than smell) is detected, the message is received on one side and projected to the other side of the body (touch in the left hand is processed in the right hemisphere); this is an example of CONTRALATERAL projections
Ipsilateral projections
When odours are detected, the message is received on one side and remains on that side of the body (smells in the left nostril are processed in the left hemisphere); this is an example of IPSILATERALprojections.
Cells in the nervous system
- The nervous system is tissue that is composed of cells
- Nerve cells firing provied the basis for process - Two major types of nervous system cells . Glia . Neurons
Glia
- Glia means glue
- They are smaller and more numerous than neurons
- About 50% of the brain volume
- Support and insulate neurons
- Supply them with nutrients
- Remove waste material
- send &
- Receive chemical signals
- Play a role in many disorders
Oligodendrocyte
- Provide support and insulation to axons in the central nervous system
- Provide support and insulation to axons in the central nervous system
- Assist in creating the myelin sheath
Myelnation
Enhances the speed of chemical communication
Three types of Neurons
- Efferent - Motor
- Afferent - Sensory
- Internuerons
Interneurons
carry information between neurons in the brain and neurons in the spinal cord
Dendrites
Receive inputs from other cells
Soma
Contains the Nucleus - “Brains of the operation”
Axon
Transmits information to the other neurons
Myelin Sheath
Facilitates transmission of information to other neurons - Covers the axon
Terminal buttons
- At the end of an axon
- Sends information to adjacent cells
Synapses
The point of connection between neurons
Neural Impulse
Electrical signal travelling down the axon
Neurotransmitter
- The chemical released by Terminal Buttons
- Sends messages that activate or inhibit to the next cells
Action Potential
Converts chemical energy to electrical energy and carries this information down the nerve.
A higher rate of action potential indicates a more intense sensation
Resting Potential
- When a neuron isn’t firing
- -70 millivolts
- Is polarised
Threshold to move from resting to action potential
- Need to move from -70 to -55 Millivolts
- When this happens it causes the axon to fire
The 6 Steps of Action Potential
- Threshold of excitation is reached, sodium channels open
- As voltage becomes more positive, potassium channels open
- At the peak of Action Potential +40 sodium channels become refractory and close
- Potassium still leaving a cell starts to polarise the membrane potential again
- Potassium channels close as potential becomes more negative
- Extra potassium outside diffuses away, sodium potassium pump restores resting potential.
Absolute Refractory Period
Relative to the amount of potassium in the axon - no action potential can happen during this period
Relative Refractory Period
The period when sodium gates have closed and voltage moves up to -70 millivolts
Synaptic Transmission
Chemical communication between cells usually from dendrites to receptors
How does Synaptic Transmission happen?
- Neurotransmitters stored in vesicles in pre-synaptic membrane
- When synapse is activated, vesicles fuse with pre-synaptic membrane
- NT defuses across synaptic cleft
- Is recognised by receptors on post synaptic membrane
How does Synaptic Transmission happen?
- Neurotransmitters stored in vesicles in pre-synaptic membrane
- When synapse is activated, vesicles fuse with pre-synaptic membrane
- NT defuses across synaptic cleft
- Is recognised by receptors on post synaptic membrane
Midsaggital view of the brain
shows the three major parts of the brain,
- cerebrum
- cerebellum
- brain stem.
As though the brain is dissected through the corpus callosum
Primary somatosensory cortex
Receives sensory information like touch, pressure, temperature, pain and spatial attention
Primary motor cortex
- Critical to initiate and co-ordinate motor movements.
- Dfferent parts of this cortex control different parts of the body
Prefrontal Cortex
- Plays a role in “higher order” thinking, executive function, planning and reasoning.
- Also involved with personality and emotion and social behaviours
Primary auditory cortex
Processes auditory information and is part of the auditory system, performing basic and higher functions in hearing, such as language switching.
Primary visual cortex
The primary visual cortex is the part of the neocortex that receives visual input from the retina.
Hindbrain
The lower part of the brainstem comprising of the:
- Cerebellum
- Pons
- Medulla oblongata.
