Unit 2: Introduction to the Nervous System Flashcards
(150 cards)
1
Q
Nervous System
(controls everything, manages all other systems, every body part has its own nerves)
What is it?
A
-The network of nerve cells and fibers which transmits nerve pulses (messages) between parts of the body.
2
Q
Sensory Information
A
any information about the external environment carried from sensory organs (retina in the eye, cochlea in the ear etc, senses) or the internal (body temp, water levels) to the brain (CNS) by somatic NS=Peripheral NS
3
Q
Motor Information
A
Any information about how to respond to (stimuli) external environment carried from brain (CNS) to internal organs (heart or lungs, or muscles for movement)
4
Q
Central Nervous System (CNS)
A
-The CNS is composed of the brain and spinal cord.
-It processes sensory information to activate appropriate actions.
-This process occurs extremely rapidly and continuously.
- if question is abt any judgment of sensory info, must be CNS
5
Q
Brain’s function in CNS
A
Constantly receives and processes information and co-ordinates a response.
6
Q
Spinal cord function in CNS
A
Spinal cord connects the brain to the rest of the body.
functions:
- it sends info. from sensory neurons in various parts of the body to the brain.
- it relays motor commands back to muscles and organs via motor neurons (from brain to PNS)
7
Q
What could happen if spinal cord is damaged?
A
- loss of sensation (touch, temp, etc.) because sensory info can’t flow from sensory organs to brain
- loss of motor control (movement)
8
Q
Peripheral Nervous System (PNS)
A
The PNS is connected to the spinal cord and consists of all nerves outside the CNS.
-It carries sensory information from the body to the CNS, and motor information from the CNS to the body/ bodily organs
- peripheral means outside - of CNS
9
Q
Two divisions of PNS:
A
Somatic nervous system and Autonomic nervous system
10
Q
Somatic Nervous System
A
-The Somatic NS transmits sensory information to the CNS from sensory organs and carries out its motor commands.
-Then conveys motor information from CNS to voluntary skeletal muscles for voluntary muscle movements.
11
Q
Sympathetic Nervous System
A
- readies the body for the flight or fight response when it exposed to threats, stimulus or stressors (doesn’t necessarily mean stress) e.g a sound or person
-throws off homeostasis
12
Q
2 divisions of nervous system
A
- central nervous system
- Peripheral NS
Both work together
13
Q
Autonomic Nervous System
A
-is responsible for automatic/ involuntary responses
-carries info between the CNS and internal bodily structures (organs) that carry out basic life processes e.g heart rate and breathing
14
Q
Divisions of Autonomic Nervous System
A
- Sympathetic
- Parasympathetic
15
Q
Parasympathetic nervous system
A
-supports more mundane, or routine activities, that maintain the body’s store of energy (e.g, regulating blood sugar levels, secreting saliva)
- maintains homeostasis= brings everything back to normal
-when a threat has passed the parasympathetic NS resumes control from the sympathetic NS
16
Q
Sympathetic responses
- during high levels of threat part 1
A
-dilates pupils of the eyes allow for more light to enter the eyes and improve sight when needed e.g under threat
-heart rate increases to energise the body for activity by increasing delivery of O2 and glucose to voluntary skeletal muscles
-bladder relaxes=pee your pants to allow for more essential bodily functions during activity
17
Q
Sympathetic responses
- during high levels of threat part 2
A
-lung airways relax and expand to allow for increased oxygenation required for more intense activity
-digestion is inhibited to allow for more essential bodily functions needed during activity
-adrenal glands secrete stress hormones to energise the body
18
Q
Parasympathetic responses
-during rest and inactivity
part 1
A
-constricts pupils of the eyes according to the light levels required to see optimally
-heart beats at a rate best for optimal functioning during inactivity by directing blood flow evenly around the body as skeletal muscles don’t need increased blood flow at rest.
-lung airways constrict for ideal breathing rate at rest
19
Q
Parasympathetic responses
-during rest and inactivity
part 2
A
-digestion operates to allow for regular eating
-bladder constricts and is controlled
-adrenal glands don’t secrete stress hormones to allow the body to rest
-body reduces release of glucose so it doesn’t deplete the body of energy.
20
Q
sensory/afferent neurons
A
-transmit info from sensory cells in the body(called receptors), PNS to the brain, CNS (either directly or through the spinal cord), takes the afferent pathway
-in the PNS
21
Q
interneurons
A
-function= organises and integrates sensory info in the brain, then initiates and coordinates motor responses. Provide link between sensory and motor neurons
-in the CNS
22
Q
motor/efferent neurons
A
-transmits commands from the interneurons to the effector glands, organs and muscles of the body, from CNS to body
-takes efferent pathway
-in the PNS
23
Q
synaptic knobs or terminal buttons
A
contain vesicles which hold neurotransmitters involved in moving signals to adjacent cells, transmit chemical info to other neurons
24
Q
synapse or synaptic gap
A
-the space between neurons where transmission occurs
-where neurons meet but never physically touch
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Electrochemical communication
neurons communicate using electrochemical energy
-electrical=within the neuron-electrical impulse is transmitted along the neuron
-chemical= between neurons- takes place in the synapse when a neurotransmitter are sent from the axon terminals of the presynaptic neuron, to the dendrites of the post synaptic neuron.
-electrical signal stimulates the chemical
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Glial cells
main function= provide the structural framework that enable a network of neurons to remain connected
other functions=
-supply nutrients and 02 to neurons so they can function
-destroy and remove dead neurons
-soak up excess neurotransmitters at the synapse that can clog the communication between neurons
-block the entrance of toxic barriers to the brain
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Communication between neurons
relies on an action potential
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Neurotransmitters- 3 Key steps of chemical communication?
1. Synaptic vesicles store neurotransmitters within the nerve cell, inside the axon terminals
2. When an action potential reaches the axon terminals of a presynaptic neuron, the synaptic vesicles release neurotransmitters into the synapse.
3. These neurotransmitters bind to the receptor sites on the dendrites of the post synaptic neuron and alter its action.
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The cerebral cortex, function
-is the largest part of the brain
function= receiving and processing sensory information, initiating motor responses.
- plays a key role in memory, attention, perception, cognition, awareness, thought, language and consciousness
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What is meant by "complementary molecular structure"
-This means that the distinct molecular structure of the neurotransmitters being matched by the receptor site means that the receptor site will only respond to specific neurotransmitters and ignore others
- not the same shape but complementary
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Detailed flow chart of Neural communication
Dendrites receive neurotransmitters from a previous neuron which stimulates an action potential> the signal pass through the cell body which collects the message> axon generates an action potential> the neural impulse reaches the axon terminals of the presynaptic neuron> then it reaches the terminal buttons which causes the vesicles to release the neurotransmitters into the synaptic gap> the neurotransmitters diffuse across the synapse> the neurotransmitters (key) then bind to receptor sites (lock) on the dendrites of the postsynaptic neuron> the neurotransmitters then make the post synaptic neuron have a excitatory effect= stimulates/activate post synaptic neuron, increasing the likelihood of firing an action potential e.g glutamate OR an inhibitory effect= suppress/slow down post synaptic neuron, decreasing the likelihood of firing an action potential e.g GABA
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Contralateral organisation
Right hemisphere receives sensory info from the LHS of the body and controls movements on LHS of the body. The opposite is true of the left hemisphere
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Glutamate
-an excitatory neurotransmitter
function and location
-found in the hippocampus and outer layers of the cerebral cortex
-associated with= cognition, learning ( when practicing a new skill Glutamate is release by neurons in brain= reinforces neural pathway and retain what you have learned), memory, behaviour, movement, sensation
-When combined with the receptor site NMDA, it is associated with LTP
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What is LTP?
Long term synaptic strength following high frequency stimulation of synapse
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Too much Glutamate?
-abnormal neural development (inappropriate neural connections forming e.g additional reflexes, sensation etc)
-neurodegenerative diseases- neuronal damage or death e.g motor neuron disease
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GABA (gamma amino butyric acid)
- an inhibitory neurotransmitter
- function and location
-found extensively through the whole nervous system
-reverses the effects of excitatory neurotransmitters e.g reduces stress b/c low levels of GABA are associated with high anxiety levels and GABA is used to treat anxiety
-ends fight or flight response
-alcohol can decrease GABA activity
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Neural transmission requires a balance between Glutamate and GABA b/c ?
-overstimulation of neurons can lead to nerve damage
-if there are only excitatory neurotransmitters there would be no flexibility in responses of post synaptic neuron ( they would only be able to fire an action potential in response to inputs
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cerebral hemispheres
two divisions of the cerebral cortex
- a longitudinal fissure seperates these two hemispheres
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gyri
the elevation points of the brain
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sulci
the folds or groove that seperate gyri
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Specialized functions of Left Hemisphere
-verbal functions: aspects associated with language, writing, speaking, reading
-analytical functions: logical reasoning, critical evaluation
-non-verbal: sensory and motor functions from the RHS of body ( if damaged= sensation of RHS=lost
-if Left hemisphere=damaged= no communication
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Specialised Functions of the Right Hemisphere:
* Non verbal functions:
* Spatial and visual thinking e.g. jigsaws, map reading, recognizing faces, appreciating art and music, creativity and fantasy
* Recognition of emotions relating to facial expressions.
* Sensory and motor functions of LHS of body ( if right is damaged= sensation of LHS=lost)
-no language capacity b/c no Broca's area, can't perform verbal functions on its own
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corpus callosum
- Bridge of nerve tissue that connects the two cerebral hemispheres
- allows for communication between the two hemispheres
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the 4 divisions of lobes
Frontal lobe
Occipital lobe
Parietal lobe
Temporal lobe
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Primary motor cortex of Frontal lobe, function and how is it organised
- controls voluntary bodily movement of skeletal muscles, controls simple motor skills
- organised contra-laterally
-Areas of specialisation are organised so that parts higher on the body are controlled e.g lips by the lower parts of PMC and vice versa
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Broca's area
* Broca's area is a region in the frontal lobe of the left hemisphere
Broca's area is linked to:
* Producing speech articulate speech
* coordinates muscles responsible for clear speech (e.g tongue, mouth, vocal cords)
* Capacity to use words other than simple nouns and verbs
* Capacity to at add suffixes to words
* Capacity to produce written language
36
Primary auditory cortex of temporal lobe
- sound processing and higher level auditory processing (recognising aspects of sound which are specific to speech)
-verbal sound are mainly processed in Left Hemisphere
-non -verbal (e.g music) are mainly processed in right hemisphere
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Wernicke's area
* Wernicke's area (Temporal lobe) →
Involved in the comprehension of speech (i.e., making sense of verbal communication).
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what is Broca's Aphasia
(non-fluent aphasia)
the damage to Broca's area and characterized by non-fluent speech, language comprehension is normal, person is aware of their problems
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what is Wernicke's Aphasia
(fluent aphasia)
-results in deficits in the comprehension of language
-severe= complete absence of understanding language (verbal, written or sign)
-speech is fluent but it may not make sense to listeners and patients don't understand what they are saying=meaningless speech or jargon aphasia
- patients= unaware of problems, can't function independently
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Function of Nervous System
-It receives and processes sensory information from the environment and transmits motor information around the body, that, in turn, determines our reaction to environment stimuli.
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Damage to primary auditory cortex?
e.g stroke= might cause deficits in ability to detect changes in pitch, localize sound in space or understand speech
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What is aphasia?
is an impairment in language production or comprehension brought by neurological damage
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Association areas of temporal lobe
-memory= linked to hippocampus= essential for converting short term memories to long term, linking emotions to memory, determining appropriate emotional responses to memory
-face and object recognition
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Damage to temporal lobe?
-lead to amnesia= inability to recognise someone as a person they know or a place
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Other functions of frontal lobe/ executive functions
-planning, personality, judgement, decision making, thinking, feeling, behaving, impulse control
-it is the end point for most sensory info that is processed by other lobes, coordinates functions of other lobes
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homunculus?
-is a visual representation of what the body would look if there was a 1:1 ratio of cortical area to body parts
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Parietal lobe, Primary Somatosensory cortex (primary cortical area), function?
function of primary ss cortex= receives and processes information from skin and body, enabling perception of bodily sensations,
-other function of parietal lobe=
visual attention, spatial reasoning (e.g interpreting maps), locating objects
48
How is primary Somatosensory cortex organised?
-Contralaterally
-separated from motor cortex in frontal lobe by the central sulcus
-parts higher on the body e.g lips are controlled by the lower parts of PMC and vice versa
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Homunculus and somatosensory cortex
body parts that are have more sensory receptors/ more sensitive to sensory stimuli e.g the lips will receive more areas of the cortex than others compared to those that are less sensitive e.g neck
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Spatial Neglect
-is the inability of a person to process and perceive stimuli on one side of the body or env.
-commonly contralateral to damaged hemisphere e.g to right parietal lobe=left spatial neglect
-attention deficit not visual deficit
e.g when drawing a clock they will only draw half, b/c think they've drawn everything
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Occipital lobe
Primary visual cortex=processes info from the eyes
specialised neurons detect and respond to different elements of what we see e.g orientation, shape, motion, colour
-association areas interact with other lobes
52
Neural Pathways from the eyes
-Right visual field goes to left receptive field in the eye and then to left visual cortex, vice versa for left visual field
-there is cross over of both RVF and LVF when both eyes are used= they both go to both eyes, just to their sides e.g RVF will go to left side of both eyes
53
Explain how the central and somatic NS would act as a communication system to tell Efran to walk away after the dog had bit him?
Efran's body as part of the somatic NS would register the aggressive dog's bite and send sensory messages abt it to the CNS. The CNS would process this pain/touch info (if it was visual info= CNS will perceive it as a potential threat) and coordinate a response, telling the leg skeletal muscles in the SNS to walk away via motor messages.
54
Why are there sympathetic responses during high levels of threat?
B/c our body will interpret certain things as a threat so the body is adapting to help us deal with the threat
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Structure of Cerebral cortex
structure= convoluted ( folded), 2 hemispheres,
each hemisphere divided into four cortical lobes
-each lobe has a sensory or motor function referred to as a primary cortical area (PMC)
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What is hemispheric specialisation?
although each hemisphere is responsible for different aspects of the brain functions, both the left and right work together to coordinate responses/functions
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What is split brain surgery?
-to cure epilepsy, reduce severity of seizures
-involves cutting the corpus callosum t/f there's no communication b/w the two hemispheres
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Experiments on ppl with a split brain?
Due to contralateral function (explain it)
-patients were able to recognise/ name/ draw images projected in RVF ( as info was sent to left hemisphere= can operate language functions on its own
- w/a objects in the left visual field could not be named and recognised
-H/w ppl still saw the pencil on the LFV and were able to locate it with left hand (b/c on LVF) despite not being able to verbalise it (b/c info from LVF goes to right hemisphere, which has no language capacity on its own and no communication b/w two hemispheres b/c of severed corpus callosum) = purely a language deficit not visual
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Specialised regions of cerebral cortex?
primary cortex of each lobe, Broca's area and Wernicke's area
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What is the Limbic system?
-combines higher-order mental functions and primitive emotion into one system
-located beneath the cerebrum on both sides of thalamus
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Amygdala/ amygdalae location?
is a small, almond shaped collection of neurons located deep inside temporal lobe
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Function of Amygdala
(process fear faster than cerebral cortex therefore we react to danger before we are consciously aware of it)
-involved in emotional reactions and processing fear
-when we are exposed to a fearful or dangerous stimulus, this info is send directly to amygdala which then passes it to hypothalamus, which activates the fight of flight response
-forming and storing long term, emotional memories, learning new info, decision making
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Damage to amygdala leads to?
-loss of fear response
-impaired decision making=lose natural aversion to risk and loss
-memory loss
-hypervigilance= becomes sensitive to minor facial expression=possible threat
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Explain memory loss in terms of damage to amygdala?
-hippocampus and amygdala closely work together to process memories. Amygdala encodes emotional aspect of memory w/a hippocampus encodes context. If damaged, this double encoding can't happen -> harder for brain to sort which memories are important -> more memory loss (emotional memory) b/c can't connect emotion to context
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a function of hippocampus/hippocampi?
-convert short term to long term memory
-note: does not permanently store memories, memories are converted to cerebral cortex for long term storage
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What don't you loose when there is damage to hippocampus?
-don't lose previously formed memories
-don't lose procedural memory (Basal Ganglia and Cerebellum)= knowing how to do something
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The amygdala and the hippocampus are situated close to one another b/c ?
important emotional experiences need to be transferred to long term memory so that they can be recalled
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How is the thalamus a filter?
-sits on top of brainstem, deep in center of brain
-acts as a sensory way station for all incoming sensory info to relevant primary area of cerebral cortex so that it can be processed accordingly, unimportant info is filtered out, it does this for all sensory information except smell.
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Damage to thalamus?
- risk of coma ( x reactivate sensory awareness)
-can lead to sensory changes in a body part ( x know where to send sensory info e.g visual -> blindness)
-movement disorders, lack of movement ( inappropriate inefficient motor response to stimuli)
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main function and location of hypothalamus?
located= below the thalamus, on top of brainstem
function= maintenance of homeostasis, connects NS to endocrine system (hormones), controls hunger, sexuality, hormone regulation but not heart rate= controlled by brainstem
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Damage to hypothalamus
- x regulate homeostasis, hormonal disorder ( too much or too little of a specific hormone)
-damage to ventro medial hypothalamus= lose capacity to feel full= becomes obese
-damage to lateral hypothalamus= lose capacity to feel hungry= force fed or starve
-similar with thirst response
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location of cingulate gyrus
beneath cerebral cortex, above brainstem
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functions of cingulate gyrus
coordinates sensory input with emotions, emotional responses to pain, regulates aggressive behaviour, communication (links with Broca's area), maternal bonding, language expression (links with Broca's area), decision making
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Emotional and behavioral disorders linking to damage to cingulate gyrus include:
depression, anxiety disorders, obsessive compulsive disorders (OCD)
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Function and location of Basal Ganglia
-is a group of cells located deep in the frontal lobes
-organises habitual motor behaviour and procedural memories, complex motor skills
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What is an actional potential?
-electrical message that is sent down along the neuron
-firing neuron that is carried along axon
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How does CT work?
- a CT scanner emits a series of narrow beams through the human body as it moves through an arc
-the CT scanner's x-ray detector can see hundred of different levels of density, it can see tissues within a solid organ
-this data is transmitted to a computer, which builds up a 3D cross sectional picture of the part of the body and displays it on the screen.
-sometimes a contrast dye is used
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how is a CT different from an x-ray machine?
-this is different from an x-ray machine which sends one radiation beam. The CT scan produces a more detailed final picture than an X-ray machine
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What is a contrast dye?
injection, shows a little more brain tissue/ micro differences
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Advantages of CT
-provides clear and accurate images
-allows for comparison b/w 'normal' and 'abnormal' brains
-relatively non-invasive (just an injection=contrast dye which is not radioactive)
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Limits of CT
-only shows brain structure
-pregnant women can't use it b/c risk the radiation (x-rays) may cause damage to unborn child
-allergic reaction to contrast injection (rare)
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What energy source does a CT rely on?
radiation
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How does a PET scan work?
-Tracks blood flow by measuring the use of glucose (source of energy in 02) by neurons in the active area of the brain
-radioactive material (fluorodeoxyglucose: glucose -> sugar) is injected into the blood stream. This travels to brain and emits various levels of radioactive signals. These are detected and processed by the PET computer to produce PET scans.
-Different colours are used to indicate different levels of brain activity
-least to most activity: violet, blue, green, yellow and red
-more glucose= more activity e.g cancer cells are red
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Advantages of PET
-detailed colour-coded images of functioning of brain
-allows researcher to see how different areas of the brain function together for certain tasks
-colours make interpretation simple
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Limitations of PET
-requires injection of radioactive substance
-use of radio activity means that longitudinal studies are difficult and dangerous
-PET scans need 40 secs rest b/w each 30 sec scan thus it may miss rapid changes in brain function
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How does MRI work?
- uses strong magnetic fields and radio waves to generate signals from the body. These are picked up by a radio antenna and processed by a computer to create pictures of soft tissue inside of your body
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What is MRI useful for?
-diagnosing tumors, joint or spinal injuries or diseases, soft tissue injuries or diseases of internal organs e.g brain and heart
-it can show up problems in your veins and arteries w/o need for surgery
-useful for planning some treatments of some areas
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Advantages of MRI
-clearer and more detailed images than CT
-non-invasive
-no x-rays or radio activity involved
-very detailed pictures
-no x-ray radiation
-no pain
-can be used on pregnant women
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Limitations of MRI
-only shows structure and anatomy
-cannot be used on ppl with internal metallic devices
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How does a fMRI work?
detects changes in 02 levels and blood to show level of functioning of neurons to show brain function, colour changes indicate activity levels whilst performing a task
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advantages of fMRI scan
-little exposure to radiation
-detailed images of brain functioning
-combination of structure and function
-can be used on pregnant women
-can detect images in rapid succession, unlike PET scan
- can be applied to hemispheric specialisation studies
92
Limitations of fMRI
-same as MRI regarding metallic devices
-expensive and limited access
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What is the difference of structural and functional neuroimaging techniques?
structural= shows what brain looks like and damaged areas of the brain w/a functional= shows how brain works, which areas are most active during particular tasks
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In what way has neuroimaging advanced brain research compared with research that did not have access to this technology?
Before neuroimaging, to study the brain researchers had to wait until brain damage patients died before they could slice it open w/a now with neuroimaging techniques scientists are provided with vital info abt how brain works, normal and abnormal functioning and has led to treatment for specific brain disorders.
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Drugs
-Any substance (with the exception of food and water) which, when taken into the body, alters the body's function either physically and/or psychologically
-most work my changing functioning of neuron at synapse
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Psychoactive Drugs
these drugs affect the central nervous system and alter a person's mood, thinking and behavior.
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examples of psychoactive drugs
stimulants, depressants and hallucinogens
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4 groups of most common psychoactive drugs ( classified by how they affect synapse)
- depressants
- stimulants
- hallucinogens
- cannabis
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depressants
have an inhibitory factor which means they reduce the activity of the central nervous system.
-slows down reaction and strength of responses
-eventually lead to drowsiness sleep or sometimes death depends on dosage)
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examples of depressants
heroin and alcohol
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stimulants
exhibiotory which means increase the functioning of the CNS for a short-period of time
- most cases they have the capability to improve performance on many tasks and keep someone awake h/w lead to a cycle of arousal followed by depression in the time that the drug is wearing off.
- individual develop increased dependence +larger dosages
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examples of stimulants
cocaine and ice
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Hallocinogens
have the capability to produce perpetual and temporal distortions
- affect perception and thinking = pleasurable or upsetting/frightening
- lead to anti-social behavior
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examples of hallocinogens
magic mushrooms, cannabis hemp, LSD
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cannabis
has a variety of effects on people and does not fit neatly into any of the above categories because it can act as a stimulant, depressant and a hallucinogen
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when is a drug addictive
affects psychologically (thoughts) as a person has difficulty controlling how much of a drug is used and continued use despite negative consequences e.g can't stop drinking alcohol every morning
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when is a drug depended on
the substance dependence refers to the body's physiological (physical) reliance on a drug e.g pain medication/ alcohol before it becomes addictive
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homunculus, primary motor cortex
body parts with higher dexterity and complexity of movement ( capacity for motor control e.g face and hands) are enlarged b/c area of cortex devoted to them w/a body parts that are less dexterous (elbow, legs) are smaller b/c less area.
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What type of communication are neurotransmitters?
nt's are chemicals= chemical communication (b/w neurons)
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What type of communication is an action potential?
electrical b/c within the neuron
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What does synapse include?
synaptic gap, terminal buttons of presynaptic neuron and dendrite of post synaptic neuron
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How to most drugs work?
psychoactive drugs normally mimic or manipulate neurotransmitters e.g dopamine's and serotonin's, neural function is changed
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Why is dopamine important?
-release of small amounts of dopamine in the brain reinforces the body with pleasure so that behaviors are likely to occur in the future e.g hunger= less dopamine= eat= increase dopamine so body can get nutrients
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How is the mesolimbic dopamine pathway associated with addiction or dependance?
-drugs may come to command attention and take control of behavior
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how can drugs lead to dependance and addiction?
drug increases the levels of dopamine by stopping reabsorption into presynaptic neuron= builds up in synapse= constant state of euphoria and overstimulation= overtime decreased sensitivity to dopamine= normal activities don't provide enough dopamine the only rewarding thing is the drug, and indicates to the body that can receive dopamine from external sources thus reducing the production of dopamine= increase intake and overdose, withdrawal symptoms
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Importance of serotonin
happiness is associated with serotonin release, sadness= serotonin release is stopped
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difference between dopamine and serotonin release
dopamine= addictive, short term, visceral= it's felt in the body, too much leads to addiction
serotonin= not addictive, long term, ethereal=felt above the neck, think abt, psychological experience, too little leads to depression
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similarities between dopamine and serotonin
-both release in high levels through psychoactive drugs, both can lead to dependence and both are neurotransmitters
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drug: ecstasy
-causes release of serotonin, mimics structure of serotonin
-increase in alertness, sexual arousal, euphoria
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side effects of ecstasy use
-nausea, muscle cramping, fever, sweating, chills, tremors, hallucination, blurred vison, increase in BP, feeling faint
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overdose of ecstasy symptoms
- high BP, lightheadedness, panic attacks, seizures, loss of consciousness, extreme increase in body temp which may lead to organ damage, death by heart stroke or failure
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withdrawal symptoms
loss of appetite, depression, dilated pupils etc
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long term effect of ecstasy use
-may become unhappy and irritable
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What is homeostasis?
A state of balance among all the body systems needed for the body to survive and function correctly.
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What are neurohormones?
are chemicals synthesised in the neuron that are secreted directly into the blood stream (via capillaries- tiny blood vessels)
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Neurohormones vs Neurotransmitters part 1
-Neurohormones= secreted into the blood for transport to target cells w/a NT= secreted into the synaptic gap
-neurohormone messages travel more slowly w/a NT= messages travel faster
- neurohormones act on distant sites= only stimulate certain cells with certain receptor sites w/a NT= only focuses on adjacent target cells
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Adrenaline and Noradrenaline
-fight and flight response includes the release of two neurohormones= adrenaline and noradrenaline
-both work to increase activity of the individual to allow them to adapt and cope with the stressor
-both are released from a presynaptic neuron into the bloodstream so that they can have an affect on multiple organs and body systems
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Role of adrenaline
-enhances the consolidation of long term memories of emotionally arousing experiences e.g memories associated with fear= more likely remembered
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How adrenaline carries out its role?
-an emotionally arousing event stimulates the release of adrenaline which then induces the release of noradrenaline in the amygdala
-noradrenaline then activates the amygdala to signal the hippocampus t/f the emotionally arousing event will be more likely to be consolidated
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what occurs in the body when individual with insomnia can't sleep?
body is flooded with fight/flight stress chemical and adrenocorticotropic hormones (adrenaline) this leads to increase in HR, BP and puts body in a state of hyperarousal or hypervigilance
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What is Bright light therapy/ phototherapy?
-involves timed exposure of the eyes to intense but safe amounts of sunlight or artificial light e.g light box
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Essential factors of Bright light therapy?
-appropriate timing
-the right amount of light
-safe exposure
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appropriate timing and Bright light therapy
-must occur at the right time in order for the person to feel awake
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right amount of light and Bright light therapy
-light intensity and length of exposure should be built up gradually to avoid negative effects e.g headaches
-light intensity and length of exposure should be appropriate for the disorder and the desired changes to a person's circadian rhythm
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safe exposure and Bright light therapy
-should not look directly at light
-face should be adequate distance from the light
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what is a delayed sleep wake cycle/ disorder?
-is a biological shift causing a person to fall asleep later thus experiencing a delayed onset of sleep.
-This is often associated with adolescents where they may feel sleepy 1 to 2 hours later into the night. This results in sleeping longer into the following morning e.g only falling asleep at 11pm or 12am and if not waking up for school, they could sleep until 9 or 10am
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What is an advanced sleep wake cycle/ disorder ?
-is a biological shift causing a person to fall asleep earlier and t/f waking up earlier e.g falling asleep at 8pm and waking up at 3am
-often associated with old age= less total sleep required, more frequent awakenings and lighter sleep (more easily disrupted)
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When to expose light for delayed sleep wake disorder
-optimal time for light exposure is 9am as a result this shifts the sleep wake cycle forward/ earlier
-avoid bright evening light
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When to expose light for advanced sleep wake disorder
-optimal time is 6pm this shifts sleep wake cycle backward/ later
-avoid bright morning light
