Nervous system and Diseases I Flashcards
Define neurological disorders
condition in the central/peripheral NS that affects its functioning
- brain, spinal cord or nerves
- structural, biochemical or electrical abnormalities
Neurological disorders causes
genes
environment
bacterial or viral infection
traumatic injuries or accidents
How many known neurological disorders are there?
> 600
What are the four main categories of neurological disorders?
sudden onset
intermittent and unpredictable
progressive
stable with changing needs
Sudden onset examples
stroke, traumatic brain injury, spinal injury, meningitis
Intermittent and Unpredictable Examples
epilepsy and migraine
Progressive Examples
parkinsons, dementia, motor neuron disease
Stable with changing needs examples
tourettes, narcolepsy, cerebral palsy
Rate of people with neurological disorders
1/6
What does mental health conditions cause?
significant distress or impairment of personal functioning
What is mental health conditions characterised by?
by a combination of abnormal thoughts, perceptions, emotions, mood, behaviour and relationships with others
Direct cost of mental health in Europe
all costs that are completely attribute to the use of a heath care intervention or illness
Direct medical cost of mental health in Europe
- value of resources used in treatment , care and rehabilitation of a patient
- medication
- consumable eg. needles, cannulas
- staff costs
Direct non-medical cost of mental health in Europe
- transport
- caregiver time
- equipment maintance
- insurance
- heating and lighting
Indirect cost
value of economics resources lost because of disease-related disability or premature mortality
Economic burden of brain disorders
high
What does the central nervous system comprise of?
brain and spinal cord
Function of Nervous System
sensory - direct internal and external stimuli
integration - process information and make decisions
motor - effect an appropriate response
Neurons Structure
- dendrites, cell body, axon
- form complex networks
What do neurons do?
- electrical excitability
-> convert stimuli into an action potential
-> action potential propagates along the axon
- most are unable to undergo mitotic divisions
Glial Cells - astrocytes
protoplasmic
- short branching processes found in grey matter
fibrous
- long unbranched processes found in white matter
Astrocytes protoplasmic
short branching processes found in grey matter
Astrocytes fibrous
long unbranched processes found in white matter
Astrocytes
A subtype of glial cells that make up the majority of cells in the human central nervous system (CNS)
What allows astrocytes to support neurons?
microfilament structure
What does Astrocytes do?
maintain appropriate chemical environment for generation of nerve impulses
may play a role in learning and memory
-> influence formation of neural synapses
Microglia
phagocytes
remove cellular debris, microbes and damaged nervous tissue
Oligodendrocytes
form and maintain myeline sheath around CNS axon
insulates axons and increase speed of nerve impulse condition
Myelin sheath
multilayered lipid and protein covering
Blood brain barrier (BBB)
tight junction - seal together endothelial cells of brain blood capillaries
thick basement membrane that surrounds capillaries
restricts access for substances in blood to enter brain
Blood brain barrier transport
- diffusion
- facilitated transport
- slow or no transport
BBB- diffusion
- lipid-soluble substance
CO2, O2, steroid hormones, alcohol, nicotine, caffeine - water
BBB - facilitated transport
- a few water-soluble substance such as glucose
BBB- slow or no transport
- ions very slowly
- proteins and most antibiotics do not cross BBB
What are the two protection mechanisms of Cerebrospinal Fluid (CSF)?
mechanical protection
chemical protection
Mechanical protection of CSF
shock-absorbing medium to protect brain and spinal cord
Chemical protection of CSF
optimal chemical environment for neuronal signalling
(action potentials and postsynaptic potentials)
CSF Circualtion
allows exchange of nutrients and waste products between blood and adjacent nervous tissues
Cerebrum
seat of intelligence
- outer cerebral cortex - grey matter
- cerebral white matter
What does the Cerebral Cortex Consist of?
Frontal lobes
Temporal lobes
Parietal lobes
Occipital lobes
Frontal Lobe
higher cognitive functions
- decision-making, conscious thought, control of emotion and behaviour, language production
Temporal Lobe
memory, hearing, emotion and some aspects of language
Parietal Lobe
Intergrating sensory information and movement co-ordination
Occipital lobes
visual processing
What are the parts of the midbrain?
Superior colliculi
Inferior colliculi
Substantia nigra
Superior colliculi
coordinate movements of head, eyes and trunk in response to visual stimuli
Inferior colliculi
coordinate movements of head, eyes and trunk in response to auditory stimuli
Substantia nigra
dopaminergic nucleus which has a critical role in modulating motor movement and reward functions
What are the parts of the basal ganglia?
deep cerebral nuclei
Basal ganglia function
motor function
- initiation, coordination of movement, posture, tone
cognition, precipitation and emotional behaviours - including reward system
Parts of the brainstem
Pons
Medulla Oblongata
Pons
- relay signals from motor areas of cerebral cortex to cerebellum
- respiratory regulations
Medulla Oblongata - Cardiovascular
regulates heart beat and blood vessel diameter
Medulla Oblongata - Respiratory
regulates breathing
Medulla Oblongata - Reticular formation
consciousness and arousal
Cerebellum
co-ordinates skilled movement
regulates posture and balance
evaluates how well movements initiated by motor areas in the cerebrum are actually being carried out
feedback to motor areas of cerebral cortex
damage to cerebellum can result in ATAXIA
loss of ability to coordinate muscular movement
abnormal walking movement - altered speech
Hypothalamus
controls and integrates activities of autonomic nervous system
hormone production eg. oxytocin and antidiuretic (ADH)
regulates emotional and behavioural patterns
feeding and satiety centres
thirst centres
suprachiamastic nuclei (SCN)
Regulation of body temperature
Thalamus
relays sensory information to cerebral cortex
Role of Thalamus
motor function
- transmits info from cerebellum and basal nuclei to motor area or cerebral cortex
role in maintain consciousness
What does the limbic system control?
emotion, behaviour, long-term memory and olfaction
What are the components of the limbic system?
cortical areas
- limbic lobe - frontal and temporal
subcortical areas
- amygdala, hippocampus
some thalamic nuclei
some hypothalamic neclei
Why is the limbic system unique to mammals?
species preservation
- reproduction, instinctive behaviour
self-preservation
- feeding behaviour, aggression
expression of fear
motivation
emotions
learning and memory
Dopamine
substantia nigra, ventral tegmental area and hypothalamus
excitatory, inhibitory and modulatory
reward, addiction, motivation and motor control
Serotonin
inhibitory NT
Role- mood, emotion, appetite and digestion
Precursor to melatonin - sleep
balances out excessive excitaroy NT effects
GABA
gamma-aminobutyric aicd
primary inhibitory NT
regulate anxiety, vision and motor control
low levels can cause irritability and anxiety
Glutamate
most abundent NT in CNS
excitatory NT
cognitive functions, memory and learning
Adrenaline/Noradrenalin
excitatory NT - sympathetic nervous system
hormone
produced in adrenal glands
stress réponse
