Chapter 2 & 3 Flashcards
How much does an adult brain weigh?
3 lbs
blood-brain barrier
ensures that at vascular level, harmful substances cannot pass through membrane to harm brain
Meninges
3 membranes or layers that act as a protective, vascular web
3 layers of meninges
dura mater
arachnoid mater
pia mater
dura mater
“hard matter” like a heavy plastic covering
arachnoid mater
spider web-like layer that bridges the brain’s wrinkles and folds
pia mater
molds around every tiny crook and crevice on the brain’s surface
brainstem made up of
midbrain
pons
medulla
brainstem purpose
relays info into and out of the brain
central point for all incoming and outgoing info and basic life functions
medulla function
vital life functions
- breathing
- heart rate
- blood pressure
- swallowing
- vomiting
- sneezing
pons function
- facial movements & sensations
- hearing
- coordinating eye movements
- serves as bridge of nerve fibers connecting the cerebral cortex and cerebellum- can impact coordination and control of body movements
midbrain function
- seeing and hearing
- alertness and arousal
diencephalon made up of
thalamus
hypothalamus
diencephalon location
above midbrain
thalamus function
relay station for incoming and outgoing sensory info (except smell)
injury to thalamus can cause
- severe attention and concentraion issues
- memory and storage retrieval issues
- weakened mental stamina
- decreased sensory info
- decreased reactions to stress/emotional responses
- disorders in eating/drinking/sleeping/sexual functioning
hypothalamus function
control center for
- hunger
- thirst
- sexual response
- endocrine levels
- temperature regulation
- fight or flight reactions
- anger
- fatigue
- memory
- calmness
- emotional regulation
- connected to pituitary gland (release of hormones)
Limbic system made up of
hippocampus
basal ganglia
amygdala
Limbic system location
middle section of brain, sits on top of brainstem
Limbic system function
“mammalian brain”
contains elemental drives, emotions, and survival instincts
Damage to limbic system can cause
- uncontrollable /dysregulated emotions
- under/over reacting
- impulsivity
amygdala and hippocampus directly tied to what other system?
olfactory
3 parts of limbic system
hippocampus
amygdala
basal ganglia
hippocampus function
memory
facilitates encoding and storage of info in systematic manner that is typically associative
damage to hippocampus can cause
info not being processed in an organized manner
-difficulties with accurate storage and retrieval of info
amygdala function
- closely tied to emotional memories & reactions
- aggressive responses
- fight or flight response
- fears
- smell/taste memories
basal ganglia function
- handle physical movement
- relays info from cerebral cortex to brainstem and cerebellum
- on alert for when something is not working the way it should be
- responds to LOB
damage to basal ganglia can cause
- Parkinson’s symptoms
- slowness and loss of movement (akinesia)
- muscular rigidity
- tremor
cerebellum function
coordinates, modulates, and stores all body movement
- monitors impulses from motor and sensory centers (brainstem, basal ganglia, sensorimotor cortex) to help control direction, rate, force, and steadiness of a person’s movements
- proprioception
- eye hand coordination
- posture
- muscle tone
damage to cerebellum can cause impairments in
- coordination
- fine motor movements
- trajectory of movement
- balance
- proprioception
How much of the brain’s mass does the cerebellum account for
1/8th
Frontal lobe primary parts
primary motor cortex
prefrontal cortex
prefrontal cortex function
executive function emotional response to circumstances -goal-oriented behavior & motivation -short term/working memory -ability to learn from consequences
damage to prefrontal cortex can cause impairments in
executive function
ability to synthesize signals from the environment, assign priorities, make decisions, organize and prioritize, initiate, or inhibit actions
awareness of deficits
multitasking
antecedent-based behavior model
helping the person see the circumstances that usually precede behavior, rather than warning of consequences of a behavior
Parietal lobe function
primary sensory cortex
- respond to sensory information
- body awareness
damage to R parietal lobe can cause
may not recognize that anything is wrong with movement of L side of body
Occipital Lobe function
primary visual cortex- assembles a whole image from visual information
-allows person to recognize shape, position, size, etc of objects
Damage to occipital lobe can cause
visual-perceptual-motric distortions
Temporal lobe function
language and hearing
also involved in memory
Where is Broca’s area located
lower portion of motor cortex in L frontal-temporal lobe
Broca’s area function
production of speech
Wernicke’s area location
L temporal-parietal lobe
Wernicke’s area function
comprehension of language
Hearing pathway
outer ear
middle ear
inner ear
vibrate hair cells in organ of Corti inide cochlea
hair cells send signals through 8th CN to brainstem
how does damage to temporal lobe affect memory?
impairs system for understanding, storing, and retrieving new info
how many vertebrae in spinal cord
33
3 critical ligaments for spinal stability
anterior longitudinal ligament
posterior longitudinal ligament
ligamentum flavum
glial cells
non-communicating cells that support and nourish the neurons
reticular activating system location
brainstem
reticular activating system comprised of
nerve fibers and nuclei
reticular activating system function
modulates: arousal alertness concentration basic biological rhythms
CT imaging
X-ray beam to create a computerized image of brain in slices at a time
- captures images in a horizontal/axial plane
- will determine if there is hemorrhaging or blood clot forming
What type of imaging is the standard of care for BI?
CT
MRI imaging
provides greater anatomical detail and clarity compared to CT and more sensitive to displaying a variety of pathologies
DTI imaging
(diffusion tensor imaging)
- comes from MRI scan
- identifies major tracts/axon bundles in the brain
neuroprotective compound or strategy
limits neuronal death following injury and/or enhances recovery
are there any approved neuroprotective therapies for treatment of human BI?
no
only for stroke
tissue plasminogen activator
(tPA)
-a protein involved in breakdown of blood clots and approved for therapeutic use in stroke up to 3-4.5 hours after incident
Magnesium (Mg2+) benefits for BI
- increased antioxidants
- used for neuroprotection after TBI due to its roles in cellular respiration, protein synthesis, membrane stability, regulation of vascular tone, and pathophysiological processes following TBI
What happens to brain if Magnesium diffiency?
reduced antioxidant capacity of brain resulting in excessive production of free-radicals and mild inflammation
Progesterone function
decreases cerebral edema
what level of progesterone dose showed greatest level of improvement on reference memory task?
low
Nicotinimide function
(vitamin B3)
- reduce injury volume
- decrease glial activiation
- reduce BBB breaches
- reduce edema
window for Vitamin B3 treatment post TBI
6-24 hours depending on task and treatment regimen
Plasticity definition
change in the expression of genes or proteins related to neuroplasticity
long term potentiation (LTP)
strengthening of neural connections
long term depression (LDP)
weakening of neural connections
exitotoxicity
occurs when a neuron cannot maintain its resting potential, resulting in its repeated firing. This creates toxic levels of sodium and calcium ions, leading to cell death
Transcranial magnetic stimulation (TMS)
non-invasive method of stimulating the brain using electromagnetic induction. It is used for treatment of stroke, depression, migranes, dystonia, tinnitus, and Parkinson’s disease
Best treatment strategy for BI
combination of neuroprotection and neuroplasticity
