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The Nervous System Part 2

Terms in this set (86)

4 regions of the brian
cerebrum, diencephalon, brain stem, cerebellum
cerebrum
largest of four main areas of brain; divided into right and left hemispheres; encloses diencephalon and most of the brain stem; humans have the most developed cerebrum
surface of cerebrum
cerebral cortex
ridges of cerebral cortex
gyri
grooves of cerebral cortex
sulci
gray matter
outermost layer (cerebral cortex); composed mostly of unmyelinated cell bodies (where processing occurs)
white matter
myelinated axons inside they gray matter; mainly for transportation of signals
fissures
deeper grooves that separate large regions of the brian
longitudinal fissure
deep groove separating the cerebral hemispheres
corpus callosum
large collection of axons connecting the cerebral hemispheres
4 lobes of the cerebral hemisphere
frontal, parietal, temporal, occipital
frontal lobe
involved in higher thinking, emotions, speech and movement
parietal lobe
processes sensations of touch tempereture, pain, and taste
temporal lobe
involved with hearing, smelling, and memory
occipital
deals with vision
special areas of the cerebrum
prefrontal cortex, broca's area, primary motor cortex, somatosensory cortex, amygdala, hippocampus
prefrontal cortex
anterior part of the frontal lobe that is involved in personality expression, making complex decisions, and moderating social behavior
broca's area
region in frontal lobe of one hemisphere (usually left) with functions linked to speech roduction
primary motor cortex
strip of frontal lobes that allows one to consciously move the skeletal muscles; pathways are crossed so that each side of the body is controlled by opposite hemisphere (decussation)
somatosensory cortex
strip of parietal lobes that receives and interprets info from sensory receptors that detect pressure, temperature, and pain
amygdala
almond-shaped set of neurons deep in the temporal lobe; linked to fear responses, pleasure, aggression and storage of memories associated with emotion
hippocampus
seahorse shaped structure deep in the temporal lobe ; plays critical role in consolidating info from short term memory to long term memory and with spatial navigation
diencephalon
consists of thalamus and hypothalamus; sits on top of brain stem and enclosed by the cerebral hemispheres
thalamus
relay station for sensory impulses that transfers impulses to correct part of cortex
hypothalamus
helps regulate body temperature, water balance, and metabolism; regulates the pituitary gland (master gland of the endocrine system)
structures near the diencephalon
choroid plexus and pineal body
pineal body
gland that produces the sleep hormone melatonin
choroid plexus
structure that forms the cerebrospinal fluid
brain stem
attaches to diencephalon and spinal cord; mostly contains bundles of axons but also houses reflex centers for many critical life functions; made of midbrain, pons and medulla oblongata; most important in critical life functions
midbrain
contains interneurons of reflex arcs for vision and hearing
pons
contains interneurons of reflex arcs involved in breathing control
medulla oblongata
contains interneurons of reflex arcs involved in heart rate control, blood pressure regulation, swallowing, vomiting, and breathing
cerebellum
concerned with coordination of voluntary muscle activity and balance; made up of two convoluted (wrinkly) surfaces; assists in coordination of skeletal muscle activity; critical for balance, equilibrium, and precise movement
where is most of brains energy devoted/
maintaining electrical resting potentials
an adult brain accounts for __ percent of the bodys mass but consumes ___ percent of glucose burned
2; 20
a child brain uses what percentage of daily glucose burned?
50
an infant brain uses what percentage of daily glucose burned?
60
the invention of what gave humans a great evolutionary advantage?
cooking
how much of the brain should be used at any given moment?
1 to 16%
how does cooking provide more energy than raw foods?
soft and denatures proteins so theyre more easily absorbed
what does sparse coding of nerve impulses imply?
small number of signals can carry a lot of info
why is multitasking inefficient?
selective attention - we dont have energy to do so
short term memory
stored for anywhere from a few seconds to up to a few minute; typically most effective for seven or less items (frontal lobe)
long term memory
hippocampus transfers memory to cortex for permanent storage (consolidation); info relating te events w strong emotional or sensory associations; info recalled periodically / repeated many times especially over time
declarative memory
"knowing that"; remembering names dates and facts
procedural memory
"knowing how"; (riding a bike or signing your name)
HM suffered what when skull cracked
seizures and blackouts and loss of control of bodily functions
after hippocampus was removed, what stayed the same?
his personality
what did Brenda Milner prove
long term and short term memories are stored in different brain areas
Milner found that HMs unconscious motor centers remembered what?
his conscious mind forgot
dementia
general term for a decline in mental ability severe enough to interfere with daily life; caused by physical changes in the brain;memory loss, impaired communication and language skills,inability to focus, impaired judgement, impaired visual perception
alzheimers disease
most common type of dementia (60-80% of cases)
alzheimers brain changes
beta-amyloid plaque deposits, tangled strands of the tav protein; nerve cell damage death in the brain
spinal cord
2 way conduction pathway that links the brain to the torso, arms,and legs, and also acts as a major reflex center
physical structure o spinal cord
extends from medulla oblongata to just below the bottom rib, 16-18 inches ; shaped like flattened cylinder diameter of ur thumb; 31 pairs of spinal nerves connect to skin, uscles, etc. in limbs, chest and abdomen
cauda equina
collection of spinal nerves at the end of the spinal cord; horse tail
what is the center of the spinal cord made of?
grey matter (cell bodies)
what is the external part of spinal cord made of?
white matter (myelinated axons)
central canal
hole in middle of grey mater where cerebrospinal fluid flows
relfex
rapid involuntary predictable response to stimulus
spinal reflexes
involve nerve pathways that connect through the spinal cord without relaying signals to the brain
incomplete spinal cord injury
leads to loss of some movement and sensation below the injury
complete spinal cord injury
paralysis below the level of injury
quariplegia
high spinal cord injury- all 4 limbs paralyzed
paraplegia
lower spinal cord injury - only legs paralyzed
spinabifida
birth defect where the bones of the spine dont completely form , causing the spinal cord and meninges to stick out of the childs back
how many pairs of cranial nerves connect directly to the brain?
12
olfactory nerve
relays info about smells from nose to temporal lobe (sensory)
optic nerve
relay visual info from retina of eye to visual cortex of occipital lobe (sensory)
vestibular cochlear nerve
relays info concerning hearing and balance from inner ear to brain (sensory)
facial nerve
delivers motor signals to facial muscles (motor)
the cns has a protective system that consists of?
meninges, cerebrospinal fluid, blood-brain barrier, and bone
meninges
3 layers of connective tissue membranes that cover and protect the brain and spinal cord
pia mater
delicate layer that lies directly over brain and spinal cord
arachnoid mater
middle layer; looks like a spider web; cerebrospinal fluid flows in the "subarachnoid space" between pia mater and arachnoid mater
dura mater
outermost and toughest layer
meningitis
inflammation of meninges due to infection
cerebrospinal fluid
clear liquid made of water and nutrients that forms a watery cushion to protect the brain and spinal cord ; formed by choroid plexus and replaced every 8 hours
spinal tap / lumbar puncture
procedure used to remove a sample of CSF by inserting a hollow needle between two lumbar vertebrae (used to diagnose disorders , infections, cancers, etc)
how much of the bodys blood does the brain use?
20 percent
where do the blood vessels extend from?
carotid and vertebral arteries
incidents that cause blood flow to the brain to stop causing oxygen deprivation and brain damage
stroke, cerebrovascular accident, brain attack
ishemic stroke
blocked blood vessel
hemorrhagic stroke
burst blood vessel (produced by brain anyrism)
blood brain barrier
network of cells that surrounds the blood vessels that prevents many potentially harmful substances from passing into the brain or spinal cord
what does blood brain barrier not stop?
respiratory gases (oxygen, carbon dioxide), nutrients: proteins & glucose), water, and psychoactive drugs
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