Chapter 2 - The Nervous System Flashcards
2 aspects of nervous system
CNS and PNS - central and peripheral nervous system
purpose of brain
control peripheral nervous system + move body
CNS
brain and spinal cord - spinal cord is encased by vertebrae
PNS
neurons and nerve processes outside CNS - ie. sensory connections to receptors in the skin, motor connections to body muscles, sensory and motor connections to internal body organs and gut
afferent signals
body into CNS
ex: sensory receptors
at the brain
efferent signals
exit the CNS
motor signals
efferent aka exit
sensory endings
distinguish between different sensations - pain, head, etc.
divisions of nervous system
cns and pns
division of cns
brain and spinal cord
division of pns
somatic nervous system, autonomic nervous system, enteric nervous system
somatic nervous system
- conscious
- transmits sensation and motor movements
autonomic nervous system
autopilot
work without conscious decision
enteric nervous system
digestive system
enteric nervous system
stomach and intestines
signals to the brain via vagus nerve
affected by stress and anxiety
impacted by psychobiotics
vagus nerve
one of the cranial nerve
psychobiotics
target enteric system to reduce stress and anxiety
system is lined with a lot of neurons - effected by state of mind
live organisms calm enteric system which affects brain
nerves in somatic nervous system
cranial nerves and spinal nerves
cranial nerves
around the head/neck - allow face, sensation movement, seeing and hearing
spinal nerves
travel down the spinal cord - allow feeling and sensation
division of autonomic nervous system
sympathetic and parasympathetic
sympathetic divison
arousing - gets you stressed - flight or fight
parasympathetic division
calming down
how many pairs of cranial nerves
12
olfactory nerve
small and goes to olfactory bulb
optic nerve
eye and goes to optic chiasm
facial nerve
face movement + taste at the front of mouth
vagues nerve
internal organs + keeps tabs on how it’s functioning
migrane
most intense and painful type of headache
can last between 4 to 74 hours
photofobia and phonofobia
caused by trigeminal nerve
10% suffer
trigeminal nerve
around eyes and head
dermatomes
section of the spinal nerves
c3-s5
allows signals coming in and those being sent out
paraplegia
damage to t1 and below
limited feeling in arms and will not be able to breathe
no functionof legs
quadriplegia
injuring spinal nerve c1 to c8
loses function of arms legs digestive system and unable to breathe
worst spinal injury
c1 and c2
cervical nerves
c1 - c8
head and neck and lungs
thoracic nerves
t1-t12
chest and bsvk
lumbar nerves
l1-l5
damage = no control over legs
no control over bowels or urine
sacral nerves
s1-s5
bottom of legs
and arms
damage = lost feeling in arms and some in legs
reflex
some sensations don’t require brain
spinal cord
transmits sensory and pain signals to the brain
transmits motor signals to extremites
relay for spinal reflexes
health brain
85 billion neurons and equal # of gilial cells
gyrus
high points and hill of the groove
sulcus
low points + the groove itself
fissure
particularly deep sulcus
the one going the length of the brain
longitude node fissure
the fissure that goes the length of the brain
dorsal
top
ventral
bottom
medial
towards middle of brain
lateral
away from the brain towards surface
anterior
front
posterior
back
anatomical orientation
coronal, horizontal, saggital
coronal
front view - cut the brain in half short wise
horizontal
dorsal view - cut the brain like ur cutting the top of a cake
sagittal
cut the brain in half length wise - medial view
cerebral hemispheres
two specialized halves connected by the corpus callosum
franz gall
brain is where the mind is at
different parts = different aspects of personality
larger region = more parts of personality
early attempt to understand how the brain works
temporal lobe
auditory processing, langauge and memory, taste and smell, hearing and processing and understanding language
frontal lobe
planning, organizing, impulse, and motor control - executive function
parietal lobe
touch and spatial awareness - movement and motor control
occipital lobe
visual processing,
cerebellum
motor coordination and control
meninges
the three layers that protect the brain and spinal cord
duramater
outer layer - tough paper substance but flexible
subarachnoid space
carries cerebral spinal fluid
pia mater
clear outer covering - closest to brain
vesicles
filled with cerebrospinal fluid and secretes it into the spinal cord
white matter of ventricles
because of myelin - signals are being sent out
grey matter
more cell bodies and less signals
cerebrospinal fluid
brain is encased - protects it from shaking
waste removal
immune response role
constantly produced absorbed
choroid plexus
lining of ventricles produce the fluid
hydrocephalus
overproduction or cerebrospinal fluid is not absorbed - creates pressure on brain
blood and brain
arteries and vessels carrying blood to diff parts of brain - different nutrients within blood to find its way into brain cells
blood and brain
arteries and vessels carry blood so it doesn’t touch brain cells - provides oxygen to brain
ischemic stroke
blockage of blood - isn’t providing oxygen - blood cells could die
hemorrhagic stroke
blood bleeds into brain usually cus of artery bursting - could be fatal
forebrain (cortex)
responsible for most complex behaviours
planning, listening, unique factors, higher cognitive functioning
brainstem
source of behaviour in simpler animals and responsible for most of our unconscious behaviours - simple breathing and functioning of organs - keeping you alive
brainstem characteristics
begins where spinal cord enters the skull
recieves afferent signals coming from senses and sends efferent signals to control movement
3 regions
3 regions of the brainstem
- hindbrain - bottom
- midbrain - middle
- diencephalon - top
hindbrain
involved in diff cycles of sleep
bridge from cerebellum to diff parts of brain
made of 3 diff parts
parts of hindbrain
pons and reticular formation
medulla
cerebellum
pons and reticular formation
send signals for being alert - wake you up
medulla
controls heartbeat and heart rate
cerebellum
involved in motor control and coordination
cerebellum
bigger size = fine coordinated movements
cerebellum in humans
takes up 10% of the brain
posterior medial
makes up 80% of total neurons
doesn’t contain a lot of gilial cells
midbrain
made up of 4 parts - tectum, tegmentum, substantia nigra, PGM
tectum
roof of the midbrain
2 main parts of tectum
superior colliculus
recieves visual input in the tectum and midbrain - coordinates eye movement
inferior colliculus
recieves auditory input - is involved in locationg sounds and identifying where a sound comes from
tegmentum
means floor
below tectum
substantia nigra
has black cells - controls movement and chemical signals in the brain - parkinsons if damaged
periaqueductal gray matter
involved in panperception
sends signals down spinal cord
in animals - can eliminate pain
superior and inferior colliculus
sound and vision in a unified sense - intergration
diencephalon
top of brainstem
includes 3 structures
thalamus
dead center, sensory hub, organizing stimuli, signals from body and brain pass through here
hypothalamus
releasing hormanes into bloodstream and sending commands to pituatiry gland
parts of midbrain
tectum tegmentum substantia nigra and pgm
parts of hindbrain
pons and reticular formation, medulla, and cerebellum
parts of diencephalon
thalamus, hypothalamus, and pituitary gland
pituitary gland
releases hormones based on the command of hypothalamus
subortical strctures of forebrain
basal ganglia, amygdala, and hippocampus
basal ganglia
movement and coordination
basic habits and repeated behaviours may form the walls of certain centricles
OCD
limbic system
amygdala and hippocampus
amygdala
allows us to express emotional experiences
hippocampus
long term memories
very sensitive structure
allows us to process fearful experiences
alzeimers
neocortex
outer part of brain
neucortex function
high level of cognitive functioning
how many layers in neocortex
6
two parts of neocortex
motor and sensory cortex
what makes us smart
forebrain - higher cognitive functioning
what do we have that other animals dont in their brain
grooves and fold - increase surface area of gray matter - higher functioning
why is brain size not the best measurement for intelligence
animal might have a big brain cus it has a big body - not because it is smarter
best measurement for intelligence
number of neurons - humans have most
evidence against using number of cortical neurons as a measure of intelligence
dolphine has comparble number of neurons in humans
long finned pilot whale has double the number of neurons that we do
developmental brain damage reduces numer of cortical neurons
developmental brain damage reduces numer of cortical neurons examples
hemispherectomy - people with one hemisphere and cerebellum - can lead normal lives
microcephaly - reduces frotnal lobe - less developed - serious to mild condition - could have normal intelligence
if number of neurons isnt the answer to intelligence what is
neural tissue has the capacity to adapt to the world by changing how its functions are organized - neuroplasticity
flynns effect
iq in humans have steadily risen in the 20th century - people are undergoing education, knowledge experience - neuroplasticity through experience
speech and comm related areas in primate
are ready at birth to recieve info - including extrapolating to reading
exaptation
a new brain region takes on specialization even though it was never meant to do that in the first place
which two areas develop for reading
hippocampus and visual word form area
hippocampus and reading
new memory stoarge
respond to spatial info
GPS location and autobiographical
visual word form area
area starts to engage new pathways for reading when someone starts to read - meant for visual recogniton
