neuro system Flashcards
snervous system
-co-ordinated actions/interpret sensory by transmitting signals to the body
endocrine system
-system of glands that produce hormones (chemical messages)
-regulate processes
nervous system two main divisions
-central nervous system
-peripheral nervous system
central nervous systems
-brain
-spinal cord
peripheral nervous system
-sensory nerves (intake info)
-motornerves (out put info)
*provides connections between CNS and rest of the body
sensory nerves
(IN)
-picks up sensory stimuli
-sight, hearing, smell, touch
motor nerves
-dierctions from brain to muscles and glands (OUT)
somatic nervous system
under voluntary control, assosciate with skeletal muscle
sensory + motor nerves
ligament movement, winking, walking
autonomic nervous system
involuntary control, body processes
-heart rate, blood pressure, breathing, digestion, arousal
divisions of the autonomic nervous system
-sympathetic nervous system
-parasympathetic nervous system
divisions of the peripheral nervous system
-somatic
-autonomic
-sympathetic nervous system
prepare the body “for stress”
-increases organ activity
-adrenaline
parasympathetic nervous system
returns body to “normal”
-bringing you back down
-decreases organ activity
-digestion
nervous systems –>
central and peripheral
peripheral system –>
somatic and autonomic
autonomic system –>
sympathetic and parasympathetic
support cell
-neuroglin
-structural/metabolism support
neurons
transmit electrical signal throughout
neurons
transmit electrical signal throughout
-structural and functional unit of the nervous system
parts of a neuron
-cell body (soma)
-nucleus
-dendrites
-axon
-myelin sheath
-nodes of ranvier
-axon terminal
dendrites
one or more projections of the cytoplasm
-conduct impulses from specialized receptors/other nerve cells
axon
long cytoplasmic extension from soma
-conducts impulses from soma to other nerves
-can extend to 1m in length
-very thin
myelin sheath
protects neuron and conducts impulses faster
-fatty protein
-insulator/speeds up nerve
-made up of schwann cells wrapped around axons
nodes of ranvier
area between sections of myelin
-exposes the neuron membrane to external enviroment
-jumps from node to node (speeding up)
axon to terminal
carry nerve impulses from axon to end of nerve cell
-release neurotransmitter to pass message onto next neuron
myelinated axons
-all neurons in peripheral nervous system
-white matter in central nervous system
-myelinated by oligodrocytes
unmyelinated axons
no myelin sheath
-grey matter in central nervous system
conductivity in regards to the axon (size)
the larger the diamter of the axon, the faster the impulse
-faster in myelinated axons
-depolarized at nodes of ranvier
saitatory conduction
current from one node to node
difference between white and grey matter
-only white matter can regenerate at all
-grey matter cannot regenerate, any damage is permanent
three types of neurons based function
-sensory neurons
-interneurons
-motorneurons
sensory neurons
IN
-afferent
-transmit info about enviroment
-realy infor from sensory nodes
-longer dendrites, shorter axons
-involves senses
interneurons
MIDDLE
-link neurons in the body by carrying impulses
-completely within central nervous system
-INTEGRATE AND INETRPERATE sensory info, connect to outgoing
motorneurons
EXIT
-relay info from central nervous system, then causes things to happen
-longer axon shorter dendrites
-cell body in central nervous system
two different neural circuits
-sensory neurons to brain to effector neuron
-reflex arc, no brain (automatic)
membrane potentials
difference in charge
higher charge = higher voltage
sodium potassium pump
-creates polarized
-2 potassium in, 3 sodium out
-neuron is negative, outside is positive
oscilloscope
measures membrane differences
neuron resting potential
sodium wants in, potassium wants out
-negative chagre
-membrane is polarized
action potential
neurons become active/excited by a stimulus
- brief depolarize to trigger channels to open
three parts to an impulse
-polarized impulse
-depolarized membrane
-repolarization
polarized impulse
-resting cell
-more sodium outside and potassium inside
due to NA/K pump and diffusion potential
depolarized
-channels open, sodium in
-cell becomes positive
-action potential
repolarization
channel pushes out potassium to rebalance
-prepares cell for new AP
refractory period
time needed to become repolarized
-membrane is not responsive to another stimulus
threshold
intensity of stimulus needed to produce an action potential
-must be strong enought o depolarize the entire membrane
ALL OR NOTHING
stimulus strenght determined
by number of an action potential or frequency of impulses
transmission
strength of stimulus remains constant as it travels along axon
hyperpolarization
voltage drops too far turns on SPP to rebalance
-harder to achieve AP
neural fatigue
occurs when all the NA is inside and all the K is outside
direction of transmission -muscle
action potential moves from middle to end
direction of transmission -nerve
action potential initiates at one end and moves in direction to the other end
(down the axon)
the synapse
junction between two neurons
-or between neuron and effector
presynaptic neuron
sending the signal
-sends through axon terminal
postsynaptic neuron
receiving cell
-dendrite
-brings on energy potential
steps of synaptic transmission
- AP rrives at end of fibre
2.Ca ions into neuron
3.vesicle ruptures and release NTs in exocytosis - NTs diffuse to post neuron
5.NT attaches to recptor
6.Na gushes into fibre
7.enzymes break down NTs
8.neurotransmitter receptor bond is broken
9.NT pieces reabsorbed
10.fibre repolarizes
inhibitory neuron
causes inhibitory neuron potential
-hyperpolarized
-more difficult for threshold
-opens K channel
excitatory neuron
cause excitatory synaptic potential
-depolarized
-easier to threshold
-opens Na channels
brain and spinal cord
relay centre communicating with the rest of the body
cerebrial spinal fluid
fills ventricles and surrounds brain
-shock absorber
medulla oblongata
most inferior part of brainstem
-controls autonomic NS muscle activity
-cardiac center
-vasomotor center
-respatory center
-vital reflexes
pons
bridge between spinal and brain
-conductive nerve tracks
-arousal
cerebellum
11% of brain mass, controls motor coordinations and balance
-2 hemispheres
-uses info from sense receptors, for timing of skeletal patterns
-subconscious
midbrain
top most inner part of the brain
-sensory infor fromm ears
-area of high melanin/dark color
-termaton, arousal of the whole brain
thalamus
-sensory info converges, all senses
-pain receptors/consciousness
hypothalamus
-brainstem cap
-controls homeostasis in the body
-cordinator of autonomic NS
-influences hunger/sex/behavior/emotions
cerebrum
outer/inner : grey matter
middle : white matter
-voluntary muscle control
-intelligence, memory, info storage/synapsis
frontal lobe
-personnality
-intellect
-speech
contains Brocas area
-decision making and rational thought
brocas area
-speech
-volunatry muscles
-motor cortex
temporal lobe
-auditory + visual memory/interpretation
-hearing and smell
-judgement, periperal
-wernickes area
wernickes area
-speech understanding
motor cortex
genereates signals to direct movements of the body
sensory cortex
processes somatic sensations
parietal lobe
top mid portion of the brain
-sensory
-senses
-temperature
-emotions
occipital lobe
-vision (bilateral vision)
left side of the brain
-artistic, hollistic
controls RIGHT SIDE of the brain
right side of the brain
-analytical, linear
controls LEFT SIDE of the brain
corpus callosum
connection between L/R hemispheres
spinal cord
links brain to the nervous system
-reflex actions
-sympathetic/parasympathetic
outer of the spinal cord
myelinated interneurons white
inner of the spinal cord
unmyleinated interneurons grey
protection within the brain and spinal cord
brain - skull
spinal cord - vertebrae
both - meninges
meninges
protects the brain and spinal cord
-three membranes (three layers)
dura mater
very outside of the meninges
-durable
orachnoid mater
middle layer of the meninges
-thin, weblike
pla mater
inner layer of the meninges
-delicate, highly vascularized (blood vessels)
meningitis
inflammation of meninges
-bacteria into the brain
cerebral spinal fluid
floats the brain, prevents from crushing itself
-nurishful
-shock absorber
where is cerebral spinal fluid found
imbetween pla and orachnoid meninges
blood brain barrier
seperate blood borne substances (like chemicals) from space/neurons
-selective (still lets oxygen in and out)
-less present in some areas of the brain
ventral root
nerve track, that carries infor away from spinal cord
MOTOR
dorsal root
nerve track, that carries infor into spinal cord
SENSORY
somatic nervous system
neurons connect to skeletal muscle
somatic means BODY
neuromuscular junction
release of ACN will depolarize the muscle fiber membrane
-muscle contraction
autonomatic nervous system originates from
spinal nerves and cranial nerves
spinal nerves
exit of spinal cord at thoraic/lumber/sacral areas
cranial nerves
directly from brain
autonomatic nervous system
involuntary regulation of
-gastrol intestianol
-excretory
-respiration
maintains homeostasis
sympathetic nervous system has nerves from
thoratic and lumbar spine
-comes together as ganglia
-branches out nerves to organs
preglanglionic nerve
releases acetylcholine
acetylcholine
neurotransmitter
- contracts smooth muscles
-dilates blood vessels,
-increases bodily secretions
-slows heart rate
postganglionic nerve
releases norepinephrine
norepinephrine
neurotransmitter
-increase heart rate
-arousal
-attention
parasympathetic nervous system nerves come from
cervical and sacral regions
-longer strands to ganglia
thoratic
upper/middle spine
lumber
lower spine
cervical
neck region spine
sacral
very low spine, near hip bones
sensory neurons
conver stimulus to electrical signals
SENSATION
-specific to one type of sitmulus
generator potential
potential will determine strength of stimulus
high potential, high stimulus
mechanoreceptor
detect changes in pressure
-touch
propriocepter
detects muscle orientation
-upsidown
chemoreceptor
detects chemicals or molecules
-smell/taste
thermoreceptor
detects change in temperature
-usually hot
photoreceptor
detects changes in light
-and different lightings
merkel disks
on roots of hair follicles
-detects movement (brushing by)
meissner corpuscle
senses touch
pacinian corpuscle
senses pressure
-how hard
krause and bulb
temperature detector in skin
-cold
nociceptor
senses pain
-severed nerve
-no ending
skin baro and thermo receptors
-temperature
-concentration depends on location
larger the difference in tempature the more noticeable
neurotransmitter
signaling molecule secreted by a neuron to affected another cell across a synapse
synape
space between two cells
-spot of communication
baroreceptors
detect blood pressure
-autonomic
how is a smell receptor triggered?
chemicals in the air dissolve into mucus, stimulate receptors
-odor molecules attach to recptor
-axon depolarizes
-message received to brain
where is smell receptor information sent?
olfactory lobe in cerebrum
how are taste receptors triggered?
dissolved food chemicals stimulate tastebuds
-taste is 3/4 your sense of smell
receptor hair cells
taste receptor
-intiates action potential
where is taste receptor information sent?
parietal lobe
sensory adaptation
odor fades after a period of time
-receptor is used to a stimulus
what does it mean by “our brain filters out white noise”
the brain will not notice things if they are occuring constantly, it filters out these things so we can focus on more “important” stimuli
stretch receptor
stretching and contraction stimulates receptors
support cell
provide support nutrition, insulation, signal
schwann cell
insulator cell
amitotic
once they take on role, cannot divide
voltage
measure of potential energy
purpuse of membrane
seperating charges which creates POTENTIAL
ion channel
ions move across membrane to even out charge
-homeostasis
