Exam 5: February 13 - February 17 Flashcards
what are the parts of the central nervous system?
brain and spinal cord
what are the parts of the brain?
cerebellum, diencephalon, and cerebrum
what does the cerebellum look like?
like coral or a ball of yarn
what are the functions of the cerebellum?
1) balance and coordination of muscle activities
2) muscle tone
how does the cerebellum help with balance and coordination of muscle activities?
so complex activities instead of having to individually work, the cerebellum kind of sorta does a feedforward type process and is proactive about the idea that if I have to stand up the same sort of muscles need to work
knows which muscles need to be involved and gets them involved
how does the cerebellum help with muscle tone?
if there’s damage to the cerebellum, muscles don’t get engaged as much as they would so muscle tone gets lost
what is the diencephalon?
it’s a two part brain component that is one area but has two distinct parts that each have their own functions as well
what are the two parts of the diencephalon?
thalamus and hypothalamus
what does the thalamus do?
part of the diencephalon that controls your movements
major relay station for motor control to get messages off to the muscles
also a major relay station for crude level sensation
how does the thalamus help with crude level sensation?
your thalamus is a major relay station for crude level sensation
visual goes through your thalamus so it registers big things about your visual like is there something moving in my field of vision? Is there something moving that could attack me or is there something I could eat?
Another crude sensation it picks up on is sound so really loud sound or high pitched sound
where is the hypothalamus located?
it’s located below the thalamus
“hypo”
what is the function of the hypothalamus? how does it accomplish it?
part of the diencephalon that maintains homeostatic regulation
helps get the appropriate things activated to get us back to steady state
it does this by being the link between the nervous system, registering those change, realizing we’ve moved away from steady state and realizing we need to activate the endocrine system to get us back to steady state
what is the cerebrum? what are the components of the cerebrum?
cerebral cortex
it’s 80% of your brain by weight and volume
what is the cerebral cortex? what does it look like?
often times it will get equated to be the cerebrum but this isn’t exactly true – it’s an outer shell (cortex)
it’s highly convoluted, it’s not a smooth surface, it’s ridged like how you imagine the brain, it’s coral looking – convoluted shape gives us more surface area which gives us more function since it’s the outer layer – high function within space
what are the parts of the cerebral cortex?
1) matters
2) corpus callosum
3) ventricles
4) basil nuclei
what are the types of matter in the cerebral cortex?
grey and white matter
if you crack open your skull your brain looks grey on the outside and the white is deeper inside
axons are insulated with myelin to increase speed of communication – white parts of steak are lipids so there are probably going to be more cell bodies that don’t have a lot of oligodendricites – there’s going to be more myelin on the inside
what is the corpus callosum?
when you look at your cerebral cortex it’s actually two groupings brought together which is your left and right hemisphere – your corpus callosum is a massive bundle of axon that helps your two
it’s white matter and it’s in the middle of your brain
what are ventricles?
4 fluid filled chambers
when you get a headache it’s because n has changed. Since V is constant, P must increase to accommodate for the decrease in n which is what gives you a headache. drinking water helps because you can restore the number of molecules of water in the ventricles and decrease the temperature
what are the functions of the cerebral cortex?
1) perception
2) voluntary movement
3) language and learning
how does the cerebral cortex help with voluntary movement?
the ability to control where your skeletal muscles are in space
when you have a stroke it damages the cells of the cerebral cortex which is why a lot of people lose the ability to move
how does the cerebral cortex help with language?
another function is language so again after a stroke people can’t understand things or lose the ability to talk
how does the cerebral cortex help with learning and memory?
the cc is what makes you you!
if you damage this area you take away features that define you and differentiate you from the person next to you
so when people say they’re brain-dead they aren’t actually, it’s because their cc is no longer functioning
what are the components of the forebrain?
cerebrum + diencephalon
aka thalamus + hypothalamus + cerebrum
how is the spinal cord protected?
vertebrae and processes
the spinal cord needs protection because we don’t want to damage it and lose our ability to gather and send information
what do vertebrae do?
they are the main bone and are on the ventral side relative to the spinal cord aka they’re on the belly side
so they’re actually protecting us more on the inside more than the outside – this is because the biggest threat to our spine is internal movement
what are processes?
processes are what protect the spinal cord on the outside by surrounding the spinal cord and they are on the dorsal side
what is the composition of the spinal cord?
grey and white matter just like the cerebral cortex
what is in the grey matter of the spinal cord?
interneurons, part of efferent and afferent neurons within the CNS, glial cells are also within this area
what is the white matter of the spinal cord? what is it made up of?
white because of myelination
made up of axons
axons associated with afferent neurons are always dorsal to the axons associated with our efferent neurons which are on the ventral side
where are the afferent and efferent neurons in the spinal cord located?
axons associated with afferent neurons are always dorsal to the axons associated with our efferent neurons which are on the dorsal side
DAVE = dorsal afferent ventral efferent
why is position of ventral vs. dorsal axons in the spinal cord important?
It’s important because of protection. If one was going to get cut and damaged would you rather give up incoming or outgoing information? You’re more likely to see damage on the dorsal side so we protect our efferent pathway more so that we can react
what is the most used neurotransmitter in the body?
acetylcholide (ACh)
what destroys acetylcholine?
gets rapidly destroyed by ACh-esterase
this is to remind you that astrocytes clean up neurotransmitters because you don’t want the neurotransmitter to keep doing the task after it’s already done it
what does acetylcholine do?
cognition, behavior, how we interact and do things, control of glands and organs
what are the key neurotransmitters in the body?
1) acetylcholine
2) biogenic amines
3) amino acids
4) neuropeptides
what are examples of biogenic amines?
dopamine, norepinephrine, epinephrine, serotonin, histamine
what are biogenic amines?
they are a type of key neurotransmitters that control consciousness, mood and endocrine regulation
have a similar chemical structure which is why they’re grouped together
control a lot of our consciousness which is why antihistamine warning is drowsiness aka reducing consciousness
what are amino acids?
key type of neurotransmitter
some AA act as excitatory pre-synaptic potential creates so they depolarize
other ones act as inhibitory pre-synaptic potentials so they hyper polarize the potential and make it harder to reach the threshold component
what are neuropeptides?
peptides just mean a small chain of AA that’s not quite a protein yet
this category tells us that they got named neuropeptides because they don’t just act as neurotransmitters, they also sometimes as paracrine and endocrines so they can be released and removed in different ways aka they don’t have to stay as a neurotransmitter all the time
what are the components of the peripheral nervous system?
efferent (action) and afferent (sensory)
what are the components of the efferent PNS?
autonomic and somatic nervous system
our brain can use one of both of those systems if it decides we need to take action
what is the similarity between autonomic and somatic nervous systems?
both send signals from the CNS to effectors
they’re outgoing messages
what are the differences between the autonomic and somatic components of the efferent PNS?
1) # of neurons it takes to reach our effector
2) what gets innervated
3) actions
what is the difference between autonomic and somatic in the # of neurons it takes to reach our effector?
our autonomic requires 2 neurons to get to our effector while somatic only takes a single neuron to get to our effector = spinal cord
what is the difference in what gets innervated between the autonomic and somatic nervous systems?
what effectors can be controlled by our autonomic vs. somatic?
somatic only controls one category of things, your skeletal muscles
however to control basically everything else like to control your breathing, heart rate, smooth muscles, cardiac muscles, glands, digestive system is all autonomic
what is the difference between autonomic and somatic in the actions that they can perform?
how we can do things with our effectors
somatic can only excite our skeletal muscles – we can basically only get it to squeeze and we can’t force it to not squeeze, we just stop sending it signals to squeeze to get it to relax
autonomic can excite and inhibit: we can increase heart rate and decrease heart rate so we can impact in both directions
what does the autonomic components of the efferent PNS do?
regulates automatic/visceral responses
this system controls how things are going on in the background, you don’t have to think about these things like digestion or increasing your heart rate if you’re exercising
what are the components of the autonomic nervous system?
sympathic and parasympathetic
what analogy can be used to describe the autonomic nervous system?
the sympathetic nervous system is the gas in the car to speed you up while the parasympathetic nervous system is the breaks to slow you down
some effectors need to be slowed down and sped up so they’re effected by both systems
how many neurons does it take the autonomic nervous system to get to the effector?
2
because the two neurons are in series you end up seeing clustering of the second cell body outside, in our CNS
they’re called ganglia
what are ganglia?
a cluster of neurons in our autonomic nervous system
because the autonomic nervous system requires two neurons to reach the effector, you end up with a clustering of the second cell body outside in our CNS
what types of ganglia are there? what do they do?
pre-ganglionic and post-ganglionic neurons
pre-ganglionic releases neurotransmitters to post-ganglionic neurons
post-ganglionic neurons release its neurotransmitters to the effectors
what is your sympathy nervous system?
fight or flight response (efferent pathway)
it’s job is to make sure you’re alive 10 minutes from now
something has been registered as life threatening and we need to do something right now by either fighting it or get out of the way and dodge it