Lecture 5 and 6: Nervous System Organization and Glial Anatomy Flashcards
what is the overall basic function of the nervous system?
receiving information about the environment (sensation) and generating and transmitting responses to that information (motor responses)
the nervous system can be divided into 3 functional regions responsible for:
- sensation (sensory function )
- response (motor function)
- integration (cognition)
what are stimuli for each of the *big 5 senses?
- smell - chemical substances
- taste - chemical substances
- touch - physical or mechanical stimuli (ie temp or texture)
- sight - light
- hearing - soundwaves and physical stimuli (ie vibrations)
what is visceral sensory stimuli?
stimuli that is sensed by the internal organs/fluid
-osmolarity
-pH
-elasticity
ex. chemoreceptors sense a change in fluid
mechanoreceptors sense changes n elasticity
stimuli that are received by sensory structures are then processed by the_______ through a process called________
nervous system , integration
once sensory stimuli are taken in, what happens during integration?
stimuli are compared or “integrated” with other stimuli and memories of other stimuli, emotional or physiological state of the person, etc. lead to a specific response
ex. a batter in a baseball game. When you see the pitch, you dont automatically swing, you look at the pitch decide what to do and then you swing
why are the complexities of processing important?
they allow us to tailor responses to specific stimuli
what is the CNS made up of?
- brain
- spinal cord
what is the PNS made up of?
- ganglion
- nerves
what does the CNS do?
is the control center of the body/brain
what does the brain do
I mean obv it does a lot of things but like generally
-comes up with responses to stimuli, emotions, memory, and communication
what does the spinal cord do?
sends motor commands from the brain to the periphery and also relays information from the periphery back to the brain
what does the PNS do?
processes internal and external environment changes
then sends that information to the CNS and receives info from the CNS
what is the organization of the PNS?
look at chart in notes :)
Input:
-afferent signals go back to the brain
-includes the
1. somatic senses
2. special senses
3. visceral senses
Output:
-efferent signals come from the brain
1. autonomic
2. somatic
what are the somatic senses?
Information from:
-skin
-muscles
-joints
-temp
-pain
-touch
-etc
what are the special senses?
-taste
-smell
-hearing
-sight
what is the autonomic part of the PNS?
divided in 2 parts:
- sympathetic: fight or flight
- parasympathetic: rest and digest
both: heart muscles, smooth muscles, glands, GI tract
what is the somatic part of the PNS?
control over skeletal muscles
what are the basic functions of neurons?
-neurons are the basic functional unit of the CNS
-in charge of:
1. receiving integral information
2. communicating that information to TARGETS
targets can be tissues, other neurons, glands, etc.
what are the basic functions of glial cells? (aka neurological cells)
-glial cells support neurons chemically and physically
-they support structure and processes of the neuron
**glial means glue,, they hold neurons together
what are the major parts of the neuron?
make sure you can label and understand the diagraming of the different parts
- cell membrane
2.dendrites - cell body
- axon
- axon hillock
- node of ranvier
- glial cell
- myelin
- axon terminal
- synaptic end bulbs
know the up close diagram of the dendrite and how logan gated channels and g protein receptors work
this is the quick and dirty explanation :)
:)
ligan gated channels both EPSPs and IPSPs come into contact with certain neurotransmitters from other neurons and then open up letting positive or negative ions respectively into the cell
g-protein receptors are a transmembrane protein which a membrane will bind to and communicate with other cells
(can also be excitatory or inhibitory)
dendrites contain two ligan gated functions that operate like________ with _____________
a door and key , neurotransmitters
what are the two major types of ligan gated channels?
- EPSPs- allow neurotransmitters to bind to the channel and allow POSITIVE IONS to enter the cell
(makes the Em more positive) - IPSPs- allows neurotransmitters to bind to the channel and allow NEGATIVE IONS to enter the cell
(makes the Em more negative)
what are g protein receptors?
g-protein receptors are a transmembrane protein which a membrane will bind to and communicate with other cells
what are the functions of the axon?
- conduct action potentials
- transport:
(kinesin and dynein)
what is kinesin?
a protein transported from the cell body and down the axon to the axon terminal
what is dynein?
a protein transported from the axon terminal up the axon and to the cell body
what is myelin?
an insulating, lipid rich sheath that surrounds the axon of a neuron
facilitates faster electrical transmission via saltatory conduction
conserves energy for the axon
**not all neurons are myelinated
**some diseases (like MS) can lead to demyelination
what are the structural classifications of neurons?
- pseudounipolar
- multipolar
- bipolar
what is a pseudounipolar neuron?
-one process emerging from the cell body
-very long
-exclusively sensory neurons
what is a bipolar neuron?
-2 processes from the soma
-uncommon type
-responsible for special senses
what is a multipolar neuron?
-had 3 or more dendrites
-all of the other neurons that aren’t pseudounipolar or bipolar
what are the functional classifications of neurons?
- sensory: go from the PNS to the CNS
- motor: go from the CNS to the PNS
- interneurons: connect the neurons, between both like a bridge in the spinal cord
what are the 6 main types of glial cells? Which ones are in the CNS, which ones are in the PNS?
-look at photo(s) for labeling!!!
CNS:
1. Microglia
2. astrocytes
3. ependymal
4. oligodendrocytes
PNS:
5. satellite cells
6. schwann cells
what are microglia?
type of glia cell in the CNS
-ingest and digest pathogens in the body through phagocytosis
-are confined to the CNS
(cells that do this function in other parts of the body are called macrophages
what are astrocytes?
type of glia cell in the CNS
-contribute to the blood brain barrier
-maintain extracellular fluid chemical balance
-remove excess neurotransmitters
-act as glycogen reserves
-astrocytes secrete GROWTH FACTORS which stimulate endothelial cells to make receptor tighten and keep bad shit out
**look at drawing
what are ependymal cells?
type of glia cell in the CNS
-generate cerebrospinal fluid by filtering blood
-considered a component of the blood brain barrier
what are oligodendrocytes?
-myelinate axons in the CNS and cranial nerve II
-they are able to myelinate 30 to 60 axons
-however they CANNOT regenerate
what are satellite cells?
type of glia cell in the PNS
-surround the cell bodies of neurons, similar support functions to astrocytes except they don’t contribute to the blood brain barrier
-provide cushion to the cell body
what are schwann cells?
-contribute to myelination in the PNS, spinal nerves, and cranial nerves 3-12)
-different from oligodendrocytes because they are at a 1 to 1 ratio with axons
astrocytes in the CNS are to what in the PNS?
satellite cells
they both offer support
oligodendrocytes in the CNS are to what in the PNS?
schwann cells
-they both insulate and myelinate
how does the terminology for a “localized collection of neuron cell bodies” differ from the CNS to the PNS?
CNS-nucleus
PNS-ganglion
how does the terminology for “a bundle of axon” differ from the CNS to the PNS?
CNS-tract
PNS-nerve
what is gray matter?
nervous tissue regions with many cell bodies and dendrites
**not necessarily gray in color
what is the function of gray matter?
to receive information and regulate outgoing information
where is gray matter in the brain?
forms the outer layer and the inner nuclei
where is gray matter in the spinal cord?
the inner layer
what is white matter?
nervous tissue with many axons
**white in color due to the presence of myelin sheaths
what is the function of white matter?
to transmit signals to other regions of the body
what is a disease of gray matter?
Alzheimer’s (degenerative)
what are the 3 layers that cover the brain called?
meninges
what are the 3 layers of the meninges?
SKULL
dura
arachnoid
pia
BRAIN
dap me up
what does the dura do?
adheres the brain and spinal cord to bone
made up of dense connective tissue
what does the arachnoid do?
is involved in cerebrospinal fluid metabolism
what does the pia do?
is the thin sheath around blood vessels which contours to the brains wrinkles
what are the 4 major regions of the brain?
- Cerebrum
- Diencephalon
- Brainstem
- Cerebellum
What makes up the cerebrum?
-the cerebral cortex
-the corpus callosum
-the frontal, parietal, temporal, and occipital lobes
-special areas
the cerebrum makes up____________
most of the mass of the brain
the cerebral cortex
-is the wrinkled outer layer of the brain
wrinkles-gyri (gyrus)
crevices-sulci (sulcus)
-made up of gray matter
-separated by a fissure into ight and left hemispheres
the corpus callosum
-made up of white matter deep in the cerebrum
-communication pathway between the hemispheres
-sensory information from the right side of the body received by the left hemisphere and is passed to the right by the CC and vice versa
the frontal lobe
-executive functioning:
-emotional regulation
-problem solving
-motor control
-smell
-personality
the parietal lobe
touch, temp, and pain sensing
the temporal lobe
hearing, memory and emotion, language processing
the occipital lobe
visual information processing
what are the two special areas located in the cerebrum?
- Broca’s area- In the LEFT hemisphere. Involved in speech production and articulation.
Damage results in: expressive aphasia
- Wernicke’s area- in the LEFT hemisphere. Involve din language comprehension and speech production
Damage results in: receptive aphasia
what is the diencephalon?
**name means “through brain”
-connects the cerebrum and the rest of the nervous system with 1 exception:
-does everything except for
olfaction (smell)
what are the two major regions of the diencephalon?
- thalamus
2.hypothalamus
the thalamus
-collection of nuclei that pass and process information between the cerebral cortex and the PNS/spinal cord/brainstem
-all sensory information BUT SMELL passes through the thalamus before it reaches the cortex
the hypothalamus
-the executive region of the autonomic nervous system and endocrine system through the regulation of the pituitary gland
-also involved in memory and emotion
the brainstem
-made up of the midbrain and hindbrain (pons and medulla)
-cranial nerves connect through the brainstem and major ascending and descending pathways pass through the brainstem
the midbrain
-responsible for pain modulation and motor movement (primarily of the eye)
-houses many nuclei
the pons
-houses many important nuclei for the regulation of balance and breathing
the medulla
-the connection between the brainstem and spinal cord
-modulates cardiorespiratory functions, various sensory functions and information (pain/temp/pressure) and vomiting
the cerebelllum
-the “little brain”
-is covered in gyri like the cerebrum
-primarily compares information from the cerebrum with peripheral sensory feedback through the spinal cord
-plays an important role in voluntary motor movement and balance
