Test 1 - Nervous System Organization & Development Flashcards
Nerve net
simple nervous system that is organized like a net and does not have a brain
Ganglia
brain region with function in PNS - or non-brain of squid (brain-like)
clusters of nerve cells in PNS
Dorsal
whole body = back
brain = top of brain
Ventral
body = belly
brain = bottom of brain
Medial
toward midline
Lateral
toward sides
Anterior
front (rostral)
Posterior
back (caudal)
Coronal section
vertical plane from crown of head down (frontal view)
Sagittal section
lengthways from front to back & viewed from side (medial view)
Horizontal section
looking down from above the brain (dorsal view)
Lamina
layer
Tract
pathway a nerve axon travels and nerve cell receiving info
Nucleus
area/brain region with certain function in CNS
Gyrus
raised brain area
Sulcus
sunk in trenches/grooves
Fissure
deeper division that sulcus (i.e. divides hemispheres of the brain)
Ipsilateral
same side
Contralateral
opposite side
Lesion
anything that has damaged the brain - such as a concussion that bruises the brain the mark stays they forever
What is the difference between the CNS and PNS?
CNS - brain and spinal cord (medial)
PNS - cranial and spinal nerves - ANS & SNS (peripheral)
What is the somatic nervous system?
- transmits sensation
- produces movement
What is the autonomic nervous system?
balances internal function
What is the sympathetic nervous system?
arousing - fight or flight
What is the parasympathetic nervous system?
calming - rest or digest
Cortex
processing information
Hypothalamus
regulates homeostasis through hormones
Amygdala
regulates emotions
Thalamus
incorporating sensory input (sensory relay center)
Cerebellum
movement (fine motor) & sleep
Pons & Medulla
motor skills - movement - basic functions
Hippocampus
learning and memory center (interacts with prefrontal cortex)
Basal ganglia
addiction and crosslink between emotion and movement (better broken into parts)
parts:
1. caudate nucleus
2. putamen
3. globus pallidus
Substantia nigra
dopamine production center
Tectum
controls eye movements (corpora quadrigemina??)
Tegmentum
has same functions as cerebellum - sleep, regulation etc.
Pituitary gland
helps hypothalamus regulate homeostasis (growth and reproduction through use of hormones)
Superior Colliculus
receives visual input
Inferior colliculus
receives auditory input
Frontal lobe
motor and executive functions
Parietal lobe
tactile functions
Temporal lobe
visual, auditory, gustatory
Occipital lobe
visual functions
Corpus callosum
connect hemispheres for hemisphere brain communication (damage can cause seizure disorders or autism)
Ventricle
where CSF is stored & produced
Caudate nucleus, putamen, Globus pallidus of the basal ganglia
movement and emotions - all associated with OCD
Subthalamic nucleus
associated functionally (movement and emotions) with basal ganglia although not considered - OCD with damage
What are the 4 categories of nerves that extend from the spinal cord?
- cervical
- thoracic
- lumbar
- sacral
What is a dermatome
area of the body that is affected by a certain nerve location (map for expected pain relation to spinal injury)
Describe the histology of the dorsal root ganglion of the PNS. What cells are there? What other features can one see?
unipolar nerve cells- ganglion cells, nuclei, satellite cells, and capillaries
What is the proper information flow in a neuron?
Dendrite (receives info via electrical signal)-> cell body (integrates signal) -> axon (sends info)
Ependymal cell
- line ventricles
- secrete CSF
- regulates volume of CSF
Astrocytes
nutritive - keeps blood from touching brain/nerves - crosses blood-brain barrier
Microglial cell
mesodermally derived - defensive function (basically immune cells)
Oligodendrocyte
myelinate multiple cells in CNS
Schwann cell
myelinate single cell in PNS
Synaptic cleft
gap between two cells
Synaptic vesicles
release neurotransmitters from presynaptic cell (sending message)
Postsynaptic specialization
on dendrite specialized for a certain neurotransmitter
Electrical vs. chemical synapse
electrical - ion flows at gap junction
chemical - neurotransmitter at gap junction
When it comes to shape what is the difference between sensory neurons, interneurons, and motor neurons?
- sensory = pseudounipolar
- interneurons = bipolar
- motor neurons = multi-polar
What is membrane potential?
electrical potential difference across neuronal membrane reflecting a distribution of charges (+ and -) on each side of the membrane
What is the all or none conduction principle?
to get a response in muscle cell you have to meet a certain threshold for there to be a change - if not nothing will happen (a light stimulus such as a feather may not trigger a response, but an anvil definitely would)
What is an action potential?
unit of nerve impulses axons use to convey information over a long distance (all or none) - travel down axons to release neurotransmitters
What is a graded/local potential?
membrane potentials that can change in continuous values (rather than all or none)
Where do we see graded potentials?
In smell and senses - this is what causes nose blindness
What are dendritic spines?
locations on dendrites that are enriched in receptors for neurotransmitters
What is a neural circuit?
ensemble of interconnected neurons that act together to perform a specific function
Explain how the knee-jerk reflex works
It starts with a stimulus on the extensor muscle which sends a signal to the muscle spindle which then sends sensory information to the spinal cord. This sensory neuron excites the extensor motor neuron essentially activating while inhibiting the antagonistic flexor motor neuron or deactivating it (sensory neuron of extensor activates inhibitory interneuron that inhibits motor neuron of flexor). This action causes the leg to pop out when the doctor hits it with the mallet and can be an indicator of nerve damage if the reflex is not working as it should.
How are we aware of the knee-jerk reflex?
- primary somatosensory cortex - awareness of how the jerk felt
- primary motor cortex - awareness that the leg is moving
