PNB 2XB3 Study Guide - Fall 2018, Comprehensive Midterm Notes - Wireless Access Point, Squid, Spinal Cord
12 Oct 2018
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PNB 2XB3
MIDTERM EXAM
STUDY GUIDE
Fall 2018
Lecture 1 – September 4
• Neuroscience: study of the cell biology of individual neurons and nervous systems (many diff.
types)
• Neuron is a cell
• Channels are important due to ion channels (allows charged particles to cross the neural
membrane)
• Nucleus is where the DNA is and is a collection of neurons
• Many components of neurons are proteins (ex. neurotransmitters, ion channels)
• Majority of neuroscience research is done on non-human animals; primarily mice and then rats
• Discovered how action potential works through research on an invertebrate squid
• Neuroscience is interdisciplinary so a neuroscientist must understand biology, chemistry, physics,
math
• We should care about neuroscience due to:
o 1. Neurological disorders
o 2. The fascinating “3 pound universe” (nervous system within)
▪ There are 100 billion neurons in the brain (100 x 109 = 1011)
▪ We use 100% of our brain
▪ Brain uses 20 W (entire body power = 100 W) meaning it is a very efficient info
processing organ
▪ Size of a typical neuron is 10 um (cell body diameter); 1 um (micron) = 10-6 m =
1 millionth of a meter
▪ Glutamate is the most common neurotransmitter as it causes other neurons to be
excited; if you have a glutamate disorder the person would die whereas if another
neurotransmitter (Ex. dopamine) were damaged the person can still stay alive
▪ The voltage inside a neuron at rest is -65 mV
▪ The neuro-electrical impulse is called the action potential
▪ Ions involved in neuro-electric activity is K+, Na+, Cl-, Ca2+
• Central Nervous System: all parts of the nervous system within bone
o Spinal cord, brainstem, thalamus, cortex (outer layer of the brain), etc.
• Peripheral Nervous System: all parts not within bone
o Peripheral nerves
• Thalamus: deep in the cranium, sensory info is projected to here
• Cerebellum: involved in motor control
• Spinal cord is divided into 4 segments top to bottom: cervical, thoracic, lumbar, sacral
• Dermatome: slice of skin are connected to spinal segments
o If someone loses sensation in a specific part of the skin due to damage to spinal cord then
we can figure out which part of the spinal cord was damaged
• Pyramidal Neuron: has a pyramid structure w/ dendrites & axons
• Neurons are similar to other cells because:
o They have enclosure meaning they have a lipid bilayer membrane
o They have organelles: nucleus, mitochondria, etc.
• Neurons differ from other cells because:
o They have a unique morphology: dendrites, axons (all neurons have only 1 axon)
o Electrically excitable: action potential (neural Morse code pattern)
• Dendrites: receive signals from other neurons (input)
find more resources at oneclass.com
find more resources at oneclass.com
• Axons: send signals to other neurons (output)
• Action potentials take 1 ms
• Different neuronal cell types look different (each has different shape)
o Ex. cortical pyramidal cell/ cerebellar purkinjee cell
• Neurons are not the only type of cell in the nervous system
o There are glial cells (3x more glial cells than neurons)
▪ 1. Astrocyte – maintain ionic environment (right concentration of ions in the
neuron)
▪ 2. Oligodendrocyte – myelinate neuron (adds myelin sheath to axons of neurons)
allowing neurons to send action potentials down faster
▪ 3. Microglia – scavenge cellular debris and suck the dead cells to keep
environment clean
• Rostral – towards the beak/nose
• Caudal – towards the tail
• Dorsal – towards the back
• Ventral – towards the front
• Superior – above
• Anterior – in front of
• Posterior – behind
• Midline – line separating left and right
• Ipsilateral – same side
• Contralateral – opposite side
• Decussate – cross midline
• Proximal – close to point of reference
• Distal – far from point of reference
• Efferent – projecting away from reference
• Afferent – projecting towards reference
• Medial – near midline
• Lateral – far from midline
• Coronal/ Sagittal/ Horizontal (xyz axis)
• 1st pic – horizontal and sagittal, 2nd horizontal and coronal, 3rd pic is coronal and midsagittal
• There is a bend in the neuraxis due to sapphylaxis structure
• Neuroscience Rules:
o Symmetry
▪ Can’t tell which is left side as there is no clue to differentiate bw left and right to
tell if person is facing you or facing away from you; we must be told otherwise
we won’t know
o Localization of Function
▪ Functions are localized to different regions
▪ Ex. cerebral cortex has 4 lobes and each lobe has a different function
▪ Frontal lobe has a motor strip
▪ Sulcus is a groove
▪ Parietal lobe has the somatosensory cortex
▪ Dorsal part of temporal lobe has hearing
▪ Occipital lobe has primary visual cortex
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Astrocyte maintain ionic environment (right concentration of ions in the neuron: 2. Oligodendrocyte myelinate neuron (adds myelin sheath to axons of neurons) allowing neurons to send action potentials down faster: 3. Microglia scavenge cellular debris and suck the dead cells to keep environment clean. Ion transporters active transporters that actively move selected ions against the concentration gradient and they create ion concentration gradients; requires. The k+ concentration is greater inside than outside the neuron due to the action of the. At rest, the neuron is primarily permeable to k+, because the membrane contains k+ leak ion channels: 3. So k+ diffuses out of the cell, making the inside negative: electrochemical equilibrium. Diffusion: k+ diffuses out of the cell, down its concentration gradient: 2. Electrostatic force: as k+ diffuses out, the inside becomes negative compared to the outside. This makes the inside negative, counteracting the diffusion tendency (since opposite charges attract).
