Exam 2 Flashcards
Common Chemicals in Chemical Synapse?
Neurotransmitters
Signal Propagation
Think Myelinated (motor function) vs Unmyelinated (tickle, heat, etc)
What are Chemical Synapses dependent on?
What Receptors are located on the receiving cell
What would a small, Unmyelinated Neuron be good for?
Tickles, Cold, Warmth (R side of Chart)
In a Neuron, how long is an Action Potential?
Milliseconds
Where are Oligodendrocytes located?
CNS
What is Striated per Lecture?
Skeletal Muscle
How many binding sites does nACh-R have?
2 binding sites; both have to be occupied simultaneously to work
Purpose of Schwann Cells
PNS Myelin Producing Cell
Overall Slower Cell Signaling?
Longer Nerve, Narrow Diameter, Decreased Insulation
What receptors are located on the Heart at the NMJ?
Muscarinic/ACh receptors
What is the main ion that goes through an electrical synapse? Why?
Na+, it is small and can fit
What makes cells more resistant to crush injuries?
Myelin; add layer of robustness
Where are Schwann Cells located?
PNS
What action potential does Dr. Schmidt give an example of?
Electrical Probes being placed
What is Myelin?
The insulation around a Neuron
What happens if there are increased gap junctions?
Decreased resistance for AP; easier for signals to be sent
What Happens if you take away Cl- permeability?
Increased Vrm –> Seizures
Purpose of Oligodendrocytes
CNS Myelin Producing Cell
Multiple Sclerosis (MS)
Myelin sheath is damaged in the motor system, so signals are not conducted properly
How does Cl- affect the cell?
Hyperpolarizes the cell; “brakes” on the NS
What are the Macroglial Cells?
Astrocytes, Ependymal Cells, Oligodendrocytes, Schwann Cells
Normal HR per lecture?
70-72 b/min
How does Atropine Work?
Blocks normal vagus activity on the heart; Increase HR
How do Baroreceptors adapt?
Desensitize to increase in MAP, and make it the new “normal”
What does an Axon do for a Neuron?
Sends signals; Myelinated
What is a Threshold?
It determines if the cell generates an action potential. Depolarization has to get above the threshold line in order to generate an action potential
Are Electrical Synapses 1 direction?
No, 2 Directions; good or bad; if rogue cell in heart, random electrical impulses
What is the Node of Ranvier?
The spaces between the Myelin Sheath that are packed with Fast Na+ channels
Why are they named Astrocytes?
“They look like a star”
Purpose of Pseudounipolar Neuron?
Majority of sensor cells outside of spinal cord; sensory function that relays to the NS
Are Chemical Synapses faster or slower than Electrical Synapses?
Slower
Where in the Pseudounipolar Neuron is a decision made?
The Sensor
Myelinated Neuron Letter?
“A”
What does the Soma on a Pseudounipolar Neuron do?
Make proteins and replace things that need to be maintained
What is a Connexon?
A tube/cylinder protein that is implanted in the cell to conduct signals to other cells attached
Which directions can an action potential go on a cell?
Bidirectional
What Ion is Permeable in the Axon Hillock?
Cl-; suppress the CNS
What signs are a result of Hypocalcemia?
Trousseau and Chvostek Signs
What does Hypercalcemia do to Motor Neuron Activity?
Under activity of the Motor Neuron; decreased muscle contractions
What does Increased Gap Junctions mean for the Action Potential?
Decreased resistance for AP, so faster
Why is an action potential longer in the heart?
It allows for the heart to contract and pump blood; in seconds
Why would it be pointless if excitatory on Axon Hillock?
It would bypass the rest of the cell and interrupt the whole reason for making decisions
Which Vagus nerve releases ACh to the AV node?
L Vagus Nerve
What is an easier nerve to block?
Nerves that are located outside of a nerve bundle (not buried)
How does ACh and K react to each other?
ACh opens K channels, causing them to leave (makes cell more -)
How did Dr. Schmidt describe a Ca++ ion?
“Big and Clunky”
What do Dendrites do?
Receivers on the Soma; usually not myelinated
Where is the SA node located?
L side of Heart
How does ACh behave in Skeletal Muscle?
Excitatory
What is Demyelination?
Progressive loss of Myelin over time
What Neurotransmitter is located on the Axon Hillock?
GABA
In the Heart, how long is an Action Potential?
Seconds
What does Somatic Sensation mean?
“Able to be Sensed”
Guillain-Barre Syndrome
A lot of people Post-Covid got this, as their antibodies they built up were reacting and attacking their nervous system
What happens to the Fast Na+ and K+ channels that are located under the Myelin Sheath over time?
They disappear over time
Where do Paralytics work?
NMJ
What are support tissues/cells called in the NS?
Glial Cells
How do Pressure and Stretch Sensors work?
When flat and stretched, increased Na+ coming in, so Action Potential tells you there is pressure
Which takes more Local Anesthetic to block? Why?
Myelinated Cell; the density of Fast Na+ channels
Fast Adapting Sensors
Squeeze a ball and forget about it over time b/c brain does not need all this information; NS is concerned about change;
Another name for Neuron Cell Body?
Soma
Are Electrical Synapses faster or slower than Chemical Synapses?
Faster
Location of Electrical Synapses?
Myocardium, Smooth Muscle, Some Neurons
Are Schwann Cells good or bad at regenerating Myelin?
Good
Locations of Electrical Synapses?
Smooth Muscle, Myocardium, some Neurons
How many projections do Bipolar Neurons have?
2
Be Able to Label a Typical Neuron
Soma, Dendrite, Axon, Axon Hillock, Presynapsis, Postsynapsis, Myelin Sheath, Nodes of Ranvier
Normal MAP per lecture?
100 mmHg
What happens if Baroreceptors do not adapt?
If MAP jumps from 100 mmHg to 200 mmHg, without adaptation, then an action potential cannot fire any faster. This limits brain activity to get information from this high BP
Increased pressure = ? Na+ influx
Increased
What is Saltatory Conduction?
The Action Potential moving down a Myelinated Neuron
Where are Dendrites located?
Sticking out of the Soma
Purpose of Microglia Cells
Immune System in CSF cells; Macrophage that eats dead cells and clear up debris
What Ion is the “brakes” of the nervous system?
Cl-
What is Myelin derived from?
Sphingomyelin
Purpose of Multipolar Neuron?
Motor Neurons; Decision Making Cells (decides whether to fire an action potential or not)
Where is AV node located?
Top of Septum in Heart
What is very energy effecient?
Myelinated Neurons
Calcium Channels can also be called what?
L-Type channel
Important example of ADAPTATION?
Baroreceptors
How does Mg+ work in the cell?
Similar to Ca++; hyperpolarizes the cell; reduces electrical activity of the cell (heart)
Lightly Myelinated Neuron Letter?
“B”
Which Neuron Type is considered the “decision making cell”?
Multipolar Neuron
Examples of Pressure and Stretch Sensors?
Pacinian Corpuscle, Meissner’s Corpuscle
Brain tumors are called __?
Glial Tumors
What is an Axon Hillock?
Beginning of an Axon; GABA mediated to suppress electrical activity in the CNS
What will an antimuscarinic do to the heart?
Increases HR; closes K+ channels, which makes cell more (+)
Neuron Action Potential Pathway
Brain/SC - Motor Neuron - Action Potential - Neurotransmitter released at NMJ
How does ACh behave in the Heart?
Inhibitory
What shape is nACh-R?
Doughnut shaped (-) charged; attracts (+) Na to start AP
Without the Nervous System, what would be the normal HR per lecture?
110 b/min
What Does Myelin Sheaths do to Na+ channels?
Blocks the Na+ channels, sending Na+ down the line to the Nodes of Ranvier
Motor Neurons need a ? to talk to skeletal muscle?
Neurotransmitter
What does Myelin help the cell?
Increased protection, saves energy by blocking the NaKATP pump, speeds up signal transduction
Are Oligodendrocytes good or bad at regenerating Myelin?
Bad
Non-Myelinated Neuron Letter?
“C”
How long does it take a Baroreceptor to adapt?
2 days (slow)
What does Massive Vagus Stimulation do to the HR?
Slows HR, b/c causes Hyperpolarization
When you lose Myelin, what happens to the NaKATP pumps?
The continuously pump Na+ like normal, but since nothing to keep them in, will never reach the Node of Ranvier; signal will not be sent (paralysis)
What does Decreased Gap Junctions mean for the Action Potential?
Increased resistance for AP, so slower
How many Connexins make a Connexon?
6
Overall Faster Cell Signaling?
Shorter Nerve, Wider Diameter, Increased Insulation
What happens if you lose Myelin in your CN2 or Retina?
Blind or trouble seeing
What happens if there are decreased Gap Junctions?
Increased resistance for AP; some places in heart do this intentionally to pause/delay
What would a Big,Myelinated Neuron be good for?
Motor Neuron; Left side of Chart
What structures are included in the CNS?
Optic Nerve (CN2), Retina, Brain, Spinal Cord
Where is Muscarine found, per lecture?
Rainforests
What makes a cell less prone to ischemia?
Myelin
Per lecture, how many neurons can a neuron connect with?
10,000 (all connections influence what the cell does)
Is an Action Potential a (-) or (+) feedback?
(+) feedback
Example of Bipolar Neuron in the body?
Photoreceptors in the Optic Nerve and Retina
Where do Paralytics work?
NMJ
Purpose of Bipolar Neuron?
SPECIALIZED Senses; sense info and sends to NS
What Does Hypocalcemia do to Motor Neuron Activity?
Increased Na+, as it does not block the leaky Na+ channels; Increases Motor Neuron Activity (increased muscle activity)
Is Electrical Synapse diffusion or active transport?
Simple Diffusion
Which receptor suppresses electrical activity in the heart?
mACh-R
3 Types of Neurons?
Multipolar, Pseudounipolar, Bipolar
When a cell is flattened, what happens to the Fast Na+ Channels?
They are increased, which increases action potentials
What does ACh effect in the heart?
Pacemaker activity of heart (70-72 b/min)
What is a Free Nerve Ending?
Pain Sensor
What is in the Soma of a Neuron?
Nucleus, mitochondria, etc
If the Nervous System does not need 100 million neurons, what will it do?
Try to get rid of the ones it does not need
What part of the Astrocyte binds to the endothelial cells/capillary?
Astrocytic Infoot
How does Ca++ help in Hyperkalemia?
Ca++ will block Na+ permeability, making the Cell more (-); if the cell is more (-), will pull in K+ ions
Purpose of Ependymal Cells
Produce CSF; moves it downstream via cilia to circulate
What is another name for a Free Nerve Ending?
Nociceptor
Purpose of Golgi Tendon Apparatus?
On skeletal or smooth muscle to let body know how muscles are doing and moving
4 Causes of Demyelinating Diseases?
Genetics, infection, autoimmune, polyneuropathies
What happens if an alcoholic stops drinking?
GABA is not released anymore, so crazy CNS involvement; Increased +, so seizures and DTs
What happens to an action potential when there is an increased strength of a stimulus?
Increased action potential speed
What happens to Na+ when the cell is flattened/widened?
Increases the amount of Na+ channels, which increases amount of action potentials
What do 2 Connexons make?
Gap Junction
What are included in the PNS?
Everything outside of the Spinal Cord
Which Vagus nerve releases ACh to the SA node?
R Vagus Nerve
What is Dihydropyridine (DHP)?
A class of CCB, specifically for smooth muscle and heart. Vasodilator with little effect upon cardiac contractility
Purpose of Astrocytes
BBB support; maintain/buffer electrolyte balance within CNS (CSF);wrapped around BBB tight junction and capillaries
What are the subunits of “A”? - Order largest to smallest
Alpha, Beta, Gamma, Delta
Alcohol is a __ Agonist?
GABA
Superior
Head (top)
Inferior
Feet (bottom)
Dorsal
Back (posterior); fin of a dolphin or shark
Ventral
Front (anterior)
Anterior
Front
Posterior
Back
Medial
Middle
Lateral
Side
Rostral
Front and Upper (think Beak of a Bird)
Caudal
Lower and Rear (Tail of a Bird)
Distal
Further from NS
Proximal
Closer to NS
CNS Divisions: 4 Parts
Superficial
Closer to skin
Deep
Deeper in skin
Sagittal
Cut from L to R side of body (median); line right down the middle
Coronal
Cut Anterior to Posterior
Horizontal
Cut Superior to Inferior (head to feet)
Oblique
“Goofy or Odd Angle”
CNS: Telencephalon
The cerebral hemispheres or cortex; the upper and outer part of the brain
CNS: Diencephalon
The more inner part; middle between the Telencephalon and Brain Stem
CNS: 3 parts of Brainstem
Midbrain, Pons, Medulla Oblongata
Another name for Telencephalon?
Cerebral Hemispheres
Another name for Midbrain in Brain Stem? Location?
Mesencephalon; top of Brain Stem
Shape of Pons in Brain Stem? Location?
Olive Shaped Structure;
Lowest Level of Brain Stem?
Medulla Oblongata
What is a Sulcus?
It is a “groove” on the brain
What is a Gyrus (Gyri)?
“Lump” on brain; lumps of neurons and tissue
What is a Fissure?
“Really Deep Groove”
What do Grooves separate?
Groups of Tissue
What does the Frontal Lobe do?
It is the Thinking System of the brain; also, when you are “thinking to yourself”
What are the 4 Major Lobes?
Frontal, Parietal, Occipital, Temporal (separated by Sulci/Grooves)
What does the Parietal Lobe do?
Somatosensory (pain); located behind (posterior/dorsal) to the Frontal Lobe
Where is the Parietal Lobe in location to the Frontal Lobe?
Posterior/Dorsal
What does the Occipital Lobe do?
Vision processing and visual cortex; dorsal/posterior to Frontal
Where is the Occipital Lobe in relation to the Frontal Lobe?
Dorsal/Posterior
What does the Temporal Lobe do?
Auditory processing; located on Lateral side; “language listening and determining who is singing the song”
Major Landmarks in the Brain Divisions?
Central Sulcus and Temporal/temporolateral Fissure
What is the main anatomical marker when dissecting a brain?
The Central Sulcus
Why is the Temporal Fissure Important?
It separates the Temporal Lobe from the Frontal/Parietal Lobes
Why is the Precentral Gyrus Important?
It is the Primary Motor Cortex
Where is the Precentral Gyrus in relation to the Frontal Lobe?
It is Posterior to the Frontal Lobe
Why is the PostCentral Gyrus important?
It is the sematosensory portion of the parietal lobe
Where is the PostCentral Gyrus in relation to the Central Sulcus?
It is Posterior to the Central Sulcus
Why is the Longitudinal Fissure Important?
It separates the Left and R hemispheres
What does the Corpus Callosum do?
Cross Talk Communication between both sides of the brain
Where is the PreCentral Gyrus in relation to the Central Sulcus?
It is Anterior to the Central Sulcus
Why is the Corpus Callosum a lighter color on the diagram, per lecture?
It shows that it has a lot of myelinated neurons for cross talking
Per lecture, how do you expose the Corpus Callosum on the brain diagram?
Cut it in half with a saw
Per lecture, where does a concussion damage the brain?
Damages the gray areas of the brain; leads to decreased process in that area
What is the CSF a buffer between?
The Brain and the Cranium
Where is Gray Matter in relation to White Matter?
Superficial (closer to the cranium)
Where is White Matter compared to Gray Matter in the brain?
Deep to Gray Matter
Why is it easy to get blood flow to the Gray Matter?
The blood vessels are on the outside, so close in proximity to the Gray Matter
Why is Broca’s Area important?
The act of speaking and thinking about word formation/speaking is done here
Why is Wernicke’s Area Important?
Area where language comprehension is processed
Why is the Motor Cortex Important?
It is the primary acting on the action of motor functions
Why is the Limbic System Important?
It is the Emotional responses
Where are the Motor Plans Executed?
Back of the Frontal Lobe (Posterior, Dorsal)
Where are the Motor Plans Thought of?
Front of the Frontal Lobe (Anterior, Ventral)
What is White Matter?
Myelinated; generally axons; not many cell bodies; important for SENDING AND RECEIVING DECISIONS
T or F: The Spinal Cord does not have reflex decision making or problem-solving abilities
False
What is Gray Matter?
Unmyelinated; Butterfly shape; axons and dendrites; important for DECISION MAKING CENTER
Is Gray Matter Myelinated or Unmyelinated?
Gray Matter is Unmyelinated
Is White Matter Myelinated or Unmyelinated?
White Matter is Myelinated
What is the Anterior White Commissure (X-Over)? (AWC)
White portion of the spinal cord cross section that allows for signals to get from the L–> R side of the spinal cord (vice versa)
What shape is Gray Matter?
Butterfly shape
Describe the Posterior Median Sulcus
Really deep but narrow
Why is there a color difference in White and Gray Matter?
The myelination shows as a lighter color
Describe the Anterior Median Fissure
Wider (has an artery to wedge inside)
What are the 2 parts of Gray Matter?
Dorsal Horns and Ventral Horns
What are Dorsal Horns?
In the back of Gray Matter; have cell bodies on it; used for SENSORY
What are Ventral Horns?
In the front of Gray Matter; has cell bodies on it; used for MOTOR FUNCTION
Which access is easiest to get to the Dorsal Horns of Gray Matter?
Superficial Approach (epidurals, spinals)
Which way does information get into the Gray Matter?
Comes in from a horizontal direction, then jumps from Dorsal to Ventral horns
What is the Central Canal?
The center part of the gray matter that is responsible for producing the CSF and moving it down the Spinal Cord
What Surrounds the Central Canal?
Lamina 10
What Cells are in the Central Canal?
Ependymal Cells (CSF producing and Cilia moves it)
Lamina 10
The Gray Matter L and R side of cord connection; surrounds the Central Canal; made of Commissures
What is the Lateral Horn (Visceromotor)?
Random horn Dr. Schmidt pointed out in lecture
What is the Anterior Approach to blood supply in the Spinal cord?
Intercostal Arteries
What is the Posterior approach to blood supply in the Spinal Cord?
Upper Neck and Brain Stem
A Spinal Nerve is __ + __?
Posterior Rootlets + Anterior Rootlets
What functions do Spinal Nerves contain?
Sensory and Motor Function
Where are Posterior Rootlets attached?
Dorsal Horns
Where are Anterior Rootlets attached?
Ventral Horns
What are Posterior Rootlets used for?
SENSORY FUNCTION
What are Anterior Rootlets used for?
MOTOR FUNCTION
Where do all the Posterior Rootlets meet at?
The Posterior Root
Where do all the Anterior Rootlets meet at?
The Anterior Root
What is the Spinal Ganglion?
Where the big collection of cells on the posterior root side congregate
What type of Neurons are located on the Spinal Ganglion? Why?
Pseudounipolar Neurons; these are the sensory neurons so help with sensory signals being sent up the posterior side (to the Dorsal Horn)
What is the Primary purpose of the Descending Spinal Tract?
Motor Response
What is the Primary Purpose of the Ascending Spinal Tract?
Sensory
5 sections of the Spine?
Cervical, Thoracic, Lumbar, Sacral, Coccygeal
How many Vertebrae are located within the Cervical Region?
7 vertebrae
How many Pairs of Spinal Nerves are located within the Cervical Region?
8 spinal nerve pairs
Where are the spinal nerve pairs in the Cervical region compared to the location of the Cervical Vertebrae?
The 1st 7 pairs are above their vertebrae; the 8th is below the 7th vertebrae, setting up for the rest of the vertebrae and their nerve pairs
How many vertebrae are in the Thoracic region?
12 vertebrae
How many vertebrae are in the Sacral region?
5 vertebrae
How many spinal nerve pairs are in the Thoracic Region?
12 nerve pairs
How many Vertebrae are in the Lumbar region?
5 vertebrae
How many spinal nerve pairs are in the lumbar region?
5 spinal pairs
How many spinal nerve pairs are you born with in Coccygeal?
2, combine to 1 as you grow older
How many pairs of spinal nerves are in the sacral region?
5 pairs of spinal nerves
How many spinal nerve pairs are in the Coccygeal region?
1 pair
Where are the spinal nerve pairs located in relation to the vertebrae (excluding cervical spine)?
they originate under their vertebrae
What are Dermatomes? Dermatome Man?
The regions of the body split up by spinal nerves; the guy bend over with different colored regions of nerves
From a frontal view, what kind of curve is Thoracic Kyphosis?
Concave Curve
What are C2,C3 for?
Sensors for head and neck
What is Cervical Lordosis?
A natural occurring anterior curve of the neck
From a frontal approach, what kind of curve is Cervical Lordosis?
Convex Curve
What is Thoracic Kyphosis?
A natural posterior curve; if increased, leads to “hunchback”
What is Sacral Kyphosis?
A natural posterior curve
From a frontal view, what kind of curve is Sacral Kyphosis?
Concave curve
What is Scoliosis? What type of curve?
The lateral curvature of the spine; L–R; abnormal
What is Kyphotic Curvature?
Outward curve to force concave curve (from the front)
What is Lordotic Curvature?
Inward curve to force convex curve (from the front)
Is pathologic Lordosis normal or bad?
BAD
Is pathologic Kyphosis normal or bad?
BAD
What shape is the spine normally, per lecture?
“S” shaped
What is the most common abnormal curvature?
Kyphoscoliosis
What curvature are we born with? Which one do we develop as we get older?
We are born with kyphotic curves (thoracic); as we grow older, we develop Lordotic curves (cervical)
What is considered “hunchback”?
Increased Thoracic Kyphosis (think old ladies)
Why can a baby not hold their head up?
They do not have Cervical Lordosis yet; to be developed
What is Lumbar Lordosis?
A natural anterior curve
From a frontal view, what type of curve is lumbar lordosis?
Convex curve
What is the Vertebral Body of the Vertebrae?
the weight supporting part of the vertebrae; intervertebral discs sit on this
What are the 2 parts of the Vertebral Branch?
the Pedicle and the Lamina
What is the Superior Articular Process?
Superior from the Arch; connects with the Inferior Articular Process from the superior vertebrae (up above)
What is the Inferior Articular Process?
Inferior to the Arch; connects with the posterior vertebrae (from below)
What is a “Process”
A bony extension
What is the Transverse Process?
the 2 bony extensions that stick out of both directions
What is the Spinous Process?
The palpable portion of the vertebrae; the back (dorsal/posterior) portion of the vertebrae
In the lower back, are the Vertebral Bodies bigger or smaller? Why?
Bigger; have to hold more weight
In the upper back, are the Vertebral Bodies bigger or smaller? Why?
Smaller; have to hold less weight
What is the palpable portion of the vertebrae?
The Spinous Process
What is the Vertebral notch?
The area where the spinal nerves rest/stick out
Where is the vertebral notch in comparison to the pedicle?
Inferior to the Pedicle
What is the “gray” on the Interior Articular Facet?
Cartilage
Where is the Lamina compared to the Pedicle in this picture?
Posterior to the pedicle
What is the Inferior Articular Facet?
The joint
What is a Foramen?
An opening
What is the Vertebral Foramen?
The opening where the spinal cord would hang out; wider in cervical
Where do the Carotid Arteries Pass through?
The Anterior Portion of the body
What do the Vertebral Arteries Feed?
The brain and spinal cord
Where do the Vertebral Arteries pass through?
C1-C6 transverse foramen
Where do the Vertebral Arteries not pass through?
The C7 transverse foramen
How is a spinous process in the Cervical region different than the other regions?
it is Bifid in nature, rather than single process (besides C7)
What does Bifid mean?
2 bony projections
C2-C5 Spinous Process?
Bifid, almost always
C6 Spinous Process?
50% bifid, 50% chance to be singular
C7 Spinous Process?
0.3% people have a Bifid C7
Pedicle
1st part of the Vertebral Branch; spinal nerves sit here
3 Structures only in the Cervical Vertebrae?
Transverse process with Sulcus for Spinal Nerve, Bifid Spinous Process, Transverse Foramen for Vertebral Arteries
Describe Sulcus for Spinal Nerve
Hollow, Divet, Groove
What is the C1 also called?
The Atlas
What is the C2 also called?
The Axis
What does the C1 do?
Bares the weight of the skull, so has a unique connection
What is Broca’s Area?
The region where speaking and word formation is processed
What is Wernicke’s Area?
Area where language comprehension is processed
What is the Motor Cortex?
The area where motor function is processed and completed
What is the Limbic System?
Area on Temporal Lobe that is responsible for emotional responses
Where does the Execution of Motor Plans take place?
Back of the Frontal Lobe (posterior/dorsal)
Where does the Thinking of Motor Plans take place?
Front of the Frontal Lobe (Anterior, ventral)
Which receptors undergo reverse adaptation?
Nociceptors
2 Ways to stop pain in nociceptors before it gets too bad?
Take your scheduled pain meds and nerve block the area
Which way would a magician cut their assistant?
Horizontal Plane
What are the 2 parts of the Diencephalon?
Thalamus and Hypothalamus
Diencephalon: Thalamus
Relay Center between Cerebral Hemispheres and Brain Stem
Diencephalon: Hypothalamus
sensory and control center, osmo receptors, body temp receptors
Where is the Hypothalamus in comparison to the Thalamus?
Deep
Where is the Diencephalon compared to the Telencephalon?
Inferior; Deep
Where is the Diencephalon to the Brainstem?
Superior; Superficial
Which structure separates the Frontal from the Parietal Lobe?
The Central Sulcus
Which structure separates the Temporal Lobe from the Frontal and Parietal Lobes?
Temporolateral Fissure
What Lobe is Broca’s Area a part of?
Frontal Lobe
What lobe is Wernicke’s area a part of?
Temporal Lobe
Is Broca’s Area motor or sensory?
Motor
Is Wernicke’s Area Motor or Sensory?
Sensory
What Lobe is the Frontal Cortex in?
Frontal Lobe
How Wide is the Spinal Cord, per lecture?
No wider than the size of a quarter
Where is the PostCentral Gyrus in relation to the Parietal Lobe?
The most Anterior Portion of the Parietal Lobe
What is the Location of the Motor Cortex?
Anterior to the Central Sulcus; most Posterior part of the Frontal Lobe
What Lobe is the Limbic System located on?
Temporal Lobe
What makes the Gray Matter darker than White Matter?
Less Myelin and More Cell bodies (make it darker)
Is Lamina 10 Gray or White Matter?
Gray Matter
Are the main blood vessels for the brain superficial or deep?
Superficial; easier to supply to Telencephalon
What structures separate L and R side of the spinal cord?
Posterior and Anterior Median Sulcus/Fissure
Where is CSF produced?
The brain
Is the Anterior White Commissure (X-Over) White or Gray Matter?
White Matter
How is CSF sent from the Brain down the Spinal Cord?
The Central Canal in the Spinal Cord
Neck: Posterior and Occipital
1.) Occipital Condyle
2.) Dens of Axis
3.) Atlas (C1)
4.) Axis (C2)
* Pivot Points - Nod up and down
Ascending Pathway
Up the Brainstem and Spinal Cord (posterior, lateral, anterior cord)
Why is there no Anterior Spinal Ganglion?
No Anterior Ganglion b/c cell bodies anterior are located in Anterior horn, so no extra cells to give (motor function), per lecture
Where are Descending Pathways on the Cord?
Lateral and Anterior areas
Where do the Inferior Articular Process and Superior Articular Process meet?
The Inferior Articular Facet
Why is the Cervical Vertebral Foramen Wider than others?
The top of the Spinal Cord is larger towards the neck
Name the structures
1) Soma
1a) Integrates signal
1b) Cellular machinery
2) Dendrites
2a) Receives and processes signal
3) Axon hillock
4) Myelin
5) Node of Ranvier
6) Axon
6a) Sends signal
7) Presynaptic terminal
7a) Releases neurotransmitters
Name the structures
1) Brain stem
1a) Midbrain (mesencephalon)
1b) Pons
1c) Medulla oblongata
2) Telencephalon (cerebral hemisphere)
3) Diencephalon
4) Cerebellum
5) Spinal cord
Name the structures
Grey Matter:
A) Dorsal Horns
B) Ventral Horns
C) Posterior medial sulcus
D) Anterior medial sulcus
E) Central Canal
F) Lamina 10 (grey portion); White portion is AWC
Brain Superficial view
Name the structures
- Frontal lobe
- Lateral sulcus
- Temporal lobe
- Pons
- Medulla oblongata
- Cerebellum
- Occipital lobe
- Post Central gyrus
- Central sulcus
10) precentral gyrus
Brain: Coronal X-Sectional View
Name the structures
- Cerebral cortex
- Caudate nucleus
- Putamen
- Globus pallidus
- White matter
- Claustrum
- Amygdala
- Diencenhalon
Brain Sagittal X-Section:
Name the structures
- Cingulate gyrus
- Pineal
- Corpus callosum
- Hypothalamus
- Hypophysis
- Pons
- Cerebellum
- Medulla oblongata
- Occipital lobe
Spinal Nerves Detail
What do the red arrows indicate? Dorsal: Sensory
Ventral: Motor
Answer Blank Lines: Posterior Rootlets, Posterior Root, Spinal Ganglion, Anterior Rootlets, Anterior Root
Cervical Vertebra
Vertebral Foramen, Lamina, Pedicle, Transverse Process with Sulcus for spinal nerve, Spinous Process, Superior Articular Facet, Transverse Foramen
Ascending Spinal Tract
Rear of the Cord, Horizontal Cross-Section, White = ?
CSpine Vasculature
Vertebral Transverse Foramen, Atlas, Axis, Transverse Process, Spinal Nerve in Sulcus, C7 Spinal Nerve, Vertebral Artery
Dermatome Man
C2-C3 Sensory head and neck, T1,T2, L1-L5, S1,S5
Descending Pathway
Laterial and Anterior Portions
Spinal Curvature
Cervical Lordosis, Thoracic Kyphosis, Lumbar Lordosis, Sacral Kyphosis
Vertebra Superior View
Spinous Process, Superior Articular Facet, Transverse Process, Superior Articular Process, Vertebral Foramen, Vertebral Arch, Body, Nerve Roots
Normal Vertebral Anatomy
Vertebral Body, Vertebral Arch (pedicle, lamina), Superior/Inferior Articular Process, Spinous Process, Transverse Process
Lateral Vertebral Anatomy
Body, Pedicle, Vertebral Notch (inferior), Inferior/Superior Articular Process, Spinous Process, Inferior Articular Facet
Posterior Body View
1.) Iliac Crest
2.) Posterior Superior Iliac Spine
3.) Greater Trochanter of Femur
Spinal Cord: Lateral View
1.) Inferior Costal Facets
Red Circles
Thorax: Anterior View
1.) Sternum
a.) Manubrium
b.) Body
c.) Xiphoid Process
Sacrum: Posterior View
1.) Posterior Sacral Foramen
2.) Sacral Canal
3.) Superior Articular Facet
4.) Lateral Sacral Crest
5.) Median Sacral Crest
6.) Medial Sacral Crest
7.) Sacral Hiatus
8.) Sacral Cornua
Neck: Ligaments
1.) Anterior Atlanto-Occipital Ligament
2.) Posterior Atlanto-Occipital Ligament
3.) External Occipital Protuberance
Neck: Posterior and Occipital
1.) Occipital Condyle
2.) Dens of Axis
3.) Atlas (C1)
4.) Axis (C2)
* Pivot Points - Nod up and down
Spinal Ligaments
1.) Anterior Longitudinal Ligament
2.) Posterior Longitudinal Ligament
3.) Ligamentum Flava
4.) Interspinous Ligament
5.) Supra Spinous Ligament
6.) Inter Transverse Ligament
Posterior Pelvis
1.) Iliolumbar Ligament
2.) Supraspinous Ligament
Spinal Meninges
1.) Pia Mater
2.) Arachnoid Mater
3.) Subdural Space
4.) Dura Mater
Intervertebral Discs
1.) Anulus Fibrosus
2.) Nucleus Pulposus
3.) Hyaline Cartilage End Plate
Neck Ligaments
1.) Supraspinous Ligament
2.) Nuchal Ligament
Rib Articulations
1.) Costal Facet (transverse process)
2.) Costal Tubercle
3.) Joint of Head Rib
Shape? Heart shape body
Aorta? compresses L side of vertebral bodies of T spine
Disc Herniation
1.) Nucleus Pulposus
2.) Postolateral Herniation
3.) Spinal Nerve
Anterior Pelvis
1.) Pubic Tubercle
2.) Promontory
3.) Anterior Superior and Inferior Iliac Spines
Posterior Pelvis
1.) Iliac Crest
2.) Posterior Superior and Inferior Iliac Spines
3.) Sacral Canal
Thoracic Vertebrae
1.) Body
2.) Inferior Costal Facet
3.) Inferior Articular Facet
4.) Spinous Process (diagonal)
5.) Costal Facet on Transverse Process
6.) Transverse Process
7.) Superior Articular Facet
8.) Superior Costal Facet
Lumbar Spine
1.) InterVertebral Foramen
a.) Inferior Vertebral Notch
b.) Superior Vertebral Notch
2.) Inferior Articular Facet
3.) Spinous Process
Neck MRI
1.) Apex of Dens (C2)
2.) Nuchal Ligament
Spinal Cord
1.) Inter Transverse Ligament
2.) Posterior Longitudinal Ligament
3.) Anterior Longitudinal Ligament
4.) Ligamenta Flava
* Which structure was taken off for exposure? The vertebral Body
Axis Superior
1.) Dens
2.) Transverse Process
3.) Spinous Process
4.) Vertebral Arch
5.) Transverse Foramen
Lateral Sacrum
1.) Promontory
Atlas
1.) Posterior arch
2.) Superior Articular Facet
3.) Facet for Dens
4.) Anterior Tubercle
5.) Anterior Arch
6.)Transverse Foramen
7.) Transverse Process
8.) Posterior Tubercle
Anterior Sacrum
1.) Promontory
2.) Superior Articular Process
3.) Anterior Sacral Foramen
4.) Transverse Lines
Rib
1.) Neck
2.) Head
3.) Costal Tubercle
Axis Lateral View
1.) Anterior Articular Facet
2.) Dens
Why is the C1 name Atlas, per lecture?
Atlas was the God who held the world on his shoulders
Does the Atlas have a vertebral body?
No; Anterior Arch instead
Does the Axis have a vertebral body?
Yes
How do C1 and C2 connect?
On the anterior arch; C1 has a Facet for the Dens (posterior) for the Dens of C2 (anterior)
How does C1 connect with the base of the skull?
C1 - Superior Articular Facets; Skull - Occipital Condyles (inferior)
What is the Foramen Magnum?
Opening in the inferior skull for the spinal cord
What are the Atlanto-Occipital Ligaments for?
Ant/Post - connect top of the spine together in the Foramen Magnum
What is the Dens of Axis? Where is it located?
Connects C2 with C1 in the Posterior Anterior Arch (C1); located on superior portion of C2
How are we able to “Nod up and down”?
Pivot points located on Base of Skull and C1
How are we able to move our head side to side?
Swivel point on Dens of Axis (bone to bone connection, but flexible)
Spinal Ligament: Anterior Longitudinal Ligament
Anterior portion of vertebral body; runs from sacrum to skull; made of collagen
Spinal Ligament: Posterior Longitudinal Ligament
Posterior portion of vertebral body; made of collagen
Spinal Ligament: Supraspinatous Ligament
On top of spinous process all the way down spinal cord; made of collagen
Spinal Ligament: Inter-transverse Ligament
Links tips of transverse processes together; made of collagen
Spinal Ligament: Interspinous Ligament
connects spinal processes together; more cover area than; made of collagen
Spinal Ligament: Ligamentum Flava
connects anterior arches of vertebrae together; more stretchy and elastic (yellow color to show this); when poking with a needle, can feel a change in resistance
On the Spinal Ligaments Anterior view, which structure was removed to show the underlying structures? Per lecture
the vertebral bodies were removed and pedicles were cut
What is the midline opening/incomplete fusion in the spinal cord ligaments?
Most people have this, so when approaching cervical spine, go at a different angle to avoid hitting “empty” space
How does Dr. Schmidt describe the appearance of the Nuchal Ligament?
Fan-Like/ shape
What is the Nuchal Ligament?
The extension of the interspinous ligaments in the back of the neck; fan-like structure
What does the Posterior Atlanto-Occipital Ligament connect together?
The Arch of C1 and the posterior part of the Foramen Magnum @ base of the skull
What is the External Occipital Protuberance?
The nuchal ligament connects with the supraspinous ligament at the base of the skull
How does Dr. Schmidt describe a protuberance?
A nub or raised bump
What is the anatomical marker located on C7/T1?
Vertebral Prominens
According to Dr. Schmidt, which vertebral body is bigger? C7 or T1? What does the textbook say?
Schmidt - T1>
Textbook - C7>
What is different about the Thoracic vertebrae?
It is sloped at a downward angle, so must go in at a different angle than midline
How many ribs do we have?
24, 12 pairs
How does Dr. Schmidt describe the Thoracic Spine?
Very strong and robust, do to all the connections
What does Robust mean?
Strong
How many connections do most ribs have on the T-spine?
2; body of thoracic vertebrae and transverse process
What are our true ribs?
Pairs 1-7
What are the False ribs?
Pairs 8,9,10
What are the floating ribs?
Pairs 11,12
Why are they called false ribs?
They connect to the 7th rib’s cartilage, rather than the sternum itself
What are the 3 parts of the Sternum?
Manubrium, body, xiphoid process
How would a rib connect to a thoracic vertebrae? Specific example
Head attaches to superior costal facet of T7 and inferior costal facet of T6
Where does the Neck of the rib combine with the transverse process of T spine?
The costal tubercle
What is the T-spine body shape, per lecture
Heart
Per lecture, why is the left side of the T-Spine vertebral body flat?
The Aorta compresses it
What can you have a pt do to open up the L-spine further?
Make them lean forward
How does L5 connect with S1?
L5 inferior articular facet and S1 superior articular facet
What are the Intervertebral Foramen?
Inferior and Superior Vertebral Notch; come off the pedicle and give a space for spinal nerves to leave the spine
How many Sacral Vertebrae are we born with?
5; fused by 14-15 years
What do Sacral Transverse Lines Show?
Fusion of the 5 Sacral Vertebrae
Why is the Sacral Promontory Important?
Has intervertebral disk sitting on it and helps bind S1 to L5
Why is the Sacral Canal important?
The spinal ligaments and spinal nerves exit here
How many anterior/posterior foramen do we have?
8 front/ 8 back (4 each side)
What are the directions for a S2 block, after finding the anatomical marker?
Down 1 cm, midline 1 cm - right at S2
What is the Anatomical Marker for a S2 block?
Posterior Superior Iliac Spine
What is the less common anatomical marker for a S2 block?
Posterior Inferior Iliac Spine
What is the palpable portion of the sacrum?
The remnants of the spinous processes
What is the Lateral Sacral Crest?
Fusion of the transverse processes
What is the Medial Sacral Crest?
Fusion of the Superior/Inferior Articular Processes
What is the Sacral Hiatus?
The portion of the sacrum that allows for ligaments and the 1 coccygeal nerve pair to exit
What are Sacral Cornu?
Raised projections on the Sacral Hiatus
How many Coccygeal Vertebrae are we born with? Which ones fuse together?
4; 2,3,4 fuse together and 1 stays alone (giving us 1 pair)
What is the Iliac Crest?
Most Superior ridge of the pelvis; palpable; if you draw a line between the iliac crests, you will be at the L4 body
Anatomical marker for spinals/epidurals
Iliac Crests/L4 body
What is the Pubic Tubercle?
Raised bump for the inguinal ligament to attach to
What is the Inguinal Ligament?
Connects the Anterior Superior Iliac Spine to the Pubic Tubercle
What is the Pubic Symphasis?
The cartilage that connects the L and R side of the pelvis anteriorly
What is the Iliolumbar Ligament?
Connects L4,L5 to the Posterior Superior Pelvis
How does a female pelvis differ from a male?
Wider and broader hips
2 sets of hips?
Lower Set - Greater Trochanter of the Femur
Higher Set - Top side of the pelvis
Where is the Supraspinous Ligament?
On the tips of the spinous process all the way down the spinal cord
Do Sacral Vertebra have intervertebral disks?
No, all fused together
What is the Nucleus Pulposus?
The gel-filled center of the disk
What is the Anulus Fibrosis?
The fiber wrapped around the disk
How does Dr. Schmidt describe the Anulus Fibrosis?
ROBUST/STRONG
How does the Anterior Anulus Fibrosis differ from the Posterior portion?
Anterior has a criss-cross pattern, making it more STRONG; back has normal pattern, making it WEAKER
What are 3 ways to fix disc herniation?
Discectomy, Spinal Fusion, Laminectomy
What is the Hyaline Cartilage End Plate?
The cartilage that “sandwiches” the tops and bottoms of the disks together
Spinal Fusion
Very Invasive; plates and screws added to the front of the vertebrae; after 6-7 years, can damage the disks above and below do to increased stress
Discectomy
Minimally Invasive; remove the herniated disk
Per lecture, who should do your spinal surgery?
Neurosurgeon>ortho
Laminectomy
Shave part of the lamina bone to relieve pressure by giving the nerve a wider space
Ways to help your back problems?
PT and Hamstring stretches
Pia Mater
Layer directly attached to neurons and glial cells
Arachnoid Mater
Layer superficial to Pia and Large blood vessels; translucent in color
Dura Mater
Outermost Meninge; superficial; tough and robust
Subdural Space
A “potential space” between the Dura Mater and Arachnoid Mater
CSF in the Meninges
Located in the Subarachnoid Layer
Out –> In layers of Meninges
Dura, Arachnoid, Pia Mater
Blood vessels in the Meninges
Sit above the pia mater and below the arachnoid layer
Neuron Types
1.) Multipolar
2.) Pseudounipolar
3.) Bipolar
Glial Cells
1.) Astrocyte
2.) Ependymal Cell
3.) Oligodendrocyte
4.) Microglial Cell
Spinal Cord: Lateral View
1.) Anterior Longitudinal Ligament
2.) Posterior Longitudinal Ligament
3.) Ligamentum Flava
4.) Interspinous Ligament
5.) Inter-transverse Ligament
Spinal Cord Blood Supply
1.) Sulcal Artery
2.) Anterior Spinal Artery
3.) Anterior Segmental Medullary Artery (BF from Costal Arteries)
4.) Posterior Segmental Medullary Artery (BF from Costal Arteries)
5.) Vasocorona Artery
6.) Posterior Spinal Arteries (BF from Brain, Spinal Cord)
Putting the Neck Together
- Intervertebral Disc: Name 3 Parts
- Anterior Longitudinal Ligament
- Posterior Longitudinal Ligament
- External Occipital Protuberance
- Dens of Axis
- Posterior Atlanto-Occipital Ligament
- Nuchal Ligament
- Ligamentum Flava
- Transverse Process
- Vertebral Foramen
- Spinous Process
- Interspinous Process
- Supraspinous Process
Putting the Neck together
1.) Supraspinous Ligament
2.) Atlas (C1)
3.) Dens of Axis
4.) Ligamenta Flava
5.) Nuchal Ligament
6.) Anterior Longitudinal Ligament
7.) Posterior Longitudinal Ligament
1.) Epidural Space (filled w/adipose tissue - yellow)
2.) Subarachnoid space
3.) Arachnoid Mater
4.) Spinal Dura Mater
5.) Posterior Root (dorsal)
6.) Anterior Root (Ventral)
7.) Spinal Nerve
8.) Spinal Ganglion
1.) Dural Sac
2.) Spinal Dura Mater
3.) Spinal Ganglion
4.) Cauda Equina
5.) Epidural Space
1.) Vertebra Prominens (C7)
2.) Cervical Enlargement
3.) Lumbrosacral Enlargement
4.) Conus Medullaris
5.) Cauda Equina
6.) Spinal Dura Mater
7.) Spinal Arachnoid
8.) Spinal Ganglia
1.) Spinal Ganglion
2.) Cauda Equina (post/ant spinal roots)
3.) Spinal Dura Mater
4.) Spinal Arachnoid
5.) Filum Terminale
6.) Sacral Hiatus
1.) Cervical
2.) Thoracic
3.) Lumbar
4.) Sacral
5.) Cauda Equina
6.) Conus Medullaris
7.) Nerve Roots
1.) Conus Medullaris
2.) Cauda Equina
3.) Filum Terminale
1.) Subarachnoid Space (CSF)
2.) Cerebellum
3.) Medulla
4.) Cisterna Magna
5.) Spinal Cord
6.) Spinous Process
7.) Ligamentum Flavum
1.) Vertebral Bodies
2.) Intervertebral Disc
3.) Conus Medullaris
4.) Lumbar Cistern
Why 15 degree angle?
To avoid hitting the T-Spine Spinous Process, at is is sloped at an inferior diagonal angle
1.) If ventricles grow, hydrocephalus
2.) 3rd Ventricle
3.) Cerebral Aqueduct
4.) 4th Ventricle
5.) Lateral Apertures (Foramen of Luschka)
1.) Arachnoid Granulations
2.) Superior Sagittal Sinus
3.) Dura Mater
4.) Pia Mater
1.) Dura Mater
2.) Arachnoid Mater
3.) Tentorium cerbelli
1.) Epidural Hematoma
2.) Arachnoid Mater
3.) Arachnoid Trabeculae
4.) Pia Mater
5.) Cerebral Artery
6.) Subarachnoid Space
7.) Cerebral Vein
8.) Subdural Hemorrhage
9.) Dura Mater
10.) Cranial Bone
1.) Arachnoid Granulations
2.) Choroid Plexus (lateral vent)
3.) Choroid Plexus (3rd vent)
4.) Straight Sinus
5.) Cerebral Aqueduct
6.) Confluent of the Sinuses
7.) Choroid Plexus (4th vent)
8.) Cerebellomedullary Cistern (Cisterna Magna)
9.) Median Aperture (Foramen of Magendie)
10.) Central Canal of the Spinal Cord
11.) 4th Ventricle
12.) 3rd Ventricle
13.) Interventricular Foramen ( Foramen of Monroe)
14.) Superior Sagittal Sinus
1.) Corpus Callosum
2.) Interventricular Foramen (Foramen of Monroe)
3.) Medulla Oblongata
4.) Pons
5.) Hypothalamus
1.) Lateral Ventricle
2.) Cerebral Aqueduct
3.) Median Aperture of 4th vent (Foramen of Magendie)
4.) Central Canal
5.) Lateral Aperture of 4th vent
6.) 4th Vent
7.) 3rd Ventricle
8.) Interventricular Foramen (Foramen of Monroe)
Other name Median Aperture of 4th Ventricle?
Foramen of Magendie
1.) Superior Sagittal Sinus
2.) Confluence of the Sinuses
3.) Transverse Sinus
4.) External Occipital Protuberance
5.) Sigmoid Sinus
6.) Internal Jugular Vein
1.) Falx Cerebri
2.) Superior Sagittal Sinus
3.) Inferior Sagittal Sinus
4.) Tentorium cerebelli
5.) Sinus Confluence
6.) Transverse Sinus
Another name for Interventricular Foramen?
Foramen of Monroe
1.) Cavernous Sinus
2.) Sigmoid Sinus
3.) Transverse Sinus
4.) Confluence of the Sinuses
5.) Superior Sagittal Sinus
6.) Straight Sinus
7.) Tentorium Cerebelli
Another name for Cerebellomedullary Cistern?
Cisterna Magna
Another name for Lateral Apertures of 4th ventricle?
Foramen of Lushka
1.) Superior Sagittal Sinus
2.) Inferior Sagittal Sinus
3.) Straight Sinus
4.) Sinus Confluence
5.) Transverse Sinus
6.) Sigmoid Sinus
7.) Cavernous Sinus
8.)
9.)
10.) Falx Cerebri
11.) Tentorium Cerebelli
1.) Superior Sagittal Sinus
2.) Inferior Sagittal Sinus
3.) Straight Sinus
4.) Confluence of Sinuses
5.) Transverse Sinus
1.) Superior Sagittal Sinus
2.) Sinus Confluence
3.) Transverse Sinus
4.) Sigmoid Sinus
5.) External Jugular Vein
6.) Interior Jugular Vein
1.) External Carotid Artery
2.) Common Carotid Artery (Internal)
3.) Vertebral Artery
Where are vessels located in the meninges?
Inferior to the Arachnoid Layer
What is the middle ground between the CNS and PNS?
Spinal Nerve
What is the Epidural Space filled with? How does this effect blocks?
Adipose and vessels; makes onset of lipophilic anesthetic slower and end longer
Safest place to do a spinal block? Why?
Cauda Equina; spinal cord is not behind these nerves, so less dangerous
What does Cauda Equina mean?
“Horse’s Tail”
Where does the spinal cord start and stop?
The medulla to the Conus Medullaris (at L1)
What is the end of the spinal cord called? Where does it stop?
Conus Medullaris (L1)
What are the 2 enlargements in the Spinal Cord? Why?
Cervical (C3-C6) and Lumbar (T11-L1); high sensory and motor functions such as hands, arms, legs, feet
What does the Cervical Enlargement turn into?
Brachial Plexus (lots of nerves in shoulder)
What does the Lumbar Enlargement turn into?
Lumbar Plexus/Sciatic Nerve
What is the Conus Medullaris?
The end of the spinal cord @ L1 level
What is the Cauda Equina?
“Horse tail”; collection of nerves that extends off Conus Medullaris
What is the Filum Terminale (internum)?
Connective tissue that anchors the dural sac in place; located between the Conus Medullaris and the end of the Dural Sac
What is the Filum Terminale (externum)?
Connective tissue that keeps the dural sac in place; located outside the dural sac and ends at the coccyx
How far does the Dural Sac extend?
from below the Conus Medullaris to the “S2” area of the sacrum
What is the Dural Sac? Another name for it?
A sac full of CSF; Lumbar Cistern
What are the Filum Terminale’s extensions of?
The Pia Mater/Pia Layer
The bone grows faster than the _ lengthens?
Cord
In a newborn, where is the Conus Medullaris?
L3
Nuchal Ligament is an extension of what?
Interspinous Ligaments
How wide is the spinal cord?
As wide as a quarter
What color is CSF/water on a CT scan?
Black
Describe T-Spine spinous process, per lecture
Inferior diagonal angle
How does CSF get from the brain down the spinal cord?
The central canal and the ependymal cells within
Where can CSF get stale?
The Dural Sac (Lumbar Cistern)
Where can you get CSF samples?
L3-L4, L4-L5, Sacral Hiatus
What angle off midline do you use to get past an unfused Ligamentum Flava in the spine?
15 degrees off midline
Which plane do you cut through to see the Corpus Callosum?
Sagittal Plane
What controls the CSF?
Astrocytes
pH of CSF?
7.31
HCO3 of CSF
Lower in brain than Plasma
Why is the CSF more acidic than the blood?
HCO3 buffers CO2 off brain cells from metabolism
Na+ in CSF
Similar to body (140 mOsm/L)
Cl- in CSF
Higher in CSF; close to Na+ levels (increased permeability = resting)
K+ in CSF
40% less than in plasma
Mg in CSF
Higher than plasma volume
All of the differences in electrolytes in the CSF combine to become _ of the CNS?
“Brakes”
Glucose in CSF vs Plasma
60 mg/dL vs 90 mg/dL
How does glucose get into the CSF?
Glut-1 transporters from the CV system via facilitated diffusion
What color is CSF (normally)
Clear
How much total CSF is in the body if we took it out and put it in a beaker?
150 mL
How much CSF do we produce each day? How many times does it get refreshed per day?
500 mL; 3 times per day; faster near brain
What is an Epidural Hematoma? What is a common way to get one?
Bleeding in the epidural layer (Superior to the Dura); Skull fracture
Is an Epidural Bleed: Arterial vs Venous Bleed?
Arterial
Columns between the Pia and Arachnoid that create space for vessels and CSF?
Arachnoid Trabeculae
What is a Subdural Hemorrhage?
Bleeding under the dura (inferior)/subdural space
What type of bleed is a Subdural Hemorrhage: Arterial or Venous
Venous
What does the Dura Mater go along with? Reason why it is a venous bleed in a subdural hemorrhage?
Goes along with the Venous Sinuses
True or False, The cranial bone has arteries and veins?
True, bone needs to perfuse too
What is a Subarachnoid Hemorrhage?
Vessels under the arachnoid layer rupture
What type of bleed is a Subarachnoid Hemorrhage?
Arterial
Which bleeds faster, Arterial or Venous bleed?
Arterial
How do the Ependymal Cells push Na+ out from the Blood to the CSF?
Na+ ATPase pump
What are Ependymal Cells “Leaky” to?
Na+, Cl-, H20
What regulates the K+ in CSF?
Astrocytes
What is the Tissue Group of Ependymal Cells responsible for producing CSF?
Choroid Plexus
CSF Flow in Brain?
Lateral Vents –> Interventricular Foramen (Foramen of Monroe) –> 3rd Ventricle –> Cerebral Aqueduct (Aqueduct of Sylvius) –> 4th Ventricle –> Lateral Apertures (Foramen of Luschka) OR Median Apeture (Foramen of Magendie) OR Central Canal
Another Name for Cerebral Aqueduct
Aqueduct of Sylvius
What is the Cerebral Aqueduct?
Takes CSF from 3rd Ventricle to 4th Ventricle
What happens if you block one of the paths of CSF flow?
CSF builds up in the Ventricles = increased ICP
2 Types of Hydrocephalus
Communicating and Non-Communicating
Communicating Hydrocephalus
Structures work fine, but CSF is not absorbed/removed like normal (issues with Arachnoid granulations); non-swelling vents
Non-Communicating Hydrocephalus
Issues with blocking of CSF flow structures, leading to swelling ventricles
What are Arachnoid Granulations
“Blow off Valves” located on superior brain @ longitudinal fissure; when ICP gets high, open up and release CSF
Easiest CSF path to block? Why? Solution?
Cerebral Aqueduct (Aqueduct of Sylvius) b/c it is narrow; Cranial bolt
Normal ICP per lecture
10 mmHg
What does the Cerebellum do?
Coordinates complex tasks such as “walking down the street”
What feeds the Cerebellum CSF from the Median Aperture (Foramen of Magendie)
The Cerebellomedullary Cistern (Cisterna Magna)
Another name for the Cerebellomedullary Cistern?
Cisterna Magna
What is the Straight Sinus?
Sinus that connects the Superior and Inferior Sagittal Sinuses
What is the Sinus Confluence?
Sinus where all Sinuses come together before lateral flow
Sigmoid Sinus and what kind of “turn” per Schmidt
Drains sinus into Internal Jugular; “hairpin” turn
Transverse Sinus
Sends Blood Flow L or R
Falx Cerebri
Connective tissue that separates L and R hemispheres
Tentorium cerebelli
The floor for the occipital lobe to sit on like a shelf; cerebellum is deep compared to this structure; occipital lobe is superior
Common (internal) Carotid Artery
Feeds brain blood
External Carotid Artery
Feeds superficial structures blood
Brain Blood Flow
750 mL/min OR 50 mL/min/100G of brain tissue
Normal CO per lecture
5L/min
Brain Blood flow is what % of the CO?
15%
What % of weight in body is the brain
2-3%
What % of Brain Blood Flow is Routed to White areas?
20%
What % of Brain Blood Flow is routed to grey areas?
80%
- Ruptured Aneurysm
- Superior Sagittal Sinus
- Falx Cerebri
- Inferior Sagittal Sinus
- Ruptured middle meningeal artery
- Subarachnoid Space
- Dura Mater
- Anterior Cerebral Artery
a.) A2, Postcommunicating Anterior Cerebral Artery
b.)A1, Precommunicating Anterior Cerebral Artery - P2, Postcommunicating Posterior Cerebral Artery
- Posterior Cerebral Artery
- P1, Precommunicating Posterior Cerebral Artery
- Anteroinferior Cerebellar Artery
- Posteroinferior Cerebellar Artery
- Vertebral Artery
- Basilar Artery
- Superior Cerebellar Artery
- Posterior Communicating Artery
- Middle Cerebral Artery
- Internal Carotid Arteries
- Anterior Communicating Artery
- Vertebral Arteries
- Internal Carotid Arteries
- Basilar Artery
- P1, Precommunicating Posterior Cerebral Artery
- P2, Post-communicating Posterior Cerebral Artery
- Posterior Communicating Artery
- A1, Precommunicating Anterior Cerebral Artery
- A2, Post-communicating Anterior Cerebral Artery
- Anterior Cerebral Artery
- Anterior Communicating Artery
- Pons
- Superior Cerebellar Artery
- Middle Cerebral Artery
- Superior Cerebellar Artery
- Basilar Artery
- Anteroinferior Cerebellar Artery
4.Posteroinferior Cerebellar Artery - Vertebral Artery
What is the largest artery in the Circle of Willis?
Middle Cerebral Artery
What are the 4 main arteries that feed brain circulation?
Carotid Arteries (2 internal), Vertebral Arteries (2)
Brain Flow is dependent on _? Coma BF?
Cerebral Metabolism (CO2); Coma = Decreased metabolism (decreased CO2)
Why is the Circle of Willis Important?
It is a pathway that ensures collateral blood flow if one of the arteries is blocked or damaged
What do the 2 Vertebral Arteries form?
Basilar Artery
3 Large Arteries in Brain
Anterior Cerebral Artery, Posterior Cerebral Artery, Middle Cerebral Artery (internal carotids)
Which cerebral artery connects the 2 sides of the Anterior Cerebral Artery?
Anterior communicating artery
Which artery connects the Posterior Cerebral Arteries to the Middle Cerebral Arteries?
Posterior Communicating Arteries
What is autoregulation?
The system able to maintain blood flow to the brain, despite changes
AR: Increase in BP, what happens to the vessels?
Vasoconstriction to maintain normal BP
AR: Decrease in BP, what happens to the vessels?
Vasodilation to maintain normal BP
AR: Normal Range
50 mmHg - 150 mmHg
Shape of line if no AR?
Linear
Shape of Line with Volatile Anesthetics?
Sloped Line (increased slope = increased change in AR)
Pressure Examples in AR
MAP, CPP
No AR: HTN
Blow up Aneurysms; vessels can only constrict so much, so after >150 mmHg, BP will increase
No AR: Hypotension
Cell Death, vessels can only dilate so much, so once under 50 mmHg, BP will decrease
Chronic HTN AR: What happens to arteries? What happens to LLA and ULA?
They harden to help constrict better (Arteriosclerosis); they increase as they adapt (cannot drop Pt to original LLA as it may cause cellular death)
AR: Limits
2 points that if we go past, no AR will occur (<50 mmHg)(>150 mmHg)
Chronic HTN AR: ULA and LLA
Right shift, as body and brain adapt to these chronic changes; Ex: 50 - 100 and 150 - 200
How do Volatile Anesthetics affect AR?
They reduce the amount of AR (Slope line); more effected = more slope
AR: How do DM2 and HTN affect blood vessels?
Zap the vessels ability to dilate, leading to increased stroke and HR risks
AR: CV health = ?
Ability to dilate vessels
AR: Error Bars
More variability in the data = longer length (means data is inconclusive)
What are P-Type Ca++ Channels? How do they open?
Calcium channels that release Ca+ into the presynaptic cell after depolarization
Ways the Cell resets a Motor Neuron Post AP (4 ways)
NaK ATPase pump, Ca++ ATPase pump, V-G K channels (open during AP), Ca++ sensitive K+ channels (Ca++ influx sends K out)
What does Ca+ bind to within the Presynaptic cell? What do these cells do?
ACh vesicles near the cell wall; called Vesicle Pool 2 cells [VP2}; bind to the cell wall and release ACh into the NMJ
Difference between VP2 and VP1 Vessicles?
VP2 are near cell wall and ready to drop ACh into the NMJ; VP1 are immature and need to finish filling up OR work on moving closer to the cell wall
How does Calcium get shut off in the Presynaptic Cell?
Ca ATPase pump sends Ca++ out of the cell via Active Transport, preventing VP2 from being activated, stopping the release of ACh
ACh receptors on Skeletal Muscle
Very close to NMJ, 2 binding sites that have to be bound simultaneously, nACh-R bound opens up for Na+ to flood in with small amounts of Ca++ (K+ small amount out)
What is an End Plate Potential?
Type of Depolarization that is on the Postsynaptic terminal that results from influx of Na+ into the cell (localized depolarization)
End plate potential, in comparison to, AP
EPP is the initial stimulus and AP is the reaction to that initial stimulus
How does the Postsynaptic Terminal (skeletal muscle) create an AP?
The fast Na+ channels are next to the nACh-R, so with depolarization/end-plate potential, the Fast Na+ channels will be activated, creating an AP within the skeletal muscle, leading to muscle contraction
What is the Sarcoplasmic Reticulum?
Sarco means muscle; The ER of a muscle cell; stores Ca++
What are muscles good for?
Keeping body warm, locomotion, communication, expression
How do Volatile Anesthetics effect Muscles?
They take them offline (no warmth, etc)
How many motor neurons does it take to innervate a skeletal muscle? Give example of a Muscle that takes more than 1 Motor Neuron
1 or Many motor neurons; ocular muscle uses many motor neurons
How do Motor Neurons get the signal to contract?
Descending pathways from the brain and spinal cord on the ventral horn or Reflex arcs (sensory/pain) from the dorsal horn
What are transverse tubules and why are they important?
Since the muscle cells are very large, transverse tubules take the AP DEEPER into the muscle, making sure the muscle gets the full contraction; Perpendicular Pathway
What is Actin/Myosin in a Skeletal Muscle? What are they driven by?
The contractile elements of the muscle; driven by Ca++
Do muscles shorten or lengthen during a contraction?
Shorten
How long is the longest muscle cell?
Over a foot
What is AChesterase? How does it work and where is it located
Breaks down ACh as it comes in contact with Skeletal muscle; it is fastened to the skeletal muscle; limits rate of depolarization, as it breaks down ACh
How does AChesterase break down ACh?
It uses Hydrolysis to degrade the Ester bond, separating Acetyl and Choline
How is Choline sent back into Motor Neuron?
Choline is sent back to the Motor Neuron via a Choline ATPase pump and a 2nd Active Transport pump of Choline/Na+
What produces Acetyl (acetate) in the Motor Neuron to be bound with choline?
The mitochondria
Difference between Primary and Secondary Clefts on Skeletal Muscle
Primary - 1 infold (subneural)
Secondary - 2 infold
How many ACh molecules does a motor neuron need to send to generate a response?
About 1 million (2 binding sites); usually will send around 2 million ACh molecules, as some do not make it and get chopped up by AChesterase
How many ACh-R are located on Skeletal Muscle at NMJ
5 Million
How many ACh-R are activated during a typical response?
500,000 (10%)
How does K+ generally leave a skeletal muscle/motor neuron?
Leaky K+ channels
What is Curare? Where is it found? What drugs are derived from it?
A paralytic agent found in the rainforest; NDMR are derived from Curare
What is the DHP-receptor/sensor?
Dihydropyridine Sensor; senses an Action Potential and pulls on the door of the RyR channel, releasing Ca++ into the Sarcoplasm to cause contractions of the Actin/Myosin
Where can we store extra choline?
Cell wall via Phosphatidylcholine
The NMJ is _ dependent? What is this process called?
Ca++ dependent to send off VP2 cells to cell wall; Exocytosis
What is a cleft on a skeletal muscle?
Place where ACh-R and Fast Na+ channels are located
When a nACh-R is open, what ions come in? Out?
In - Na+ 1st, Ca++ 2nd
Out - Small amounts of K+
What is the RyR channel? Where is it located?
Ryanodine Channel that has Ca++ stored behind a “door”; when an AP comes through, the DHP-Sensor will open the door, allowing for Ca++ to flood into the Sarcoplasm. It is located on the SR
Where are the DHP-receptors located?
Cell wall and T-tubules (send contraction deep into the muscle)
How is Ca++ put back into the SR after a muscle contraction?
The RyR door shuts and a SERCA Ca++ pumps uses active transport/ATP to shove the Ca++ back in
Is MG a presynaptic or postsynapic disease?
Postsynaptic Disease
What is the SERCA Pump? What does it do?
Sarcoplasmic Endoplasmic Reticulum Calcium ATPase Pump; pushes Ca++ back into the SR via active transport
How does Ca++ get into the Motor Neuron?
After activated by an action potential, P-Type Ca++ channels send Ca++ into the Motor Neuron
What is an End-Plate Potential?
Initial Stimulus on Skeletal Muscle that causes an Action Potential
What structure in the Motor Neuron creates Acetate?
Mitochondria
Patho of MG
Immune response to goofy Thymus; Antibodies bind to nACh-R and immune system destroys them and cause scarring in the Clefts (decreased surface area for Fast Na+ channels and nACh-R); no muscle contractions as decreased ACh binding/no fast Na+ activated
How do “Stigmines” treat MG
Block AChesterase, allowing for increased depolarization at NMJ and allow for more ACh to bind to cause an AP (leading to muscle contraction)
Tx for MG
Remove Thymus, Plasmapheresis, “Stigmines”
What is LEMS/ELMS?
Lambert-Eaton Myasthenic Syndrome; Developed when a person has Lung Cx; Motor Neuron Based disease (Presynaptic); Send antibodies to block the P-Type Ca++ channels, resulting in less ACh being sent to the cell wall
Tx for LEMS/ELMS
Plasmapheresis, Removal of Lung Tumor, Drugs: TEA [Tetraethyl ammonium] and 4-5 diaminopyridine (they block K+ channels, making it more depolarized to allow for more Ca++ to come in via unblocked P-Type Channels)
Why are the drugs used to treat LEMS dangerous?
Although they block K+ channels, causing increased depolarization for more Ca++ to come in via P-Type Ca++ Channels, they are not specific to motor neurons. Can also block K+ channels in the heart, leading to arrythmias
Curare NDMR
Block the nACh-R on skeletal muscle, which stops ACh from binding, leading to muscle paralysis [only has to block 1 receptor site, not both]
What is Succinylcholine? What is the drug class?
Depolarizing muscle blocking agent that causes local depolarization at the NMJ; it is 2 ACh combined into 1, so AChesterase cannot break it down as it cannot reach the Ester bond
Is LEMS a presynaptic or postsynaptic disease?
Motor Neuron based Disease (Presynaptic)
Sux Phase 1
Muscle contraction/quiver
Sux Phase 2
Constant Na+ leaking into cell, so constant depolarization makes the cell more + at this location and prevents the cell from repolarizing (pushes more K+ extracellularly)
How much does Sux increase Serum K+? Why? In a healthy Pt
Increase by 0.5 mEq (4-4.5); increased depolarization sends more K+ out of the cell down the concentration gradient, leading to more K+ ECF
When to Avoid giving Sux?
Hyperkalemic, Pre-existing slow HR or conditions, Pts with poor muscle quality such as stroke or paralyzed pts (denervated)
Why avoid Sux in Pts with denervation or stroke like injuries?
These types of injuries cause more NMJ at different lengths of the Skeletal Muscle; if give Sux, then all the NMJ will increase the amount of K+ being pushed extracellularly, leading to increased hyperkalemia
