Central Nervous System (Exam II) Flashcards
What are the 4 major lobes of the brain? What do they control?
- Frontal (Personality, planning, thinking, etc.)
- Parietal (Sensory info processing, somatosensory cortex)
- Occipital (Vision primarily)
- Temporal (Right and Left, Hearing and Language)
What are the 3 neuron types found in mammals? Which one is not in mammals?
- Multipolar
- Pseudounipolar
- Bipolar
True Unipolar not found in mammals.
Which neuron type is the most common? What is the defining trait of these?
- Multipolar
- This is the “decision making” neuron.
What is the purpose of pseudounipolar cells? Where are pseudounipolar neurons found? What is the purpose of the nucleus in these cells?
- Sensory information processing.
- They are found in ganglia
- The nucleus mainly just provides cell support.
Where are bipolar neurons found?
- Eyes and ears (i.e. retinas and cochlear/vestibular structures of the ears.)
At resting state, are V-G Na+ channels of most somatic sensory nerve receptors open or closed? What changes this state?
- V-G Na+ channels are closed at Vrm.
- Changes by stretch or pressure opens V-G Na+ on your somatic sensory nerves. This is how we perceive our sensory information.
The Telencephalon is also known as what?
The cerebrum
The Diencephalon controls what functions of the brain? What incredibly important structure is located here?
- Hypothalamus
- Automated functions are controlled in the diencephalon (I.e. infection response, body temp, etc.)
What other name does the midbrain go by?
Mesencephalon
What are the three structures of the brain stem in descending order?
- Midbrain (mesencephalon)
- Pons
- Medulla Oblongata
What does the cerebellum control?
- Complex movement coordination (I.e. sports, driving a car, etc.)
Where does the spinal cord terminate?
Around L1 to L2
What information does the anterior horn of the spinal cord process?
Motor
What information does the lateral horn of the spinal cord process?
Visceromotor
What information does the posterior horn of the spinal cord process?
Sensory
What differentiates vertebral arteries in the C-spine area from vertebral arteries throughout the rest of the spinal column?
Vertebral arteries in the c-spine area are protected by the cervical vertebrae.
Which spinal nerves are necessary for breathing?
C3, C4, and C5
Spinal nerves flow out alongside which bony structures?
Transverse Processes
What foramen do vertebral arteries pass through?
The tranverse foramen
What bony structure of the spine allows for “head swivel”? Which vertebrae is this structure located on? Where does this structure attach to?
- Dens Process
- C2 Axis
- C1 Atlas: Dens Facet
Which two facets fit to the base of the skull, connecting the skull with the vertebrae?
The right and left superior articular facets
What is another name for the C1 Vertebrae? How about the C2 Vertebrae?
- C1 = Atlas
- C2 = Axis
What are the 3 main arteries that feed the spinal cord?
- Anterior Spinal Artery
- Right Posterior Spinal Artery
- Left Posterior Spinal Artery
What thoracic arteries feed the main vertebral arteries? Are these normally located next to each other?
Posterior and Anterior Segmental Medullary Arteries.
No, they are normally staggered.
Which two vascular structures sit inside the Anterior Fissure of the spinal cord?
Anterior Spinal Artery and Anterior Spinal Vein
How many large veins run off the spinal cord? Where are they located?
4 run off the spinal cord. 1 anteriorly and 3 posteriorly.
How many pairs of spinal nerves run through the cervical spine? How many vertebrae are located in the c-spine?
8 pairs of nerves
7 vertebrae
How many pairs of spinal nerves run through the Thoracic spine?
12 pairs of nerves
How many pairs of spinal nerves run through the Lumbar spine?
5 pairs of spinal nerves
How many pairs of spinal nerves run through the Sacral spine?
5 pairs of spinal nerves
How many pairs of spinal nerves run through the Coccygeal spine?
1 pair
Spinal nerves emerge _____ respective vertebrae. Which spinal nerve is the exception and why?
Below
Spinal nerve 1 exits above the C1 Atlas
Why do vertebrae get larger as we progress from the cervical spine to the Lumbar spine?
Vertebrae become larger to account for more weight to hold.
What is scoliosis? Does it usually present with any other conditions? Is it hereditary?
Scoliosis is left or right abnormal curvature of the spine
It usually presents with a degree of kyphosis
Yes, it is hereditary.
What spinal condition could affect ventilation?
Excessive Thoracic Kyphosis could prevent adequate thoracic expansion and compress the heart as well.
What consequences are there when excessive kyphosis or lordosis of the spine is treated with spinal fusion?
Metal fusing plates in the spine prevent normal shock absorption and lung expansion.
What is the joint where C1 meets C2, and rotation of the skull occurs, called?
Atlanto-Axial Joint
Which portion of the Vertebrae is the weight supporting portion?
The Vertebral body
Which spinal nerve runs on top of it’s respective vertebrae as opposed to below?
Spinal Nerve 1.
Comes out above C1
What structural difference of the spinous process would differentiate cervical vertebrae from other vertebrae?
Biphid Spinous Processes
Which two vertebrae have no disc in between them?
C1 and C2
What differentiates newborn spinal curvature and adult spinal curvature? What does this do to a toddler’s gait?
Newborn spinal curvature is mostly kyphotic.
This means that a toddler’s spine development, not being complete yet, makes them unstable and prone to falling.
Where do spinal nerves exit out of the spinal cord space? What two bony structures are above and below this exit space?
The intervertebral foramen
The superior pedicle and the inferior pedicle
What are the portions of the sternum in descending order?
Manubrium
Sternal Angle
Sternal Body
Xyphoid Process
Which ribs are known as “true” ribs? Why?
Ribs 1-7 because the cartilage directly connects to the sternal bone
Which ribs are known as “false” ribs? Why?
Ribs 8-10
This is because the cartilage on these ribs attaches to the cartilage of the ribs above
Which rib connects to the sternal angle?
Rib 2
Which ribs are known as “floating” ribs? Why?
Ribs 11 and 12
This because these ribs have no connection to the sternum
What is the purpose of rib cartilage?
Flexibility for breathing
Shock absorption
From a top down view, what general shape would a lumbar vertebral body possess?
Kidney bean shape
need to verify
From a top down cut view, what shape do the vertebral body’s of thoracic vertebrae have?
Heart shape
What is the purpose of the flattened portion of the vertebral body on the thoracic vertebrae?
This provides room for the thoracic Aorta
Where do spinal nerves exit out of the vertebral foramen? What is directly above and below this exit site?
Spinal nerves exit out of the interveterbral foramen.
Directly above is the pedicle of the superior vertebrae
Below is the pedicle of the inferior vertebrae
What procedure makes access into the spinal column much more difficult?
Spinal fusion surgery.
What are two treatments for disc herniation? What is the problem with one of these?
- Discectomy (less invasive)
- Spinal Vertebral Fusion (last resort) more tension is placed on discs above and below, precluding them for the same problem later. Fusion usually has to be extended.
What is a really good, non-invasive way to treat back pain?
Physical Therapy (duh)
Strengthening of core muscles and hamstrings takes strain off of the vertebrae’s job in stabilizing the back.
Where are the most common sites of disc herniation?
L3 - Sacrum
What two functions does the CSF provide to the spinal cord?
- Nutrient support (glucose and such)
- Shock absorption
What are the 3 layers of the spinal meninges in order of superficial to deep? Is there any space in between these layers? If so, what inhabits this space?
- Dura Mater
- Arachnoid Mater
- Pia Mater
There is the Arachnoid space in between the arachnoid mater and the pia mater for blood vessels and CSF.
Where does the lumbo-sacral enlargement occur?
T11 - L1
What is the name of the tip of the spinal cord? Does this differ in newborns and adults?
Conus Medularis
Adults CM terminates at L1
Newborns CM terminates at L2
What is the range of the Cauda Equina?
L3 - S5
What condition would occur from blocking the arachnoid granulations? What is this?
Communicating Hydrocephalus
Communicating hydrocephalus is characterized by CSF that can’t exit the CNS but all the ventricles are unblocked.
How much CSF circulates at any given time?
150cc
How much CSF is produced every day?
450cc
Is there a pump for CSF fluid? When is CSF produced most?
No CSF flow is passive.
When asleep or under anesthesia
What is the pH range for the CSF?
7.31 - 7.32
Are there proteins in the CSF? What does CSF fluid with proteins look like?
Proteins shouldn’t be in the CSF
If there are proteins in the CSF, it will be cloudy
What is the K+ concentration of the CSF?
- 40% plasma concentration
(Ex. Serum Plasma k+ = 4, then CSF K+ = 2.4)
What is the Chloride concentration of the CSF?
15% greater than the plasma
What is the glucose level of the CSF? Is insulin used for glucose transport in the brain?
60 mg/dL
No, concentration gradient is required
Neurons need constant supply of O2 and glucose.
What is the pCO2 of the CSF?
≈ 47 mmHg
What is the bicarbonate level of the CSF?
20
What changes in this plasma electrolyte greatly effect the CSF?
Na+
What electrolyte is involved in the constant inhibitory effect exhibited by the brain? What neurotransmitter works in tandem with this electrolyte?
Cl-
GABA
What is the average adult male brain mass?
1350 grams
How much of Cardiac Output is utilized by the Brain? What is the takeaway from this?
12 - 15%
This is a large percentage of CO going to a single small organ.
What is the equation for cerebral blood flow?
50cc/ 100g/ min
What 4 stimuli cause an increase in blood flow to the brain?
- ⇡ CO2
- ⇡ Adenosine
- ⇣ O2
- ⇡ H+
What is the major driving force for determining cerebral blood flow?
MAP
CPP = _______________.
MAP - ICP
What is normal ICP?
5 -10 mmHg
Describe what autoregulation means?
The ability of the body to compensate for a Low MAP to a High MAP. Ex:
- Lower Limit of Autoregulation (LLA) = 60 mmHg
- Upper Limit of Autoregulation (ULA) = 140 mmHg
What is another name for the blood pressure autoregulating system of the brain?
The Myogenic Response
What would chronic hypertension due to the brain’s autoregulation capability? What other consequences should be considered?
It would shift it to the right so that the Upper Range of Autoregulation was higher (160mmHg rather than 140)
This adjustment makes the brain unable to compensate for hypotension. (Think Valley Stroke)
What are the components that utilize the most energy in the brain?
Electrophysiology = 60% (think action potentials and signaling)
Homeostasis = 40% (cell division, protein replacement, etc.)
What CNS energy expenditure component can be limited? By which drugs and by how much (percentage wise)?
- Electrophysiologic Component (signaling)
- Barbiturates, inhaled anesthetics, propofol
- 60% decrease.
Which drugs do not affect CNS energy expenditure?
Nitrous Oxide and Ketamine
What is the equation for calculating brain O2 demand? How much O2 is used by the brain relative to the rest of the body?
3.5ml O2 / 100g/ min
Around 20% of all O2 usage comes from the brain.
How much O2 does the body, as a whole, use every minute?
250 ml