Lecture 1: Intro to the Nervous System Flashcards
The Nervous System anatomically contains two parts:
1.
2.
Explain where the neurons are within each
Nervous System contains two parts:
- Central Nervous System (CNS): Comprised of neurons that sit within the confines of the protective layer named Dura
- Peripheral Nervous System (PNS): contains neurons that are outside of the dura
Explain the following anatomical planes:
Coronal
Horizontal
Sagittal
What is the difference between a nucleus and a ganglion?
Ganglion is a cluster of neurons that perform the same function… ganglion are located in the PNS
Nucleus are located in the CNS
Explain the directions within the Nervous System:
For the Brain
Explain the directions in the nervous system:
For the Spinal Cord
What are the meninges?
Name the three layers within the CNS
The meninges are a set of three specialized membranes that protect the CNS
CNS Meninges: Dura, Arachnoid, and Pia
Explain the CNS Meninges in Detail
Dura Matter: outer layer, tough layer that protects the CNS from penetration
Arachnoid Matter: middle layer, spider like, forms a fluid-resistant sac around the brain and spinal cord
Pia Matter: innermost membrane: very thin and delicate membrane seperated by the subarachnoid space from the arachnoid, the brain’s CSF flows within this space
Within which layer does the brain’s fluid and CSF reside?
The brain’s CSF resides within the space between the arachnoid and pia matter…called the subarachnoid space
Explain the set of analogous meninges in the PNS
CNS: Dura, Arachnoid, Pia
PNS: Epineurium, Perineurium, and Endoneurium
Explain the dura mater
Dura matter: outer layer, tough layer that protects the CNS from penetration
Explain the arachnoid mater
Arachnoid mater: middle layer, spider like, forms a fluid-resistant sac around the brain and spinal cord
Explain the pia mater
Pia mater: not visible to the naked eye…innermost membrane, very thin delicate membrane seperated by the subarachnoid space from the arachnoid..
the CSF flows in this space
Cerebral Spinal Fluid (CSF)”
- Normal volume is roughly _____ mL, most is in the _________
- Secreted at a rate of _____ per day
- Explain the composition of CSF in respect to protein, glucose, and RBCs
CSF:
- Normal volume is roughly 150 mLs, most is within the subarachnoid space
- Secreted at a rate of 500 mL per day (passive diffusion from blood and active transport from ependymal cells)
- Composition: much lower protein than serum blood, glucose slightly higher, virtually no RBCs
CSF:
- How can it be used diagnostically?
- How do clinicians obtain samples?
Cerebral Spinal Fluid:
Deviations in its composition is very useful diagnostically
Samples are obtained via a spinal lumbar puncture (L2-L5)
List the functions of the CSF:
1.
2.
3.
Functions of Cerebral Spinal Fluid:
1. Maintains a constant enviornment for neurons and glia by regulating ionic concentrations, pH, and glucose
- Removes harmful metabolites from circulation
- Provides a protective hydraulic suspension system for the brain
How much protein is within the CSF vs the blood?
CSF only has 35 mg/dL of protein
The blood has 7000 mg/dL
Both the ____ and the _____ are contained within the skull, whereas the spinal cord is contained within the ______
Both the forebrain and the brainstem (midbrain and hindbrain) are contained within the skull
The spinal cord is contained within the vetebral column
The forebrain is divided into two sections:
1.
2
which are further divided up as…..
Forebrain:
- telencephalon
- diencephalon
Telencephalon: cerebral cortex, striatum and pallidum, and the amygdala
Diencephalon: thalamus and hypothalamus
What are the core elements of the basal ganglia?
The core elements of the basal ganglia are striatum and pallidum
Draw a cross-section of a brain and label the following components:
cerebral cortex, corpus callosum, thalamus, midbrain, pons, medulla, and cerebellum
What does the frontal lobe control?
What does the parietal lobe control?
Frontal lobe: motor center, primary motor cortex, executive function
Parietal Lobe: sensory centor, primary somatosensory cortex
Where is the primary visual cortex located within the brain?
Primary visual cortex is in the occipital lobe
Where is the primary auditory cortex and the hippocampus located?
The temporal lobe is where the primary auditory cortex is located
The _____ supports higher abstract brain functions
Like language, thought, action, conciousness, memory
The FOREBRAIN supports higher abstract brain functions
Like language, thought, action, consiousness, and memory
Explain the flowchart with the brain, skeletal muscle and the ganglia
Explain afferent vs efferent
Afferent is sensory (sensory inputs start in sensory neurons and then travel up to the brain)
Efferent are signals that originate in the brain and travel down to motor neurons
Think A before E
Explain the connections within the CNS when it comes to the following:
1. Walking and chewing: motor activities, depend on sensory input and motor input from the ___ and the ____
- Gaze control: depend on connections between the ___, ____, and _____
- Homeostasis: blood pressure maintenance when rising from the sitting position: ______, _____, and ____
Walking and chewing: motor activities, depend on sensory input and motor output from the spinal cord and hindbrain
Gaze control: depends on connections between midbrain, hindbrain, and cervical spinal cord
Homeostasis: blood pressure maintenance when rising from sitting position: brainstem, spinal autonomic motor neurons
The _____ contains circuits with the most distant connections to sensory inputs and motor outputs
These circuits are involved in abstract functions such as memory, attention, and thought.
The FOREBRAIN contains circuits with the most distant connections to sensory inputs and outputs
It is involved with abstract functions such as memory, attention, and thought
Explain what the CNS vs the PNS comprises of
Explain sensory vs motor divisions
Then explain Autonomic vs Somatic
What are the final common pathway for expression?
The only way to access the 750 skeletal muscles in the body is via ____
Muscles cannot operate independently: ____ are essential for motor function
Motorneurons are the final common pathway for expression
The only way to access the 750 skeletal muscles in the body is via motor neurons (MNs)
Muscles cannot operate independently: MNs are essential for motor function (they do not work without CNS instructions, they cannot even hold tone in the absence of neural input)
What controls the center that are critical for voluntary movement?
What learns from motor experience to ensure accurate movement execution?
Cortex and Brainstem control centers critical to voluntary movement
The cerebellum learns from motor experiences to ensure accurate movement execution
What does the autonomic nervous system comprise of?
Autonomic nervous system comprises of the sympathetic, parasympathetic and enteric
Explain how homeostasis is like a “smart feedback loop” within the human body
Smart feedback loop:
Homeostasis circuits prevent out of range exursions BEFORE they happen
Examples: pancreas releases insulin, glands release saliva in anticipation of eating
Increase in blood pressure prior to standing up from supine position (forebrain pathway)
The _________ chooses which movements occur
Reflexes are controlled at the _____
The Basal Ganglia choose which movements occur
Reflexes are controlled by the lowest level, at the spinal cord
Explain the baroreceptor reflex:
Where are the sensors?
What does each one detect?
Which cranial nerves are involved?
Baroreceptor Reflex: Catorid Sinus (detects BP increase and decrease)
Aortic Arch (BP increase only)
Nerves IX (glossopharygal) and X (cranial)
Explain the baroreceptor reflex when there is:
an increase in BP
a decrease in BP
Increase in BP: is detected by both the aortic arch and the carotid sinus… eventually decreases HR, decreases contracility and decreases vasoconstriction
Decrease in BP: detected by carotid sinus… increases HR, increases contractility, and increases vasoconstriction
Note, the signal goes to the medulla within the brain
