Midterm 2 Exam Prep Final - Study Guide

**[Study Guide for Midterm 2]** The following is provided to help you review L8-L11 in preparation for the midterm exam. It is NOT an exhaustive list of information that we learned this quarter, nor is it a list of\ everything that will be tested on the midterm exam. If something is not included be...

**[Study Guide for Midterm 2]** The following is provided to help you review L8-L11 in preparation for the midterm exam. It is NOT an exhaustive list of information that we learned this quarter, nor is it a list of\ everything that will be tested on the midterm exam. If something is not included below it\ does not mean that it is not important.   **[Definitions: ]** **Hemispatial neglect (hemineglect)**: no conscious awareness of the opposite side of the world, or oneself   **Circle of Willis**: connected arteries at the base of the brain **Arteries** carry blood away from the heart. Arterial blood is oxygenated, except for the blood in pulmonary artery (deoxygenated) **Veins** carry blood toward the heart. Venous blood is deoxygenated, except for the blood in pulmonary vein (oxygenated) **Unilateral**: One side **Bilateral**: Two sides **Ipsilateral**: Same side of the body **Contralateral**: Opposite side of the body **Dermatome**: area of skin with innervation mainly supplied by a single spinal nerve The diaphragm is the main muscle that controls breathing, and it is innervated by segments C3 -- C5 (phrenic nerve). **Upper motor neurons**:  These are the neurons in the brain (primary motor cortex) and are involved in sending the signal for voluntary movement to the ventral horn of the spinal cord **Lower motor neurons**: These are the motor neurons in the ventral horn of the spinal cord, the axons of which exit the CNS inside spinal nerves to innervate skeletal muscles **Ganglion**: collection of neuron cell bodies, located outside the brain/spinal cord. Note the exception of basal ganglia, which are nuclei (groups of cell bodies in the CNS, even though they are called "ganglia". **Dorsal columns**:  Axons that carry information about touch from the ipsilateral side of the body **Corticospinal tract**: axons that carry information to allow voluntary movement on the ipsilateral side of the body **Motor control** refers to the process by which the nervous system coordinates the muscles and limbs to achieve a desired movement **Reflexes** are relatively rapid, stereotypical, involuntary responses, e.g., withdrawal, coughing, sneezing, swallowing, grasp reflex **Postural reflexes** are responsible for maintaining body posture, balance and fluidity of movement in a gravity-based environment **Voluntary movements** are purposeful, goal-directed, initiated in response to external or internal stimuli. The performance of voluntary movements becomes better with practice, e.g., playing the piano, driving, eating **Direct pathway**: Enables movement initiation ("Go ahead") **Indirect pathway**: - Inhibits movement initiation ("no-go") through inhibition of thalamus **Neuromodulator:** Neurotransmitter that modulates neural activity without directly opening ion channels. **Pluripotent stem cells:** de-differentiated cells that can divide infinitely and can give rise to all of the cell types that make up the body **[Key topics/concepts to know: ]** Consequences of brain damage to different regions Frontal lobe Temporal lobe Brainstem Cerebellum Occipital lobe Parietal Lobe Why is brain vasculature crucial to maintain function  Circle of Willis  Blood circulation Flow of oxygenated vs deoxygenated blood  Chambers of the human heart Veins vs arteries   Consequences of circulation getting blocked Strokes Types of strokes Hemorrhages Consequences of strokes The spaces and meninges of the brain  Anatomical planes and sections Sagittal Coronal Transverse (horizontal) Laterality: Unilateral, bilateral, ipsilateral, contralateral The spinal cord Vertebral segments Spinal nerves  Spinal injuries Paralysis extent due to injury at different regions of the spinal cord  Diaphragm Cross section of a spinal column  Gray matter vs white matter regions Dorsal root ganglion  Horns vs roots  Consequences of lesions Relationship between the spinal cord and vertebral column  Lumbar puncture  Cauda equina Upper motor neurons Lower motor neurons Information flow in and out of the spinal cord  Efferent vs afferent information  The reflex arc Spinal tracts, where does information cross, where does it go Touch pathway (dorsal column) Motor pathway (Corticospinal tract), acts through lower motor neurons Treating spinal cord injuries, regeneration Types of movement Voluntary vs reflexive  Brain regions involved in voluntary motor control Motor cortex -\> corticospinal tract  Somatotopy in M1 Effects of lesions to the motor cortex  The cerebellum: Refinement of movement, multisensory  Indirect communication with the spinal cord and motor cortex  Motor Thalamus Basal Ganglia: Initiation of movement  Cortico-basal ganglia loop  Direct pathway (go) Indirect pathway (no go)  Dopamine as a neuromodulator  Dopamine receptors Substantia nigra  Nigro-striatal pathway and dopamine Go/No Go pathways in the basal ganglia  Source of dopamine Substantia nigra Effects of pathway dysregulations -\> disease Therapeutics L-DOPA Deep brain stimulation  Stem cell treatment  Embryonic stem cells  Pluripotent stem cells  Induced pluripotent stem cells  Investigative research Regenerative medicine Personalized treatments Neuron to neuron communication Neural circuits Effects of increased and decreased activity Glutamate vs GABA signaling Motor disorders Bradykinesia Akinesia Dyskinesia Spina bifida Flaccid paralysis Spastic paralysis Polio (if the virus reaches the lower motor neurons) Tetraplegia Quadriplegia Other disorders Ischemic/Hemorrhagic Stroke Ruptured aneurysm TBI Posterior spinal syndrome Chronic Traumatic Encephalopathy Sciatica Herniated disk Parkinson's disease Ataxia Intention tremor Resting tremor Key Topics from previous sections CNS organization Neuron morphology White vs grey matter CNS vs PNS Glia vs Neuron Action potentials Why they are important What ions and channels are important Order of events What is happening to ions and channels during the event How they travel down an axon (propagate) Chemical synaptic transmission Why it is important Important ions, channels, receptors Order of events Glut vs GABA synapse Neurotransmitters Neurotransmitter receptors Coupled ion channels Effects on postsynaptic cell Disease and drug relevance Pre vs Postsynaptic cells Presumed function of brain regions Frontal lobe Motor cortex, Broca's area Parietal lobe Somatosensory cortex Occipital lobe Temporal lobe Wernicke's area Cerebellum Basal Ganglia/Striatum Substantia nigra Thalamus Key diseases and research tools Epilepsy MS EEG/ECOG fMRI/MRI Lesions **[Disorders: ]** Right Parietal Lobe Syndrome: loss of awareness to opposite side of the world/oneself  Hemispatial neglect (hemineglect)  Prosopagnosia (face blindness; inferior temporal lobe): Inability to recognize faces Stroke: Brain tissue is damaged from a sudden loss of blood flow, leading to loss of neurological function  Hemorrhagic: Bleeding into or around the brain when a blood vessel ruptures.  Traumatic brain injury (TBI): insult to the brain caused by an external physical force Diver's disease (The Bends): dissolved nitrogen gasses coming out of solution into bubbles inside the body, a type of embolism. Hematomas: Bleeding over or under the dura Epidural: between the skull and dura-typically ruptured artery Subdural: Collection of blood underneath the dura, in the subdural space Coup-contrecoup injury: Collision of the brain tissue with the skull Herniated disc: The softer "jelly" pushes out through a crack in the tougher exterior Spinal bifida: A birth defect that occurs when the vertebrae do not form properly around the spinal cord Meningitis: Inflammation or swelling of the protective membranes (dura, arachnoid, pia) covering the brain and spinal cord.  Flaccid paralysis: Lower motor neuron injury  Polio: Caused by the polio virus and can lead to meningitis and flaccid paralysis in some cases Spastic/rigid paralysis: Caused by upper motor neuron injury  Ataxia: Damage to the cerebellum  Parkinson's: Degeneration of dopaminergic neurons in substantia nigra, primary effects on movement control  Indirect pathway  Direct pathway Therapies L-DOPA Deep brain stimulation  Stem Cells    **[Test your knowledge:]** 1\. The figure shows a spinal cord section from the level of C5. If the shaded region is the area of a lesion caused by an old knife wound, what would be symptoms of a person who had the lesion: a\. Loss of touch bilaterally b\. Loss of touch on the side ipsilateral to the lesion c\. Loss of voluntary movement on the side contralateral to the lesion d\. Loss of involuntary movement (reflexes) bilaterally 2\. The basal ganglia exert their effects on motor behavior through the: a\. Corticospinal tract  b\. Dorsal columns c\. Dorsal root ganglia  d\. All of the above 3\. You work in a neuroscience lab. You perform an experiment where you inject an anterograde (= forward direction; away from cell body) tracer dye into the left motor cortex, and specifically the hand area. A few days later you expect to find dye: a\. In the left dorsal horn of the spinal cord b\. In the right ventral horn of the spinal cord c\. In the muscle that moves the right hand d\. In the spinal nerve that innervates the right hand 4\. Which therapeutic approach is commonly used to manage Parkinson\'s disease symptoms by increasing dopamine levels? Choose the BEST answer. a\. Deep brain stimulation b\. L-DOPA medication c\. Stem cell transplantation d\. Antiepileptic medications 5\. You are about to pick a piece of hair off of your shirt with your [right hand]. Pinching your fingers together to retrieve the hair is a [fine motor movement]. Which of the following BEST describes the pathway that motor information will follow in order for you to make this movement? A\) Left Motor cortex -\> Left Corticospinal tract -\> Right Dorsal horn B\) Left Basal ganglia -\> Right thalamus -\> Right Ventral Horn C\) Left sensory cortex -\> Left Motor cortex -\> Right Ventral horn D\) Left Motor cortex -\> Right Corticospinal tract -\> Right Ventral horn 6\. In a hypothetical experiment, you selectively activate the indirect pathway of the basal ganglia. What consequences would you anticipate on an individual\'s ability to control movement? a\. Increased inhibition of movement b\. Increased initiation of movement c\. Decreased inhibition of movement d\. None of the above 7\. Which of the following correctly pairs a brain region involved in voluntary motor control with its primary function? a\. basal ganglia; movement coordination, planning/prediction b\. motor thalamus; gateway to cortex c\. cerebellum; go/no-go d\. None of the above 8\. Cell bodies in which of the following are responsible for transmitting sensory information from the body to the brain? a\. Dorsal root ganglion b\. Ventral root of spinal cord c\. Gray matter of spinal cord d\. White matter of motor cortex 9\. A cut along which plane would separate the body into anterior and posterior portions? a\. Sagittal b\. Coronal c\. Transverse d\. All of them 10\. What type of paralysis results from lower motor neuron injury? a\. Flaccid paralysis b\. Spastic paralysis c\. Rigid paralysis d\. Ataxia 11\. Which of the following regarding aneurysms and the "ballooning" associated with them is true? a\. An aneurysm is a blood clot; ballooning causes increased blood flow b\. An aneurysm is a ruptured blood vessel; ballooning leads to decreased blood circulation c\. An aneurysm is an abnormal widening of an artery; ballooning can cause bleeding into or around the brain d\. An aneurysm is a type of stroke; ballooning results in blockage of blood vessels 12\. A patient is prescribed medication that selectively activates D2 receptors in the basal ganglia. How might this medication impact the balance between the direct and indirect pathways, and what potential effects could be expected? a\. Inhibits the indirect pathway; relieves rigidity b\. Facilitates the indirect pathway; improves fine motor control c\. Inhibits the direct pathway; alleviates symptoms of bradykinesia d\. Activates both pathways equally; exacerbates dyskinesia **[Test your knowledge (ANSWERS):]** 1\. The figure shows a spinal cord section from the level of C5. If the shaded region is the area of a lesion caused by an old knife wound, what would be symptoms of a person who had the lesion: a\. Loss of touch bilaterally b\. Loss of touch on the side ipsilateral to the lesion c\. Loss of voluntary movement on the side contralateral to the lesion d\. Loss of involuntary movement (reflexes) bilaterally  2\. The basal ganglia exert their effects on motor behavior through the: a\. Corticospinal tract  b\. Dorsal columns c\. Dorsal root ganglia  d\. All of the above 3\. You work in a neuroscience lab. You perform an experiment where you inject an anterograde (= forward direction; away from cell body) tracer dye into the left motor cortex, and specifically the hand area. A few days later you expect to find dye: a\. In the left dorsal horn of the spinal cord b\. In the right ventral horn of the spinal cord c\. In the muscle that moves the right hand d\. In the spinal nerve that innervates the right hand 4\. Which therapeutic approach is commonly used to manage Parkinson\'s disease symptoms by increasing dopamine levels? Choose the BEST answer. a\. Deep brain stimulation b\. L-DOPA medication c\. Stem cell transplantation d\. Antiepileptic medications 5\. You are about to pick a piece of hair off of your shirt with your [right hand]. Pinching your fingers together to retrieve the hair is a [fine motor movement]. Which of the following BEST describes the pathway that motor information will follow in order for you to make this movement? A\) Left Motor cortex -\> Left Corticospinal tract -\> Right Dorsal horn B\) Left Basal ganglia -\> Right thalamus -\> Right Ventral Horn C\) Left sensory cortex -\> Left Motor cortex -\> Right Ventral horn D\) Left Motor cortex -\> Right Corticospinal tract -\> Right Ventral horn 6\. In a hypothetical experiment, you selectively activate the indirect pathway of the basal ganglia. What consequences would you anticipate on an individual\'s ability to control movement? a\. Increased inhibition of movement b\. Increased initiation of movement c\. Decreased inhibition of movement d\. None of the above 7\. Which of the following correctly pairs a brain region involved in voluntary motor control with its primary function? a\. basal ganglia; movement coordination, planning/prediction b\. motor thalamus; gateway to cortex c\. cerebellum; go/no-go d\. None of the above 8\. Cell bodies in which of the following are responsible for transmitting sensory information from the body to the brain? a\. Dorsal root ganglion b\. Ventral root of spinal cord c\. Gray matter of spinal cord d\. White matter of motor cortex 9\. A cut along which plane would separate the body into anterior and posterior portions? a\. Sagittal b\. Coronal c\. Transverse d\. All of them 10\. What type of paralysis results from lower motor neuron injury? a\. Flaccid paralysis b\. Spastic paralysis c\. Rigid paralysis d\. Ataxia 11\. Which of the following regarding aneurysms and the "ballooning" associated with them is true? a\. An aneurysm is a blood clot; ballooning causes increased blood flow b\. An aneurysm is a ruptured blood vessel; ballooning leads to decreased blood circulation c\. An aneurysm is an abnormal widening of an artery; ballooning can cause bleeding into or around the brain d\. An aneurysm is a type of stroke; ballooning results in blockage of blood vessels 12\. A patient is prescribed medication that selectively activates D2 receptors in the basal ganglia. How might this medication impact the balance between the direct and indirect pathways, and what potential effects could be expected? a\. Inhibits the indirect pathway; relieves rigidity b\. Facilitates the indirect pathway; improves fine motor control c\. Inhibits the direct pathway; alleviates symptoms of bradykinesia d\. Activates both pathways equally; exacerbates dyskinesia