Module 7: Nervous System Flashcards
Anatomy of CNS
Brain and Spinal Cord
Anatomy of PNS
- Cranial and spinal nerves
- Sensory neurons
- Motor neurons
Physiology of CNS
- Communication and control centre of the body
- Receives information, processes information, evaluates inputs
- Maintains homeostasis
- Voluntary and Involuntary response
- Reflex response
What protects the brain?
Meninges
Anatomy of Meninges
- Dura matter (outermost layer)
- Subdural space
- Arachnoid (middle layer)
- Subarachnoid (CSF)
- Pia mater (inner layer)
Physiology of Cerebral Spinal Fluid (CSF)
- Provides cushion for the brain and spinal cord
- Provides nutrients to the brain
- Removes waste
- Formed by choroid plexus and ventricles
- maintain intracranial pressure
Physiology of the Blood Brain Barrier
- Capillaries in the brain
- Limits passage of materials to the brain
- Controls balance of electrolytes, glucose and proteins
- Lipids pass through easily
Hemisphere lobes - Five major lobes
1) Pre-Frontal
2) Frontal
3) Parietal
4) Temporal
5) Occipital
Anatomy of Cerebral Hemisphere
Longitude fissures that separate the brain into two hemispheres
Physiology of Left Hemisphere
- Control right side of body
- Logical
- Analytical
- Science/Math
- Critical Thinking
Physiology of Right Hemisphere
- Controls left side of body
- Artistic
- Creativity
- Performance
Broca’s Area
Motor function for speech production
Wernicke’s Area
- Integration center
- Comprehends language
Prefrontal cortex
- Cognitive behaviour
- Personality
Basal Nuclei
Control and coordination of skeletal muscle
Limbic System
Emotional reactions of feelings
Anatomy and Physiology of Frontal Lobe
- Broca’s
- Prefrontal Cortex
- Motor
- Intellectual function
- Voluntary movement
- Skilled movement
- Speech
Anatomy and Physiology of Parietal Lobe
- Somatosensory
- Sensations (pain, touch)
Anatomy and Physiology of Occipital Lobe
- Visual cortex
- Vision
Anatomy and Physiology of Temporal Lobe
- Auditory cortex - Hearing
- Olfactory cortex - Smelling
- Wernicke’s- Comprehension of speech
- Memory & Learning - Hippocampus
Physiology of Cerebellum
“Cerebellum = CereBALANCE”
- Body Balance
- Positioning
- Coordination of movement
- Equilibrium
- Smooth balanced movement
Physiology of Medulla Oblongata
- Control and coordination
- Respiration activity
- Cardiovascular activity
- Swallow reflex (cough, vomiting)
Physiology of Hypothalamus
- Main role is maintaining Homeostasis
- Autonomic system
- Endocrine
- Body temperature
- Fluid balance
- Thirst and Hunger
Physiology of Thalamus
Relay centre for incoming sensory impulses
Physiology of Reticular Activating System (RAS)
Arousal and Awareness
“AAA = Activate Arousal and Awareness”
Physiology of Diencephalon
Contains thalamus and hypothalmus
- Relays sensory information
- Control autonomic functions of PNS
Anatomy and Physiology of Brain stem
- Pons
- Midbrain
- Medulla Oblongata
- Cranial nerves, efferent and afferent fibers
- Function is the parts made up of brainstem
Arteries that supply blood to the brain
- Cerebral artery - Supplies frontal lobe
- Middle Cerebral artery
- Basilar artery - branches to brain-stem and cerebellum
Anatomy of Cranial Nerves
- 12 pairs
- Originates from various parts of brain
- Sensory, Motor and Mixed Fibers
Cranial Nerve 1
Olfactory - Smell (Senosory)
Cranial Nerve 2
Optic - Vision (Sensory)
Cranial Nerve 3
Oculumotor - Eye movements - Accommodation (Motor)
Cranial Nerve 4
Trochlear - Eye movements - Oblique eye muscles (Motor)
Cranial Nerve 5
Trigeminal - Facial Sensation (Mixed)
Cranial Nerve 6
Abducens - Eye movements - Up and Down
Cranial Nerve 7
Facial - Facial sensory (taste) and facial expressions (Mixed)
Cranial Nerve 8
Vestibulocochlear - Hearing (Sensory)
Cranial Nerve 9
Glossopharyngeal - Taste, soft palate, Swallowing (Mixed)
Cranial Nerve 10
Vagus - Heart/Lungs and Smooth muscle
- Heart rate
- Digestion
(Mixed)
Cranial Nerve 11
Spinal Accessory - Head movements (Motor)
Cranial Nerve 12
Hypoglossal - Muscle of tongue (Motor)
Physiology of the Spinal Cord
- Receives neuron impluses
- Sends information to the brain for processing
- Protected by the vertebral column
- White and Grey matter in the core
Spinal Cord - Gray Matter
- Nerve cell body - Unmylienated
- Motor neuron
Spinal Cord - White Matter
- Afferent - Sensory
- Efferent - Motor
- Ascending and Descending tracts
- Mylienated neuron
How many pairs of Spinal Nerves?
31
What are the two main Spinal nerve fibers?
- Efferent fibers (Motor)
- Afferent fibers (Sensory)
Reflex Response
Autonomic rapid response to a stimulus
- Stimulus triggers sensory system, impulse follows afferent fibre up the Ascending tract to Spinal Cord
- Impulse to the brain (integrate, evaluate, process)
- Impulse follows efferent fibre (motor) down Descending tract to effector removing from stimulus
What is a Neuron?
- Highly specialized cells
- Conduct impulses to CNS and PNS
- Require glucose and oxygen
- Supported by Glial cells
Anatomy of the Neuron
- Cell Body - Nucleus
- Dendrites - Conduct impulses toward cell body
- Axon - Conduct impulses away from body
- Axon covered in myelin sheath
- Schwann Cells
- Gaps between cells - node of Ranvier
- Impulse ends up in synapse
Physiology of the Myelin Sheath
- Insulation
- Speeds up conduction
- Performs by saltatory conduction
- Formed by oligodendrocytes (Glial Cell)
How do impulses conduct?
Action Potential - Re-polarization of outward movement of K+
- Sodium Potassium pump (3 Na+ ions out and 2 K+ ions in)
Neurotransmitter
Substance that is released into the synaptic cleft on stimulus
- Epinephrine/Norepinephine
- Acetylcholine
Types of Neurotransmitters (5)
- Acetylcholin - Para - Excitatory
- Norepinephrine/epinephrine - Sympa - Excitatory
- Dopamin/Serotonin - Excitatory
- Glycine - inhibitory- (Spinal cord)
- Gamma-aminobutryic acid (GABA) - inhibiting
What is the Sympathetic Nervous System?
- Flight or fight
- Neurotransmitters = norepinephrine/epinephrine (post ganglia)
- Acetylcholine (pre ganglia)
- Contains Alpha and Beta receptors
What is the Parasympathetic Nervous System?
- Rest and Digest
- Aids recovery
- Acetylcholine neurotransmitter
- Nicotinic and Muscarinic receptors
What Diagnostic tests are used to evaluate nervous system conditions?
- Computer Tomography Scans (CT) - Creates cross-sectional images - detailed scan
- Magnetic resonance imaging (MRI) - anatomical and physiological image of the brain/body
- X-Ray - Images of tissues and structures
- Doppler ultrasound
- Electrocephaolography (EEG)
- Cerebral angiography
- Lumbar puncture - CSF
Alterations in Nervous System functioning - Local Effects
Signs related to specific area of the brain or spinal cord in which lesion is located
Alterations in Nervous System functioning - Expanding Lesions
Caused by tumours or hemorrhages
- Supratentorial lesions - dysfunction
- Infratentorial lesions - LOC, affects motor/sensory
Alterations in Nervous System functioning - Levels of Consciousness
Decreased consciousness and responsiveness
- Leads to memory loss, difficulty in arousal, coma
Alterations in Nervous System functioning - Vegetative State
- Loss of awareness and mental capabilities
- Brain damage
- Person is unresponsive to external stimuli
Alterations in Nervous System functioning - Locked in Syndrome
Person is aware and capable of thinking but is paralyzed and cannot communicate
Alterations in Nervous System functioning - Brain Death Criteria
- Cessation of brain function
- Absence of brain stem reflex and responses
Alterations in Nervous System functioning - Motor Dysfunction
- Damage to upper motor - weakness/paralysis
- Damage to lower - weakness/paralysis
- Decorticate/decerebrate position - severe brain damage
Alterations in Nervous System functioning - Sensory
- Somatosensory cortex - Touch, pain, temperature, vision, hearing impairements
- Visual loss - Hemianopia - damage to visual pathway
Language Disorders - Aphasia
- inability to comprehend/express language
Language Disorders - Wernicke’s Aphasia
Receptive - unable to understand written/spoken language
Language Disorders - Broca ‘s Aphasia
Expressive - cannot speak/write fluently/appropriately
Language Disorders - Global Aphasia
Damage to both areas - cannot express and comprehend language
Language Disorders - Dysarthia
Motor dysfunction affecting muscles used in speech
- Slow and drawn out speech
Language Disorders - Agraphia
Impaired witing
Language Disorders - Alexia
Impaired reading
Language Disorders - Agnosia
Loss of recongnition/association of words
Transient Ischemic Attacks (TIA)
Temporary localized reduction of blood flow in the brain - Stroke
- Partial occlusion of artery
- Athlerosclerosis
- Small embolus
- Vascular Spasms
Transient Ischemic Attacks (TIA) - Signs and Symptoms?
- Difficult to diagnose
- Ischemia
- Muscle weakness in arms/legs
- Visual disturbances
- Confusion
- Numbness/parathesia in the face
- Transient aphasia
Transient Ischemic Attacks (TIA) - Treatment
- Medications - Anti-platelets and Anti-coagulants (Heparin/Warfarin)
- Surgery
- Can be seen by CT and MRI
Cerebrovascular Accident (CVA)
Stroke
- Infarction of the brain
- Rupture of cerebral vessel
- Ischemia
Cerebrovascular Accident (CVA) - Risk factors
- Diabetes
- Hypertension
- Age
- Heart disease
- Smoking
- Inactivity
Cerebrovascular Accident (CVA) - Signs and Symptoms?
- Lack of voluntary movement
- Flaccid paralysis
- Spastic paralysis
Cerebrovascular Accident (CVA) - Treatments
- Medications - Glucocorticoids
- Surgery
- OT/PT
- SLP
Brain Tumors
Benign and malignant tumours that can be life threatening
- Secondary brain tumour - metastasized from breast/lung tumour
Brain Tumors - Signs and Symptoms?
- Seizures
- Headaches
- Vomiting
- Irritability
- Personality/behaviour changes
- Vision changes
- Malignant tumours can cause death before general effects occur
Brain Tumors - Treatments
- Surgery
- Chemotherapy
- Radiation (Some tumours are radio-resistent)
Brain Injury
- Skull fractures
- Hemorrhage and edema
- Mild injuries
- Swelling of the brain
- Destruction of brain tissue
Brain Injury - Concussion
- Blow to head or whiplash
- Reversible
- Minimal brain trauma
Brain Injury - Contusion
- Bruising of brain tissue
- Blunt blow to head
Brain Injury - Closed head injury
- Skull not fractured in injury
- Brain tissue is damaged
- Extensive damage
Brain Injury - Open head injury
Fracture/penetration of the skull
Brain Injury - Depressed skull fractures
Displacement of bone
Brain Injury - Basilar Fracture
Leakage of CSF
Brain Injury - Contrecoup
Brain bounces off skull
Brain Injury - Primary Injuries
- Laceration/compression of brain tissue
- Rupture/compression of blood vessels
Brain Injury - Secondary injuries
- Cerebral edema
- Hemorrhage
- Hematoma (Meninges damage)
- Ischemia
Brain Injury - Signs and Symptoms?
- Seizures
- Cranial nerve impairment
- Leaking CSF
- Fever
Brain Injury - Treatment
- Medications - Glucocorticoids
- Antibiotics
- Surgery
- Physiotherapy
Spinal Cord Injury
Fracture and dislocation of vertebrae
- compression, stretches or tears in spinal cord
Spinal Cord Injury - Cervical Spine injury
Neck Injury
- Hyperextension or hyperflexion of neck
- Can be fatal
Spinal Cord Injury - Disclocation of Vertebrae
Crush/compression of spinal cord
Spinal Cord Injury - Compression
Force on top of skull or to the feet
Spinal Cord Injury - Signs and Symptoms
- Increased BP
- Increased ischemia
- Bruising
- Sensory motor or autonomic function
- Infections
- Spinal shock (Inflammation and scar tissue)
- Paralysis - Paraplegic (Paralysis of lower extremities), Quadriplegic (Paralysis to all 4 limbs)
Spinal Cord Injury - Treatment
- PT/OT
- Surgery
- Glucocorticoids
- Dermatome maps can identify the degree and damage of recovery
Herniated Intervertebral Disc
Protrusion of the nucleus pulposus
- Common location = Lumbrosacral discs
- Tear can happen suddenly or gradually
- Predispositions - age, metabolic, obesity
Herniated Intervertebral Disc - Signs and Symptoms
- Sensory, motor and autonomic function impairment
- Signs depend on location and extent
- Pain
- Weakness
- Numbness
Herniated Intervertebral Disc - Treatment
- Reduce weight bearing
- Rest
- Ice, heat compression
- PT/OT
- Surgery
- Medications
Seizure Disorders
Spontaneous and excessive discharge pf the neurons in the brain
- Inflammation
- Hypoxia
- Bleeding in brain
- Genetics
Seizure Disorders - Focal
Specific sites
Seizure Disorders - Generalized
Both areas of the hemispheres are affected at the same time
- Absence (Loss of Awareness)
- Atonic (loss of muscle)
- Tonic- Clonic (sudden stiffening of body)
- Myoclonic (rapid contractions of body)
- Febrile seizures (occur in children - high fever)
Seizure Disorders - Partial and Continous
Partial - sparing
Continuous - life threatening
Seizure Disorders - Signs and Symptoms
- Decreasing LOC
- Headaches
- Nausea
- Papilledema
- Late signs - dilated pupils
- After seizures - LOC, confusion, extreme fatigue
Seizure Disorders - Treatment
- Medications
- Pacemaker implant
- Rehabilitation
Multiple Sclerosis
- Degenerative disorder
- Progressive demyelination of the neurons in the brain, spinal cord and cranial nerves
- Loss of myelin interferes with conduction and impulses
- Onset 20-40 yrs of age
- Causes unknown, but maybe due to:
- Autoimmune
- Nutritional deficit
- Changes in blood flow to neurons
- Genetic
- Immunological
- Different types and severity
Multiple Sclerosis - Signs and Symptoms
- Blurred vision
- Weakness in legs
- Double vision
- Dysarthria
- Numbness, burning tingling
- Weakness and paralysis
- Loss of coordination, bladder, bowel and sexual dysfunction
- Chronic fatigue
Multiple Sclerosis - Treatment
- No definitive test/treatment
- MRI to diagnose
- PT/OT
- Medication to prolong symptoms
- Home remedies
- Cannabis
Amyotrophic Lateral Sclerosis (ALS)
- Lou Gehrigs disease
- Progressive degenerative disease affecting the upper and lower motor neurons
- Cognitive is unimpaired (Stephen Hawking)
- Could be genetic
Amyotrophic Lateral Sclerosis (ALS) - Signs and Symptoms
- Spastic paralysis
- Decreased muscle tone and weakness
- Stumbling and falling
- Death may occur due to respiratory failure
Amyotrophic Lateral Sclerosis (ALS) - Treatment
- No specific treatment
- Stem cell therapy
- Medications to slow profession
- SLP
- PT/OT
Myasthenia Gravis
- Autoimmune disorder
- Destruction of receptor sites
- Prevents muscle stimulation
Myasthenia Gravis - Signs and Symptoms
- MSK weakness
- Facial and occular muscles
- Dysphargia and aspiration
- Head droops
- Impaired vision
- Upper respiratory infections
Myasthenia Gravis - Treatment
- Serum antibody test
- Electromyography (electric activity of muscle)
- Medication - Glucocorticoids, Anticholinesterease agents
What is the function of the Pons?
- Controls breathing
- Communication station to other parts of the brain
What are the types of Glial Cells?
- Oligodendrocytes (Schwann Cells)
- Microglia (Immune)
- Astrocytes (Metabolic)
- Ependymal (Create CSF)