Exam 1 Flashcards
What is the fasciculus cuneatus (posterior or dorsal column) tract?
- Sensory
- For trunk, neck, and UE proprioception, vibration, two-point discrimination, and graphesthesia
- Cross in brainstem
What is the fasciculus gracilis (posterior or dorsal column) tract?
- Sensory
- For trunk and LE proprioception, two-point discrimination, vibration, and graphesthesia
- Cross in brainstem
What is the spinocerebellar tract (dorsal)?
- Sensory
- Tract ascends to cerebellum
- Ipsilateral subconscious proprioception, tension in muscles, joint sense, and posture of trunk and LE
What is the spinocerebellar tract (ventral)?
- Sensory
- Ascends up to cerebellum with crossing and recrossing at the pons
- Ipsilateral subconscious proprioception, muscle tension, joint sense, and posture of trunk, UE, and LE
What is the spino-olivary tract?
- Ascend to cerebellum
- Relay info from cutaneous and proprioceptive organs
What is the spinoreticular tract?
- Afferent pathway for reticular info that influences levels of consciousness
- Located next to lateral spinothalamic tract
What is the spinotectal tract?
- Sensory
- Provides afferent info for spinovisual reflexes and assists with the movement of the eyes and head towards a stimulus
What is the anterior spinothalamic tract?
- Sensory
- Light touch and pressure
- Cross at level of entry to SC or 1-3 levels above
What is the lateral spinothalamic tract?
- Sensory
- Pain and temp sensation
Where do sensory tracts originate from?
- Cells of spinal ganglia
- Intrinsic neurons within gray matter
What are descending tracts responsible for?
- Motor function
- Mm tone
- Reflexes
- Equilibrium
- Visceral innervation
- Modulation of ascending sensory signals
Where do smaller descending tracts originate from?
- Nuclei in the midbrain, pons and medulla
What is the lateral corticospinal tract?
- Pyramidal motor
- Voluntary fine motor movement
- Thought that it controls more distal parts
What happens if there is damage to the lateral corticospinal tract?
- Positive Babinski
- Absent superficial ab reflex
- Cremasteric reflex
- Loss of fine motor or skilled voluntary movement
What is the anterior corticospinal tract?
- Pyramidal motor
- Ipsilateral voluntary, discrete, and skilled movements
- Thoughts that it controls the more proximal parts
What is the reticulospinal tract?
- Extrapyramidal motor tract
- Facilitation or inhibition of voluntary and reflex activity through influence of alpha and gamma motor neurons
What is the rubrospinal tract?
- Extrapyramidal motor tract
- Motor input of gross postural tone, facilitate activity of flexor muscles, and inhibit extensor muscles
- Originate in red nucleus (midbrain) and crosses immediately
What is the tectospinal tract?
- Extrapyramidal motor tract
- Contralateral postural muscle tone associated with auditory/visual stimuli
- Cross in midbrain
What is the vestibulospinal tract?
- Extrapyramidal motor tract
- Ipsilateral gross postural adjustments subsequent to head movements
- Facilitate extensor muscles and inhibit flexors
What happens if there is damage to the extrapyramidal tracts?
- Significant paralysis
- Exaggerated DTR
- Clasp-knife reaction
What is the interhemispheric fissure?
- AKA medial longitudinal
- Separate two hemispheres
What is the Sylvian fissure?
- Anterior
- Separates temporal and frontal lobes and temporal from parietal
What is the central sulcus?
- Sulcus of Rolando
- Separate frontal and parietal lobes laterally
What is the calcarine sulcus?
- Separate occipital lobe into superior and inferior halves
What is the function of the frontal lobe?
- Voluntary movement, intellect, and orientation
- Contains Broca’s area = speech and concentration
- Personality, temper, judgement, reasoning, behavior, self-awareness, executive function
What happens if there is an impairment to the frontal lobe?
- Contralateral weakness
- Preservation, inattention
- Personality changes, antisocial behavior
- Impaired concentration, apathy
- Broca’s aphasia
- Delayed or poor initiation
- Emotional lability
What is the function of the parietal lobe?
- Sensation of touch, kinesthesia, perception of vibration, and temp
- Receive info from other areas of the brain regarding hearing, vision, motor, sensory, and memory
- Provide meaning to objects
- Interpret language and words
- Spatial and visual perception
What happens if there is an impairment to the parietal lobe?
- Dominant hemisphere = agraphia, alexia, agnosia
- Non-dominant hemisphere = dressing apraxia, constructional apraxia, and anosognosia
- Contralateral sensory deficit
- Impaired language comprehesion
- Impaired taste
What is the function of the temporal lobe?
- Primary auditory processor and olfaction
- Wernicke’s area location (typically left side) = ability to speak, verbal and general memory, and assist with understanding language
- Rear portion enables humans to interprets others emotions and reactions
What happens if there is an impairment to the temporal lobe?
- Learning deficits
- Wernicke’s aphasia
- Antisocial, aggressive behavior
- Difficulty with facial recognition and memory
- Inability to categorize objects
What is the function of the occipital lobe?
- Visual information processor (colors, shapes, light, etc)
- Judgement of distance and seeing in 3D
What happens if there is an impairment to the occipital lobe?
- Homonymous hemianopsia
- Impaired extraocular Mm movement and visual deficits
- Impaired color recognition
- Reading and writing impairments
- Cortical blindness with B lobe involvement
What is the L hemisphere responsible for?
- Language
- Sequencing and performing movement
- Understand language
- Produce written and spoken language
- Analytical
- Controlled
- Logical
- Rational
- Math calc
- Express positive emotions
- Process verbally coded info in an organized and logical manner
What is the R hemisphere responsible for?
- Nonverbal processing
- Process info in holistic manner
- Artistic abilities
- General concept comprehension
- Hand-eye coordination
- Spatial relationships
- Kinesthetic awareness
- Understand music
- Understand nonverbal communication
- Math reasoning
- Express negative emotions
- Body image awareness
What makes up the CNS?
Brain and SC
Where does the spinal cord truly end?
~ L1-L2
What is the importance of the brainstem?
Regulate HR and RR
What constitutes the brainstem?
- Midbrain
- Pons
- Medulla oblongata
What is the function of the hippocampus?
- Form and store memories of personal history or declarative info
What is the function of basal ganglia?
- Voluntary movement
- Regulation of autonomic movement, posture, tone, and control of motor responses
What is the amygdala?
- Emotional and social processing
What is the function of the thalamus?
- Relay station for info going to cerebral cortex
What is the function of the hypothalamus?
- Receive and integrate info from ANS and assist in hormone regulation
What is the function of the subthalamus?
- Regulate movements produced by skeletal Mm
What is the function of the epithalamus?
- Pineal gland
- Secrete melatonin and involved in Circadian rhythm
What is the function of the midbrain?
- Large relay center for info passing through to the cerebrum, cerebellum, and SC
- Reflex center for visual, auditory, and tactile responses
What is the function of the cerebellum?
- Fine tuning of movement
- Assist in maintaining posture and balance
- Control ability to perform rapid movements
What is the function of the pons?
- Assist in regulation of RR and orientation of the head in relation to visual or auditory stimuli
What CN run through the pons?
CN V - VII
What is the function of the medulla oblongata?
- Influence autonomic nervous activity and regulation of RR and HR
- Reflex center for vomiting, coughing, and sneezing
What is the function of the brainstem?
- Relay station, sends messages between parts of the body and cerebral cortex.
- Primitive functions for survival
Where are most CN located?
Brainstem
What is the function of the meninges?
Protection from contusion and infection
What are the layers of meninges from deep to superficial?
- PAD –> pia, arachnoid, and dura
What is the function of the ventricular system?
Protect and nourish the brain
What is the function of CSF?
- Nutrition to CNS
- Removal of metabolites
- Provide support and buoyancy
What is the function of the BBB?
Exchange of nutrients from CNS and vascular system
What makes up the BBB?
- Meninges
- Protective glial cells
- Capillary beds
What is Broca’s aphasia?
- Can comprehend conversation
- Have difficulty getting thoughts across and words out
What is Weirnikes aphasia?
- Cannot process conversation
- Can talk and talk in circles
What is the function of dopamine?
Needed for motor patterns
Where is dopamine produced?
Substantia nigra
What is Horner’s syndrome?
- Descending sympathetic tract
- Sx/Sx: miosis (small pupil), ptosis (droopy eye), and decrease sweating
What is POTS?
- Postural orthostatic tachycardic syndrome
- HR increases significantly when changing positions
- ANS disorder
How is sensory info processed?
Moves up the brain and into dorsal root
How is motor information processed?
Through a descending tract through the anterior horn of SC to initiate muscle contraction
What is RAS?
- Reticular Activating System
- Sleep/wake cycles
What is communicating hydrocephalus?
No blockage
What is non-communicating hydrocephalus?
Blockage
What is the function of the spinal cord?
- Send signals to the brain
- Send motor neurons down the efferent pathway
Is gray matter myelinated or unmyelinated?
Gray hair is UN-wanted = unmyelinated
What is an extrapyramidal system?
- Motor system
- Involuntary reflex and movement
- Modulation of movement
- Found in reticular formation of pons and medulla
- Target neurons in SC involved in reflexes, locomotion, complex movement, and postural control
What is the pyramidal system?
- Include corticospinal tracts
- Directly innervate anterior horn
What is the Babinski test?
- Stroking sole of foot and toes should curl
- Reflex takes place until about 2 years old
- Abnormal = toes splay
Where do sensory nerves originate?
Dorsal root ganglion
Where do motor nerves originate?
Ventral horn
Which receptors are cutaneous sensory end-organ receptors?
- Thermoreceptors
- Nociceptors
- Mechanoreceptors
- Chemoreceptors
- Photoreceptors
What are the different types of mechanoreceptors?
- Merkel’s disc
- Ruffini’s corpuscle
- Pacinian corpuscle
- Meissner’s corpuscle
- Muscle spindle
- Golgi tendon organ
- Free nerve ending
What is the function of Merkel’s disc?
Sustained touch and pressure
What is the function of Ruffini’s corpuscle?
Slow adaptation to pressure - IE. stretch of skin
What is the function of Pacinian corpuscle?
Deep pressure and fast vibrations
What is the function of Meissner’s corpuscle?
Light touch
What is the function of muscle spindle?
Prevent overstretching by Mm contraction
AKA stretch reflex
Contract
- Only has to go to the SC and back
What is Golgi tendon organ function?
Inhibit Mm activation
Detects Mm tension
Relax
What is the function of free nerve endings?
Unspecialized, sends signal to sensory neuron
What is the function of chemoreceptors?
- Detect change and send to CNS
- Response for homeostasis