Anatomy CNS Flashcards
Parietal lobe functions
Key in overall function
- sensory perception, body image, emotional response
Frontal lobe functions
Control movement, personality, planning for the future (immediate), speech production
Temporal lobe functions
Hearing, aspect of learning, memory, language recognition
Occipital lobe function
Vision
Broca’s area
- frontal lobe, usually on left. Important in language production
Broca’s Aphasia
Few words are produced not able to actually produce thoughts
-“motor” or “expressive” aphasia
Wernickes area
Able to produce words but the sequence used is random and defective
-temporal
Types of Lower Motor Neuron
Alpha, Beta, Gamma
Left hemisphere specialization
More organized, gross motor skills, more analytical, math, numbers, concrete.
Dorsolateral system
- movement of contralateral extremities
1. Lateral corticospinal tract- controls distal extremities
2. Rubrospinal tract- controls proximal extremities
3. Corticobulbar tract- controls face and head
Right hemisphere specialization
More creative, liberal arts, design, emotional, “left-hemi neglect”
-music appreciation
Ventromedial system
- dedicated to control posture and balance
1. Vestibulospinal tract-balance
2. Reticulospinal tract-life support
3. Tectospinal tract- head/eye movement
4. Ventral/Anterior Corticospinal tract- posture
Left hemisphere behavioral deficits
-have a hard time getting out what you want to say Processing delays Difficulty initiating tasks Distractability Compulsive behaviors Low frustration levels
Right hemisphere behavioral deficits
Unrealistic expectations Poor judgement Impulsive behavior Rigidity of thought Emotional liability Irritability and/or confusion Lethargy Denial of problems
A-Beta Afferent neuron
- light touch/vibration
DCML
Fastest
A-Delta Afferent neuron
Fast/sharp pain
Neospinothalamic tract
C fibers
Unmyelinated
- paleospinothalamic tract
- free nerve endings
- slow pain
DCML Pathway
Mechanoreceptor -stimulated in periphery
First order: enters ipsilateral side and into cord via dorsal root. Doesn’t synapse here. Immediately goes to medulla and synapses.
Second order: Turns into 2 order neuron crosses midline immediately goes to contralateral VPL. Continues up to Thalamus. Diencephelon regulates sensory information. Reroute a information and sends it in diff fervent directions.
Third order: sends to primary sensory cortex. Third order neuron. Thalamus to cortex.
LE travels via fasciculus gracilis, and everything from UE follows the Fasciculus cuneatus.
Neospinothalamic Tract
-fast pain, pressure, temperature
Nociceptor- wherever the pain is
First order: synapses directly at root of injury and crosses midline wherever it enters dorsal root. Delta neuron is sent to DRG. Synapses exactly where it enters and where injury is.
Second order: neuron travels up to contralateral VPL or VPM.
Third order: neuron from VPL or VPM sent to sensory cortex.
First order
Periphery to medulla
Second order
Medulla to thalamus
Third order
Thalamus to cortex
Paleospinothalamic Tract
Slow pain, this is what we treat
Nociceptor
- May travel and synapse at multiple levels, can’t pin point exact location or level
First order: C fiber to DRG. Travels up and down and synapses at different locations.
Second order: synapses at various places including
Limbic- affective behavior, emotion
Reticular formation- control motor, autonomic , and sensory
PAG- release of endogenous opiates, try to inhibit pain by descending response
Hypothalamus- regulates vegetative and endocrine functions
Third order: neuron synapses in sensory cortex
Spinal reflex pathway
Straight to the spinal cord and back.
Lower motor neuron types
Alpha, Beta, Gamma
Dorsolateral system
dedicated to learned, willed, and skilled movement of the contralateral extremities.
- Lateral corticospinal tract- controls distal extremities
- Rubrospinal tract- controls proximal extremity, shoulders/hips. Gives us proximal stability so we can position our extremity in space. Without rubrospinal lateral corticospinal wont function well either.
- Corticobulbar tract (head and face)- UMN ends in brainstem to control cranial nerves. Controls face and head
Ventromedial System
- Vestibulospinal tract- balance
- Reticulospinal tract- life support
- Tectospinal tract- head/eye movement
- **Ventral/Anterior Corticospinal tract- Posture. 85% of this tract is crossed (left side of brain controls right side of body) and other 15% remains uncrossed and controls ipsilateral (right controlling right side)
* A lot of these motor tracts function together.
Medulla
Contains CN 9-12, contains life support, if compromised large risk of death
Pons
Contains life support
- CN 5-8
- “bridge” that connects right and left sides of cerebellum
Midbrain
- Controls eye movement, visual and auditory reflexes.
CN 3-5
Cerebellum
- Located below occipital lobe and behind Pons.
- Learning of coordination
- Helps control and coordinate voluntary movement
- Damage to cerebellum will result in intention tremors and ataxic gait.
- Creates more force production by recruiting motor units when you miss something or don’t realize the weight of a object.
- Proprioception, this tells you that you have to navigate around object to get to a certain point. Ex: Reaching for a water bottle
- Damage to ataxic gait, not a smooth gait when falling, or drunk.
Role of Thalamus
- Receives auditory, somatosensory and visual sensory signals.
- Regulator of sensory information
- Relays sensory signals to the appropriate areas of the cortex.
Role of hypothalamus
- Controls Autonomic functions
- Emotions
- Endocrine functions
- Homeostasis
- Motor functions
- Regulates food and water intake
- Regulates sleep and wake cycle
Basal Ganglia
- Group of nuclei that interconnect with the cerebral cortex, thalamus, and brainstem. Associated with a variety of functions; motor control, cognition, emotions and learning.
- Substantia Nigra- Parkinson’s, dopamine (neurotransmitter) is released here. Low levels of Dopamine lead to these type of patterns.
- Internal driven movements, NOT reactionary movements like the cerebellum.
Primary visual cortex association area
Occipital lobe
Primary somatosensory area: association area
Parietal lobe
