E-TEST 1 Flashcards
What are the functions of the frontal lobe?
Voluntary movement, expressive language, managing higher-order functions (e.g., executive functions)
What is executive functioning?
Higher-level cognitive skills you use to control and coordinate other cognitive abilities
What are the association areas of the frontal lobe?
Supplementary motor cortex & premotor cortex
What is the supplementary cortex involved in?
Involved in programming complex sequences of movement & bilateral movements
What is the premotor cortex involved in?
Planning and organising movements and actions
What happens when there is damage to the frontal lobe?
Deficits in thinking, flexibility, problem-solving and voluntary movement
What is the function of Broca’s area and what occurs when there is damage to this area?
Located in the frontal lobe
Concerned with the production of speech (frontal lobe)
Broca’s aphasia = characterised by hesitant, fragmented speech with little grammatical structure
What is the function of the parietal lobe?
Responsible for receiving and processing sensory input such as touch, pressure, heat/cold, and pain, also involved in the perception of body awareness in relation to the environment
What happens when there is damage to the parietal lobe?
Trouble identifying sensation location or type & spatial disorientation and navigation difficulties
What are the association areas of the parietal lobe?
Somatosensory cortex = processes sensory information
What is the function of the superior colliculus?
Physically directs the sensory structures of the head towards stimuli of interest (located in the midbrain)
What is the function of the pretectal area?
Composed of 7 nuclei and is a part of the midbrain a part of the subcortical visual system
Involved in modulating motor responses to visual input
What is the function of the primary motor cortex (pre-central gyrus)?
Deals with pure motor information and plays a role in producing movement (planning & initiation)
What is the function of the primary sensory cortex (post-central gyrus)?
Plays a role in processing somatic sensations
What are the functions of association areas?
Help to interpret the information from primary sensory areas in ways that are meaningful to self and the environment
Responsible for the processes that go on between the arrival of input from primary sensory areas and the generation of behaviour
What happens when there is damage to association areas?
E.g., pre-motor cortex damage = an individual can generate movement but will be limited in the ability to make that movement organised and purposeful for specific tasks (motor apraxia)
What is the function of the temporal lobe?
Plays a role in processing auditory information and with the encoding of memory
Also plays a role in processing emotions and understanding language
What happens when there is damage to the temporal lobe?
Difficulty understanding language and loss of skill associated memory
What is the function of Wernicke’s area and what happens when there is damage to this area?
Located in the temporal lobe (Brodmann area 22)
Role in understanding language and critical for speech production
Wernicke’s aphasia = impaired language comprehension (normal rate, rhythm, grammar)
What is the function of the occipital lobe?
Associated with visuospatial processing (distance, depth, perception, colour determination), object & face recognition and memory formation
What happens when there is damage to the occipital lobe?
Difficulty recognising objects & words and inaccuracy in seeing
What is the role of the primary visual cortex?
Receives, segments and integrates visual information
What is the function of the reticulospinal tract?
Controls posture, muscle tone, spinal reflexes, reciprocal inhibition, control of autonomic functions (HR & breathing) and control of sympathetic/parasympathetic outflow
What is the function of the tectospinal tract?
Controls blinking reflexes and eye pursuit movements when tracking an object
What is the function of the rubospinal tract?
Modulation of flexor tone and flexor withdrawal reflex
What is the function of the vestibulospinal tract?
Acts on anti-gravity muscles to maintain upright posture (balance)
What are the descending (motor) pathways?
Reticulospinal tract, tectospinal tract, rubospinal tract, vestibulospinal tract & corticospinal tract
What is the function of the corticospinal tract?
Responsible for the production of movement, fractionated movement and regulates muscle tone
Describe the course of the corticospinal tract
Originates in the primary motor cortex travels through the internal capsule and the midbrain (pons)
Here 85% of fibres cross at the medulla to travel down the lateral tract, through the spinal cord to synapse with a LMN in the ventral horn which reaches the effector muscle
15% of fibres descend down the ventral tract, descends ipsilaterally down the spinal cord and crosses at the level of a LMN then reaching the effector muscle
What happens when there is damage to the corticospinal tract?
Paralysis (severe/total loss of muscle function)
Paresis (mild/moderate muscle weakness)
Plegia (weakness)
Spasticity (increased tone)
Loss of fractionation (the ability to control 2 adjacent body systems separately)
What are upper motor neurons and where do they originate and terminate?
Nerve fibres responsible for communication between the brain and spinal cord
Originate within the cerebral cortex, pass through the midbrain and terminate at the spinal cord
What happens when there is damage to UMN’s?
Spasticity (increased muscle tone on the opposite side of the body)
Hyperflexia (increase in deep tendon reflexes)
Decreased muscle control
Weakness
What are lower motor neurons and where do they originate and terminate?
Responsible for transmitting information from UMN’s to the effector muscle to perform a movement
Originate within the spinal cord and terminate at the muscle/gland
What happens when there is damage to LMN’s?
Loss of muscle tone
Hypoflexia (reduction in deep tendon reflexes)
Muscle atrophy (decrease in muscle size and muscle wasting)
Flaccid paralysis of muscle (loose/floppy limbs)
How can the reflex arc be over-ridden?
It is not only pain that can trigger a reflex action of the muscle
If only the lower motor neurons were working other triggers could create muscle reflex action including; muscle lengthening, stress, noise etc.,
Upper motor neurons can thus act as inhibitors of the reflex arc - that is, you can decide in some situations not to withdraw your finger from the hot iron
If the upper motor neuron that inhibits that lower motor neuron is not working - then the lower motor neuron will respond to any stimuli in a primal way (it will fire)
What are the ascending pathways?
Spinocerebellar tract, spinothalamic tract and dorsal column/medical lemniscal system
What is the function of the spinocerebellar tract?
A somatosensory part of the sensory nervous system that relays unconscious proprioceptive information from the lower limbs and trunk to the cerebellum (ipsilateral)
What is the function of the dorsal column/medial lemniscal system?
Deals with conscious appreciation of fine touch (kinesthesia), 2 point discrimination, conscious proprioception, vibration sensations from the entire body except the brain (contralateral)
What is the function of the spinothalamic tract?
Sensory tract that carries nociceptive (noxious stimuli such as tissue damage), temperature, crude touch and pressure from our skin to the somatosensory area of the thalamus
What are the 3 core motor areas of the brain?
Corticospinal tract, basal ganglia and cerebellum
What is the function of the basal ganglia?
Subcortical - a collection of nuclei at the base of the cerebrum
Involved in learned motor patterns (autopilot = why we can walk normally without thinking about it)
Executes the go and no-go pathways
Modulates the size and vigour of automatic movements