OT 6000- Test 5- Ch 26 Flashcards
How thalamus directs attention
- Relay nuclei: relays information from the sensory system, basal ganglia and cerebellum
- Association nuclei: thalamus has some loops that connect it to the cortex
- Nonspecific nuclei: help with consciousness, arousal and attention (reticular formation plays with the thalamus to provide arousal)
Thalamic lesions
Will result it:
- Loss of contralateral sensation
- Thalamic pain syndrome possible (neuropathic)
Lateropulsion
-Contraversive pushing: pt has damage on one side of the brain causes pt to lose input to the contralateral inner ear, which will lose the pull of gravity to that side. They will feel the pull towards side of damage and push they push themselves away from pull of gravity away from side of damage and may fall over.
Hypothalamus functions
- Homeostasis: body temperature, metobolic rate, blood pressure
- Survival of the species: eating, reproduction, fight/flight
- Expressing emotion: spinoemotional pathway
- Circadian rhythms: sleep wake cycle
Beta-endorphin of hypothalamus
Beta-endorphins are the precursors of opiate compound that is important for pain relief
-if this is chronically active it is bad because it promotes cortisol release which is the stress hormone
Visual issues from pituitary tumors (in diencephalon)
Will result in bitemporal hemianopsia (damage cuts off optic chiasm)- lateral visual fields in both eyes cut off
Subcortical white matter
- Projection fibers: internal capsules (connects up and down) which have body map organization
- Commissural fibers: corpus callosum- connects left to right
- Association fibers- connect front to back
Damage to internal capsule
- Decreased voluntary control (contralateral side)
- Decreased postural control (contralateral)
- Decreased somatosensation (controlateral)
- Possible homonymous hemianopsia (controlateral)
Cerebrum vs. Brainstem stroke
- Cerebrum: affects all central neurons- face opposite, body opposite
- Brainstem: affects peripheral neurons of the CN’s, but central neurons for the body (face same side, body opposite)
Basal Ganglia motor loop
Selects muscles to activate, creates muscle synergies, sequences movement, regulates muscle force
Brodman’s area
Portion of cerebral cortex which holds areas of specialized functions
-Can apply electrodes to specific areas to determine what areas link to what body regions
Primary somatosensory cortical area
Allows us to establish characteristics of certain objects; smooth, rough, cylindrical, etc.
- DOES NOT provide meaning, only description
- Damage: leads to loss of tactile localization and conscious proprioception
Primary auditory cortical area
Where we have conscious discrimination of things we hear; pitch, loudness, quality of sound
-If damaged on one side; not deafness on this side, will have loss of localization of sound
Primary visual cortical area
Where we begin to characterize what we see; light and dark, size and shape, location (not color)
-if damaged: homonymous hemianopsia- one hemisphere is damaged (one whole side will be blind on both eyes)
Primary vestibular cortical area
Discrimination among head positions and head movements- contributes to perception of vertical movement (balance and equilibrium)
-Damage to this area: won’t know how their head is moving and will not know the pull of gravity (likely to show pusher syndrome)
Agnosia
Inability to recognize objects when using a specific sense, even though discrimination ability with that sense is intact
-Damage to secondary sensory cortices produces agnosia
Secondary somatosensory cortical area
Where stereognosis and memory of the tactile and spatial environment formed
-damage here causes: astereognosis (cannot get meaning from what you touch)
Secondary visual cortical area
Analyzes motion and color and helps give meaning to what you see. Divided into Ventral and Dorsal streams
- Damage to ventral stream this area will have visual agnosia: inability to give meaning to what it is that I see
- Damage to dorsal stream will have optic ataxia: will not be able to reach with precision towards you see
Dorsal vs. Ventral visual stream
- Ventral stream: able to perceive, classify ad give name to what we see (give meaning)
- dorsal stream: visual guide moves towards an object of interest
Secondary auditory
Where we classify what we hear: auditory association area determines if it is speech or not, if it is it will hand it to Wernicke’s area. If it is not it will assign meaning to sounds
-Damage will cause auditory agnosia: can tell difference between speech and sound, but cannot name specific sounds (only characteristics)
Primary motor cortex area
Pre-central gyrus (UMN’s): where we have voluntary controlled and fractionated movement
-Damage to this area: Loss of fine motor control, paresis and spastic dysarthria
Flaccid vs Spastic Dysarthria
- Flaccid: soft and not atriculated (LMN)
- Spastic: forced, tight and nasally sounding (UMN)
Premotor area
Helps plan movement of core and proximal muscle movement and helps create anticipatory feed-forward movements
-If this area is damaged, will lead to apraxia: a breakdown between concept and performance of movement
Supplementary motor area
In motor loop with basal ganglia- helps create sequenced movements and to start movements
-If damaged: perseveration (continue after the need of the task is complete)
