chapter 11 - sensorimotor system Flashcards
afferent
arrival to the brain
efferent
exiting the brain
direction of initiating a motor sequence
PFC (idea) —–> pre-motor cortex (organizies) —–> motor cortex (action)
In the motor cortex, the ___ motor neurons contain a homuculus map
upper
Basal Ganglia
motor control
the feed back loop between basal ganglia the _____ , and the ______is called the _____ loop
motor cortex; thalamus; consulting
In the basal ganglia, the ____ is where info comes in, and the _____ is where info leaves
straitum (lateral);
Globus pallidus (medial)
Parkinsons
motor disease in basal ganglia
-loss of dopaminergic neurons in the substantia nigra
Hypokinetic (slow movement) and Hyperkinetic (excessive movement) symptoms
Huntingtons disease
-erratic function
-cognitive decline
How did research find out about the dopaminergic damage in the basal gangia during parkinsons
rodent model
used a neurotoxin called MPTP
Habit related disorders
OCD
tourettes
axons of upper motor neurons descend to the brainstem via ________
internal capsul
Corticobullar tracts vs. Corticospinal tracts
Corticobullar tracts: motor complex —>
Corticospinal tracts: motor complex —> spinal cord
Corticalspinal anterior and lateral
anterior - controls body’s midline
lateral: controls limbs
Exteroceptive sense
anything that touches the skin
Proprioceptive Senses
what the body is doing, awareness of the body
Interoceptive Senses
internal organ, blood pressure (you are not aware of it yourself)
Merkel Receptors
the closest to the skin, allows the feeling of touch
Ruffini Corpuscles
stretching of the skin
Pacinian Corpuscles
vibration
Free Nerve Endings
sense of something hot, cold, painful
Two-Point Threshold
tow point threshold:
* the distance when they feel only one point
Most sensitive two point areas
fingers, hand
lip, nose, cheek
least sensitive two point areas
arm, shoulder, calf(#1), back,
C-tactile (CT) mechanoreceptors
are nerve receptors in the skin that respond to gentle touch and are thought to convey pleasant sensations
Three general categories of pain
– Nociceptive by free nerve endings close to the skin
– Inflammatory
– Neuropathic involved in nerve pathways and it is deep
Two dimensions of pain
– Affective: emotional
– Discriminative: part of the body
where is pain processed
PAIN MATRIX
-parietal lobe
- pre-frontal cortex
- Limbic —> amygdala
The traditional theory of pain
Sensation of pain explained in purely physiological
terms
Problems with the traditional theory
- it doesn’t explain the placebo effect
- injured in a game you keep playing
and you feel it in much lesser degree, this shouldn’t happen
according to the traditional theory
the gate control theory:
the sense of pain is based on the opnein and closing of a gate.
* if you open the gate you feel more pain (you can close it by mechanical stress)
* the signal from the nociceptors (pain receptors) opens the gate
* touch receptors close the gate
* the gate control theory has an additional aspect which is called the central
control which is our state of mind
◦ the persons mind and expectations affects the pain
