Ch 16 Flashcards
Sensation
the conscious or subconscious awareness of a stimulus
Perception
the conscious awareness and the interpretation of the meaning of sensations.
Modalities
a unique type of sensation, the neuron is associated with one modality.
ex: pain/touch
somatic senses
associated with the body
ex: pain receptors
Special Senses
receptors are located in complex sensory organs that are located in specific regions of the body
ex: sight/hearing
Visceral Senses
provides info about the conditions with internal organs
ex: chemoreceptors
Free nerve endings
bare dendrites that have no apparent structure
ex: Thermoreceptors
Encapsulated nerve endings
dendrite is enclosed in a connective capsule
ex: pressure receptors
Separate Cells
associated with special senses
designed to receive specific stimulas
Exteroceptors
located near the external surface of the body; are sensitive to external stimuli
Interreceptor
located internally, monitor the homeostasis of our internal environment
Proprioceptor
located in muscles, joints and internal ear.
monitors body position
Mechanoreceptors
detect mechanical pressure these respond deformation.
Nocicreceptors
respond to damage to tissues ex: pain receptors
Adaptation
decrease in sensation when a receptor is constantly stimulated
The Somatic Sensory Pathway
these relay information from the somatic sensory receptors to the brain.
First Order Neurons
conduct the nervous impulse from the somatic sensory receptors to the brain
Second Order Neurons
conduct nerve impulses from First Neurons to the Thalamus on the opposite side of the body.
these axons will cross over the Spinal Cord and brain stem. 1st and 2nd synapse in the brain stem.
Third Order Neurons
conduct nervous impulses from the thalamus to the Primary Somatosensory Area (Post Central Gyrus)
2nd and 3rd neurons synapse in the thalamus.
Somatic Motor Pathways
transport nerve pathways associated with movements from the brain.
Transection
severing of all or part of the spinal cord
Direct Motor Pathways
also known as Pyramidal Pathways
Paralysis
loss or impairment of motor function
Upper Motor Pathways
originate in the Precentral Gyrus
axons descend to medulla oblongata most cross over to the other side of the body
remaining axons will cross over in spinal cord