Int. Environ. Ext. environ. Sensory N.S.. Sensation. Reaction. Body func. Cont. Sensory N.S.. Sensory receptor. Afferent Nerve. CNS(sensory center)

자극 반응 1. 감수기 5. 효과기 2. 감각입력 4. 운동출력 3. 중추통합 1. Reception of Information (sense organ-sensory system) 2. Storage of Information (higher nervous system) 3. Release of Information (activation or inactivation of motor sys)

중추신경계 말초신경계

Mapping in Sense 1) Objective sensory physiology: material phenomena describable in physical and chemical term 2) Subjective sensory physiology: sensation and perception: activity of mind

Basic dimension of Sensation 1. Modality and Quality Modality: kinds of sense –sight,hearing,touch,taste,smell,temp,vibration, pain and enteroceptive one (thirst,shortness of breath,hunger etc.) Quality: –special receptor within a sense organ

Basic dimension of Sensation 2. Intensity and Quantity birightness, loudnes of tone, quantity of sensory impression, amplitude of receptor potential, frenquency of action potential in sensory nerve

Sensory receptor ( 감각수용기 )

Sensory Receptor Information processing –Receptor receive information –Nervous system transmits, filters & integrates Various energy RECEPTOR RECEPTOR POTENTIAL (TRANSDUCER)

Classification of receptor by Sherrington – (1) exteroceptor ( 외계감각수용기 ) – (2) interoceptor ( 내계감각수용기 ) – (3) proprioceptor ( 고유체위감각수용기 )

Stimulus Environmental change The action of environmental energy on the body through activation of one or more sensory receptors * adequate stimulus: stimulus with lowest strength which activate a receptor

Receptive field( 수용야 ) The peripheral area which can activate the sensory n.fiber with an adequate stimulus

Presynapticinhibition Recurrent Collateral I.

(From Berne, RM and Levy, MN: Principles of Physiology, ed 3, St Louis, 2000, Mosby.) A, Myelinated mechanoreceptor B, Receptor potential B A

Properties of receptor potential  Electrotonic decay  Graded response  No refractory period

(From Berne, RM and Levy, MN: Principles of Physiology, ed 3, St Louis, 2000, Mosby.) Receptive fields: A, Meissner's and pacinian corpuscles B, Merkel and Ruffini's corpuscles BA

Sensory pathway ( 감각로 )

Law of specific nerve energy (labeled line principle) for a specific sense, there are specific – (1) sensory receptor – (2) afferent nerve – (3) central pathway – (4) sense area in the CNS

Law of projection “ phantom limb ”

Sensory modalities tested clinically The choice of sensory modalities for clinical testing does not necessarily reflect psychophysical principles. The modalities are chosen partially for convenience and ease of testing and largely for the purpose of localization of the point of damage that has been done to pathways carrying sensory information within the spinal cord and brain stem in patients with nervous system disease

The most commonly tested somatic sensory modalities can be grouped into TWO TWO sets. (1) Discrimitive touch Vibration sensibility Joint position sense (2) Crude (nondiscriminative) touch Pain Temperatur sensibility dorsal column pathway anterolateral pathway

Somatic Sensory Pathway ( 체성감각로 ) Two important ascending pathways in the spinal cord mediate somatic sensation arising in the extremities & trunk (1) DORSAL COLUMN PATHWAY discriminative touch, vibratory sensibility, joint position sense (2) ANTEROLATERAL PATHWAY crude touch, pain, temperature sensibility

Somatic Sensory Pathway ( 체성감각로 ) Somatic sensory information from the face is conveyed largely by way of the TRIGEMINAL NERVE

Somatic Sensory Pathway ( 체성감각로 ) In addition to joint position sense, the sensory equipment of the head includes a special proprioceptive system, the vestibular apparatus.

피부절 (dermatome)

Somatic Sensory Pathway ( 체성감각로 ) THALAMUS - 2 Functional Group (1) SPECIFIC project to or get projection from a specific area of the cerebral cortex all the sensory information is relayed at a specific thalamic nu. (except olfactory & some pain) ventrobasal nuclear group (VPL. VPM) (2) NONSPECIFIC no or diffuse projection to the cerebral cortex intralaminar nu., midline nu. gr., etc.

Somatic Sensory Pathway ( 체성감각로 ) All of the somatosensory pathways relay in the THALAMUS in the VP (ventral posterior) nuclei. pathways from body terminate in the VPL nu., pathways from the face end in the VPM nu.

Primary afferent fibers in the spinal cord

(From Berne, RM and Levy, MN: Principles of Physiology, ed 3, St Louis, 2000, Mosby.) Homunculus

Somatosensory cortex Somatosensory cortex area I – Large part of the postcentral gyrus – Sensory modality specificity – Somatotopic organization – Contralateral input Somatosensory cortex area II – Small area in the lat. part of the postcentral gyrus – No sensory modality specificity – No somatotopic organization – Bilateral input Projection from the Nonpecific thalamic nu.

(From Berne, RM and Levy, MN: Principles of Physiology, ed 3, St Louis, 2000, Mosby.) Trigeminal nerve: A, Distribution B, Synaptic terminals C, Descending branches D, Cell bodies BA DC

Pain ( 통각 ) Receptor Activation adequate stimulus: tissue damage stimulus  chemical mediator  ion conductance change  receptor potential chemical mediator: algesic chemical librated from tissue or n. ending (5-HT, Ach, K+, ATP, bradykinin, substance P)

Referred Pain ( 연관통 ) definition : pain produced at one location but perceived at another location

(From Berne, RM and Levy, MN: Principles of Physiology, ed 3, St Louis, 2000, Mosby.) A, Endogenous analgesia system B, Action of enkephalin B A

(From Berne, RM and Levy, MN: Principles of Physiology, ed 3, St Louis, 2000, Mosby.) 끝입니다