03 Somatosensory system

03 Somatosensory system - LEARNING OBJECTIVES: THE...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
N-38 LEARNING OBJECTIVES: THE SOMATOSENSORY SYSTEM 1. From the table on p. N-40, memorize the receptor type, axonal type, location, and function. 2. Define “dermatome,” and describe the anatomical basis for dermatomes. 3. Identify the structures of the dorsal column – medial lemniscal system, spinothalamic system, and trigeminal system. Compare and contrast the anatomy and functions of these three systems. Identify the location and sensory modality on the body and head that are lost following lesions in the spinal cord or brain that damage one of these three systems. 4. Define the two components of pain, and the afferent fibers that transmit them. List five chemicals that can sensitize nociceptors. 5. Define primary and secondary hyperalgesia, and visceral pain. 6. Describe how the gate control system works. List four areas from which nociceptive input can be modified. List four ways to prevent or reduce pain.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
N-39 Robert W. Blair, Ph.D. THE SOMATOSENSORY SYSTEM Reading: Widmaier et al., Human Physiology, 12 th ed., pp. 197-202 I. Classification and Types of Sensory Receptors A. Fiber Sizes Afferent Efferent Diameter ( μ ) Conduction Velocity (m/s) Skin Muscle Muscle 12-20 72-120 -- Ia:Spindle Ib:GTO α 6-12 36-72 A β II 1-6 6-36 A δ III γ < 1 < 2 C IV B. Classification of Sensory Receptors 1. Superficial: Touch, pressure, flutter, vibration, tickle, warmth, cold, pain, itch 2. Deep: Position, kinesthesia, deep pressure, deep pain 3. Visceral: Hunger, nausea, distension, visceral pain 4. Special: Vision, audition, taste, olfaction, balance
Background image of page 2
N-40 C. Major Types of Somatic Sensory Receptors (for skin, see Fig. 7-15, p. 198) Receptor Type Axons Location Function Rate of Adaptation Free nerve endings C, A δ All skin Pain, temperature, crude touch (non-discriminative) Slow Meissner’s corpuscles A β Mainly glabrous skin Touch, pressure (dynamic) Rapid Pacinian corpuscles A β Subcutaneous tissue, viscera Deep pressure, vibration (dynamic) Rapid Merkel’s disks A β All skin, hair follicles Touch, pressure (static) Slow Ruffini’s corpuscles A β All skin Stretching of skin Slow Muscle spindles Ia, II Muscles Muscle length Slow and rapid Golgi tendon organs Ib Tendons Muscle tension Slow Joint receptors Joints Joint position Rapid II. Organization of the Somatic Sensory System A. Dermatomes: Area of skin innervated by a single dorsal root B. Dermatomal maps Figure 1: Dermatomes. Source is Haines, Fundamental Neuroscience , Churchill Livingstone, 1997, p. 241.
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
N-41 We will divide the somatosensory system into three major systems C. The dorsal column - medial lemniscal system (Fig. 7-19b, p. 201) 1. Transmits information regarding touch, pressure, and movement of hairs from the body and back of the head. 2.
Background image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 10

03 Somatosensory system - LEARNING OBJECTIVES: THE...

This preview shows document pages 1 - 5. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online