rav65819_ch45_897-918

rav65819_ch45_897-918 - ; 45 5 mm chapter ALL INPUT FROM...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
;;;;;;;;;; 45 5 m m chapter ALL INPUT FROM SENSORY NEURONS to the central nervous system arrives in the same form, as action potentials. Sensory neurons receive input from a variety of different kinds of sense receptor cells, such as the rod and cone cells found in the vertebrate eye shown in the micrograph. Different sensory neurons lead to different brain regions, and so are associated with the different senses. The intensity of the sensation depends on the frequency of action potentials conducted by the sensory neuron. The brain distinguishes a sunset, a symphony, and searing pain only in terms of the identity of the sensory neuron carrying the action potentials and the frequency of these impulses. Thus, if the auditory nerve is artificially stimulated, the brain perceives the stimulation as sound. But if the optic nerve is artificially stimulated in exactly the same manner and degree, the brain perceives a flash of light. In this chapter, we examine sensory systems, primarily in vertebrates. We also compare some of these systems with their counterparts in invertebrates.
Background image of page 1

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

View Full DocumentRight Arrow Icon
Sensory Systems introduction concept outline 45.1 Overview of Sensory Receptors n Sensory receptors detect both external and internal stimuli n Receptors can be grouped into three categories n Sensory information is conveyed in a four-step process n Sensory transduction involves gated ion channels 45.2 Mechanoreceptors: Touch and Pressure n Pain receptors alert the body to damage or potential damage n Different receptors detect touch, depending on intensity n Muscle length and tension are monitored by proprioceptors n Baroreceptors detect blood pressure 45.3 Hearing, Vibration, and Detection of Body Position n The lateral line system in Fsh detects low-frequency vibrations n Ear structure is specialized to detect vibration n Transduction occurs in the cochlea n Some vertebrates have the ability to navigate by sound n Body position and movement are detected by systems associated with hearing systems 45.4 Chemoreceptors: Taste, Smell, and pH n Taste detects and analyzes potential food n Smell can identify a vast number of complex molecules n Internal chemoreceptors detect pH and other characteristics
Background image of page 2
45.5 Vision n Vision senses light and light changes at a distance n Vertebrate photoreceptors are rod cells and cone cells n Visual processing takes place in the cerebral cortex 45.6 The Diversity of Sensory Experiences n Some snakes have receptors capable of sensing infrared radiation n Some vertebrates can sense electrical currents n Some organisms detect magnetic Felds 897 rav65819_ch45_897-918.indd 897 rav65819_ch45_897-918.indd 897 12/6/06 2:53:52 PM 12/6/06 2:53:52 PM 45.1 Overview of Sensory Receptors When we think of sensory receptors, the senses of vision, hearing, taste, smell, and touch come to mind— those senses that provide information about our environment. Certainly this external information is crucial to the survival and success of animals—but sensory receptors also provide information about internal
Background image of page 3

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

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 10/15/2010 for the course BIO BIO1 taught by Professor Lipke during the Fall '09 term at CUNY Brooklyn.

Page1 / 48

rav65819_ch45_897-918 - ; 45 5 mm chapter ALL INPUT FROM...

This preview shows document pages 1 - 4. Sign up to view the full document.

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