Anatomy and Physiology (Chapter 9: Senses)

Anatomy and Physiology (Chapter 9: Senses)

1. CHAPTER 9: SENSES SECTIONS 9.1-9.4

2. 9.1 Sensation CHAPTER 9: SENSES SECTIONS 9.1-9.4 Senses — means by which the brain receives information about the environment and the body Sensation — process initiated by stimulating sensory receptors Perception — conscious awareness of those stimuli

3. Senses — means by which the brain receives information about the environment and the body Sensation — process initiated by stimulating sensory receptors Perception — conscious awareness of those stimuli 9.1 Sensation Sensory receptors respond to stimuli by generating action potentials that are propagated to the spinal cord and the brain Perception only occurs when action potentials reach the cerebral cortex

4. Sensory receptors respond to stimuli by generating action potentials that are propagated to the spinal cord and the brain Perception only occurs when action potentials reach the cerebral cortex 9.1 Sensation TWO BASIC GROUPS OF SENSES: (1) GENERAL SENSES (2) SPECIAL SENSES Senses — means by which the brain receives information about the environment and the body Sensation — process initiated by stimulating sensory receptors Perception — conscious awareness of those stimuli

5. TWO BASIC GROUPS OF SENSES: 9.1 Sensation (1) GENERAL SENSES (2) SPECIAL SENSES Sensory receptors respond to stimuli by generating action potentials that are propagated to the spinal cord and the brain Perception only occurs when action potentials reach the cerebral cortex

6. GENERAL SENSES 9.1 Sensation have receptors distributed over a large part of the body divided into two groups: Somatic Senses (touch, pressure, proprioception, temperature, pain) — provide sensory information about the body and environment Visceral Senses (pain, pressure) — provide information about various internal organs, primarily involving pain and pressure TWO BASIC GROUPS OF SENSES: (1) GENERAL SENSES (2) SPECIAL SENSES

7. SPECIAL SENSES 9.1 Sensation specialized in structure and are localized to specific parts of the body the special senses are: Smell (Olfaction) Taste Vision Hearing Balance GENERAL SENSES have receptors distributed over a large part of the body divided into two groups: Somatic Senses (touch, pressure, proprioception, temperature, pain) — provide sensory information about the body and environment Visceral Senses (pain, pressure) — provide information about various internal organs, primarily involving pain and pressure

8. 9.2 Sensory Receptors SPECIAL SENSES 9.1 Sensation specialized in structure and are localized to specific parts of the body the special senses are: Smell (Olfaction) Taste Vision Hearing Balance Sensory Receptors — sensory nerve endings or specialized cells capable of responding to stimuli by developing action potentials RECEPTOR TYPES: Mechanoreceptors Chemoreceptors Photoreceptors Thermoreceptors Nociceptors

9. Sensory Receptors — sensory nerve endings or specialized cells capable of responding to stimuli by developing action potentials 9.2 Sensory Receptors RECEPTOR TYPES: Mechanoreceptors Chemoreceptors Photoreceptors Thermoreceptors Nociceptors respond to stimuli, such as the bending or stretching of receptors respond to chemicals respond to light respond to temperature changes respond to stimuli that result in the sensation of pain

10. Mechanoreceptors 9.2 Sensory Receptors Chemoreceptors Photoreceptors Thermoreceptors Nociceptors respond to stimuli, such as the bending or stretching of receptors respond to chemicals respond to light respond to temperature changes respond to stimuli that result in the sensation of pain

11. 9.3 General Senses Mechanoreceptors 9.2 Sensory Receptors Chemoreceptors Photoreceptors Thermoreceptors Nociceptors respond to stimuli, such as the bending or stretching of receptors respond to chemicals respond to light respond to temperature changes respond to stimuli that result in the sensation of pain have sensory receptors widely distributed throughput the body include senses of: touch pressure pain temperature vibration itch proprioception

12. have sensory receptors widely distributed throughput the body 9.3 General Senses include senses of: touch pressure pain temperature vibration itch proprioception many of the receptors for the gen. senses are associated with the skin; others are associated with deeper structures such as: tendons, ligaments, and muscles

13. many of the receptors for the gen. senses are associated with the skin; others are associated with deeper structures such as: tendons, ligaments, and muscles 9.3 General Senses have sensory receptors widely distributed throughput the body include senses of: touch pressure pain temperature vibration itch proprioception Free Nerve Endings structurally, the simplest and most common type of receptor distributed throughout almost all parts of the body some respond to painful stimuli, temperature, to itch, and some to movement

14. Free Nerve Endings structurally, the simplest and most common type of receptor distributed throughout almost all parts of the body some respond to painful stimuli, temperature, to itch, and some to movement 9.3 General Senses many of the receptors for the gen. senses are associated with the skin; others are associated with deeper structures such as: tendons, ligaments, and muscles Cold Receptors respond to decreasing temperature but stop responding at temperatures above 12°C (54°F) Warm Receptors respond to increasing temperatures but stop responding at temperatures above 47°C (117°F) RECEPTORS FOR TEMPERATURE:

15. Cold Receptors respond to decreasing temperature but stop responding at temperatures above 12°C (54°F) Warm Receptors respond to increasing temperatures but stop responding at temperatures above 47°C (117°F) RECEPTORS FOR TEMPERATURE: 9.3 General Senses structurally more complex than free nerve endings enclosed by capsules types: Merkel Disks Hair Follicle receptors Meissner Corpuscles Ruffini Corpuscles Pacinian Corpuscles TOUCH RECEPTORS:

16. structurally more complex than free nerve endings enclosed by capsules types: Merkel Disks Hair Follicle receptors Meissner Corpuscles Ruffini Corpuscles Pacinian Corpuscles TOUCH RECEPTORS: 9.3 General Senses Cold Receptors respond to decreasing temperature but stop responding at temperatures above 12°C (54°F) Warm Receptors respond to increasing temperatures but stop responding at temperatures above 47°C (117°F) RECEPTORS FOR TEMPERATURE: Merkel Disks — small, superficial nerve endings involved in detecting light touch and superficial pressure Hair Follicle receptors — associated with hairs, are also involved in detecting light touch. Meissner Corpuscles — for fine, discriminative touch and are located just deep to the epidermis. These receptors are very specific in localizing tactile sensations Ruffini Corpuscles — deeper tactile receptors and play an important role in detecting continuous pressure in the skin Pacinian Corpuscles — deepest receptors and are associated with tendons nd joints. These receptors relay information concerning deep pressure, vibration, and body position ( proprioreception ) TYPES OF TOUCH RECEPTORS:

17. Merkel Disks — small, superficial nerve endings involved in detecting light touch and superficial pressure Hair Follicle receptors — associated with hairs, are also involved in detecting light touch. Meissner Corpuscles — for fine, discriminative touch and are located just deep to the epidermis. These receptors are very specific in localizing tactile sensations Ruffini Corpuscles — deeper tactile receptors and play an important role in detecting continuous pressure in the skin Pacinian Corpuscles — deepest receptors and are associated with tendons nd joints. These receptors relay information concerning deep pressure, vibration, and body position (proprioreception) TYPES OF TOUCH RECEPTORS: 9.3 General Senses structurally more complex than free nerve endings enclosed by capsules types: Merkel Disks Hair Follicle receptors Meissner Corpuscles Ruffini Corpuscles Pacinian Corpuscles TOUCH RECEPTORS: Our sense of proprioception is important to our ability to maintain posture and to perform all various body movements throughout our day Proprioceptive information is conveyed to our cerebrum and other areas of the brain Righting Reflex — enables us to maintain an upright position, even on “uneven ground”

18. Our sense of proprioception is important to our ability to maintain posture and to perform all various body movements throughout our day Proprioceptive information is conveyed to our cerebrum and other areas of the brain Righting Reflex — enables us to maintain an upright position, even on “uneven ground” 9.3 General Senses Merkel Disks — small, superficial nerve endings involved in detecting light touch and superficial pressure Hair Follicle receptors — associated with hairs, are also involved in detecting light touch. Meissner Corpuscles — for fine, discriminative touch and are located just deep to the epidermis. These receptors are very specific in localizing tactile sensations Ruffini Corpuscles — deeper tactile receptors and play an important role in detecting continuous pressure in the skin Pacinian Corpuscles — deepest receptors and are associated with tendons nd joints. These receptors relay information concerning deep pressure, vibration, and body position (proprioreception) TYPES OF TOUCH RECEPTORS: characterized by a group of unpleasant perceptual and emotional experiences two types of pain sensation: localized , sharp, pricking, or cutting pain resulting from rapidly conducted action potentials; diffuse , burning, or aching pain resulting from action potentials that are propagated more slowly PAIN

19. characterized by a group of unpleasant perceptual and emotional experiences two types of pain sensation: localized , sharp, pricking, or cutting pain resulting from rapidly conducted action potentials; diffuse , burning, or aching pain resulting from action potentials that are propagated more slowly PAIN 9.3 General Senses Our sense of proprioception is important to our ability to maintain posture and to perform all various body movements throughout our day Proprioceptive information is conveyed to our cerebrum and other areas of the brain Righting Reflex — enables us to maintain an upright position, even on “uneven ground” Superficial pain sensations in the skin are highly localized as a result of the simultaneous stimulation of pain receptors and tactile receptors Deep or visceral pain sensations are not highly localized because of the absence of tactile receptors in the deeper structures. Visceral pain stimuli are normally perceived as diffuse pain

20. Superficial pain sensations in the skin are highly localized as a result of the simultaneous stimulation of pain receptors and tactile receptors Deep or visceral pain sensations are not highly localized because of the absence of tactile receptors in the deeper structures. Visceral pain stimuli are normally perceived as diffuse pain PAIN 9.3 General Senses characterized by a group of unpleasant perceptual and emotional experiences two types of pain sensation: localized , sharp, pricking, or cutting pain resulting from rapidly conducted action potentials; diffuse , burning, or aching pain resulting from action potentials that are propagated more slowly

21. Local Anesthesia — suppresses action potentials from pain receptors in local areas of the body through injection of chemical anesthetics near a sensory receptor or nerve General Anesthesia — suppressing pain through loss of consciousness; a treatment where chemical anesthetics that affect the recicular activating system is administered PAIN 9.3 General Senses Superficial pain sensations in the skin are highly localized as a result of the simultaneous stimulation of pain receptors and tactile receptors Deep or visceral pain sensations are not highly localized because of the absence of tactile receptors in the deeper structures. Visceral pain stimuli are normally perceived as diffuse pain PAIN

22. Referred Pain perceived to originate in a region of the body that is not the source of the pain stimulus sensory neurons from the superficial area and the neurons from the deeper visceral area converge onto the same ascending neurons in the spinal cord, causing confusion in the brain about the true source of pain helps diagnose the true cause of pain PAIN 9.3 General Senses Local Anesthesia — suppresses action potentials from pain receptors in local areas of the body through injection of chemical anesthetics near a sensory receptor or nerve General Anesthesia — suppressing pain through loss of consciousness; a treatment where chemical anesthetics that affect the recicular activating system is administered

23. 9.4 Special Senses Referred Pain perceived to originate in a region of the body that is not the source of the pain stimulus sensory neurons from the superficial area and the neurons from the deeper visceral area converge onto the same ascending neurons in the spinal cord, causing confusion in the brain about the true source of pain helps diagnose the true cause of pain PAIN 9.3 General Senses Local Anesthesia — suppresses action potentials from pain receptors in local areas of the body through injection of chemical anesthetics near a sensory receptor or nerve General Anesthesia — suppressing pain through loss of consciousness; a treatment where chemical anesthetics that affect the recicular activating system is administered Sensations of smell and taste : related both structurally and functionally, and both are initiated by the interaction of chemicals with chemoreceptors

24. 9.4 Special Senses Sensations of smell and taste : related both structurally and functionally, and both are initiated by the interaction of chemicals with chemoreceptors Sense of vision : initiated by the interaction of light with photoreceptors

25. 9.4 Special Senses Sense of vision : initiated by the interaction of light with photoreceptors Sensations of smell and taste : related both structurally and functionally, and both are initiated by the interaction of chemicals with chemoreceptors Sense of hearing and balance : function in response to the interaction of mechanical stimuli with mechanoreceptors hearing occurs in response to sound waves balance occurs in response to gravity or motion

26. Sense of hearing and balance : function in response to the interaction of mechanical stimuli with mechanoreceptors hearing occurs in response to sound waves balance occurs in response to gravity or motion 9.4 Special Senses Sense of vision : initiated by the interaction of light with photoreceptors The most sensitive mechanical receptors in humans are the hair cells found in the inner ear. A fun fact!

27. The most sensitive mechanical receptors in humans are the hair cells found in the inner ear. A fun fact! Sense of hearing and balance : function in response to the interaction of mechanical stimuli with mechanoreceptors hearing occurs in response to sound waves balance occurs in response to gravity or motion