10.1-10.5 Senses. Two categories of sensory receptors: 1.somatic-touch, pressure, temperature, pain...
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Transcript of 10.1-10.5 Senses. Two categories of sensory receptors: 1.somatic-touch, pressure, temperature, pain...
Two categories of sensory receptors:1. somatic-touch, pressure, temperature,
pain2. Special senses that are important for
smell, taste, hearing, equilibrium, and vision
CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Types of Receptors-chemoreceptors-sense changes in chemicals-pain-sense tissue damage-thermoreceptors-change in temperatures-mechanoreceptors-change in pressure or movement-photoreceptors-light stimuli
CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Sensations vs. Projection-Sensations are feelings that occur when the
brain interprets sensory impulses.-projection allows a person to figure out
where that sensation came fromex: ears hear, nose smells
-You have the ability to ignore certain stimuli-sensory adaptation
-unresponsive receptors or signal does not get to cerebral cortex
CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Type 1: Somatic Senses A. Associated with receptors in the skin, muscles, joints, and viscera (organs within the body cavities)B. Touch/Pressure, Temperature, and Pain
CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Touch and Pressure Senses-Receptors
1. Free nerve endings-in skin2. Meissner’s corpuscles-flattened
connective tissue1. Abundant in hairless areas/very
sensitive3. Pacinian corpuscles- They function to
detect deep pressure. 1. Muscle, tendons, joints, subcutaneous layer
CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Temperature Senses -warm receptors and cold receptors (free nerve
ending types)-adapt very rapidly-respond in different temperature ranges
CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Sense of PainVisceral pain receptors are the only receptors
in the viscera that produce sensations.a. Referred pain-pain may feel
like it is coming from one area other than the area that is
stimulated. b. occurs because of the
common nerve pathways leading from skin and internal organs.
CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Pain Nerve Fibersa. Fibers conducting pain impulses away from their source are either acute pain fibers or chronic pain fibers.b. Acute pain fibers are thin, myelinated fibers that carry impulses rapidly and cease when the stimulus stops.c. Chronic pain fibers are thin, unmyelinated fibers that conduct impulses slowly and continue sending impulses after the stimulus stops.
CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display.
d. Pain impulses are processed in the gray matter of the spinal cord.
e. Pain impulses are conducted to the thalamus (first to be aware of pain), hypothalamus, and cerebral cortex (determine pain intensity, locate source, mediate response..
CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Sense of Smell A. Olfactory Receptors
1. chemoreceptors2. Smell and taste work
together-food selection
CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Olfactory Organs 1. are located in the upper nasal
cavity.2. The receptor cells are bipolar
neurons with hairlike cilia covering the dendrites. The cilia project into the nasal cavity.
CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Olfactory Stimulation 1. Scientists are uncertain of how
olfactory reception operates but believe that each odor stimulates a set of specific protein receptors in cell membranes.
2. The brain interprets different receptor combinations as an
olfactory code.3. Olfactory receptors adapt quickly
but selectively.
CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Headaches
• Tension headache-due to stress, fatigue, emotional tension, anxiety– Caused contraction of skeletal muscles in
forehead, side of head, and back of neck
• Vascular headache-constriction and dilation of cranial blood vessels
• Migraine-form of vascular headache– BV constrict and produce blood deficiency
Taste
Taste buds are the organs of taste and are located within papillae of the tongue and are scattered throughout the mouth and pharynx.-papillae-tiny elevations
Taste Receptors
1. Taste cells are modified epithelial cells that function as receptors. (Each taste bud has 50-150 of these)
2. Contain the taste hairs that are the portions sensitive to taste.
Sweet-near the tipSour-lateral edgesSalt-tip and upper
portion of tongueBitter-back of tongue-this is up for debate