Worksheet IX:  Senses-General, Taste, & Smell

1. Receptors are classified in 3 ways. Name them.        _____________________________
                                                                                        _____________________________
                                                                                        _____________________________
2.  There are 2 subdivisions of receptors classified by location;  they are:                                                                                                                                     _____________________________
                                _____________________________
3. List the 5 receptors based on the kind of stimuli they detect.                                                       
                                _____________________________
                                _____________________________
                                _____________________________
                                _____________________________
                                _____________________________
4. Identify the receptors described below as:  exteroceptors or interoceptors  and any one of the 5 receptors based on the kind of stimuli they detect.
    a.  Sensitive to changes in temperature.            _____________________________
    b.  Sensitive to light and color.                    _____________________________
    c.  Respond to painful stimuli.                    _____________________________
    d. Located in joints, tendons, and muscle.        _____________________________
    e. Sensitive to sound.                                    _____________________________
    f.  Detect oxygen, CO2, and pH in blood.        _____________________________

5. Identify the kind of receptor classified by structure based on the descriptions given below.
    a.  Lg (2 mm) and resembles cut onion; detects deep
    pressure and pulsing vibrations or high frequency stimuli.___________________________
    b.  A flattened capsule found in dermis; sensitive to
    pressure and distortion of the skin.                 _____________________________
    c.  Dendrites with swellings that detect pain.        _____________________________
    d.  Egg-shaped mechanoreceptors; detect low
    frequency vibrations; light pressure or fine touch.
    surrounded by modified Schwann cells.            _____________________________
    e.  3-10 modified skeletal muscle fibers-intrafusal fibers.____________________________
    f.  Sensitive to stretching of muscle.            _____________________________
    g.  For fine touch and pressure; extremely sensitive;
    found in stratum germinativum.                    _____________________________
    h.  Tendon fibers wrapped in capsule.            _____________________________
    i.  Monitor muscle tension.                                _____________________________

6.  Taste buds are classified as: _______________________ (thermo/chemo/mechano/etc.)
7.  __a__ are the sensory organs for taste.  There are approximately 10,000 on the tongue's surface in raised projections called __b__.  Each __b__ is composed of 40-60 epithelial cells divided into 3 groups:  __c__ cells, that surround the other cells, __d__ cells that are the receptors, and __e__ cells that give rise to new __d__ cells.  The __d__ cells are bathed in saliva with a __f__ hair that protrudes through an opening called the __g__ .  Chemicals that dissolve in saliva contact __f__ hairs and bind to receptors on these hairs. The receptors give rise to EPSPs called __h__.  A nerve impulse travels to the brain via the __i__ (VII), __j__ (IX), and __k__ (X) nerves synapsing in the __l__ and then on to the __m__ region of the __n__ lobes.
    a. _____________________________        h. ___________________________  
    b. _____________________________        i. ___________________________
    c. _____________________________        j. ___________________________
    d. _____________________________        k. ___________________________
    e. _____________________________        l. ____________________________
    f. ______________________________        m. ___________________________
    g. _____________________________        n. ___________________________

8.  Name the 4 kinds of taste receptors.               
                                _____________________________
                                _____________________________
                                _____________________________
                                _____________________________
9. Identify the kind of taste receptor based on the descriptions given below.
    a. Detects acids; located on sides of tongue.        _____________________________
    b. Detects NaCl.                                                    _____________________________
    c. Detects sugars, saccharin, and some amino acids.    _____________________________
    d. Detects alkaloids-quinine, nicotine, caffeine, strychinine. ___________________________
    e. Located at back of tongue.                                                _____________________________
10. Olfactory receptors are ________________________ (extero/interoceptors).
11. The olfactory epithelium is the organ of smell located in the roof of the __________________ cavity.
12. There are approximately 5 million __a__ cells in the upper conchae. These cells are surrounded by __b__ cells.  The __a__ cells are __c__ neurons that have their dendrites anchored to __d__ hairs.  Unmyelinated axons lead from these __a__ cells forming the __e__ nerve.  This nerve penetrates the __f__ of the __g__ bone and synapse in the __h__ bulbs. With a new stimulus the __i__ cells send axons to the __j__ cortex.  Other fibers lead to the __k__, limbic system, and __l__ bodies.  Normally, other cells, called __m__ cells, in the __h__ bulb inhibit __i__ cells.
    a. _____________________________        h. ___________________________  
    b. _____________________________        i. ___________________________
    c. _____________________________        j. ___________________________
    d. _____________________________        k. ___________________________
    e. _____________________________        l. ____________________________
    f. ______________________________        m. ___________________________
    g. _____________________________