General Senses

Question 1

Mechanism of general sense

Answer 1

Stimulus (change)  Receptor  Sensory Neuron  CNS

Question 2

Mechanoreceptors

Answer 2

• respond to mechanical stimuli such as pressure or stretch

- responsible for touch, blood pressure, and muscle tension

Question 3

classes of mechanoreceptors

Answer 3

1. Tactile receptors (touch)
2. Baroreceptors (blood pressure)
3. Proprioceptors (muscle tension)

Question 4

What are considered tactile receptors

Answer 4

• meissner’s corpuscles
• pacinian corpuscles
• merkel’s disks
• ruffini’s corpuscles
• hair follice receptors

Question 5

Meissner’s Corpuscles

Answer 5

-located just beneath epidermis

-concentrated in the fingertips, palms, soles, lips, face, nipples, and external genitalia
sensitive to light touch

Question 6

Pacinian Corpuscles

Answer 6

• located in subcutaneous layer of skin

- sensitive to deep touch

Question 7

Merkel’s Disks

Answer 7

-located in the epidermis

-concentrated in the fingertips, lips, and external genitalia
senstitive to light touch

Question 8

Ruffini’s Corpuscles

Answer 8

• located deep in the skin
• sensitive to deep touch
• when someone pokes you really hard

Question 9

Hair follicle Receptors

Answer 9

• near hair follicle in skin
• monitor changes on surface of the skin; sensitive to movement of the hair
• the hair on your arm will warn you if there is a bug on your arm

Question 10

what are the parts of the baroreceptors

Answer 10

• arterial baroreceptors

- low pressure baroreceptors

Question 11

arterial baroreceptors

Answer 11

-present in arch of the aorta, and carotid sinuses of
left and right internal carotid arteries

-act to maintain arterial blood pressure to allow
tissues to receive the right amount of blood

Question 12

low pressure baroreceptors

Answer 12

• found in large veins and in the walls of the atria of
  the heart

-involved with the regulation of blood volume; determines the pressure throughout the venous system

Question 13

what are the parts of proprioceptors

Answer 13

• muscle spindle receptors

- golgi tendon organ receptors

Question 14

muscle spindle receptors

Answer 14

small elongated structures parallel to muscle
fibers
causes muscle to contract in response to stretch

Question 15

golgi tendon organ receptors

Answer 15

• found at junction of tendon and muscle fibers
• respond to stretch and contraction of muscle
• if muscle is stretched; inhibit motor neurons and decreases muscle contraction

Question 16

what are considered thermoreceptors (respond to temperature)

Answer 16

• cold sensitive thermoreceptors

- warm sensitive thermoreceptors

Question 17

cold sensitive thermoreceptors

Answer 17

a. give rise to sensations of cooling, cold and freshness
b. sense decreases in environmental temperature and internal temperature
c. use negative feedback mechanism to warm body

Question 18

warm sensitive thermoreceptors

Answer 18

a. sense increases in environmental temperature and internal temperature
b. use negative feedback mechanism to cool body

Question 19

what are nociceptors

Answer 19

• sends signals that cause the perception of pain; release Substance P
• found in skin, cornea, internal organs, muscles and joints
• Type A – fast; prickling pain
• Type C – slow, throbbing pain (ex: angina)

Question 20

chemoreceptors

Answer 20

• detect chemical changes
• monitor these chemical changes by relaying information to CNS

-many types:
•oxygen / carbon dioxide (respiratory/ lungs)

• acid / base ( blood/ organs)
• hormones (endocrine glands)
• wastes (digestive system)
• nutrients (have to monitor glucose)
• electrolytes (monitor sodium, potassium, calcium)
• taste sensors (papillae on tongue); 4 types, of which 3 contain taste buds; Fungiform papillae on tip of tongue (sweet), Foliate papillae on sides of tongue (sour & salty), Circumvallate on back of tongue (bitter); and Filiform papillae on middle to back of tongue (gag & swallow reflex; no taste buds)