A&P Unit 3- Sense Organs

ch.10

What are the 4 general types of stimuli in domestic animals?

1. mechanical

2. thermal

3. electromagnetic

4. chemical

what are some examples of mechanical stimuli?

touch, hearing, balance

what are some examples of thermal stimuli?

hot, cold

what are some examples of electromagnetic stimuli?

vision

what are some examples of chemical stimuli?

taste, smell

what are the 5 general senses?

1. visceral sensations

2. touch

3. temperature

4. pain

5. proprioception

what type of general sense is being described?

• miscellaneous interior body sensations

• vague and poorly localized

• hunger, thirst, hollow-organ fullness

• GI tract, urinary system

• chemical and/or mechanical stimuli

Visceral Sensations

what type of general sense is being described?

• sensation of something in contact with the surface of the body

• can be similar to pressure

touch (tactile sense)

what type of general sense is being described?

• 2 categories: superficial and central

• coincide with homeostasis

temperature

superficial receptors

• located in the skin

• detect changes in skin temp

central receptors

• located in the hypothalamus

• monitor temp of the blood

pain receptors, aka

nociceptors

what are pain receptors?

• sensory receptors inside and on the surface of the body

• range from simple, free nerve endings

• to more specialized structures

• protect the body from damage

• not found in the brain

4 processes of nociception

1. transduction

2. transmission

3. modulation

4. perception

transduction

conversion of the painful stimulus to a nerve impulse

transmission

move the nerve impulse up the sensory nerve fibers to the spinal cord

modulation

changing of the sensory nerve impulses that can occur in the spinal cord

perception

percepting the painful impulses by several areas of the brain

how can we classify pain?

• superficial (skin and subq)

• deep (muscles and joints)

• visceral (internal organs)

• acute (sharp and intense)

• chronic (dull and aching)

proprioception

the sense of body position and movement

5 special senses

1. taste

2. smell

3. hearing

4. vision

5. equilibrium

taste is also called

gustatory sense

what is taste

taste buds detect chemical substances dissolved in saliva

smell is also called

olfactory sense

what is smell

olfactory epithelium allows odor molecules to dissolve and interpret smells

what is hearing also called

auditory sense

what is hearing

the conversion of vibrations into nerve impulses to be interpreted as sound

what is equilibrium

the animal maintains its balance by keeping track of the position and movements of the head

what is vision

photoreceptors detect an image and send nerve impulses to the brain